designv11-23.json

[
    {
        "image_filename": "designv11_23_0003953_t-aiee.1915.4765249-Figure6-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003953_t-aiee.1915.4765249-Figure6-1.png",
        "caption": "FIG. 6 FIG. 7",
        "texts": [
            " If the slope of this curve is positive when x = 0, it is probable in all practical cases that equation (1) may be used. If, however, the slope of this curve is negative when x =0, it is probable in all practical cases that equation (1) is not true. For example, suppose that we have an e. m. f. consisting of a fundamental and a third harmonic that are either in phase or in opposition. e = E1 sin x + E3 sin 3 x E3 may be either a positive or a negative number. d -E1 cos x + 3 E3 cos 3 xdt de 1186 IRREGULAR WA VE SHAPES [June 29 If E3 is positive the curve slopes upward when x = 0 and equation (1) applies. See Fig. 6. Even if E3 is greater than El so that the curve crosses the axis more than twice in a cycle, this equation will still hold. If, however, E3 is negative and greater than one-third of E1 the curve slopes downward when x = 0 and equation (1) does not apply. See Fig. 7. The area from 0 to 7r is less than the area from a to a + r by an amount equal to twice the area from 0 to a. If we should apply equation (1) to the case where the third harmonic is three times the fundamental and in opposition to it, the form factor would be infinite, since the area from 0 to r is zero"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure24-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure24-1.png",
        "caption": "FIG. 24. FIQ. 23. FIG. 25.",
        "texts": [
            " When the block of cylinders revolves, the floating ring F revolves with it, as the resistance of the slipperpieces E is greater than that of the ball-bearings carrying it. In the central position the slipper-pieoes have no movement, and in any other positions they only move to and fro to an extent directly proportiond to the stroke of the pistons. If the cylinders are rotated in the direction of the =rows, and the path of the gudgeon-pins is concentric with the axle B, a8 in Fig. 23, no motion is imparted to the pistons, and therefore the pump is inoperative. If the path of the gudgeon-pins is moved to the left, as shown in Fig. 24, the pistons as they move above the centre line ex move outwardly, and therefore tend to create a vacuum, so that thB oil is forced into the cylinders either by atmospheric pressure or by an artificial pressure in a supply-tank through the ports H1 and H, while the pistons as they move below the centre line at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from bso. 1916. VABIABLE-SPEED G ~ A B B @OR MmoB BOAD-VEE~~C~LES. 829 zz move inwardly and discharge the oil from the cylinders through the ports K and K*, the ports HI and K1 being connected by suitable piping to the hydraulic motors"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003997_acc.1999.786533-Figure7-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003997_acc.1999.786533-Figure7-1.png",
        "caption": "Figure 7: The Caltech ducted fan.",
        "texts": [
            "m 1 1 0 5 10 1s 20 25 30 I lW Figure 4: Inversion error & NN compensation, and actuator activity. strate the performance with the actuators functioning normal at Tact = 0.05, until at t = 15 sec the actuator time constant is set t o Tact = 0.3. The dynamic nonlinear damping is added in from K, = 0, 10, 100, note: K, E K d n l d . With K, = 100 the NN is capable of compensating for the inversion error and of providing desired handling qualities. 3.2 Ducted fan trajectory control The Caltech Ducted Fan [14] is representative of the longitudinal dynamics of an agile aircraft, Fig 7. It displays many of the characteristics which make control of these type of aircraft difficult, including strongly nonlinear behavior over a wide range of unsteady operating conditions. In particular, the dynamics vary as a function of forward speed and angle of attack and exhibits both short and long period oscillations. Fig 7 illustrates the experimental setup. Singular perturbation analysis of the equations of motion show that the pitch dynamics are considerably faster than the horizontal and vertical displacements, therefore time scale separation is used in the design of the inner-loop and the guidance laws. The actuators are modeled as second order systems with a natural frequency of 25 rad/sec and 0.8 damping ratio. Control rate limits are 1 rad/sec and position limits are 50 deg for elevator and paddle deflections"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000321_pi-a.1955.0133-Figure5-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000321_pi-a.1955.0133-Figure5-1.png",
        "caption": "Fig. 5.\u2014Construction of practical stability-limit curve.",
        "texts": [
            " In plotting the curve for a salient-pole machine it is only necessary to consider accurately the under-excited region; the remainder of the curve can be completed with a circle as for a round-rotor machine. In practice, it is impossible to operate on the stability limit, and a margin must be kept between the practical and theoretical operating limits. The usual method is to take a margin of 10 % of the output in megawatts with a constant excitation. The method of deriving the practical limit is shown in Fig. 5, the procedure (a) Theoretical stability limit (Xe = 0 p.u.). (/>) Practical stability limit (Xe = Op.u.). (c) Circles of constant excitation V. being to take a circle of constant excitation and reduce the output in megawatts along that contour by 10% from the point on the theoretical limit. It is worth mentioning that the shape of the practical stability-limit curves is only slightly affected by changes in Xd, and a template of these curves can be prepared if a number of capability diagrams are to be drawn"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure16-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure16-1.png",
        "caption": "FIG. 16.",
        "texts": [
            " This is effected by causing the carrier L of the first train to move faster, which end is attained by causing the pinion carrier Q of the second train, which is coupled to the annulus C of the first train, to revolve in the same direction as the carrier L by holding the sun-wheel D of the second train stationary by means of the drum P. This causes the carrier Q, and with it the annulus C, to rotate in the same direction as the sun-wheel A, which thus augments the speed imparted to the carrier L, and therefore the speed imparted to the driven shaft. The action of this compound gear is shown diagrammatically in Fig. 16, the elements D and F being enlarged to allow them to be shown concentric with but clear of the elements A, B, and C. To obtain the highest speed-a direct drive-the clutch is brought into action which locks all the parts of the gear together, so that they revolve en ntasse. At all the other speeds the clutch is out of action. To obtain the reverse, the drum S to which the planet carrier R is h e d is held stationary, so that the annulus J, and with it the carrier L, and therefore the driven shaft, will be rotated in a reverse and opposite direction to the driving shaft by the action of the intermediate pinions H"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002133_pime_proc_1943_150_029_02-Figure6-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002133_pime_proc_1943_150_029_02-Figure6-1.png",
        "caption": "Fig. 6. Thc Prcscnt Master Worrnwhecl (360 teeth)",
        "texts": [
            " 2, Plate 1) to ascertain the cause of this noise; these tests included boring the pinion through its centre and filling the space with lead, adding flywheels to the pinion, producing axial thrust on the pinion by means of a spring and dashpot, and trying wooden gear cases and insulating material on the casing. All these experiments were of no avail, and the natural frequency of the pinion vibrating as a reed was calculated without providing any clue. t See Engineering, 1913, vol. 95, p. 371, \u201cMechanical Gearing for the Propulsion of Ships\u201d. at University of Birmingham on June 9, 2016pme.sagepub.comDownloaded from T H E PRODUCTION OF HIGH-SPEED HELICAL GEARS 173 wheel (Fig. 6, Plate 2) with 0523 pitch, split on a horizontal plane to enable the top half of the wheel to be turned round relative to the bottom half (see Fig. 7). The complete gearwheel was dipped into a bath and 0.001 inch of cadmium was deposited electrolytically on the teeth flanks. This at first seemed hopeful, but the effect of the soft metal wore off and the noise recurred. This exDeriment did. however, lead to the conclusion that the face of h e gear tee& had to be attacked to cure the noise. The sets singled out for investigation were transmitting 500 kW"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003928_s0370164600018113-Figure2-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003928_s0370164600018113-Figure2-1.png",
        "caption": "FIG. 2.",
        "texts": [
            " clxii, p . 382. Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0370164600018113 Downloaded from https://www.cambridge.org/core. Ecologie Systematique & Evolution Batiment, on 20 Nov 2018 at 16:10:33, subject to the Cambridge When the beam is loaded at more than' one point, the nature of the vibration depends upon the relation of the moments of inertia of the applied loads and the position of these relative to the fixed ends. Suppose the beam AB (fig. 2) is fixed at each end and is acted upon by two loads at C and D. Under these circumstances, the system may vibrate in one of two distinct modes depending upon the relationship between It and I2 and between lx and lt. The lowest frequency of vibration will occur when the frequency amplitude and phase of vibration are the same at the points C and D. Under these conditions, the portion CD of the beam will simply oscillate as a whole about the axis of vibration, the parts AC and DB behaving as \" fixed-free \" beams of lengths lt and l2 respectively, and having loads at their free ends whose moments of inertia are I2 and I2 respectively"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure13-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure13-1.png",
        "caption": "FIG. 13. FIQ. 14.",
        "texts": [],
        "surrounding_texts": [
            "A gear of a similar nature is the Humphris gear, which consists of a pinion-having hemispherical teeth-mounted on the end of the propellershaft which gears with one or other of a aeries of countersunk holes or hemispherical recesses in the face of a disk mounted on the differential gear-box of the axle t o be driven. Each of the concentric rows of holes or reoesses represents a different gear ratio, the slowest speed being obtained when the pinion on the propeller-shaft is in engagement with the outer row of holes or recesses in the driving disk, and the highest gear when the pinion is in engagement with the innermost row of holes or recesses. The end of the propeller-shaft is so mounted that it can be moved transversely within certain limits, for the purpose of bringing the pinion in and out of engagement with the driving disk. To change the gear, tho end of the propeller-shaft is swung over to disengage the pinion, after which the pinion is moved longitudinally on its shaft t o bring it into position to engage the particular row of holes or recesses in the driving disk which will give the desired speed. The propeller-shaft is then swung back to bring the pinion into engagement with the disk. It ie claimed for this gear that there is no side thrust and that it has an efficienoy of 85 per cent."
        ]
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure15-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure15-1.png",
        "caption": "FIG. 15.",
        "texts": [
            " To obtain the highest speed-a direct drive-the clutch is brought into action which locks all the parts of the gear together, so that they revolve en ntasse. At all the other speeds the clutch is out of action. To obtain the reverse, the drum S to which the planet carrier R is h e d is held stationary, so that the annulus J, and with it the carrier L, and therefore the driven shaft, will be rotated in a reverse and opposite direction to the driving shaft by the action of the intermediate pinions H. The action of this gear is shown diagrammatically in Fig. 15. In this gear, Fig. 17, the driving disk A is mounted on a shaft V, which is in couple with the crank-shaft of the engine, and the driven disk B is mounted on a shaft W, which is arranged at right angles to the axis of the driving shaft V and is in couple with the driving road-wheels by means of chain and sprocket-wheel or other gearing. The driven disk B is so mounted to slide on its shaft that it can be moved across the face of the driving disk A, and thus by engaging the disk at any desired position between its centre and its periphery enable any desired speed ratio to be obtained"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000321_pi-a.1955.0133-Figure6-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000321_pi-a.1955.0133-Figure6-1.png",
        "caption": "Fig. 6.\u2014Saturation characteristics, and method of determining saturation correction.",
        "texts": [
            "-voltage diagram the effect of a small change of radius is very slight; however, when a curve for a different terminal voltage is constructed the radius and centre must be accurately known, since any approximation in either affects the result directly. The object is, then, to obtain accurately the radius (and centre) of the rotor-heating limit at rated voltage when saturation is considered. The radius for another voltage may then be found by direct proportion as described later in this Section. In Fig. 6 are shown the open and short-circuit characteristics of an alternator (OY and OM respectively). Using a modified form of saturation-corrected vector diagram, the radius of the rotor-heating limit is found first for rated terminal voltage, and then, the same method being used together with the determined value ot rotor-heating limit, another diagram is constructed for the new terminal voltages. Referring to Fig. 6, OA = Vt, the alternator terminal voltage, and OAE is the unsaturated voltage vector diagram at full load BRUCK AND MESSERLE: THE CAPABILITY OF ALTERNATORS 615 and rated power factor. OFJ is the unsaturated field-current vector diagram corresponding to OAE, which is drawn in the most suitable quadrant and not in correct phase relation. The field current corresponding to open-circuit terminal voltage on the unsaturated basis is OF, and FJ (=OK) is the rated current short-circuit excitation at rated power factor, OG is the air-gap excitation, and FG, which corresponds to the voltage drop across the leakage reactance X{, is found by proportion, namely FG/FJ = Xi/Xd or otherwise"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003998_s0956-5663(98)00097-9-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003998_s0956-5663(98)00097-9-Figure1-1.png",
        "caption": "Fig. 1. Scheme of the lysine biosensor. 1, PVC electrode body; 2, female connector formed by a 2 mm gold-plated beryllium-copper contact and a polyimide moulding; 3, conducting epoxy polymer; 4, ammonium-sensitive membrane; 5, lysine oxidase membrane; 6, dialysis membrane; 7, solder; 8, O-ring.",
        "texts": [
            " An Ag/AgCl Orion 90-02-00 double-junction electrode with an external chamber filled with a 0.01 M TRIS solution (pH 8.4) was used as reference. A Selecta Tectron water bath was used to carry out calibrations at controlled temperature. A Pharmacia LKB autoanalyser (model Alpha Plus, series 2) was used for standard amino acid analysis. The lysine electrode consisted of a lysine oxidase membrane attached to the surface of an all-solid-state ammonium selective electrode by using a Viton O-ring and a dialysis membrane, as shown in Fig. 1. When not in use, the lysine electrode was stored in a TRIS solution 0.01 M (pH 8.4) at 4\u00b0C. An amount of 4.1 units of lysine oxidase were immobilized by covalent binding on an activated nylon membrane according to the procedure proposed by Hornby and Morris (1975). The membrane was activated by Oalkylation with dimethyl sulfate (for 10 min at 100\u00b0C), then treated with lysine as spacer arm and, finally, functionalization with glutaraldehyde. The all-solid-state ammonium electrode consisted of a PVC-sensitive membrane containing an ammonium ionophore and bis-(1butylpenthyl) adipate as plasticizer, which was applied directly on a conducting graphite-epoxy composite"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003882_pime_proc_1868_019_013_02-Figure49-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003882_pime_proc_1868_019_013_02-Figure49-1.png",
        "caption": "Fig. 49. 17wLnsrerse S e d w n .",
        "texts": [
            " 48 to 53, Plates 52 to 54, punches flat circular discs out of a long strip of brass, and then bulges each into the shape of a cylindrical cup, for the purpose of forming the cap chamber F in the rear of the cartridge, Fig. 3. This machine is very similar to the one already described for making the base cups, the principal difference being that the cap chambers are of smaller dimensions than the base cups, and consequently require less power for making them. The slides carrying the four pairs of hollow punches and manclrils are here placed horizontal, while the strip of brass B is fed through the machine a t an inclination, as shown in Fig. 49. The shape of the bell-mouthed aperture in the hollow punch, and the rounded end of the mandril, are shown full size in Figs. 51 and 52; but as the thickness of the brass strip is -02 inch, and the length of the finished cap chamber is about twice as great as its diameter, it is not attempted to produce the full length of cup out of the original flat disc at a single operation; the cap chamber is therefore made by this machine of the shape shown full size in Fig. 50, and afterwards undergoes a further drawing process in the machine next t o be described"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure1-1.png",
        "caption": "FIG. 1.-Diagram of Panhard Gear.",
        "texts": [
            "-About the year 1890 the firm of Renault Frhres introduced a construction of change-speed and transmission gear which may justly be said to have revolutionized the design of the transmission mechanism of the modern motor road-vehicle, as at least 90 per cent. of the motor road-vehicles driven by internalcombustion engines at present constructed embody one or other of the features of this gear. Instead of transmitting the power from the gear-box to the road wheels by means of a differential countershaft * See.Appendix, Fig. 1 (page 806). at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 786 VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHICLES. DEC. 1916. and chain gearing, the road wheels in the Renault system are mounted on a live differential axle which is coupled to the driven shaft of the gear-box by means of a longitudinally arranged shaft, commonly called a propeller-shaft. The Renault gear not only provided for a direct drive between the driving and driven shafts-which is now considered a sine pub non in all gears of the sliding type, as it materially reduces both friction and noise-but i t also rendered the lay-shafts not only idle but also quiescent during the direct drive",
            " A further advantage of the Renault construction of gear is that the length of the gearbox can be reduced to a minimum, as there is no necessity for any clearance between the different gears, owing to the wheels of the different trains being entirely out of mesh before and when the sliding element forming the clutch coupling is moved. An example of this gear is given in the Appendix, Fig. 2 (page 807). Daimler Gear.-The advance that has been made in the side meshing type of gearing will best be realized by comparing the original Panhard gearing, Fig. 1 (page 806), with an up-to-date gearing as exemplified in the modern Daimler gear, which is described in the Appendix, Fig. 3 (page 808). The Daimler gear embodies two important features not to be found in the Pmhard construction, namely, the placing of the driving and driven shafts of the gear in axial alignment, and the employment of more than one sliding element. The first of these two features enables the driving and driven shafts to be connected together by a direct couple, so that a through or direct drive from the engine to the transmission gearing can be obtained ; and the other feature enables any desired gear to be obtained without running through any other gear",
            " 1 and 2 (pages 806-7), it will also be observed that each has an advantage over the other with a corresponding disadvantage. In the former the power on all the speeds is transmitted through one pair of gear-wheels, so that the frictional losses due to the gearing are the same on each speed, while in the latter type the power on one speed is direct, that is without going through any gearing, but on the other speeds the power is transmitted through two pairs of gear-wheels, so that on all speeds other than the direct one there is twice as much frictional loss as in the type of gear illustrated by Fig. 1. This naturally directs attention t o the fact that the direct drive should give the ratio of speed between the at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 788 VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHICLES. DEC. 1916. engine and road wheels best suited to each particular vehicle and the work it is called upon to perform. The general practice is to give the direct drive on the top or highest speed, and this is probably the best all-round practice for gears which give only three forward speeds ; but when four forward speeds are provided the direct drive is sometimes on the third speed, the fourth speedwhich in this case is a geared-up one-being only intended to be used under the most favourably running conditions",
            " Against these drawbacks it has several advantages over the sliding type of gear. For instance, it is practically silent on all speeds, it is less liable to break down or to be damaged through careless handling, and it is not subject to as much wear and tear. It will be seen, therefore, that while the disadvantages are nearly all matters for the manufacturer, the advantages are all on the side of the user. The best known gear of this type giving three forward speeds and a reverse is the Lanchester-Fig. 1 2 (Appendix, page 820)-which has been used continuously and to the exclusion of all other types of gear in the Lanchester cam since 1900. The Ford car may also be cited as an automobile in which the epicyclic type of change-speed gear is exclusively used, and in this w e the increased cost of production of this type of gear certainly at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 798 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEHICLES. DEC. 1916. has not been a bar to its use, as the total cost of production of this car is known to be well below that of any other car of similar power and capacity, while its selling price has become a by-word",
            " ; The Cowey Engineering Co., Ltd. ; Commercial Cars, Ltd. ; The Daimler Go., Ltd.; The Lanchester Motor Co., Ltd.; The Scottish Commercial Cars Co., Ltd.; Tilling-Stevens, Ltd.; and The Thomas Transmission Co., Ltd., for the information which they have so kindly given him. The Paper is accompanied by an Appendix. illustrated with 28 Figs. in the letterpress. at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 806 VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHICLES. DEC. 1916. In the early Panhard gear, Fig. 1, the primary or driving shaft V-capable of being coupled to the crank-shaft of the motor by means of a friction clutch -and the secondary or driven shaft W are arranged in parallel relation to one another, the secondary or driven shaft being located above the primary or driving shaft. On the shaft V is mounted a sliding sleeve A, which carries four spur-wheels, B, C, D, and E, and on the shaft W are fixed four spurwheels, F, G, H, and K, with which the sliding wheels B, 0, D, and E can be brought into engagement one by one"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002173_t-aiee.1923.5060864-Figure8-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002173_t-aiee.1923.5060864-Figure8-1.png",
        "caption": "Fig. 8) and as it permits of power factor compensation",
        "texts": [
            " If the generated voltage exceeds the line (,Arnatu,+QQQQQ) g l voltage a braking torque will be exerted and power will be returned to the line. The small section of transformer voltage in the excitation circuit is introduced in I4ainFie id order to neutralize the resistance drops in both the cross field and main field circuits and hence maintainFJIG. 6-CRoss FIELD OIF SELF EXCITING GENERATOR the regenerated voltage exactly 180 deg. behind the linetically as a short circuit. Even if direct currents are voltage. made impossible, as in the case of a repulsion motor, Fig. 8 shows the typical shape of the speed torque there is a strong tendency for low-frequency currents to be set up, causing trouble. Also the speed torque Cr ostant'Crosefieldvolts57r I fI rmauecharacteristics obtained with this connection (See Fig. E Varesf\" wti speed 5) are not the best type for all classes of regenerative fvaries according to safuraliisn urvcu service since the torque tends to decrease as the speed ] 2a\"Varieswi,+h\"Elcaccor-dnyoZlw.ed2rceincreases for any given value of impressed voltage. 0c ,vEffOrtvaresas&x1auheywe In view of these difficulties this method of regeneration approX asq9uare of speed over he, has so far not been seriously considered for railway ap- Operof nge. plication in this country. Undoubtedly, however, due to its simplicity it has possibilities for the future. Refardng7Xrac.-tive Effo)b:RO Pro,oellt'nq Tracfiv'eEffort.REGENERATION WITH CROSs-FIELD OR SELFEXCITATION3 FIG. 8-APPROXIMATE SPEED-TRACTIVE EFFORT CHARACTER- A regenerative system of the second kind with the ISTIC WITH CROSS-FIELD EXCITATION SYSTEM main motors acting as armature (self-excited) generators characteristic obtained with this connection. is shown in Fig. 6. In this system the armature is This system is handicapped due to the fact that the supplied with an extra set of brushes b b which are armatures, and also the commutators of the main located around the commutator midway between the moos hav tob nrae ncaaiybcuete normal or motoring set"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002181_joaiee.1923.6593329-Figure14-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002181_joaiee.1923.6593329-Figure14-1.png",
        "caption": "FIG. 14",
        "texts": [
            " This assumes that the windings are so designed that there are essentially no harmonics in the space distribution of the magnetic field and that each winding will, if acting alone, produce exactly the same flux per ampere. If the currents are of the general form both the \"current\" and \"flux\" vectors shrink exponentially as they rotate. The space distribution of the magnetic field is still sinusoidal at all times but its magnitude diminishes as it moves through the air gap. Compare Fig. 13 with Fig. 14. In the latter figure let us assume that the currents took on the general form at the moment that the flux distribution was at the point indicated by the curve \u00e2, and that their generalized angular velocity is (\u2014 a + ; \u00f9). The equation of the maximum density for any later position of the field such a s\u00df i i s .B w = B0e a where t is the time required for the field to move from the position \u00e2 to \u00dfu i. e., through an angular distance X. The flux through any phase as well as the current in it may still be represented by a vector although this vector is now of the general type\u2014that is, it shrinks exponentially as it rotates"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000948_t-aiee.1941.5058395-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000948_t-aiee.1941.5058395-Figure1-1.png",
        "caption": "Figure 1. The circle diagram for the low-speed adjustment P l ;",
        "texts": [
            " The standstill input current and watts at reduced voltage A. G. CONRAD F. ZWEIG J. G. CLARKE (c). The no-load input current and watts MEMBER AIEE ENROLLED STUDENT AIEE ASSOCIATE AIEE at reduced voltage with the machine run- ning at some speed between no-load speed and standstill Synopsis: In the preceding paper' of this for a particular setting of the brushes will From the data of these three sets of series, a simple theory underlying the circle be most helpful in obtaining a general readings, the circle diagram of figure 1 diagram of the brush-shifting a-c motor was presented. It is the purpose of this paper understanding of the operation of the can be constructed. This diagram is to advance this theory, and to show how it machine for other settings. Therefore, characteristic of the machine for speed can be used to determine such quantities the diagrams used for a basis of explana- adjustments below synchronous speed. as efficiency, current, torque, and speed for tion will be those corresponding to the The line po shows the no-load current different conditions of operation",
            " 5X2-Stator reactance at standstill factor adjustment * ss~~~~~~~8Xaw-Adjusting winding reactance at V171Primary impressed voltage per List of Symbols standstill phase 02-nglofla bewee 2an =, 11-Primary current per phase E2-Voltage induced in one phase of 2Ageo a ewe 2aaf2 Ie r-Exciting current in primary cir- stator electrical degrees cuit per phase E11-Voltage generated in adjusting 0 1-Angle of lag between F11 and In iaIlvComponent of primary current winding between brushes supplying electrical degrees flowing as a result of the currents one phase of stator 0-Angle of lag or lead between pri- in stator and adjusting winding 834 TRANSACTIONS Conrad, Zweig, Clarke-Brush Shifting A-C Motor-II ELECTRICAL ENGINEERING Oc can now be constructed perpendicular current of in terms of a current in phase Figure 2. The circle diagram for the highto V1 and the line be perpendicular to pe. with the voltage, this loss caused by the speed adjustment The power supplied to the motor at stand- current of can now be laid off on a line still per phase is the current be multiplied fh drawn from f perpendicular to oc. In 2 shows the circle diagram for the same by the voltage V1. The current ce figure 1, it is labeled hj. Similarly, the motor as that of figure 1, except the speed multiplied by the voltage V1 is the per total copper losses can be determined is adjusted to approximately 150 per cent phase iron loss of the rotor, the friction for other values of input current. Thus of synchronous speed. The standstill and windage losses, and a small amount for an input current of pfi, the total current 188 for normal voltage is much of iron loss in the stator. By measure- copper loss is h1j1. By successive deter- larger, and maximum power output much ments of primary resistance, the primary minations of losses, the curve ojb can be greater. The circle is located from the copper losses per phase can be calculated constructed to show the change in copper three sets of no-load determinations defor the normal short-circuit current. losses with different values of input scribed previously. The essential differThis loss is represented by the current current. If each of the distances jh, ence of this diagram as compared with cm. The loss in the adjusting winding . ..jk j1k1 bm that of figure 1 is the shape of the curves and in the stator per phase for standstill iJIr1 are divided so that -h = - =m- a soigoprossodfeetrmr conditions is (bin)V. new curve okm can be constructed so currents. The system of notations on The copper losses can be estimated that the distance 1z1k1 shows the variation figure 1 has been maintained in figure 2, for any value of primary current in a in primary copper loss, and k1j1 shows so that the explanation of the use of mannersomewhat similiartothatnormally the variation in secondary (adjusting figure 1 will suffice for the explanation used with the ordinary induction motor. winding and stator) copper losses for of the use of figure 2. Thus for an input current of pf' it is different values of primary current. assumed that the no-load current is one The variables for the motor can now Experimental Check on the Theories component and the loss associated with be determined for any value of input of the Circle Diagram it, (ce) V,, is constant regardless of the current I1. magnitude of the load. The other In order to check the validity of the component of the primary current pf is (1) Input =(ft) V1 watts per phase theory thus far developed, tests were (2) of, and the losses associated with this O2utput =(jf) V1watts per phased made on a General Electric B",
            " Comparison of the theoretical char- I Sd-Primary impressed voltage per phase the no-load tests the circle diagram of acteristics taken from the circle diagram with 1,,-Standstill primary current the machine was constructed, and the the actual characteristics obtained by tests for II-Primary current per phasethe achie ws costruted th n,,lad seed, aproxmatey 50percentof E2-Voltage induced in stator at standcharacteristics determined from its pro- no-load speeds, approximately 50 per cent of still portions. The theoretical diagram for synchronous speed, and 150 per cent syn- El,-Voltage generated in adjusting windthis machine with this low-speed setting chronous speed ing is shown in figure 1. A second experimental check was made brushes at standstill equal to one-half Reference with the brushes set to provide a speed the stator voltage 58E2 of the stator coil of approximately 150 per cent of the to which they are normally connected. 1. THEORY OF THE BRUSH-SHIFTING A-C MOTORsynchronous speed. This can be done In addition to this, these two voltages AIEEA.AGSACTONSa,F. lumei 60,and 1J (G.CArke.t by makcing the voltage E11 across the should be in time phase with each other sectionl), pages 829-34"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002159_1.1748672-Figure2-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002159_1.1748672-Figure2-1.png",
        "caption": "FIG. 2. A five-symmetric :,tatic machine of the Toepler-Holtz type.",
        "texts": [
            " This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitationnew.aip.org/termsconditions. Downloaded to IP: 138.251.14.35 On: Sun, 21 Dec 2014 03:08:20 Feb., 1930] POLYSYMMETRIC STATIC MACHINES 59 N ow while the simplest members of this family are the two-inductor (the ordinary Holtz) and the three inductor machine (described by the author), the best insight into the action of the higher members of the family is not afforded by these two, but rather by the four (Fig. 1) and the five (Fig. 2) symmetric members, and therefore in this paper we begin with the discussion of the theory of these two machines, by which process the theory of the higher members is approached by easy stages and becomes more or less obvious. Two machines are treated rather than one, because it turns out that the even and the odd members pre sent rather different characteristics: this difference is already exempli fied by the two and the three inductor members: namely the former is primarily a direct current machine, the latter an alternator",
            " physi cally if two oppositely situated inductors are charged to equal but opposite potentials, and the other two are connected to ground (zero potentials) then the potentials will alternate--a reversal occurring every half revolution \u00ab() = Jr / 4) and at the same time increase in value, increasing 16 fold in absolute value <-v'2) 8 every revolution. The fact that this machine can act both as an alternator and direct current generator depending on original conditions, in a certain sense on excitation, is extremely interesting. It is to be noted, how ever that it is much more efficient as a direct current generator, since the potentials build up much more rapidly in the latter case (p = 2 as against yl2). In the case of the five inductor machine (Fig. 2) the a's involved in Eq. (6) are given by: 0,5 1,6 2,7 3,8 4,9 0,5 ao al a2 a3 a4 and the b's by: 0,14 1,10 2,11 3,12 4,13 0,5 bo bi b2 b3 b4 Here again we can neglect all those combinations not involving three adjacent elements and have: ao=+a bo=+a so that Eqs. (11) and (12) hold also for this case except that we must letj take the values from 0 to 4 inclusive and put m = 5. Gathering the results in a table we have; This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitationnew"
        ],
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    },
    {
        "image_filename": "designv11_23_0000352_0016-0032(52)90415-8-Figure3-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000352_0016-0032(52)90415-8-Figure3-1.png",
        "caption": "FIG. 3.",
        "texts": [
            " In spite of this difficulty, though, the ar rangement might have some merit. If the displacement were not great it would seem tha t each pad would be under a positive pressure and the arrangement should be a very stable one. I t is possible tha t a grinding machine spindle bearing of this design would have some interest to machine tool builders. But it is with cases where concentricity under radial load can be, at least theoretically, obtained tha t we will be concerned here. Consider the partial bearing of Fig. 3. By properly choosing the Jan., 1 9 5 2 . ] STEPPED SHAPE JOURNAL BEARING FILM 2 3 conditions this bearing will run in a concentric position. This may be stated another way: if the dimensions shown in Fig. 3 - - toge ther with a shaft speed, an oil viscosity and a bearing length- -are chosen arbitrarily, the shaft will run concentrically with a certain load. This load will now be obtained. The writer has shown 3 that the pressure in region (1) is given by: oo P = Z P\" sin nTrz m r x (1) .-1,3,~.,. sinh nTrcl ~ - sinh T b For region (2) it is convenient to move the Z-axis forward to the leading edge of the slider. The pressure at any point in region (2) is then given by: P = -- X] P\" sin m r z m r x ",
            "7hl and c2 -- 1.2Cl, but the change in load capacity is very small for large variations of these proportions. For all practical purposes the max imum load for a square slipper is obtained with cl = c2. If the bearing is made this way, the pressure diagrams for regions (1) and (2) are the same and the resultant load passes through the step. This is an impor tan t simplification when the results are applied to the journal bearing problem. In applying the foregoing results to a journal bearing, as in Fig. 3, the only change in the pressure equations is to make x = rO. The axial length of the journal bearing is taken as b. The angles subtended by the films of thickness hi and h2 are made equal and this determines the line of action of the resultant force, viz., along a radius through the step. In the arrangement of Fig. 3 the resultant force is vertical. This vertical load is found as follows: If W is the total load suppor ted by both halves of the bearing, then W = f b f ~ / ~ p r d O d z s i n O \" (5) 2 ao aoo The pressure, p, can be wri t ten down from Eq. 1 making the appropriate changes in the X-coordinate. P = E P~ sin sinh (O -- 0o), (6) .=1,,~,5... sinh - - b and Then d0 d00 P , = 24vrcob(h2 -- hi) nTfgOL n2~r~(hl 3 + h2 ~) coth - - i f - rt Tr g n Tr g P~ sin sinh (0 -- Oo) sin Or dO d Z %-- --U .=~,:~,5"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure26-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure26-1.png",
        "caption": "FIG. 26. FIG. 27.",
        "texts": [],
        "surrounding_texts": [
            "shaft W is coupled to the propeller-shaft Z by the usual universal coupling. The housing D is mounted to slide on a frame F (which consists of a pair of transversely arranged superimposed bars), which is pivoted at one end to one of the side members Y of the frame of the chassis and is adapted at the other end to slide in or on a suitable guide G carried by the other member Y of the frame. Means are provided both for operating the frame F for the purpose of pulling the driven disk B out of engagement with the intermediate disk C so as to disengage the driving couple, and to move the housing D carrying FIGS. 18 AND 19.-Diagrams of Cowey Friction Gear. FIB. 18. Y I' I 9: the driven and intermediate disks and their shafts laterally in relation t o the disk A so as to cause the intermediate disk C to engage the face of the disk at a different part of its aurface. I t will be seen that when the axes of the driving shaft and of the driven shaft, and therefore of the disk A and the intermediate and driven disks C and \u20ac3 are cc-axial, the apparatus is simply a direct-driving clutch, and that to obtain the lower speeds and the reverse it is only necessary to move the disks B and C across the face of the disk A so that the rim of the intermediate disk 0 will engage with a portion of the surface of the driving disk which is nearer to its centre, and obviously the nearer the driven disk is moved towards the centre of the driving disk the greater is the effective speed reduction. If the rim of the intermediate disk C is moved beyond the centre of the driving disk the direction of rotation of the driven shaft is changed, which gives the reverse drive. The housing D carrying the intermediate and driven disks C at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHICLES. 825 and B is coupled to the clutch-pedal, SO that it c a n be drawn backwards sufficiently to disconnect the engine from the disks by depressing the pedal, a suitable spring being employed to return the housing and keep the disks up t o their work when pressure on the clutch-pedal is removed. Within the housing D at the rear end of the shaft E carrying the intermediate disk C is a helical spring, which operates between the end of tho shaft and the end of the hollow part of the driven shaft W. This spring, when the housing D is drawn back, separates the intermediate disk C from the driven disk, so that when the clutch-pedal is depressed not only is the intermediate disk separated from the driving disk but also from the driven disk, so that there is no rubbing friction whatever between these parts. The effect of the use of the intermediate disk is to provide a complete annular clutch which renders wear a negligible quantity. In this gear all the drives are direct, so that 1055 in transmission is reduced to a minimum and at all speeds is silent. Further, as any gear and the reverse can be easily and rapidly engaged at any engine or car speed, a valuable emergency brake is provided. HALL HYDRAULIC UEAR. In the H d transmission, Fig. 20, three radially arranged pumps A are employed, the plungers Al of which are operated through connecting-rods by a common crank B on the shaft V, which is driven by the prime mover. Three radially arranged motors 0 are also employed, the pistons C1 of which are operated through connectingrods by a crank D on a non-rotating shaft E, which is arranged eccentrically in relation to the driving shaft V. Both the pumps A and the motors C are carried in a common casing F, which is free to rotate about the axis of the driving shaft V and is coupled to the driving toadwheels through suitable gearing. The cylinders of each pair of pumps and motors are connected by ports controlled by valves G and H, the valves G of the pumps being operated by an eccentric J on the driving shaft V, and the valves H of the motors by an eccentric K, which is loosely mounted on and in relation to the driving shaft V and is provided with means whereby it can be rotated through a given arc. The shaft E, although non-rotating, is capable of a limited amount of rotation-through the worm L and the worm-wbeel M -in order to adjust the eccentricity of the crank K. The shaft E carrying the crank D is carried in en eccentric bush or bearing N, the eccentricity of which is equal to the throw of the crank D, so that when the crank is turned so that its greatest throw coincides with the greatest eccentricity of the bush or bearing N the crank wi l l be concentric with the sEaft V, and wi l l then act merely as a &xed axle and impart no movement to the pistons 0' of the motore C as the casing F rotatus. The eocentric K on the driving shaft V, which operates the valves H of the motors, has an extension 0 which is 3 L at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 826 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEHIULES. DEC. 1916. toothed internally and engages a spur-pinion P carried on a shaft Q, which passes centrally through a hole in the shaft E. The shaft Q is provided with suitable means of rotation exterior to the casing F, so that the position of the eccentric L can be altered in relation to the crank D. By this means, in Q manner similar to that of the well-known form of loose eccentric reversal employed in marine engines, the direction of rotation of the casing F can be reversed when required. The whole of the spaces, passages, and cylinders of the casing F are Bled with oil, which is constantly pumped by the pumps A through the valves G and H to the motors C, the capacity of which exceeds that of the pumps. The action of the apparatus is as follows: Upon motion being imparted to the driving shaft V, the pumps A operate to pump oil into the back ends of the cylinders of the motors C, which thereby impart rotary motion t o the casing F, the ratio of speed betweeu the driving shaft and the casing being determined by varying the centre of the crank operating the pistons of the motors with respect to the axis of the driving shaft. When the cylinders of the motors are working t o their full capacity the greatest reduction of speed is obtained, and inversely when they are working at their lowest capacity the highest speed is obtained, the casing F then rotating at the same speed as the driving shaft V. If, as in the construction illustrated, the capaoity of the at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-BPEED QE&RB FOR MOTOR ROAD-VEHICLES. 827 motor cylinders is four times that of the pump cylinders, when the crank of the motors is in the position to impart the greatest amount of movement to the pistons of the motors,it will take four strokes of the plungers of the pumps to fill the cylinders of the motors with oil, and consequently the shaft V will have rotated four times during the time the pumps have, by filling the motors, caused the casing F to rotate once, but, as in normal working, shaft V and the casing F rotated in the same direction, one revolution of the pump shaft is lost for each revolution of the casing, so that the shaft V is geared down in relation to the casing F in proportion of 5 to 1. As before stated, when the crank D is concentric with the shaft V there is no movement of the pistons of the motors, and consequently the whole apparatus is carried round at the same speed as the shaft V, and the highest speed of rotation is imparted to the casing F. In this condition there is no circulation of the fluid in the apparatus, and except for the connecting-rods of the motors turning upon the crank D and the rods of the valves H moving upon the eccentric, there is no relative movement of the various parts of the mechanism. It will be understood that the two positions of the crank D before described are the two extremes, and that any intermediate position of the crank and consequently variation of the proportions of speed snd power of the whole apparatus can be obtained by rotating the crank D. COMPAYNE HYDBAULIO QEAB. The essential feature of the Compayne transmission is the Hele-Shaw pump, Figs. 21 and 22, which by rea8on of its construction can not only be run at a high speed without vibrations, but has a high degree of efficiency. The construction and action of this pump-which is of the rotary plunger type with a plurality of cylinders-will best be understood by reference to Figs. 23.24, and 25, which ace diagrammatic sections through the pump at right angles to its axis. The cylinders A (of which there are seven in the oonstruction shown) are formed in one block with a sleeve which is mounted on a fixed stub axle B, this sleeve being coupled to a shaft S which is driven by the prime mover. The pistons C IXRY gudgeon-pins D, which pass through slots in the cylinders end engage with slipper pieces E whioh fit in two opposed grooves in a drum F, which is mounted in ball-bearings to rotate in a housing (31. The grooves in the drum F form paths for the gudgeon-pins, and the drum F operates as B floating ring, the action and operation of which in relation to the pistons is that of a series of connecting-rods. The housing (31 is mounted to slide transversely across the casing X in suitable guides. By displacing this housing in the casing X in relation to the stub axle B on either side of its vertical centre line, that is to say, along a horizontal line r o passing through the centre of said axle, the eccentricity of the path of the 3 ~ 2 at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 828 VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHIaLE& DEC. 1916. gudgeon-pins with respect to the cylinders can be varied for the purpoge of varying the stroke of the pistons, and therefore the output of the pump as a whole. As the acceleration of the slipper-pieces and pistons above the centre line xx is balanced by the retardation of similar parts below the centre line, all the inertia forces are balanced. The drum F is kept ful l of oil by centrifugal action, and no oil is allowed to accumulate in the casing X, whereby all churning of the oil is avoided. In the stub-axle B, about which the cylinder block revolves, are two ports or groups of ports, H and K, with which ports in the bases of the cylinders A coincide as they revolve, the ports being in communication with similar ports or groups of ports, H1 and K1, at one end of the axle B exterior to the FIQS. 21 AXD 22.-Helc-Shatu Pump. Cmqayne Hydqazilic Gear. FIG. 21. FIG. 22. X casing X by m a n s of suitable passages. When the block of cylinders revolves, the floating ring F revolves with it, as the resistance of the slipperpieces E is greater than that of the ball-bearings carrying it. In the central position the slipper-pieoes have no movement, and in any other positions they only move to and fro to an extent directly proportiond to the stroke of the pistons. If the cylinders are rotated in the direction of the =rows, and the path of the gudgeon-pins is concentric with the axle B, a8 in Fig. 23, no motion is imparted to the pistons, and therefore the pump is inoperative. If the path of the gudgeon-pins is moved to the left, as shown in Fig. 24, the pistons as they move above the centre line ex move outwardly, and therefore tend to create a vacuum, so that thB oil is forced into the cylinders either by atmospheric pressure or by an artificial pressure in a supply-tank through the ports H1 and H, while the pistons as they move below the centre line at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from bso. 1916. VABIABLE-SPEED G ~ A B B @OR MmoB BOAD-VEE~~C~LES. 829 zz move inwardly and discharge the oil from the cylinders through the ports K and K*, the ports HI and K1 being connected by suitable piping to the hydraulic motors. If the path of the gudgeon-pine is moved to the right, 88 shown in Fig. 25, the pistons move outwardly when moving below the centre line m, and inwardly when moving above the line, so that the flow of the oil is reversed without altering the direction of rotation of the cylinders, the ports Kl and K becoming the suction ports and the ports H and H1 the deliveryports. In moving from the position of maximum delivery on one side to that on the other side, the dicharge is gradually reduced until the central position is resched, when the delivery ceases, after which it again increases to the maximum with the flow in the opposite direction, the change from full forward to fu l l reverse discharge being made without shock, the flow FIGS. 25 TO 25.-Diag~ams of Hek-Shaw Pump. Convpayne HyarmEic Gear. a t all times being proportional to the eccentricity of the path of the gudgeonpins. The hydraulic motor, Figs. 26 and 27, is of a simiiar construction to the pump, but is of the constant-stroke type and works inversely. The novel feature of the motor is the employment of a cam as a track for rollers carried by the gudgeon-pins. Two motors are u~ually employed, arranged either one in each road wheel or both mounted on the chassis and each driving one of the road wheels by means of chain or other gearing. The gudgeon-pins D carried by the pistons 0 carry ball-bearing rollers M at their ends, which travel within a double cam N formed in or carried by the casing Y. Owing to the shape of the cam, the pistons mnke two strokes per revolution. This gives a complete balance of the working parts, an absolute and uniform turning movement, and obviates any ehock in the system. By arranging the cam and the valve shaft so that they can both rotate a t relatively different speeds, and making the cam of a corrugated or wavy form, single revolution of the motor can be obtained from any desired number of strokes of the at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 830 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEBICLES. DEC. 1916. FICIS. 2 6 . m ~ 27.-Hydrazllic Motm. Compayne Hgdruulic Bear. pistons of the pump. T h i enables a very great turning effort to be seoured without unduly increasing the proportions of the motor. PIEPER ELECTRIC SYSTEN. In the Pieper, or Auto-Mixte, system, which is practically the same as the earlier British system of Farrow, a shunt-wound dynamo is mounted on a shaft which couples the engine with the road wheels through a magnetic clutch and suitable transmission gearing. The dynamo is connected through a controller with a battery of accumulators, a d works either as a motor or a dynamo, according as its E.M.F. is inferior or superior to that of the battery. The dynamo is fitted with commutating poles, the windings of which are connected in series with the armature, thus ensuring good commutation with heavy currents and with a weak main field. The battery, although primarily employed for assisting in propulsion, can also be used for startiig the engine and for ignition purposes. The supply of explosive mixture to the engine is controlled by the demand for current from the accumulators through a differentially wound solenoid, so that during starting and the period of extra effort the discharging current traversing its series-winding deoreases the magnetism produced by the shunt-winding, which in turn increases the supply of mixture, and thus compels the engine to give its maximum power for a at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-SP\u2019GED UEARS FOR NOTOR ROAD-VEHICLES. 831 given number of revolutions per minute. When the dynamo is charging the cells, the action of the series-winding assists that of the shunt-winding and tends to close the throttle. When the power of the engine is below that required, the battery automatically supplies energy to the dynamo, which then operates as a motor. When the power of the engine is in excess of that required for traction, or when the kinetic energy of the car can be recuperated, that is, when the car is slowing down or is running on a down-gradient, the dynamo works automatically as a generator and charges the battery. When the vehicle is on an up-gradient, and the torque on the road wheels becomes greater than the turning moment of the engine, the speed of the latter diminishes and the voltage of the dynamo fallsuntil it becomes less than that of the battery. The battery then discharges into the dynamo, and thus produces torque, which assists that of the engine until it balances the resisting torque of the engine. i)n a down-gradient, if the resisting couple ie less than the turning moment of the engine, the speed of the latter tends to increase, and the voltage of the battery rises so that the dynamo begins to charge the battery. As this charging current passes through the regulator the rate of admission of mixture to the engine is reduced to a minimum, and the torque of the engine becomes zero. STEVENS ELECTRIC SYSTEM. In the Stevens system a shunt-wound generator of the inter-polar type producing a continuous current is driven directly by the engine, and a serieswound electric motor is coupled to the transmission shaft of the vehicle, a controller box, and a shunt resistance for the generator fields being provided. The generator, which is capable of an output of from 1 to 36 kilowatts a t a speed varying from 350 to 1,400 revolutions per minute a t a voltage varying from 0 to 300, is designed with a falling characteristic, so that any increase in the demand for current when the engine is fully loaded is accompanied by a corresponding reduction in voltage. The output in kilowatts a t any speed is proportional to the power exerted by the engine, but the volts and amperes vary over a large range, according to the gradient of the soad, the speed, or the degree of acceleration required. The amperes required by the serieswound motor are approximately proportional to the torque on the transmission shaft, and the speed of the motor is to a smaller degree proportional to the voltage of the supply. Consequently, when the vehicle is running on a level road the demand for current is small, but ou up-gradients it increases with a corresponding decrease in voltage, which results in a slower speed with increased torque. This change takes place automatically. The excitation of the generator ceases automatically when the engine speed falls below 250 revolutions per minute. at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 832 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEHICLES. Dw. 1916. In ordinary running on the level, or on slight up-gradients, the speed of the vehicle is entirely regulated by controlling the speed of the engine by means of the usual gas throttle-valve ; but on stiff up-gradients, heavy roads, under other conditions requiring greater power, the shunt resistance is employed to allow of increased engine speed. The controller has three positions-forward, neutral, and reverse. As the generator ceases to excite a t 250 revolutions per minute of the engine, no electrical circuits are required to be made or broken in driving, even when stopping in traffic, as by reducing the speed of the engine to 250 revolutions per minute, or less, by means of the throttle-valve, the generation of current is stopped, and therefore no power is transmitted to the road wheels. Owing to the inter-polar construction of the generator, sparkless commutation is ensured, and as the msin circuit is never broken during driving, no sparking occurs at the contacts. A t starting, the electric motor demands a large current to develop the necessary torque for starting, which the dynamo supplies a t a low voltage, and 88 the motor speeds up, it automatically demands less current, which is supplied by the generator at an increased voltage. In other words, the voltage of the generator varies in inverse ratio with the amperes output; therefore the power required to drive the motor can never exceed a predetermined maximum, which is arranged to correspond to the maximum power of the engine."
        ]
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    {
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        "original_path": "designv11-23/openalex_figure/designv11_23_0002181_joaiee.1923.6593329-Figure7-1.png",
        "caption": "FIG. 7",
        "texts": [
            " This component decays at a rate determined by the resistance and the sum of the self and mutual inductances of the two windings. I t is due to the energy stored in the magnetic core of the transformer. Its rate of decay is much slower than that of the other component. The latter's rate of decay is determined by the resistance and leakage inductance of the windings, and this component of the currents is due to the energy stored in the leakage field. The vector diagram and oscillograph record are given in Fig. 7. In this figure the vectors 7 X and 7 2 , representing the primary and secondary currents, 392 LYON: ELECTRIC M A C H I N E R Y Journal \u0391. I. \u0395. \u0395. are rotating at an angular velocity of \u00f9. At the moment of short circuit each of these vectors abruptly stops and breaks up into two component vectors which diminish at different rates. The more usual transient condition would be one in which the short circuit occurred on the secondary side alone. In this case the current immediately after short circuit consists of the transient current together with the steady value of the short-circuit current"
        ],
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    {
        "image_filename": "designv11_23_0002133_pime_proc_1943_150_029_02-Figure5-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002133_pime_proc_1943_150_029_02-Figure5-1.png",
        "caption": "Fig. 5 . Origin31 hlaster \\Vormwheel (120 teeth)",
        "texts": [
            " The work of Sir Charles parsons was remembered at \u2018this stage, and the high-speed kicks were connected with the pitch ,f the teeth of the bobbing master wormwheel shown peak to peak) Of 1Y340 per second as compared with the Fig. 7. Method of Enabling Top Half of Wormwheel to be turned relative to Bottom Half and the The were mounted On a register and dowelled to the or@d hobbing machine, and the teeth cut with an all-ground single-lead hob having an axial pitch error Of &0.0002 inch and an OVed CUmdatiVe error Of 0.001 1 inch. A check of the pitch error of the new wheel cut from the original 120-tooth wheel was made with interesting results. The error of in Fig. 5, Plate 2. The h o b b g machine had a single-start worm and, although the gear produced had 321 teeth, the impression of each pitch of the wormwheel was so pronounced as to give $ @WI- As explained above, the slow speed was 670 r.p.m. or 11-15 7 r.p.s. Now this speed (11.15 r.p.s.) multiplied by the number of 3 \u2018 l o teeth in the machine wormwheel (120) equals 1,340 cycles per 5 - 0.~01- second, corresponding to the note emitted by the gears, as meviously explained. -bm2- and wheel of 120 teeth, and a pitch circle diameter of 60 inches; the effect of a wheel cut with only 12Clteeth"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000388_josa.34.000116-Figure4-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000388_josa.34.000116-Figure4-1.png",
        "caption": "FIG. 4. Intensity control sector, having a continuously variable transmission from 50 percent to 100 percent.",
        "texts": [
            " The cutting operation is identical to that of a lathe, but the frequent starting and stopping can be done more conveniently than with the usual lathe. The motor starts nearly instantaneously, and stops in about one second. Construction of the unit is simplified in that no bearing surfaces are required. The apparatus has been in use for about one year without showing any noticeable effect of wear. Mr. W. M. Weddell was partly responsible for the design and construction of this apparatus. The vane shown in Fig. 4 was constructed to provide a continuously variable control of the intensity of the photographed spectra. The vane is used to maintain the density of a standard line at some constant value when a difference in the speed of the photographic plates occurs. The vane has a continuously variable transmission between 50 percent and 100 percent, and affords a method of intensity control which does not depend upon changing source distance, exposure time, or the use of filters and screens. The vane is rotated at 1 revolution per second to avoid any possibility of a stroboscopic effect when used with the interrupted spark. Although calibration was carried out under the actual operating conditions using the vane in order to nullify any possible effect from the intermittancy of the exposure, no evidence for any intermittancy effect in this case has yet been discovered. A layout of the vane is shown in the upper right-hand corner of Fig. 4. To adjust the transmission factor, the vane can be rotated in the collar mounted on the end of the shaft connected to the 60-r.p.m. motor. The apparatus should be used such that the shaft to the motor is parallel to but about two inches lower than the optical axis of the spectrograph. A time-saving system has been constructed to minimize the labor required to operate the spectrograph used on the routine analysis of magnesium alloys. The actual wiring diagram of the system appears to be so closely connected with the particular requirements of this labora- tory that a detailed description would not be justified"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000352_0016-0032(52)90415-8-Figure2-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000352_0016-0032(52)90415-8-Figure2-1.png",
        "caption": "FIG. 2.",
        "texts": [
            "present writer has shown 8 that if this shape is applied to a slider of finite width (that is, considering the effect of side leakage), the load supported can be given by an explicit formula in the form of a rapidly convergent series. The extension of this stepped film design to the case of the journal bearing is a natural one. If the effect of curvature is neglected, the problem for the journal bearing, as far as pressure is concerned, is identical with the slider bearing problem when the shaft and bearing diameters are concentric as shown in Fig. 2. But such an arrangement as Fig. 2 could not run in a concentric position and carry any radial load. For if it is imagined to be running concentrically, it is in equilibrium under the resultant pressure loads of each stepped pad. An external radial load would cause a radial movement to a new position of equilibrium. This movement would have the effect of increasing the pressure on the side where 1 Assistant Professor, School of Engineering, Princeton University, Princeton, N. J. Lord Rayleigh, \"Notes on the Theory of Lubrication,\" Phil"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003928_s0370164600018113-Figure3-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003928_s0370164600018113-Figure3-1.png",
        "caption": "FIG. 3.",
        "texts": [
            " The frequency of the beam AE is given by CJ' and that of the beam BE by Equating these we have CJ' T - K (8) \u2022 (9) (10) Equation (10) has two real roots corresponding to two possible positions of the node, giving in general a higher and a lower frequency of vibration. The value of a as obtained from equation (10), when substituted either in equation (8) or equation (9), gives the frequency of vibration of the beam. When a beam is loaded at more than two points the motion becomes more and more complex as the number of loads increases. If the beam is loaded at three points C, D, and E, as in fig. 3, a possible mode of vibration is that in which nodes are formed at F and G, under which conditions the three portions AF, FG,.and GB of the beam behave as \" fixed-fixed\" beams. Expressing the condition that the frequency is the same at C, D, and E, we have A. (ii) which gives us two equations for the determination of the unknowns x Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0370164600018113 Downloaded from https://www.cambridge.org/core. Ecologie Systematique & Evolution Batiment, on 20 Nov 2018 at 16:10:33, subject to the Cambridge and y"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003857_t-aiee.1918.4765580-Figure2-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003857_t-aiee.1918.4765580-Figure2-1.png",
        "caption": "FIG. 2",
        "texts": [
            " The resulting products of sine and cosine terms would again be broken up into a series of sine and cosine terms which represent simple harmonic wave trains that are either stationary or moving at constant angular velocities. GENERAL EXPRESSIONS FOR VOLTAGE AND POWER Let the equation for one of these component wave trains be / = Bq cos (q x-j o t + caq) (1) This represents a sinusoidal distribution of maximum value B, and of wave length 2 7r/q, such as might be produced by q * P* poles moving through the airgap at an electrical angular velocity of j w/q in the same direction as does the armature. See Fig. 2. If the sign before j w t is positive the direction of rotation is opposite to that of the armature. If the coefficient j is zero the distribution is stationary with respect to the field poles. The angle aqj determines the phase of the distribution. When w t equals zero or any multiple of 7r the value of the flux *P represents the actual number of field poles. q is throughout the harmonic order of the flux distribution and is usually 1, 3, 5, 7, etc. j is usually 0, 2, 4, 6, etc. density at the reference point, 0, due to this distribution alone is i B"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003928_s0370164600018113-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003928_s0370164600018113-Figure1-1.png",
        "caption": "FIG. 1.",
        "texts": [
            " The first of these is of very little importance in the subject with which we are dealing, as the conditions necessary for the production of torsional vibrations in an unloaded beam are seldom if ever reproduced in practice, and, moreover, the natural frequency of vibration of such a beam is so high as to preclude any possibility of resonance with machinery in operation. The problem of the loaded beam is, however, of some importance, and it is intended to treat of this in some detail. Let the beam AB (fig. 1) be rigidly fixed at one end and free to rotate about the axis OO at the other end. Furthermore, let the mass moment of inertia of the beam be negligible compared with the moment of inertia of the load w whose eccentricity is r. Let 61 be the angular displacement due to the statically applied torque T ( = Wr), and let 6 be the angular displacement on each side of the mean position when the system is vibrating. From formula (1) we obtain T m (3) CJ \" I, T .where \u2014 is the static torque necessary to produce unit angular displace- Core terms of use, available at https://www"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002129_1.1749122-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002129_1.1749122-Figure1-1.png",
        "caption": "FIG. 1. c",
        "texts": [
            " lA is revolved in front of an electromagnet supplied from an alternating-current source, the magnetic attrac tion is a maximum at the time when the current is a maximum. Thus, if a rotor segment arrives in place in front of the pole piece at each current maximum, the rotor will be turning at synchro nous speed. If segment (a) in Fig. lA is slightly behind the center position when the current is a maximum, a restoring force will be produced which will tend to advance the rotor. This force will increase as the angle of lag increases until the angle is such that sector (b) also comes under the influence of the pole as in Fig. 1e. When this happens, the rotor will fall \"out of step\" and cease to rotate. It is obvious that this type of motor is not self-starting and some means must be used to bring it up to speed. It is usually combined with an induction motor for this purpose. The speed of such a motor is obviously a function of the frequency of the alternating current supply and the number of rotor segments. It is easily found from the formula: S d \u00b7 120 X frequency in cycles pee III r.p.m. = number rotor segments The motor chosen for the basis of the unit constructed was a Robbins and Myers, 110 volt 60 cycle a"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000311_1.1722169-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000311_1.1722169-Figure1-1.png",
        "caption": "FIG. 1. A schematic diagram of the crossed-coil transducer. A ferrite cylinder is clamped rigidly by supports at its midplane, but is otherwise free to vibrate. Toroid and solenoid coils are wound round the cylinder, (in practice upon a polystyrene form) to provide input and output windings.",
        "texts": [],
        "surrounding_texts": [
            "MAGNETOSTRICTIVE materials have been fre quently used in the construction of electro mechanical resonators of various types.1 - 4 Normally, these devices include only two accessible terminals, and are therefore in the nature of impedance elements. However, in some cases there are four accessible terminals, and the magnetostrictive element is used to provide a resonant coupling between an input and an output circuit. I-a Unfortunately, in these latter devices the magnetostrictive coupling is always supplemented by some undesired direct inductive coupling. The purpose of this paper is to show how a magnetostrictive coupling can be achieved between crossed coils by the application of the Wiedemann effect and its converse. By this means the direct inductive coupling is eliminated. 1 W, Van B. Roberts, RCA Rev. 14,3 (1953). 2 H. H. Hall, Proc. Inst. Radio Engrs. 21, 1328 (1933). a G. W. Pierce, Proc. Am. Acad. Arts Sci. 63, No.1 (1928). \u2022 P. Popper, Soft Magnetic Materials for Telecommunications edited by Richards and Lynch (Interscience Publishers, Inc., 1953), p. 35. which is clamped by supports at its midplane, but which is otherwise free to vibrate. A toroidal coil and a solenoidal coil are wound upon a surrounding form to provide input and output windings. For the ideal construction the fields that are produced by currents in each of the windings are everywhere orthogonal, so that there is no direct inductive coupling. In a series of early experiments Wiedemann5,6 showed that a magnetostrictive torque is produced in a ferro magnetic rod which is initially magnetized in the axial direction, and then subjected to a circular component of induction in a right plane of the rod. The converse also applies. Because of this effect, if a ferromagnetic cylinder is subject to an oscillatory driving induction in either the axial or the circular directions, in conjunc tion with a bias induction in the respective orthogonal direction, it will oscillate in torsion at the frequency determined by the driving field. If the driving frequency is an integral multiple of 2Lc, c being the velocity of shear or torsion waves in the cylinder and L its axial length, the cylinder will oscillate in resonance. Further more, if the cylinder is made to vibrate in torsion while it is subject to a bias induction in either the axial or circular directions, then an oscillatory component of the induction will be induced in a direction that is orthogonal to the bias field. It follows from a consideration of these effects that a magnetostrictive coupling between the input and output windings will be obtained if the cylinder is magnetically biased in both the axial and circular direc tions, since an oscillatory component in the axial induction combined with the circular bias will produce a torsional oscillation, which in turn will produce an oscillatory component of induction in the circular direction because of the presence of the axial bias. The resultant magnetic bias in this case has a helical configura tion. It is convenient to represent a two-pole electro mechanical resonator by means of the equivalent circuit 6 J. A. Ewing, Magnetic Induetion (D. Van Nostrand Com pany, Inc., New York, 1900), third edition. S L. F. Bates, Modern Magnetism (Cambridge University Press, London, 1951), p. 415. 1152 [This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to ] IP: 138.38.171.231 On: Wed, 26 Nov 2014 12:25:48 MAGNETOSTRICTIVE COUPLING OF COILS 1153 shown in Fig. 2.1,4,7 This consists of a linear component Z., which represents the impedance of the winding in the absence of magnetostrictive oscillations, in series with a motional impedance Zm, which represents the magnetostrictive contribution. Because of the similarity of operation of the crossed coil transducer, the two-pole equivalence may be adapted to give the four-pole equivalent circuit shown in Fig. 3. In this representation the arms of the T are the impedances of the input and output windings in the absence of magnetostrictive oscillation. The mutual impedance represents the mechanical vibration, and the electromechanical cou pling through the windings is represented by impedance transformers. These components may be assumed to remain linear for small departures from the resonant frequency. This equivalent representation is confirmed by the first-order theory which is given in the next section."
        ]
    },
    {
        "image_filename": "designv11_23_0003857_t-aiee.1918.4765580-Figure21-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003857_t-aiee.1918.4765580-Figure21-1.png",
        "caption": "FIG. 21-FLUX DISTRIBUTION DUE TO ARMATURE CURRENT. 90 DEGREES.",
        "texts": [],
        "surrounding_texts": [
            "If one tip of the field pole is more highly saturated than the other, as it usually would be, the magnetic circuit will not be quite symmetrical about its center line. This distortion is probably never very great since most of the reluctance is in the air gap. Its effect would be to introduce sine terms into the series for Aq and cosine terms into the series for C,. The final result would be to produce small quadrature electromotive forces in the armature winding which would otherwise be absent and which are neglected throughout this analysis. APPENDIX III Calculation of Coefficients. The following assumptions in regard to the distribution of flux in the air gap are ccnsidered ideal. They are chosen to represent the actual conditions as nearly as possible and still allow relatively simple calculations to be made. With these assumptions, however, it requires about fifteen pages of close calculation to obtain the desired coefficients. In practise, it may happen that the departure of the actual distributions from these ideal forms may be so great as to warrant new calculations that will more nearly fit the LYON: IIARMONIC ANALYSIS 1511 special case. The flux distributions can also be determined experimentally and the coefficients deduced therefrom. With one ampere-turn acting per field pole the flux distribution in the-air gap is assumed to be sinusoidal, with a maximum value of B1m. See Fig. 18. For the same saturation of the main magnetic circuit with one armature turn carrying one ampere, the flux distributions for different positions of the turn are shown in Figs. 19, 20 and 21. At zero degrees, with the armature coil directly opposite a field pole, the distribution is an inverted sine curve between the poles and coincides with the distribution due to a field ampere-turn under the poles. The maximum value is Bin. At 45 and at 90 degrees, the distribution is also an inverted sine curve between the poles and coincides with the distribution due to a single field ampere-turn under the pores. Taking the maximum value in each of these four cases as B, assumes that the reluctance of the armature core, pole and yoke is negligible compared with that of the air gap and teeth. This is nearly so at low saturation. For operating conditions the"
        ]
    },
    {
        "image_filename": "designv11_23_0003953_t-aiee.1915.4765249-Figure1-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003953_t-aiee.1915.4765249-Figure1-1.png",
        "caption": "FIG. 1 FIG. 2",
        "texts": [
            "' = 1 and equation (6) re- duces to the well-known form = IVR2 + (Lw- 1) The impedance of a series circuit becomes a minimum for a non-sinusoidal current when c -\\Vao- . d' L C, or, forsinu- soidal currents, when X = _/ 1 L C Graphical Solution; R, L and C in Series. Let us use for nonsinusoidal currents, the graphical relation in common use for sinusoidal currents, namely,that reactance and resistance may be 1162 MIZUSHI: ALTERNATING CURRENTS [June 29 represented by two sides of a right triangle the hypotenuse of which represents the impedance; as in Fig. 1. Thus, Z = A/ R2 + X2 From equation (6) we also have whence W\\hen 6' and a I are unity, (10) reduces to the well-knlown value for the reactance for sinusoi-dal currents, X = Lco-C; the total reactance is then the arithmetical difference of the inductive reactance and the capaci-ty reactance, which are graphically represented in the same straight line but in opposite directions. For a non-sinusoidal current, however, the inductive re- actance 6IL c and capacityreactance C> are no longer in a straight line, but are laid off as in Fig. 2 with an angle T' between them, where cost\" = -a For non-sinusoidal currents, SI\" < 180 deg., for sinusoidal currents,a' = 1 = 1,,\"= 180deg. This graphical construction is justified as follows: From Fig. 1 or Fig. 2, we have, by a well-known trigonometrical relation, X = \\(JLW)2 + (Cj) +2(8'LQL iJ)cos<' Since cos \" = -, , this is identical with (10) already obtained analvtically. J' L w, o-'/Cw and X are in one plane, at right angles to the resistance, R. Special Cases for Series Circuit. For L and C, without resistance, E = I (8'L (A))2+ ( a L(1) The reactance, as shown in Fig. 2, is the vector sum of 'Lc and C drawn with an angle \\1\" between them. With non-sinu- soidal currents, capacity and inductance cannot fully neutralize each other so as to make the total reactance zero, as in the case of sinusoidal currents",
            " A single odd harmonic which is more than of the amplitudeN of the fundamental may, and an odd harmonic which is greater than the fundamental must, reverse the resultant curve and make it pass through zero more than twice per cycle. Such a wave causes more than one maximum and one minimum value per cycle in the integral or flux wave; so that iron in a transformer is carried through a major and two or more minor hysteresis loops per cycle, causing a higher loss than that indicated by the form factor corresponding to the largest average between any two symmetrical zero points. FIG. 1 Prof. Bedell calls special attention to the combination of a fundamental wave and a third displaced 60 fundamental degrees. This would be: A1 sin 6 + A,, sin 3 (0 - 60) or A3sin -A3sin3 0 In Fig. 1, A3 is 75 per cent of A 1 and it will be noted that the third component of voltage, since it has an amplitude greater than one-third of the fundamental, reverses the resultant voltage E and makes it pass through zero four times per cycle. The flux which is the integral of the voltage wave is K (-A 1 cos 0 A3+ 33cos 36) and is shown in the heavy curve 49. Such a flux wave will carry an iron core through the hysteresis cycle shown to the left of the curves. The author's results give a form factor of 1"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure20-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure20-1.png",
        "caption": "FIG. 20.-Diagram of Hall Hgdraulic Gear.",
        "texts": [
            " The advantages claimed for hydraulic transmission are : (1) that as all the mechanism is enclosed, and works in oil under pressure, friction is reduced to a minimum, and damage is practically impossible ; (2) that a change of speed can be effected without any jar or strain on the prime mover ; (3) that it is extremely smooth and comparatively quiet in running; (4) that in changing gear there is no necessity to disconnect the prime mover; ( 5 ) that the gear can be adjusted to the constantly varying requirements of the prime mover without checking the momentum of the vehicle, and finally, that it is simple in action, durable, and economical in working. The various types of hydraulic transmissions that have been introduced onlyIdiffer from one another in the type of pump and motor employed and in various details of construction and control, and two of them are described in the Appendix, namely, the earliest-the Hall, Fig. 20 (page 826)-and the latest-the Compayne, Figs. 21 to 27 (pages 828-3O)-which is associated with the name of Dr. Hele-Shaw. The practical advantages of the Hele-Shaw system are that the pump has a uniform and steady discharge under all pressures, that sliding friction is reduced to a minimum whereby the total efficiency of the pump is materially increased; that the rotating parts of both pump and motor are perfectly balanced ; that there is no end-thrust in either the pump or the motor owing to all the forces being in the plane of rotation ; that all the parts me simple, and those that require any great degree of accuracy are cylindrical; that there is a minimum of wear on any of the parts; that although high pressures are employed no packing glands are required; that, owing to the rotary form of the valve, the slip of oil past the valves is reduced to a minimum because the oil pressure does not tend to open the valve, and that the inertia forces in both pump and motor are perfectly balanced",
            " This spring, when the housing D is drawn back, separates the intermediate disk C from the driven disk, so that when the clutch-pedal is depressed not only is the intermediate disk separated from the driving disk but also from the driven disk, so that there is no rubbing friction whatever between these parts. The effect of the use of the intermediate disk is to provide a complete annular clutch which renders wear a negligible quantity. In this gear all the drives are direct, so that 1055 in transmission is reduced to a minimum and at all speeds is silent. Further, as any gear and the reverse can be easily and rapidly engaged at any engine or car speed, a valuable emergency brake is provided. HALL HYDRAULIC UEAR. In the H d transmission, Fig. 20, three radially arranged pumps A are employed, the plungers Al of which are operated through connecting-rods by a common crank B on the shaft V, which is driven by the prime mover. Three radially arranged motors 0 are also employed, the pistons C1 of which are operated through connectingrods by a crank D on a non-rotating shaft E, which is arranged eccentrically in relation to the driving shaft V. Both the pumps A and the motors C are carried in a common casing F, which is free to rotate about the axis of the driving shaft V and is coupled to the driving toadwheels through suitable gearing"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000318_aieepas.1957.4499545-Figure9-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000318_aieepas.1957.4499545-Figure9-1.png",
        "caption": "Fig. 9. Effect of inceasing or deaeasing interpole tength on brush current and stabillty on a generator",
        "texts": [
            " A means of varying the point of application of the friction force appeared to be feasible when the effect of varying the interpole strength of a machine was considered. If the interpole current is increased, the load current tends to concentrate in the leading edge of the brush. Since the wear rate of brushes is higher with current than without, the leading edge would tend to operate at less pres- Shobert II-Carbon-Brush Friction and ChatterJUNiE 1957 273 sure than the trailing edge. This would put line OA in Figs. 1 and 6 in the position shown in Fig. 9(B) and the brushes would not chatter. On the contrary, if the interpole current is decreased, the load current concentrates at the trailing edge of the brush and the pressure under the leading edge is increased. Line OA in Fig. 9(A) is in the chatter range. To prove this, a 25-kw 120-volt d-c generator with radial brushes, as shown in Fig. 9, was operated under these conditions. As predicted, the brushes chattered when the interpole strength was decreased, but did not chatter when the interpole current was normal or increased. This effect is demonstrated on the sound film. The meter in the upper left of the screen represents the variation from normal interpole current. A fullscale deflection to the right represents a 30% decrease in interpole current, and a full-scale deflection to the left represents a 30% increase in interpole current"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000321_pi-a.1955.0133-Figure2-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000321_pi-a.1955.0133-Figure2-1.png",
        "caption": "Fig. 2.\u2014Vector diagram for salient-pole machine showing additional construction to make diagram similar to a vector diagram for a round-rotor machine.",
        "texts": [
            " If saturation had been considered the centre of the circle would have been shifted somewhat, but the radius would still have been drawn to E and the effect would be to change the position of point C slightly in Fig. 1. (2.2.2) Salient-Pole Rotor. The construction for the rotor-heating limit of a salient-pole alternator is more complicated than that for a round-rotor machine. It is based on a method described by Walker.6 The construction follows from a 2-reaction vector diagram as shown in Figs. 2 and 3. In Fig. 2 the conventional 2-reaction vector diagram is AGBDA, familiarity with which is assumed. This can be reduced to a form similar to a round-rotor vector diagram by replacing V by Vu where V{ corresponds to the excitation vector based on round-rotor theory, and BC = JSXd ~ xq) i s added at D, as shown, DH being equal to BC. The excitation-voltage vector is HC = DB, and this is produced to cut AD produced at F. A semicircle is then constructed on FD which is equal to Vt(Xd - Xq)/Xg. The excitation vector is represented by the intercept on a ray' from F between the semi- circle on FD and C, the rated power factor on the 1 per-unit current circle"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0000352_0016-0032(52)90415-8-Figure5-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0000352_0016-0032(52)90415-8-Figure5-1.png",
        "caption": "FIG. 5. Fro . 6.",
        "texts": [],
        "surrounding_texts": [
            "7zTrroL cosh sin 00 96vo~r3b(h~ - hi) ~ b W = 7r2(h? + h2~ ) ~ [n , ,70r2 ~ n r r r a \" ,,=1,3,5... n~ ~ ] ~ T - + 1 cosh T (9) The two special cases when 00 = 0 and when 00 = -- - the most interesting. These are shown in Figs. 5 and 6. 71\" are perhaps 2 First consider the case of 00 = 0. 7e = - . The load formula becomes 2 This is a half bearing and here W = 96m\u00b0r3b(h2 - ha) ~ 1 (10) ( ) 71\"2(h13 + h23) n = 1 ' 3 ' 5 ' ' \" n~ - - ~ - + 1 7r and a = 7r, the load for- For the case of the full bearing 00 = - mula becomes W = 96#\u00b0~r3b(h2 - h , ) r2(h, 3 + h~ 3) n=1,3,5 \u2022 - \u2022 ~t~2 nTv2g cosh - i f - + 1 ~ 2 - - + 1 c o s h ~ - (IU This last equat ion is not in a form ve ry suitable for computa t ion , bu t by making use of the well known relations for hyperbol ic functions it can be al tered to 192uwr3b(h2 - h , ) ~ 1 \" = \" ~ ' ~ ' \" n ~\" \\ b2 + 1 1 + tanh 2 2b ] In Eqs. 10 and 12 the ratio r/b occurs. I t is more convenient to have the diameter of the bearing rather than its radius appearing and the ratio L / D is more usual in journal bearing theory. Also the rotational speed, N, in revolutions per minute is more suitable. If these notat ions are subst i tuted in Eqs. 10 and 12 they become 0\u00a2 W = 8uNDLs(h2 -- h~) Z 1 (13) ( 5 ~ ( h l ~ + h23) .=1,3,5... n2 n21r 2 + D 2 / oo W = 16vNDLs(h2--h~) Z 1 (14) 57r(h?+h~0 .-1,3,5... 2 / 2 2 4L2 \\ / \u2022 2mr2D \\ \" . ~n~r + - ~ - ~ ) ~ l + t a n h ~ ) Equat ion 13 is the load supported by a half bearing, while Eq. 1'4 gives the load supported by a full bearing. The summat ions in these equations have been evaluated for a typical range of values of L / D . Calling KI = ~ 1 (15) ( 4L, ' .=i ,3,5. . . n2 n 2 ~ + D 2 ] K 2 = ~ ( 4 L ~ ( D 2 ] . 2nzc2D\\ . (16) n = l , 3 , ~ . - , n ~. n2,r 2 + 1 + tanh ' -~-L--) A pair of curves shows the value of K1 and K2 in Fig. 7. h2 - hi The factor hi ~ + h, 8 which appears in the load equations is easily shown to have a max imum when h2 ~_ 1.68hl. Thus for the conditions of max imum load, Eqs. 13 and 14 can be wri t ten W = .06033 gNDL3 K1 for half bearing (17) hl 2 W = .1207 vNDL~ Ks for full bearing. (18) hi S It is desirable to make comparisons of this bearing to one of conventional design but unfor tunate ly there does not seem to be a very good way in which this can be done. To begin with, the stepped film bearing does not have a single figure which can be called the clearance. If min imum film thicknesses are taken equal for the comparison it is not clear wha t clearance or wha t eccentricity should be used in the conventional bearing. The au thor has not done much to resolve this di lemma. A few trials with roughly comparable figures have shown tha t the s tepped bearing has about the same theoretical capacity as a bearing of conventional design. This is not surprising in view of the results of the stepped slipper bearing. Here the load capacity is only slightly more than for the inclined plate slipper bearing if the slipper is square. Another matter of practical concern is how such a bearing is to be made. In the case of the stepped slipper bearing all that is required is two fiat surfaces giving the slight step. This can be done by surface grinding which is one of the easiest and most accurate machine shop operations. But a cylinder having a stepped diameter is not an espe- .11 40 \u2022 08 -,% \u2022 O7 % . o z \" \u2022 a 4 \"02, \"01 0 0.6- /.0 /.6- ,~.0 LID Fz~. 7. cially easy surface to produce. It is possible that it might be scraped to fit a stepped bar which itself might be made by grinding and partial plating. A controlled sand blast might also be used. However, the use of etching seems to offer the best solution to the problem. Undoubtedly this practical matter of how best to get the desired shape is a serious obstacle to the use of the stepped film journal bearing. But it does not seem an insurmountable difficulty and the author has not considered it a sufficient reason for not giving the foregoing results to those who may find them of interest."
        ]
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        "image_filename": "designv11_23_0003959_paiee.1914.6660881-Figure10-1.png",
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        "caption": "Fig. 10 shows, in section, a double bus in stallationin which the busbars, series transformers, fuses and most of the dis connecting switches are mounted in compartments. The roof trusses are built through the cell structure, so that most of the available space is utilized. The lines enter through roof tubes between the vertical cell barriers. Connections to and from the oil switches are made with cambric-insulated wire",
        "texts": [],
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            "tomers' substations the field for the outdoor installations seems to be with the smaller isolated customer, where he has vacant space about his plant. Where the larger installations are made, the outdoor type does not seem so well adapted. Some of the advantages of outdoor installations are: 1. No cost for new buildings. 2. No space required in customer's present buildings. 3. All high tension current kept outside of customer's build ings. Some of the advantages of indoor installations are: 1. More reliable switching equipment can be installed. 2. Better facilities for inspection and repair. 3. Apparatus protected from weather. 4. Switching can be handled more easily by customer. 5. Less danger of accident to public. 6. Safer arrangement of apparatus possible. COMPANY'S SUBSTATIONS Where the operating company generates its power at a large central station, which is usually at a point quite remote from the demand, or where it purchases power from some trans mission company, it is necessary for it to receive current at a much higher voltage than that at which it can distribute to the small light and power consumers, hence, it is obliged to install a substation to transform the power from the trans mission voltage to a lower distributing voltage. The size of this substation, of course, depends upon the character of the district to be served, which may be anything from a small suburban town, having a small demand, to the thickly populated power district having several thousand kilowatts demand. When it has been decided that the time is ripe for a sub station in a certain district, one of the most important and by no means the easiest problem is the selection of a location. Some of the points which should be considered in making a selection are: 1.. Location of the present load. 2. Future development of the district. 3. Distance from existing substations on the system. 4. Outlet from the substation for the various feeders. 5. Street frontage. The above points determine the geographical location for the substation in the district. It is not always best to locat 1914] FULLERTON: SUBSTATIONS 181 in the center of the existing load, as the tendency may be to ward development in one particular direction due to natural conditions in this section. Again the demand may be too close to an existing substation to warrant a second one, therefore, it may be advisable to locate to one side of the present load, and be in a better position to handle the growth outward from the present substations. The outlet from the substation should be given considerable attention; if aerial lines are to be installed, a location such that it is possible to feed in at least two directions should be selected, and a corner lot would be preferable, where the lines could ra diate from the substation in four directions. This means that the pole line from the substation will not be so heavily loaded as if only one outlet were available. Even though it be an underground district, it is quite desirable to have several out lets and save congestion in subways. Substation Buildings.\u2014Probably one of the least expensive buildings suitable for substation purposes is that made of structural steel and corrugated iron, but while this building is comparatively low in cost, its life is also comparatively short, and on the whole is not very desirable. A type of building, which compares very favorably in cost with one of steel and corrugated iron, but which has much greater life, is shown in Fig. 6. This building is simply an en largement of the slab transformer vault construction referred to earlier in this paper. It is built up of structural steel on which are'boltedtwo-in.(5-cm.) reinforced concrete slabs of stand ard size; the roof is also made of these slabs, supported by the framework of the building. The concrete roof is covered by a tar paper and gravel roofing. About a six-in. (15.2 cm.) slope to the 12-ft. (3.6 m.) width is allowed. Steel sash, wireglass windows and steel louvres are used. For air supply, a section of concrete is left off one or two of the lower slabs, leaving the expanded metal reinforcing exposed. This allows a free inlet of air and at the same time prevents large objects from entering. Regular l^-in. (3.8 cm.) expanded metal is used in the construction of the slabs. This building compares very favorably in appearance with that of the average garage or out-building which may be found on back streets or alleys, and makes a fireproof construction. It is also portable and can be used to a good advantage at a location from which its removal at some future time may be 182 FULLERTON: SUBSTATIONS [Feb. 25 desired. This building is 12 by 18 ft. (3.6 by 5.4 m.) and 15 f t . (4.5 m.) high. In it are installed three 250-kw. transformers serving four 2200-volt feeders. Where a better type of building is required, brick or stone is usually used in the construction and as elaborate a design as is desired can be utilized. By the use of rock faced brick and sawed s t o n C ; a building very pleasing in appearance can be constructed at a reasonable cost. The cost of buildings, or their equivalents, for substation purposes varies so widely, due to location and cost of labor, that it is impossible to give an estimate that would meet all conditions; however, I am giving a relative value to the various types, taking as a unit the least expensive installation-that with the outdoor apparatus installed on a concrete platform and enclosed by a fence. Concrete foundations, poles, picket fence . . . (Fig .3 . ) 1.00 Structural steel tower ( F i g . 4 . ) 2.25 Steel and corrugated iron building (12 by 18 f t ) . . . . 4.50 Steel and concrete slab building \u00ab \" \" 6.75 Ordinary red brick building \u00ab \u00ab \" 15.00 Rock faced brick and sawed stone \u00ab \u00ab \" 25.00. Substation Installations. Like the buildings, the electrical installation has a very wide range of possible combinations.> The outdoor substation is the cheapest, especially where no switching or regulating apparatus is required. However, it does not seem particularly w e\u0302ll suited for installations where there is small apparatus such as instruments, oil switches, feeder regulators, etc., which should be housed. Of course, it would be possible to put the transformers and high-tension apparatus on the outside, erecting a building for the housing of the low-tension apparatus. Installations of this type have been made and work out very nicely for the small demands, but the present designs for outdoor switching apparatus for 10,000 and 20,000 volts are not such as to allow of very large installations being made along these lines. It frequently happens that a transmission line may pass by a small hamlet or power customer from which a small revenue can be procured and still the income will not justify making a very expensive substation installation. This class of business can be taken care of by an outdoor substation. By an in stallation of this kind the town is furnished with electric light, which it may very much desire, and the operating company receives a small revenue from a district which would not allow 1914] FULLERTON: SUBSTATIONS 183 of the installation of a regular substation building and appar atus. Fig.. 7 shows an installation of this type. The trans formers are mounted on a tower construction some feet above the ground. Pole top switches, fuses, etc., are used, no reg ulators or switches being installed on the low-tension side. If regulators are necessary, the outdoor pole type can be used. Diagram A, Fig. 15, shows the wiring of this installation. The apparatus is connected to the transmission line through a switch and fuse; a choke coil and ground horn being inserted between the switch and fuse. Diagram C shows the wiring of the installation made in the concrete slab building shown in Fig. 6. The transformers are protected by high-tension fused circuit breakers which also act as disconnecting switches for the incoming transmission lines, the transformers being connected direct to the high-ten sion bus. On the low-tension side each circuit is controlled by an oil switch and fuse. Lightning arresters are mounted on the poles outside the building. Neither of the above installations can really be said to have a high-tension switchboard. This is scarcely necessary where the substation is small and is fed by only one or two trans mission lines. Where the substation is important enough to have feeders from separate power houses, or where it is used as a switching station for high-tension lines, it is necessary to install some type of high-tension switchboard. The simplest and probably the cheapest installation that can really be called a switchboard is the open wire type. Fig. 8 shows a fair example of this type of construction. The oil switches are mounted in concrete cells, while the busbars, dis connecting switches, etc., are mounted on framework above the switch structure. The spacings of the wires are kept at 12 in. (30.4 cm.) or better for opposite polarities. Cambricinsulated flameproof wire is used throughout. Disconnect ing switches are installed on both the high-tension and lowtension sides of the transformers, so that one transformer can be disconnected without interfering with the service. Where open wiring is used, it is always painted a standard color, such as red for 11,000 volts, drab for 2200 volts and white for 110 volts, and this arrangement of colors is adhered to through out the system. Diagram B, Fig. 15, shows the wiring of a layout of this type. Both incoming and outgoing lines feed through oil circuit 184 FULLERTON: SUBSTATIONS [Feb. 25 breakers to the high-tension bus. Disconnecting switches are always installed on each side of the oil breakers. In this arrangement all wires arc separated by barriers of some description; soapstone, slate, concrete, ebony wood are some of the materials generally used. I will touch only on the use of concrete. This is probably the cheapest and gives a grounded surface for mounting the equipment, thus depending entirely upon the insulation of the apparatus. When the cell structure is referred to, we usually think of something quite massive, but it is sometimes desirable to erect a cell structure and at the same time economize floor space. P L A T E III \u0391 . I. \u0395 . \u0395 . V O L . X X X I I I , N O . 2 P L A T E IV \u0391 . I. \u0395 . \u0395 . V O L . X X X I I I , N O . 2 1914] FULLERTON: SUBSTATIONS 185 in fibre conduit mounted in the concrete wall. To the right in the figure, the 2200-volt feeder switchboard, built in a double deck arrangement, is shown. On the roof of the station are the outdoor electrolytic light ning arresters. A ladder is pro\u039b\u03acded at the end of the build ing for use in getting to the roof to operate the arrester equipment. Diagram Fig. 15, shows the wiring of this station. The 186 FULLERTON: SUBSTATIONS (Feb. 25 lines feed in through oil switches to selector type disconnect ing switches, and thence to each of the buses. One bus is sectionalized so that some of the lines ordinarily feed through to other substations entirely independent of the load in this station. Figure 11 shows the inside view of this station, with the high-tension concrete structure to the left and the 2200-volt incandescent feeder switchboard to the right. In the c o n v S t r u c - tion of this feeder switchboard, remote control oil switches were used, which means all 2200-volt apparatus was kept away from the switchboard panels. Automatic voltage regulators were used on each feeder. A more elaborate concrete structure is that shown in Figs. 12 and 13. Fig. 12 shows the front view of the concrete struc ture and Fig. 13 the section of a double bus switchboard. All circuits are connected to each bus through remote control oil circuit breakers. The insulators supporting the bus also make connection between the bus and the connections to the disconnecting switches. The switchboard panel is directly in front of each high-tension panel, thus allowing the use of hand-operated oil circuit breakers. In the structure, notice the location of the oil switch at the bottom. This is made possible by the use of single-conductor lead cable clamped to the concrete and connecting the upper disconnecting switch with the oil circuit breaker. The hori zontal barriers between buses are hung from the center web of the vStructure without any supporting p O v S t s at the outer edge. This allows of ready access to the buses. Space was also particularly valuable in this case, as is indicated by the posi tion of the roof truss. Provision is made for adding larger switches in series with the present ones on the main floor at some future time. This switchboard serves not only for substation purposes, but is a distribution board for high-tension circuits to other substations. Diagram E, Fig. 15, shows the wiring of this switchboard. All circuits are double-throw on either bus. The buses are sectionaHzed by disconnecting switches to allow of greater flex ibility in switching. The transmission lines can be operated in multiple or separately, each one feeding its own section of load. By operating separately, trouble on one section will not generally affect the other parts of the system. 1 9 1 4 ] FULLERTON: SUBSTATIONS 187 I cannot pass tlie subject of concrete cell structure without a few words regarding the method of construction. The usual method of building these cell structures is by erecting forms and pouring the concrete, using reinforcing rods where neces sary. Owing to the difficulty of securing a uniform and smooth B A S E M E N T F I G . 1 3 job, we have digressed a little from the usual method and are building an expanded metal frameworli and plastering the con crete body onto it. The thickest portions plastered are three inches. The scratch coat contains a small quantity of hair, the remaining coats being pure cement and sand. The finishing 1 8 8 FULLERTON: SUBSTATIONS [Feb. 2 5 coat is of Keen cement, which gives a hard, white, smooth surface. In the finishing coat, a small quantity of lime is used to make the cement work more smooth. expanded metal being wired to this skeleton framework. Where the structure is built as in Fig. U , the reinforcing is keyed in to the main wall. COMPARISON OF OUTDOOR AND INDOOR INSTALLATIONS In company substations, the field for the outdoor instal lation seems to be with the small towns which can be picked up P L A T E V \u0391 . I. \u0395 . F . V O . X X X I I , N O . 2 F u ; . 11 [ b U L L E R T O N j F i G . 12 [ F U L L E R T O N ] P L A T E V I \u0391 . I. \u0395 . \u0395 . V O L . X X X I I I , N O . 2 F I G . 14 I F I ' I . L E R T O N ] 1914] FULLERTON: SUBSTATIONS 189 along the route of the transmission system without considerable line extension. Where larger municipalities are handled, it is usually desirable to install emergency service which requires more or less high-tension switching, and an indoor substation is usually desirable. Some of the advantages of an outdoor installation are: 1. Little or no cost for building. 2. Less cost for high-tension apparatus. Some of the advantages of an indoor installation are: 1. All apparatus protected from weather. 2. Greater ease of inspection and repair. 3. Less depreciation on equipment. 4 . Less danger of accident to inquisitive persons. 5. More reliable high-tension apparatus procurable. 6. Safer high-tension construction possible."
        ]
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        "image_filename": "designv11_23_0002181_joaiee.1923.6593329-Figure1-1.png",
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        "caption": "FIG. 1 9 FIG. 2 0",
        "texts": [
            " If a is zero and \u00f9 is a positive quantity, it is a steady sinusoidal current of value, I sin (co t + 0). And finally, if neither a nor \u00f9 are zero, it is a diminishing sinusoidal current. In each of these cases the current, whether steady or transient, may be represented by a vector which in general has a length of J e _ a / and which makes an angle of (\u00f9 t + 0) with the horizontal axis. The projection of this vector on the vertical axis is the instantaneous value of the current. The four cases are illustrated in Fig. 1, a, 6, c and d. In each of the diagrams I marks the initial position of the vector. In the first case (a) the vector is fixed both in magnitude and in angular position. In the second case (6) the magnitude of the vector diminishes exponentially although its angular position does not change. In the third case (c) the vector has a constant 388 April 1 9 2 2 \u2014* \u00c7U Zero Axis Zero Axis C d F i g . 1 \u2014 T H E E N D OF EACH VECTOR WHICH IS D R A W N FROM THE O r i g i n IS INDICATED BY A LARGE PERIOD; THE E N D OF S m a l l VECTORS D R A W N FROM T H E S E PERIODS IS INDICATED BY ARROWHEADS",
            " In the latter case M2 1 - \u00f3 ; or \u00f3 = 1 + \u00f3 ' ' In a transformer in which the resistance of the windings may be neglected this leakage coefficient, \u00f3, is the ratio of the current on open circuit to that on short circuit with the same applied potential. kx and k2 are the reciprocals of the time constants of the two windings on open circuit. The solution for the generalized angular velocity is m = ki + k2 2~\u00f3 2 - 4 \u00f3 ki k2 2\u00f3 { } Since \u00f3 is less than unity, the values of m are both real, and the transient current consists of two direct-current components one of which diminishes much faster than the other. These currents may be represented by vectors as in Fig. 1B. In this case, in which both windings are shortcircuited, there will be no current in either winding after the transient has disappeared. Thus the only current after short-circuit occurs is the transient. Let the vectors 7 1 0 and 7 2 0 represent the primary and secondary currents before short circuit occurs. Also let Ii and Ii\" represent the components of the transient current in the primary and similarly for the secondary. Then at the moment of short circuit, the sum of the instantaneous values of the two transient components must equal the instantaneous value of the initial current in both primary and secondary",
            " in this phase is zero and the vector representing it will be at Eb for a positive relative angular velocity and at Eb\" for a negative velocity. This generated e. m. f. is equal to the product of the current in one phase of the a windings, the relative generalized angular velocity with respect to the b windings of the field that these currents produce, and the mutual inductance between the a and b windings. The mutual inductance M can be measured as follows: Fix the a and b windings with respect to each FIG. 1 7 other and send balanced polyphase currents through either, the a for windings for example. The mutual inductance M is the e. m. f. generated in one phase of the other, or b winding, divided by the product of the current in one phase of the a winding and angular velocity of this current. By the time that the flux has Ci advanced \u00f0/2 \u2014 arc tan with respect to the \u00f9 \u2014 \u00f1 b windings, the generated e. m. f. will have reached its maximum value, but the current will usually not reach its maximum value until somewhat later depending April 1923 LYON: ELECTRIC M A C H I N E R Y 397 upon the constants of the b windings and their terminal pressure"
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        "caption": "FIG. 19. -",
        "texts": [],
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            "shaft W is coupled to the propeller-shaft Z by the usual universal coupling. The housing D is mounted to slide on a frame F (which consists of a pair of transversely arranged superimposed bars), which is pivoted at one end to one of the side members Y of the frame of the chassis and is adapted at the other end to slide in or on a suitable guide G carried by the other member Y of the frame. Means are provided both for operating the frame F for the purpose of pulling the driven disk B out of engagement with the intermediate disk C so as to disengage the driving couple, and to move the housing D carrying FIGS. 18 AND 19.-Diagrams of Cowey Friction Gear. FIB. 18. Y I' I 9: the driven and intermediate disks and their shafts laterally in relation t o the disk A so as to cause the intermediate disk C to engage the face of the disk at a different part of its aurface. I t will be seen that when the axes of the driving shaft and of the driven shaft, and therefore of the disk A and the intermediate and driven disks C and \u20ac3 are cc-axial, the apparatus is simply a direct-driving clutch, and that to obtain the lower speeds and the reverse it is only necessary to move the disks B and C across the face of the disk A so that the rim of the intermediate disk 0 will engage with a portion of the surface of the driving disk which is nearer to its centre, and obviously the nearer the driven disk is moved towards the centre of the driving disk the greater is the effective speed reduction. If the rim of the intermediate disk C is moved beyond the centre of the driving disk the direction of rotation of the driven shaft is changed, which gives the reverse drive. The housing D carrying the intermediate and driven disks C at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHICLES. 825 and B is coupled to the clutch-pedal, SO that it c a n be drawn backwards sufficiently to disconnect the engine from the disks by depressing the pedal, a suitable spring being employed to return the housing and keep the disks up t o their work when pressure on the clutch-pedal is removed. Within the housing D at the rear end of the shaft E carrying the intermediate disk C is a helical spring, which operates between the end of tho shaft and the end of the hollow part of the driven shaft W. This spring, when the housing D is drawn back, separates the intermediate disk C from the driven disk, so that when the clutch-pedal is depressed not only is the intermediate disk separated from the driving disk but also from the driven disk, so that there is no rubbing friction whatever between these parts. The effect of the use of the intermediate disk is to provide a complete annular clutch which renders wear a negligible quantity. In this gear all the drives are direct, so that 1055 in transmission is reduced to a minimum and at all speeds is silent. Further, as any gear and the reverse can be easily and rapidly engaged at any engine or car speed, a valuable emergency brake is provided. HALL HYDRAULIC UEAR. In the H d transmission, Fig. 20, three radially arranged pumps A are employed, the plungers Al of which are operated through connecting-rods by a common crank B on the shaft V, which is driven by the prime mover. Three radially arranged motors 0 are also employed, the pistons C1 of which are operated through connectingrods by a crank D on a non-rotating shaft E, which is arranged eccentrically in relation to the driving shaft V. Both the pumps A and the motors C are carried in a common casing F, which is free to rotate about the axis of the driving shaft V and is coupled to the driving toadwheels through suitable gearing. The cylinders of each pair of pumps and motors are connected by ports controlled by valves G and H, the valves G of the pumps being operated by an eccentric J on the driving shaft V, and the valves H of the motors by an eccentric K, which is loosely mounted on and in relation to the driving shaft V and is provided with means whereby it can be rotated through a given arc. The shaft E, although non-rotating, is capable of a limited amount of rotation-through the worm L and the worm-wbeel M -in order to adjust the eccentricity of the crank K. The shaft E carrying the crank D is carried in en eccentric bush or bearing N, the eccentricity of which is equal to the throw of the crank D, so that when the crank is turned so that its greatest throw coincides with the greatest eccentricity of the bush or bearing N the crank wi l l be concentric with the sEaft V, and wi l l then act merely as a &xed axle and impart no movement to the pistons 0' of the motore C as the casing F rotatus. The eocentric K on the driving shaft V, which operates the valves H of the motors, has an extension 0 which is 3 L at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 826 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEHIULES. DEC. 1916. toothed internally and engages a spur-pinion P carried on a shaft Q, which passes centrally through a hole in the shaft E. The shaft Q is provided with suitable means of rotation exterior to the casing F, so that the position of the eccentric L can be altered in relation to the crank D. By this means, in Q manner similar to that of the well-known form of loose eccentric reversal employed in marine engines, the direction of rotation of the casing F can be reversed when required. The whole of the spaces, passages, and cylinders of the casing F are Bled with oil, which is constantly pumped by the pumps A through the valves G and H to the motors C, the capacity of which exceeds that of the pumps. The action of the apparatus is as follows: Upon motion being imparted to the driving shaft V, the pumps A operate to pump oil into the back ends of the cylinders of the motors C, which thereby impart rotary motion t o the casing F, the ratio of speed betweeu the driving shaft and the casing being determined by varying the centre of the crank operating the pistons of the motors with respect to the axis of the driving shaft. When the cylinders of the motors are working t o their full capacity the greatest reduction of speed is obtained, and inversely when they are working at their lowest capacity the highest speed is obtained, the casing F then rotating at the same speed as the driving shaft V. If, as in the construction illustrated, the capaoity of the at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-BPEED QE&RB FOR MOTOR ROAD-VEHICLES. 827 motor cylinders is four times that of the pump cylinders, when the crank of the motors is in the position to impart the greatest amount of movement to the pistons of the motors,it will take four strokes of the plungers of the pumps to fill the cylinders of the motors with oil, and consequently the shaft V will have rotated four times during the time the pumps have, by filling the motors, caused the casing F to rotate once, but, as in normal working, shaft V and the casing F rotated in the same direction, one revolution of the pump shaft is lost for each revolution of the casing, so that the shaft V is geared down in relation to the casing F in proportion of 5 to 1. As before stated, when the crank D is concentric with the shaft V there is no movement of the pistons of the motors, and consequently the whole apparatus is carried round at the same speed as the shaft V, and the highest speed of rotation is imparted to the casing F. In this condition there is no circulation of the fluid in the apparatus, and except for the connecting-rods of the motors turning upon the crank D and the rods of the valves H moving upon the eccentric, there is no relative movement of the various parts of the mechanism. It will be understood that the two positions of the crank D before described are the two extremes, and that any intermediate position of the crank and consequently variation of the proportions of speed snd power of the whole apparatus can be obtained by rotating the crank D. COMPAYNE HYDBAULIO QEAB. The essential feature of the Compayne transmission is the Hele-Shaw pump, Figs. 21 and 22, which by rea8on of its construction can not only be run at a high speed without vibrations, but has a high degree of efficiency. The construction and action of this pump-which is of the rotary plunger type with a plurality of cylinders-will best be understood by reference to Figs. 23.24, and 25, which ace diagrammatic sections through the pump at right angles to its axis. The cylinders A (of which there are seven in the oonstruction shown) are formed in one block with a sleeve which is mounted on a fixed stub axle B, this sleeve being coupled to a shaft S which is driven by the prime mover. The pistons C IXRY gudgeon-pins D, which pass through slots in the cylinders end engage with slipper pieces E whioh fit in two opposed grooves in a drum F, which is mounted in ball-bearings to rotate in a housing (31. The grooves in the drum F form paths for the gudgeon-pins, and the drum F operates as B floating ring, the action and operation of which in relation to the pistons is that of a series of connecting-rods. The housing (31 is mounted to slide transversely across the casing X in suitable guides. By displacing this housing in the casing X in relation to the stub axle B on either side of its vertical centre line, that is to say, along a horizontal line r o passing through the centre of said axle, the eccentricity of the path of the 3 ~ 2 at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 828 VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEHIaLE& DEC. 1916. gudgeon-pins with respect to the cylinders can be varied for the purpoge of varying the stroke of the pistons, and therefore the output of the pump as a whole. As the acceleration of the slipper-pieces and pistons above the centre line xx is balanced by the retardation of similar parts below the centre line, all the inertia forces are balanced. The drum F is kept ful l of oil by centrifugal action, and no oil is allowed to accumulate in the casing X, whereby all churning of the oil is avoided. In the stub-axle B, about which the cylinder block revolves, are two ports or groups of ports, H and K, with which ports in the bases of the cylinders A coincide as they revolve, the ports being in communication with similar ports or groups of ports, H1 and K1, at one end of the axle B exterior to the FIQS. 21 AXD 22.-Helc-Shatu Pump. Cmqayne Hydqazilic Gear. FIG. 21. FIG. 22. X casing X by m a n s of suitable passages. When the block of cylinders revolves, the floating ring F revolves with it, as the resistance of the slipperpieces E is greater than that of the ball-bearings carrying it. In the central position the slipper-pieoes have no movement, and in any other positions they only move to and fro to an extent directly proportiond to the stroke of the pistons. If the cylinders are rotated in the direction of the =rows, and the path of the gudgeon-pins is concentric with the axle B, a8 in Fig. 23, no motion is imparted to the pistons, and therefore the pump is inoperative. If the path of the gudgeon-pins is moved to the left, as shown in Fig. 24, the pistons as they move above the centre line ex move outwardly, and therefore tend to create a vacuum, so that thB oil is forced into the cylinders either by atmospheric pressure or by an artificial pressure in a supply-tank through the ports H1 and H, while the pistons as they move below the centre line at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from bso. 1916. VABIABLE-SPEED G ~ A B B @OR MmoB BOAD-VEE~~C~LES. 829 zz move inwardly and discharge the oil from the cylinders through the ports K and K*, the ports HI and K1 being connected by suitable piping to the hydraulic motors. If the path of the gudgeon-pine is moved to the right, 88 shown in Fig. 25, the pistons move outwardly when moving below the centre line m, and inwardly when moving above the line, so that the flow of the oil is reversed without altering the direction of rotation of the cylinders, the ports Kl and K becoming the suction ports and the ports H and H1 the deliveryports. In moving from the position of maximum delivery on one side to that on the other side, the dicharge is gradually reduced until the central position is resched, when the delivery ceases, after which it again increases to the maximum with the flow in the opposite direction, the change from full forward to fu l l reverse discharge being made without shock, the flow FIGS. 25 TO 25.-Diag~ams of Hek-Shaw Pump. Convpayne HyarmEic Gear. a t all times being proportional to the eccentricity of the path of the gudgeonpins. The hydraulic motor, Figs. 26 and 27, is of a simiiar construction to the pump, but is of the constant-stroke type and works inversely. The novel feature of the motor is the employment of a cam as a track for rollers carried by the gudgeon-pins. Two motors are u~ually employed, arranged either one in each road wheel or both mounted on the chassis and each driving one of the road wheels by means of chain or other gearing. The gudgeon-pins D carried by the pistons 0 carry ball-bearing rollers M at their ends, which travel within a double cam N formed in or carried by the casing Y. Owing to the shape of the cam, the pistons mnke two strokes per revolution. This gives a complete balance of the working parts, an absolute and uniform turning movement, and obviates any ehock in the system. By arranging the cam and the valve shaft so that they can both rotate a t relatively different speeds, and making the cam of a corrugated or wavy form, single revolution of the motor can be obtained from any desired number of strokes of the at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 830 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEBICLES. DEC. 1916. FICIS. 2 6 . m ~ 27.-Hydrazllic Motm. Compayne Hgdruulic Bear. pistons of the pump. T h i enables a very great turning effort to be seoured without unduly increasing the proportions of the motor. PIEPER ELECTRIC SYSTEN. In the Pieper, or Auto-Mixte, system, which is practically the same as the earlier British system of Farrow, a shunt-wound dynamo is mounted on a shaft which couples the engine with the road wheels through a magnetic clutch and suitable transmission gearing. The dynamo is connected through a controller with a battery of accumulators, a d works either as a motor or a dynamo, according as its E.M.F. is inferior or superior to that of the battery. The dynamo is fitted with commutating poles, the windings of which are connected in series with the armature, thus ensuring good commutation with heavy currents and with a weak main field. The battery, although primarily employed for assisting in propulsion, can also be used for startiig the engine and for ignition purposes. The supply of explosive mixture to the engine is controlled by the demand for current from the accumulators through a differentially wound solenoid, so that during starting and the period of extra effort the discharging current traversing its series-winding deoreases the magnetism produced by the shunt-winding, which in turn increases the supply of mixture, and thus compels the engine to give its maximum power for a at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-SP\u2019GED UEARS FOR NOTOR ROAD-VEHICLES. 831 given number of revolutions per minute. When the dynamo is charging the cells, the action of the series-winding assists that of the shunt-winding and tends to close the throttle. When the power of the engine is below that required, the battery automatically supplies energy to the dynamo, which then operates as a motor. When the power of the engine is in excess of that required for traction, or when the kinetic energy of the car can be recuperated, that is, when the car is slowing down or is running on a down-gradient, the dynamo works automatically as a generator and charges the battery. When the vehicle is on an up-gradient, and the torque on the road wheels becomes greater than the turning moment of the engine, the speed of the latter diminishes and the voltage of the dynamo fallsuntil it becomes less than that of the battery. The battery then discharges into the dynamo, and thus produces torque, which assists that of the engine until it balances the resisting torque of the engine. i)n a down-gradient, if the resisting couple ie less than the turning moment of the engine, the speed of the latter tends to increase, and the voltage of the battery rises so that the dynamo begins to charge the battery. As this charging current passes through the regulator the rate of admission of mixture to the engine is reduced to a minimum, and the torque of the engine becomes zero. STEVENS ELECTRIC SYSTEM. In the Stevens system a shunt-wound generator of the inter-polar type producing a continuous current is driven directly by the engine, and a serieswound electric motor is coupled to the transmission shaft of the vehicle, a controller box, and a shunt resistance for the generator fields being provided. The generator, which is capable of an output of from 1 to 36 kilowatts a t a speed varying from 350 to 1,400 revolutions per minute a t a voltage varying from 0 to 300, is designed with a falling characteristic, so that any increase in the demand for current when the engine is fully loaded is accompanied by a corresponding reduction in voltage. The output in kilowatts a t any speed is proportional to the power exerted by the engine, but the volts and amperes vary over a large range, according to the gradient of the soad, the speed, or the degree of acceleration required. The amperes required by the serieswound motor are approximately proportional to the torque on the transmission shaft, and the speed of the motor is to a smaller degree proportional to the voltage of the supply. Consequently, when the vehicle is running on a level road the demand for current is small, but ou up-gradients it increases with a corresponding decrease in voltage, which results in a slower speed with increased torque. This change takes place automatically. The excitation of the generator ceases automatically when the engine speed falls below 250 revolutions per minute. at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from 832 VARIABLE-SPEED QEARS FOR MOTOR ROAD-VEHICLES. Dw. 1916. In ordinary running on the level, or on slight up-gradients, the speed of the vehicle is entirely regulated by controlling the speed of the engine by means of the usual gas throttle-valve ; but on stiff up-gradients, heavy roads, under other conditions requiring greater power, the shunt resistance is employed to allow of increased engine speed. The controller has three positions-forward, neutral, and reverse. As the generator ceases to excite a t 250 revolutions per minute of the engine, no electrical circuits are required to be made or broken in driving, even when stopping in traffic, as by reducing the speed of the engine to 250 revolutions per minute, or less, by means of the throttle-valve, the generation of current is stopped, and therefore no power is transmitted to the road wheels. Owing to the inter-polar construction of the generator, sparkless commutation is ensured, and as the msin circuit is never broken during driving, no sparking occurs at the contacts. A t starting, the electric motor demands a large current to develop the necessary torque for starting, which the dynamo supplies a t a low voltage, and 88 the motor speeds up, it automatically demands less current, which is supplied by the generator at an increased voltage. In other words, the voltage of the generator varies in inverse ratio with the amperes output; therefore the power required to drive the motor can never exceed a predetermined maximum, which is arranged to correspond to the maximum power of the engine."
        ]
    },
    {
        "image_filename": "designv11_23_0002131_t-aiee.1933.5056392-Figure3-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002131_t-aiee.1933.5056392-Figure3-1.png",
        "caption": "FIG. 3 (LEFT)-FLOW OF ENERGY RELATIONS AS EXPRESSED BY Fig. 6, following eq 9, may be called the component EQ 5 FOR RESISTANCE AND INDUCTANCE IN SERIES power and reactive volt-ampere vector diagram. The",
        "texts": [
            " Volt-amperes = El (1) The rate at which energy is stored into the system or Reactive Volt-amperes El sin a the work done by the force in producing motion We may represent the electromotive force E cos against the inertia of the system is d- Li2 The cot by two equal vectors of length equal to one-half the * 2 mean squarevalue, on rotatin positimaximum inflow of stored energy therefore occurs mean square value, one rotating positively tne other when the stored energy is one-half its maximum and negatively, denoting the positively rotating vector increasing, and therefore when the rate of dissipation E and the negatively rotating vector by 12 is one-half its maximum value and increasing, and the E +EL Eeiwt + Ee-iw maximum outflow of stored energy occurs at the e \\ E cos cot A -A= + same point of the stored energy cycle when it is i += Ie(jit-a) +Ie(j(ot-a) decreasing, that is at the same point of the de-ICos(cut-a) = V2 (2) creasing dissipation cycle. The cycle of inflow of ei =Alf + E1 + El +N iGfstored energy is therefore in phase advance of the2 2 cycle of dissipation or power inflow by a right angle. In the vector representation of electromotive forces These cyclic flow of energy relations are shown in and currents the convention is to use the positively Fig. 1, as expressed by eq 4 and in Fig. 3 for those rotating vectors E and I. It will be observed that E and I enter into the expression for ei symmetrically and therefore with equal authority. On RiR the other hand in practical problems E is the known function of the independent variable t while I is the it2 / d d dependent function, it would therefore seem con- dt 2 sistent to define energy flow into the circuit by P + jQ = LI (3) This convention is seen also to be consistent with / E E the d-c analogy; namely, since the impedance Z in an a-c system takes the place of resistance R in a d-c system then FIG"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0003903_pime_proc_1916_091_015_02-Figure17-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0003903_pime_proc_1916_091_015_02-Figure17-1.png",
        "caption": "FIG. 17.--Diagram of C m m Farna of F&tion Gear.",
        "texts": [
            " In some cases two such pulleys are employed, so coupled together that as one is expanded the other is contracted, while in other cases one expanding pulley is employed, the slack at MCGILL UNIVERSITY LIBRARY on June 9, 2016pme.sagepub.comDownloaded from DEC. 1916. VARIABLE-SPEED GEARS FOR MOTOR ROAD-VEEIaLE8. 799 being taken by. a spring-controlled jockey-pulley. In all these systems belts are employed as an expanding pulley capable of running with a chain is not yet a commercial proposition. fiction Bearing -A common form of frictional drive mechanism -Fig. 17 (Appendix, page 823)-consists of two friction disks arranged a t right angles to one another, so that the periphery of one engages the face of the other, the relative positions of the axis of one and the path of rotation of the other being capable of being varied. An interesting modification of this type of gearing is the Cowey-Figs. 18 and 19 (Appendix, page 824)-in which the driving and driven disks engage one another face to face. Feed-Motion Qearing.-The most common form of variablespeed gear workfng on the feed-gear principle is one in which reciprocating pawls operate ratchet wheels, provision being made whereby the angle through which the pawls travel can be varied",
            " To obtain the highest speed-a direct drive-the clutch is brought into action which locks all the parts of the gear together, so that they revolve en ntasse. At all the other speeds the clutch is out of action. To obtain the reverse, the drum S to which the planet carrier R is h e d is held stationary, so that the annulus J, and with it the carrier L, and therefore the driven shaft, will be rotated in a reverse and opposite direction to the driving shaft by the action of the intermediate pinions H. The action of this gear is shown diagrammatically in Fig. 15. In this gear, Fig. 17, the driving disk A is mounted on a shaft V, which is in couple with the crank-shaft of the engine, and the driven disk B is mounted on a shaft W, which is arranged at right angles to the axis of the driving shaft V and is in couple with the driving road-wheels by means of chain and sprocket-wheel or other gearing. The driven disk B is so mounted to slide on its shaft that it can be moved across the face of the driving disk A, and thus by engaging the disk at any desired position between its centre and its periphery enable any desired speed ratio to be obtained"
        ],
        "surrounding_texts": []
    },
    {
        "image_filename": "designv11_23_0002133_pime_proc_1943_150_029_02-Figure14-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002133_pime_proc_1943_150_029_02-Figure14-1.png",
        "caption": "Fig. 14. Arrangement for Measuring Variations in Pitch Errors of Wormwheel of Hobbing Machine",
        "texts": [
            " The practice of running-in with abrasive powder has been avoided, since this expedient cannot possibly result in the teeth flanks following a true involute as is the case on a proper involute generating machine. It has been found from experiments rhat hollows in a tooth flank are enlarged by the use of grinding powders, for the powders seek out the relative quietness of these \u201cpools\u201d during contacts and the so-called runningin. Main arm, 2/1 ratio; final lever, 5/1 ratio; clock gauge divisions equal 0.0001 inch error in pitch. Various methods of checking machine tool and cut gearing have been devised (see Fig. 14), but the pitch bridge gauge made to span single pitches is preferable to the Admiralty standard gauge of bridging several pitches. No method of checking, however, can compensate for errors fundamental to the hobbing machine. As a development of the above-mentioned types, a hobbing machine has been designed with a wormwheel of 93 inches diameter and having 580 teeth. This will give a hobber frequency of 4,850 cycles per second at 500 r.p.m. Further, the internal gears and shaft have all been cut down to a minimum by arranging to cut helical gears without the differential mechanism",
            "0035 ,, Such results could not be obtained without the utmost care on the part of the machine builder, nor did they furnish much foundation for the author\u2019s assertion (p. 177 of the paper) : \u201cA machine may be more flexible with prime and helical differential mechanisms, but each of these items introduces errors and complications which are just as well avoided\u201d. All the machines upon which the gears he had mentioned were cut, had creep, spiral differential, and prime differential. With reference to the testing of wormwheels illustrated in Fig. 14, p. 177 of the paper, his former chief and he had tried that method thirty years ago, but not quite in the way used by the author. Instead of the two clock gauges shown in the diagram, they had used a theodolite telescope fixed on the centre of the wheel which, with its tackle, was carried on a gallery at the far end of the workshop. At the other end of the shop they had fixed a white scale marked in proportion to its distance from the wormwheel. That method had three failings. First, it did not show the real state of the wheel, because there were too many elements each contributing some inaccuracy",
            "comDownloaded from COMMUNICATIONS ON HIGH-SPEED HELICAL GEARS 193 which were given about in their order of importance-that it was not an easy matter to eliminate the periodic error. I t could only be done by careful attention to each detail. The methods of detecting such errors were, however, fairly simple, and each factor could be tested individually. An overall check was also desirable, and that could be applied by using one of the methods now available for testing the relative angular velocities of moving parts. The method shown in Fig. 14, p. 177 of the paper, was not satisfactory for detecting errors that might cause undulations, because it checked the position of the wheel after each complete turn of the worm, and therefore only measured tooth-to-tooth pitch errors in the wormwheel. Actually, it was the errors occurring during each single turn of the worm which caused the undulations. Ratio of Indexing Worm Gears. The final indexing worm gears on hobbing machines invariablv had either a single-thread worm, or a muls-thread worm of whch the number of threads was exactly divisible into the number of teeth in the wheel"
        ],
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    },
    {
        "image_filename": "designv11_23_0002181_joaiee.1923.6593329-Figure5-1.png",
        "original_path": "designv11-23/openalex_figure/designv11_23_0002181_joaiee.1923.6593329-Figure5-1.png",
        "caption": "FIG. 5 FIG. 0",
        "texts": [
            " It is in this respect that the vector diagrams representing the transient state differ from those that represent the steady state. If the electric circuit is linked with a magnetic circuit in which eddy current and hysteresis losses may occur, it is customary, though strictly speaking it is incorrect, to represent both the current and the magnetic flux by vectors when they have a steady sinusoidal variation. In this case the flux is represented as lagging the current which produces it by a constant angle \u00df. See Fig. 5. This is equivalent to assuming that the hysteresis loop is an ellipse and that the eddy currents are all in time quadrature with the flux in the core. The fall in reactive pressure j \u00f9 LI, leads the flux, \u00f6, by 90 deg., but the current by an angle which is somewhat less. This being the case, it is necessary to represent the inductance by a complex number, i. e. L = L i \u2014 j L2; where L 2 / L i = tan \u00e2. T h u s ; \u00f9 LI = j \u00f9 (Li \u2014 j L2) I = \u00f9 L21 + j \u00f9 L] I Similarly if the current is of the general form,\u2014and we make the same assumption in regard to the constancy of the phase angle between the flux and the current,\u2014 the fall in pressure due to inductance is (\u2014 a + j co) (Li \u2014 j L2) 7, which may still be written m L I, understanding now that both m and L are complex numbers"
        ],
        "surrounding_texts": []
    }
]