GB890545A - Variable speed constant power fluid transmission - Google Patents

Abstract

890,545. Hydraulic transmission of power. WAGNER, E. E. Dec. 7, 1959, No. 41505/59. Class 69 (2). [Also in Group XXII] A variable-speed constant-power fluid transmission comprises a balanced vane-type unit having an independently-rotatable housing 20, Fig. 3, which encloses a rotor 15 to provide pumping chambers, is formed with inlet and outlet passages 22, 22a, 23, 23a, and connected to an output shaft 35, a stationary body 27 cooperating with the end to form a rotary valve having inlet and outlet ports, and a variabledelivery reversible unit 54, Fig. 10a, having a fixed housing which encloses a rotor 69 to form pumping chambers and is provided with inlet and outlet passages 63, 64 connected to the inlet and outlet ports of the balanced vane-type unit for transferring the speed-regulating fluid volume between the units, the rotors of the balanced vane-type unit and the variabledisplacement unit being coupled to an input shaft 55 mounting a driving means. The balanced vane-type unit has a fixed displacement and consists of an input-shaft 10, Fig. 3, which is splined to the rotor 15 having vanes 18, Fig. 7, extending into chambers 38, 38a formed in a cylinder 19 of the housing 20. Passageways 22, 22a and 23, 23a are provided in the housing and co-operate with an inlet port 28 and outlet port 29, respectively, in turn connected to inlets 30, 30a and outlets 31, 31a, Fig. 5, in a valve body 27 held against rotation by springs 75, 76 abutting a casing 34. A member 39 permits the fluid expelled from the valve to act against a surface 43 in the casing to balance the force of fluid passing through the outlet 31. The fixed-displacement vane-type unit is incorporated in the transmission shown in Figs. 10a and 10b and has its rotor 70 driven by an input shaft 55 which is connected to the rotor 69 of the variable-delivery reversible unit 54 and is driven by an electric motor 58 or other driving means. The output shaft 50 of the transmission may drive the spindle of a machine-tool. The unit 54 controls the flow of fluid passing through the fixed-displacement unit 51 and has ports 63, 64 connected to the ports 61, 62 of the unit 51. When the adjusting-ring 71 of the unit 54 is in its central position, flow through the units 51, 54 is stopped and the output shaft 50 rotates at substantially the same speed as the input shaft 55. Movement of the adjusting- ring 71 in one direction causes fluid from the unit 51 to be pumped through the unit 54 which in this case acts as a motor and drives the input shaft 55 so that the output shaft is driven at reduced speed but with increased torque. When the ring is moved in the opposite direction, the unit 54 acts as a pump and the output shaft is driven at increased speed but with less torque. The displacement of the unit 54 may be such as to reduce the direction of rotation of the output shaft. Temperature-limiting controls, relief valves, shuttle valves and flushing valves may be incorporated in the transmission.