HYDRAULIC DRIVING DEVICE OF WORK MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic driving device of a work machine that can control pump capacity while effectively avoiding hunting of the pump capacity.SOLUTION: A hydraulic driving device includes: a pump oil passage 12a through which a discharge pressure of a hydraulic pump 2 is led; a control pressure supply oil passage 12b through which a control pressure for setting a target pump discharge pressure of the hydraulic pump 2 is led; and a pump control device 100. The pump control device 100 includes: a regulator 11 in which the pump discharge pressure acts so as to reduce the capacity of the hydraulic pump 2 and the control pressure acts so as to increase the capacity of the hydraulic pump 2; and a regulator adjustment spring 11d that generates force in a capacity reduction direction made larger as the capacity of the hydraulic pump 2 increases.