公开(公告)号：US10794380B2

公开(公告)日：2020-10-06

申请号：US16307275

申请日：2017-05-23

Applicant: KYB Corporation

Inventor： Yuki Sakai ,  Tetsuya Iwanaji

IPC: F04B49/20 ,  F04B49/12 ,  F04B49/22 ,  F15B11/05 ,  F15B11/00 ,  F15B11/02

Abstract: A pump device includes a variable capacity first pump, a tilt actuator that controls a tilt angle of a swash plate of the first pump in accordance with the control pressure, a regulator that regulates the control pressure in accordance with a front-rear differential pressure of a control valve, a fixed capacity second pump driven by the same drive source as the first pump, the control actuator that operates in accordance with the front-rear differential pressure a resistor so as to drive the regulator to reduce the control pressure in response to an increase in the front-rear differential pressure of the resistor, an auxiliary passage that leads an auxiliary pressure to the control actuator, the auxiliary pressure acting on the control actuator against a upstream pressure of the resistor, and a switch valve that switches between connecting and shutoff the auxiliary passage.