Hydraulic system for recovering potential energy
AssigneesCaterpillar Inc., Shin Caterpillar Mitsubishi Ltd.
InventorsJiao Zhang, Pengfei Ma, Michael Schwab, Kalpesh N. Patel, Tonglin Shang
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Abstract
A hydraulic system may include a hydraulic actuator. The hydraulic system may also include a pump having a pump inlet and a pump outlet, and the pump may be configured to supply fluid to the hydraulic actuator. The hydraulic system may further include an energy recovery system operatively connected between the hydraulic actuator and the pump. The energy recovery system may be configured to store fluid from the hydraulic actuator under an overrunning load condition, and the stored fluid may be directed through the pump inlet and into the hydraulic actuator.
Claims22
A hydraulic system, comprising:
- a hydraulic actuator;
- a pump having a pump inlet and a pump outlet, the pump configured to supply fluid to the hydraulic actuator;
- an energy recovery system operatively connected between the hydraulic actuator and the pump, the energy recovery system including a first accumulator and a second accumulator;
- wherein the first accumulator is configured to store fluid from the hydraulic actuator under a first condition, and the stored fluid is directed through the pump inlet and into the hydraulic actuator;
- and
- wherein the second accumulator is configured to receive fluid from the hydraulic actuator under a second condition different than the first condition.
A method for recovering energy in a hydraulic circuit including a pump, the method comprising:
- directing a fluid exiting from a hydraulic actuator into a first accumulator of an energy recovery system under a first condition without circulating the fluid through the pump,
- directing the fluid exiting from the hydraulic actuator into a second accumulator of the energy recovery system under a second condition different than the first condition;
- storing the fluid in the energy recovery system;
- and
- releasing the stored fluid into an inlet of the pump.
A machine comprising:
- a work implement;
- a hydraulic circuit configured to actuate the work implement, including:
- a hydraulic actuator, and
- a pump configured to supply fluid to the hydraulic actuator;
- and
- an energy recovery system, including a first accumulator and a second accumulator;
- wherein the first accumulator is configured to directly receive the fluid from the hydraulic actuator under a first condition without circulating the fluid through the pump, and recirculate fluid into an inlet of the pump;
- and
- wherein the second accumulator is configured to receive the fluid from the hydraulic actuator under a second condition different than the first condition.
A hydraulic system, comprising:
- a hydraulic actuator;
- a pump having a pump inlet and a pump outlet, the pump configured to supply fluid to the hydraulic actuator;
- an energy recovery system operatively connected between the hydraulic actuator and the pump, the energy recovery system including:
- a first accumulator,
- a charge valve configured to place the hydraulic actuator into fluid communication with the first accumulator,
- a second accumulator, and
- a check valve configured to selectively place the second accumulator into fluid communication with the pump inlet;
- and
- wherein the stored fluid is directed through the pump inlet and into the hydraulic actuator.
Dependencies are inferred from the claim text.