Patent GB-744304-A (GB)
Title: A self-propelled vehicle with electro-hydraulic driving means
IPC: B60L9/24
Filed: 1952-11-14
Abstract: 744,304. Motor driving arrangements. VOITH GES., J. M. Nov. 14, 1952 [Nov. 17, 1951], No. 28839/52. Class 35. [Also in Groups XXIX and XXXI] A vehicle is driven through a non-controllable electric motor 13 and an infinitely-variable and extemally-controllable hydrodynamic power transmission system 15, 16. As shown applied to a rail vehicle the motor 13, of the squirrel cage induction type, drives axles 11, 12 through step-up' gearing 17 a shaft 18 and the transmission system 15, 16 in the form of hydraulic torque converters a, b. The drive to each axle is through a universally jointed shaft 21 and a reversing gear 22, each shaft 21 being connected through gearing 24 to a sleeve 23 arranged between the converters a, band carrying the driven elements of the converters, and the shaft 18 carrying the driving elements thereof. The reaction elements of each converter are controllable by means of rings 28 conjointly operable by means of rods 29 connected to a shaft 30 which is operated by a servomotor cylinder 32. The converters of each pair are constructed to give different ratios, the converters a covering a lower speed range and the converters b an upper speed range. A pump 33 driven by the shaft 18 feeds liquid to the converters through a control valve (not shown). In the control system shown in Fig. 2 the converters are controlled in response to the current or power of the electric driving motor. A rotary magnet 40 responding to the current or power carries a two-armed lever 41, one end of which is spring connected to a bridge piece 42 which is axially adjustable by an electric motor 44 through gearing 45, the motor 44 being controllable from the driver's platform. The other end of the lever 41 is connected by a rod 47 to a valve 48 controlling the piston of the servomotor 32, and a dashpot connection 49 is provided to damp and stabilize the movements of the lever 41. In an alternative control system shown in Fig. 3 the converters are controlled by the vehicle speed, the temperature of the liquid in the converters and the power or current of the electric motor. A lever 54, which normally pivots, about a point 63, is connected by a rod 53 to a piston in a cylinder 52 connected to a pump 51 driven at a speed proportional to the vehicle speed. A spring 60 also engaging the lever 54 can be adjusted through gearing 62 by a motor 61 controlled from the driver's platform, and so long as the vehicle travels at the desired speed the lever 54 remains in the position shown. The lever 54 is connected by a rod 55 to a control valve 56 of a servomotor 57 controlling the rings 28, a dashpot connection 58 arranged between the servomotor and the lever 54 and a resilient restoring or follow-up member 59 being also provided. The pivot 63 of the lever 54 is linked to a two-armed lever 64, one end of which is connected to a thermostat 66 responding to converter liquid temperature and normally bears against a stop 70. The other end of the lever 64 is linked to an arm 67 carried by a rotary magnet similar to that shown in Fig. 2; the arm 67 being normally spring urged against a stop 69. The converters may be controlled alternatively by such means ad displacement of the blades of the driving or driven elements. The converters may be combined with mechanical change-speed gearing, the converters interrupting the transmission during changing of the gearing, or with planetary gearing, part of the transmission being through the converters and part through the gearing. When two converters are employed of different ratios, change-over can be effected by filling and emptying the converters. The filling of the starting converter may be effected by the vehicle driver and change-over to the other converter and a converse change may be effected automatically in dependence, for example, on vehicle speed. For simplification the driving motor may be operated by a 15,000-volt 50 cycles per second electric supply, a small transformer being carried for operation of auxiliary parts, such as a compressor, lighting equipment and heaters. Each axle may be driven from a separate electric motor. An alternative number of axles may be driven. Where two axles are provided the hydraulic gear may be arranged so that each axle is driven through a half-power converter at low speeds and at higher speeds only one axle is driven through a full power converter. Thus the full power converter may drive one axle at low speeds for half power and at higher speeds such converter may drive at full power whilst a half power converter for the other axle is switched off.