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US 6,379,119 B1Granted
Hybrid electric and hydraulic actuation system
AssigneeGlobemag L-P
InventorRolf Truninger
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AssigneeGlobemag L-P
InventorRolf Truninger
Estimating the term…
A system that includes a pump driven by a variable speed electric motor, the pump being directly connected to a hydraulic actuator by an open hydraulic circuit. This setup allows using one motor pump combination to drive any number of axes sequentially. The main advantages are significant energy savings but also higher control quality achieved by the substitution of control valves. Power control is dedicated to electronic power transistors while hydraulics are used for power transmission. For two and four quadrant operation, a hydraulic accumulator is proposed exerting a spring load on the hydraulic actuator. This allows for driving and braking the actuator and the associated machine axis in both directions of motion while the hydraulic pressure is always applied to the same port of the pump. The other pump port can be connected to tank.
A hybrid electric and hydraulic actuator system for the actuation of a dynamic machine axis, comprising a variable speed electric motor, a pump, a hydraulic actuator, and an open hydraulic circuit that includes a tank, the motor being arranged to drive the pump to suction from the tank, the pump being in fluid communication with the hydraulic actuator so as vary pressure and/or speed and/or position of the hydraulic actuator in accordance with the speed of the electric motor without the use of control valves, the hydraulic actuator being arranged to actuate the dynamic machine axis.
A hybrid electric and hydraulic actuator system comprising a variable speed electric motor, a pump, an open hydraulic circuit that includes a tank, a hydraulic cylinder and a hydraulic accumulator, the motor being arranged to drive the pump to suction from the tank, the hydraulic cylinder having a piston movable between retracted and extended positions within the hydraulic cylinder, the pump being in fluid communication with the hydraulic cylinder on one side of the piston, the hydraulic cylinder being in fluid communication with the hydraulic accumulator on another side of the piston so that hydraulic energy routes to the accumulator as the piston moves in one direction and the accumulator supplies energy for the reverse direction of motion of the piston.
A hybrid actuation apparatus, comprising:
Dependencies are inferred from the claim text.