Abstract: An energy storage system, for a hybrid vehicle including an internal combustion engine having an output shaft and a transmission operably coupled to the output shaft, includes a reservoir containing working fluid, a reversible pump/motor in fluid communication with the reservoir, a first clutch selectively drivably coupling the output shaft of the engine and the reversible pump/motor, a second clutch selectively drivably coupling an output shaft of the transmission and the reversible pump/motor, and an accumulator containing working fluid and gas. The accumulator is in fluid communication with the reversible pump/motor to deliver pressurized working fluid to the reversible pump/motor when operating as a motor to drive one of the respective output shafts of the engine and the transmission, and to receive pressurized working fluid discharged by the reversible pump/motor when operating as a pump driven by the one of the respective output shafts of the engine and the transmission.

Abstract: An energy storage system for a hybrid vehicle, including an internal combustion engine having an output shaft and a transmission operably coupled to the output shaft, includes a reservoir containing working fluid, a first reversible pump/motor in fluid communication with the reservoir and selectively drivably coupled to the output shaft of the engine, a second reversible pump/motor in fluid communication with the reservoir and selectively drivably coupled to an output shaft of the transmission, and an accumulator containing working fluid and gas. The accumulator is in selective fluid communication with at least one of the first and second reversible pump/motors to deliver pressurized working fluid to the one of the first and second reversible pump/motors when operating as a motor, and to receive pressurized working fluid discharged by the one of the first and second reversible pump/motors when operating as a pump.

Abstract: An energy storage system for a hybrid vehicle, including an internal combustion engine having an output shaft and a transmission operably coupled to the output shaft, includes a reservoir containing working fluid, a first reversible pump/motor in fluid communication with the reservoir and selectively drivably coupled to the output shaft of the engine, a second reversible pump/motor in fluid communication with the reservoir and selectively drivably coupled to an output shaft of the transmission, and an accumulator containing working fluid and gas. The accumulator is in selective fluid communication with at least one of the first and second reversible pump/motors to deliver pressurized working fluid to the one of the first and second reversible pump/motors when operating as a motor, and to receive pressurized working fluid discharged by the one of the first and second reversible pump/motors when operating as a pump.