Patent attributes
An energy storage system for a hybrid vehicle, with an internal combustion engine having an output shaft, includes a reservoir containing working fluid, a reversible pump/motor in fluid communication with the reservoir, and an accumulator containing working fluid and gas. The accumulator is in selective fluid communication with the reversible pump/motor to deliver pressurized working fluid to the reversible pump/motor when operating as a motor, and to receive pressurized working fluid discharged by the reversible pump/motor when operating as a pump. The energy storage system also includes an electric motor having a rotor selectively coupled to the output shaft to transfer torque to the output shaft. The reversible pump/motor is coupled to the rotor to transfer torque to the rotor when operating as a motor, and to receive torque from the rotor when operating as a pump.
