Variable displacement pump

摘要

A cam case 23 is provided which swingably support a cam ring 34 fitted to a rotor 33 having a vane 33a so as to form a pump chamber 36 from the outer surface such that the cam ring 34 is swingably supported by using a swingable pin 35 disposed in the axial direction as a fulcrum, the cam case 23 serving as an intermediate body. Pump bodies are disposed on the two ends of the cam case in the axial direction. Moreover, a front body 21 and a rear body 22 for rotatively supporting a rotational shaft 40 of the rotor are disposed. A valve hole 75 for forming a relief valve 74 for relieving fluid pressure in the discharge portion of the pump to a suction portion of the pump when the fluid pressure has been made to be not lower than a predetermined level is a blind hole having an end which is, in the rear body, opened in a joining surface with the cam case. Valve elements 74a received in the valve hole are anchored by the joining surface of the cam case.