Work machine with a hydraulic drive system and hydraulic drive system

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic drive device capable of suppressing hunting of a hydraulic actuator which occurs by a rapid operation input by an operator.;SOLUTION: The hydraulic drive device includes: a variable displacement hydraulic pump P; and a pump control unit 150 that controls a discharge oil amount of the hydraulic pump P by changing the capacity of the hydraulic pump P. The pump control unit 150 includes: a capacity cylinder 151 that changes the variable capacity of the hydraulic pump P by using a capacity control hydraulic pressure; and a regulator valve R that produces the capacity control hydraulic pressure by using a load hydraulic pressure acting on the hydraulic actuator. The regulator valve R includes a hydraulic pressure fluctuation suppressing unit that suppresses influences of fluctuation in the load hydraulic pressure when the load hydraulic pressure varies, and produces the capacity control hydraulic pressure.;COPYRIGHT: (C)2012,JPO&INPIT