Variable displacement pump, valve timing control device using the variable displacement pump, and valve timing control system using the variable displacement pump, for use in internal combustion engines

摘要

A variable displacement pump including a chamber volume varying mechanism including a moveable member, a first biasing member always biasing the moveable member in such a direction as to increase volumes of the working fluid chambers, and a second biasing member that is disposed with a set load and applies a biasing force to the moveable member in such a direction as to increase the volumes of the working fluid chambers when the moveable member is displaced against a biasing force of the first biasing member by a predetermined amount or more. The biasing force of the first biasing member is set such that before the moveable member is displaced against the biasing force of the first biasing member, the valve timing control device is shifted to a release state in which an open-and-closure timing of an engine valve is variably controlled.