HYDRAULIC REGENERATIVE DRIVE SYSTEM AND CONTROL

摘要

A hydraulic regenerative drive system for a vehicle is disclosed. An electronic controller (28) receives a nominal engine throttle signal (35) and generates a time-variant torque signal (26) therefrom. A hydraulic control circuit (18) receives controlling signals (15) from the electronic controller (14). A reservoir (62) is in fluid communication with the hydraulic control circuit (18) for storing hydraulic fluid. A pump/motor unit (60) has a controlled element (61) providing variable displacement, and is in fluid communication with the hydraulic control circuit (18). The pump/motor unit (60) is adapted for connection to the drive train (12) of the vehicle. An accumulator (64) is in fluid communication with the hydraulic control circuit (18). The controller (28,14) controls a controlled-torque retard mode of operation, in which the controlled element (~l) of the pump motor unit (60) is controlled by the torque signal (26) to impart a dynamically calculated retarding torque to the drive train (12), and the pump/motor unit (60) pumps fluid from said reservoir to the accumulator (64) via the hydraulic control circuit (18). The controller (28,14) also controls a controlled-torque propulsion mode of operation in which the controlled element (61) is controlled by the torque signal (26) to impart a dynamically calculated propelling torque to the drive train (12), and the pump/motor unit (60) motors under influence of fluid from the accumulator (64) passing to the reservoir (62) via the hydraulic control circuit (18).