Pump device having a device for restricting movement of a movable member movable to pressurize working fluid

摘要

A pump device comprising a support member having a fitting recess, a movable member which is reciprocated in said fitting recess to suck a working fluid, pressurize the fluid and deliver the pressurized fluid, and a movement restricting device operable to deform a wall at least partially defining the fitting recess of the support member, such that the wall is deformed toward the movable member, for restricting a reciprocating movement of the movable member in the fitting recess, at least when an amount of the pressurized fluid required to be delivered by the pump device is smaller than a nominal delivery amount of the pump device.