Abstract: The hydraulic regenerative drive system for a vehicle includes an electronic controller, a hydraulic control circuit that receives control signals from the electronic controller, a reservoir in fluid communication with the hydraulic control circuit, a pump/motor unit having a controlled-angle swash plate element providing variable displacement, an accumulator in fluid communication with the hydraulic control circuit and a pump/motor unit speed sensor and pump/motor unit pressure sensor providing measured speed and measured pressure signals to the electronic controller. The electronic controller generates a torque signal and a modified engine throttle signal on the basis of a mathematical model, converts the torque signal to a swash plate angle, and controls a controlled-torque retard mode of operation and a controlled torque propulsion mode of operation.

Abstract: An energy management system operable in three modes of operation including a driving mode to drive a vehicle drive shaft (110), a retarding mode to retard the vehicle drive shaft and a neutral mode to have no driving or retarding influence on the vehicle drive shaft. The system comprises an energy accumulator (100, 101) operable to store and release energy through receipt and release of fluid, a pump (104) having a pump drive shaft and being in fluid communication with the energy accumulator, a reservoir (107) of fluid in communication with the pump, and a coupler adapted to couple the pump to the vehicle drive shaft. In the retarding mode, the vehicle drive shaft drives the pump to pump fluid to the energy accumulator. In the driving mode, the energy accumulator releases fluid to drive the pump which drives the vehicle drive shaft. In the neutral mode, the pump is inoperative to exert any driving or retarding influence on the vehicle drive shaft.

Abstract: An energy management system operable in three modes of operation to either drive or retard the drive shaft (110) of a vehicle, or in a neutral mode, to have no driving or retarding influence on the drive shaft. The system includes energy accumulating means (100, 101) which is operable to store and release energy through receipt and release of fluid, pumping means (104) in fluid communication with the energy communication means (100, 101), a reservoir (107) of fluid in communication with the pumping means (104), and coupling means for coupling the pumping means (110) to the drive shaft (110). Whereby in the retarding mode of the system, the drive shaft (110) drives the pumping means (104) to pump fluid to the energy accumulating means (100, 101), and whereby in the driving mode of the system, the energy accumulating means (100, 101) releases fluid to drive the pumping means (104) which drives the drive shaft (110).