High Efficiency Hydro-mechanical Vehicle Transmission

摘要

A vehicle transmission consisting of two or more fixed displacement hydraulic pumps mounted on a common shaft (input) which provide the fluid to drive one or more fixed displacement hydraulic motors on a second common shaft (output) and a means of selectively activating and deactivating the pumps and motors to change the rotational speed of the second shaft with respect to the first shaft. The two shafts are connected by a selectable one way clutch to allow the hydraulic elements to be bypassed under certain operating conditions. Variations include the use of a reduction gear driving the input shaft and a two or more speed mechanical transmission on the output shaft. A hydraulic reservoir and accumulator are provided for energy storage and to accomplish instantaneous torque control. When used to provide hydraulic regenerative braking, the roles of pumps and motors are reversed.