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AssigneeHitachi Construction Machinery Co., Ltd.
InventorsKiwamu Takahashi, Shingo Kishimoto, Yoshifumi Takebayashi, Kazushige Mori, Natsuki Nakamura
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An electrically-operated hydraulic work machine drives an actuator with a hydraulic pump driven by an electric motor and exercises load sensing control by controlling the rotation speed of the electric motor. The useful life of an electrical storage device, which is an electrical power source for the electric motor, is increased by suppressing the horsepower consumption of the hydraulic pump. This prolongs the operating time of the electrically-operated hydraulic work machine, and reduces the size of the electric motor. A controller exercises load sensing control over a variable displacement main pump by controlling the rotation speed of the electric motor, and provides the main pump with a torque control device that reduces the delivery rate of the main pump when the delivery pressure of the main pump increases, or provides the controller with a control algorithm that performs the same function as the torque control device.
A hydraulic drive system for an electrically-operated hydraulic work machine, the work machine having
Dependencies are inferred from the claim text.