Energy recovery method and system
AssigneeParker-Hannifin Corporation
InventorMarcus Rösth
Life of this patent
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Abstract
The object of the present invention is to provide an inventive energy recovery method for a hydraulic system comprising a hydraulic cylinder (1), a pump (2), a tank (3), a supply conduit (4), a return conduit (5), and a hydraulic accumulator (7), the method comprises the steps of charging said hydraulic accumulator (7), and storing fluid in said hydraulic accumulator (7), wherein said energy recovery method comprises the step of directing fluid from said hydraulic accumulator (7) into an expanding chamber (8, 9) of said hydraulic cylinder (1) during an overrunning load condition.
Claims15
An energy recovery method for a hydraulic system comprising a hydraulic cylinder, a pump for supplying pressurized fluid to the hydraulic actuator, a tank, a supply conduit, a return conduit, and a hydraulic accumulator that is fluidly connected to said return conduit at an accumulator coupling point, the method comprising the steps of:
- charging said hydraulic accumulator,
- storing fluid in said hydraulic accumulator,
- directing, independently of the pump, fluid from said hydraulic accumulator into an expanding chamber of said hydraulic cylinder during an overrunning load condition, and
- controlling the flow of fluid from said hydraulic accumulator into said expanding chamber by an accumulator control valve that is controlled by an electronic control unit,
- wherein said step of charging said hydraulic accumulator includes regulating the charging pressure of said hydraulic accumulator by using a counter pressure valve that is controlled by the electronic control unit and arranged at said return conduit between said accumulator coupling point and said tank.
A hydraulic system comprising
- a hydraulic cylinder,
- a pump configured to supply fluid to at least said hydraulic cylinder,
- a tank,
- a supply conduit connecting said pump and said hydraulic cylinder,
- a return conduit connecting said hydraulic cylinder and said tank, and
- a hydraulic accumulator,
- wherein said hydraulic system is configured to direct, independently of the pump, fluid from said hydraulic accumulator into an expanding chamber of said hydraulic cylinder during an overrunning load condition,
- wherein the flow of fluid from said hydraulic accumulator into said expanding chamber is controlled by an accumulator control valve,
- wherein said hydraulic accumulator is fluidly connected to said return conduit at an accumulator coupling point,
- wherein a counter pressure valve is arranged at said return conduit between said accumulator coupling point and said tank for regulating the charging pressure of said accumulator, and
- wherein both the accumulator control valve and counter pressure valve are controlled by an electronic control unit.
Dependencies are inferred from the claim text.