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 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: A method of varying a charge in an accumulator includes providing an accumulator containing working fluid and gas, providing a reservoir containing gas, transferring gas from the reservoir to the accumulator to increase the gas pressure in the accumulator, and transferring gas from the accumulator to the reservoir to decrease the gas pressure in the accumulator.

Abstract: An accumulator system includes an accumulator containing working fluid and gas, an isolation valve through which working fluid selectively flows to and from the accumulator, an actuator operably coupled to the isolation valve, and a passageway fluidly communicating the actuator with gas in the accumulator. The actuator maintains the isolation valve in an open configuration at a first gas pressure to allow working fluid to flow to and from the accumulator. The actuator also allows the isolation valve to close at a second gas pressure less than the first gas pressure.

Abstract: 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.

Abstract: 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.

Abstract: A method of varying a charge in an accumulator includes providing an accumulator containing working fluid and gas, providing a reservoir containing gas, transferring gas from the reservoir to the accumulator to increase the gas pressure in the accumulator, and transferring gas from the accumulator to the reservoir to decrease the gas pressure in the accumulator.

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 accumulator system includes an accumulator containing working fluid and gas, an isolation valve through which working fluid selectively flows to and from the accumulator, an actuator operably coupled to the isolation valve, and a passageway fluidly communicating the actuator with gas in the accumulator. The actuator maintains the isolation valve in an open configuration at a first gas pressure to allow working fluid to flow to and from the accumulator. The actuator also allows the isolation valve to close at a second gas pressure less than the first gas pressure.

Abstract: A hydraulic energy conversion and dissipation system comprises a hydraulic retarder pump driven by a source of a mechanical energy needed to be dissipated for converting the mechanical energy into a waste hydraulic energy, a hydraulic flow retarder provided for converting the waste hydraulic energy into a thermal energy, at least one heat exchanger for dissipating the thermal energy generated by the hydraulic flow retarder and at least one cooling fan provided for producing a forced air flow through the heat exchanger. The cooling fan is driven by a corresponding hydraulic motor powered by the waste hydraulic energy of the pressurized hydraulic fluid flow generated by the hydraulic retarder pump for further dissipating the waste hydraulic energy. The system further includes a hydraulic fluid reservoir in fluid communication with an inlet of the hydraulic retarder pump.

Abstract: A hydraulic service module is provided for a hydraulic fluid system, which includes a fluid reservoir for storing an appropriate amount of a hydraulic fluid. The hydraulic service module comprises an outer casing defining an enclosure therewithin including an air chamber in fluid communication with an ambient air. The hydraulic service module houses one or more fluid pressure accumulators mounted within the enclosure and a heat exchanger provided for cooling the hydraulic fluid.

Abstract: A hybrid hydraulic drive system for a vehicle comprises a prime mover, a transmission connecting the prime mover to drive wheels, a fluid energy storage accumulator, and a reversible hydraulic machine in fluid communication with the energy storage accumulator and drivingly coupled to the prime mover upstream of the transmission. The hybrid hydraulic drive system is arranged such that in a retarding mode the reversible hydraulic machine retards the drive wheels of the vehicle by pumping fluid into the accumulator. In a driving mode the reversible hydraulic machine supplies a supplementary power to the drive wheels of the vehicle using the pressurized fluid from the accumulator to assist propulsion of the vehicle. In a neutral mode the reversible hydraulic machine is disconnected from the prime mover to render the reversible hydraulic machine substantially inoperative to exert any significant driving or retarding influence on the drive wheels.

Abstract: A pressurized hydraulic fluid system includes a charge pump, a hydraulic motor drivingly coupled to the charge pump, and a main hydraulic unit adapted to function as a pump to drive the hydraulic motor. The charge pump is in fluid communication with the main hydraulic unit for maintaining a sufficient inlet pressure in the main hydraulic unit when it functions as the pump. The system further includes a hydraulic fluid reservoir in fluid communication with an inlet of the charge pump, a hydraulic accumulator in fluid communication with the main hydraulic unit, and a return flow passage fluidly connecting the main hydraulic unit with the hydraulic fluid reservoir for returning an excess flow of the hydraulic fluid generated by the charge pump to the hydraulic fluid reservoir.