Patent GB-1098264-A (GB)
Title: Device for controlling a driving system
IPC: F16H61/64
Filed: 1965-09-27
Abstract: 1,098,264. Control of hydraulic variable-ratio gearing. C. SCHULER-VOITH, M. VOITH, H. W. SCHWEPPENHAUSER and C. KNAPP, [trading as VOITH GETRIEBE KOMM. GES.]. Sept. 27, 1965 [Sept. 26, 1964], No. 41043/65. Headings F2C and F2D. [Also in Division F1] In a railway locomotive drive comprising a diesel engine 10 driving an output shaft 16 through step-up gears 11 and parallel lower (starting) and upper stage turbo-converters 14a, 14b, a driver's control lever 45 controls engine speed by a lost-motion linkage 47, 49, 48 connected to the engine fuel pump 51, emptying and filling of the lower range converter 14a by a cam 26 acting on the piston 22a of a selector valve 22 and, for shunting, pressure in, and hence degree of filling of, the lower range converter by a cam 44 determining the opening pressure of a separate, spring-loaded relief valve 34 in the lower range converter outlet line. The fuel pump 51 is controlled by a lever 50 spring- biased to an L/1 idling speed position. A converter filling pump 20 is gear-driven from the converter input shaft 12. An output speedresponsive governor 29 is arranged to fluidpressurize a space 32 of the selector valve 22 to shift the piston 22a for change from lower to upper range converter operation at a predetermined speed. The driver's control lever 45 moves over the following positions: O, engine stationary, both converters empty (piston 22a in uppermost position); L, engine idling, converters still empty; I (shunting with small traction), engine still idling, lower range converter 14a operative, relief valve 34 set for small converter pressure; II and III (shunting with greater traction), engine still idling and lower range converter still operative, relief valve 34 set for increasing converter pressure; 1 (smallest traction without converter regulation), engine still idling, lower range converter still operative, relief valve 34 set for converter pressure corresponding to full converter filling; 2-6 (normal running with medium and high traction), fuel lever increasing engine speed, relief valve 34 remaining invariably set closed for full converter filling with increasing pressure at increasing speed, upper range converter rendered operative by governor 29 at predetermined output speed overriding the continuing lower range converter selection of cam 26. Despite part converter filling, during shunting, the maximum quantity of oil flows from the pump 20 through a heat exchanger (not shown) and the valve 22 set for full converter operation, for satisfactory cooling which is particularly important when braking with a partly filled converter. During shunting, a throttle in the inlet line to the converter may also be controlled to vary the degree of filling. The relief valve 34 comprises an outlet portcontrolling piston 36 acted on by converter pressure in a chamber 35 and loaded by a spring 37 supported by an abutment 42 fast on a stem 41 adjustably movable to vary converter pressure. At full converter filling pressure, there is direct contact between the piston 36 and the abutment 42. As shown, the stem is acted on directly by the cam 44. In Fig. 3 (not shown), the stem is actuated by a spring-biased servomotor the air-energization of which is controlled by an adjustable pressure reducing valve acted on by the cam 44. While this arrangement may function as that shown, the pressure reducing valve, or the cam, and the servomotor may be so arranged that with decreasing servomotor pressure converter pressure increases, this latter arrangement rendering the transmission system capable of normal operation even if the shunting control fails.