Patent ID: 8407994
Filing Date: 2013-04-02
Classification: E02F,F04B,F15B

Abstract:
1. A rotation control system of a hoist pump, the system comprising: the hoist pump; an engine that drives the hoist pump; a working equipment driven by a hydraulic cylinder that is extended and retracted by hydraulic oil delivered through the hoist pump; a hydraulic oil tank that stores the hydraulic oil supplied to the hoist pump and receives the hydraulic oil returned from the hydraulic cylinder; a detector that detects an operation condition of the hydraulic cylinder; and a controller that controls a rotation speed of the hoist pump to be an allowable rotation speed, wherein when the operation condition detected by the detector indicates lowered pressure in the hydraulic oil tank, the controller controls the rotation speed of the hoist pump to be an allowable rotation speed for preventing cavitation that is lower than an allowable rotation speed of the hoist pump when the operation condition detected by the detector does not indicate lowered pressure in the hydraulic oil tank.