Patent ID: 9416782
Filing Date: 2016-08-16
CPC Classification: F04C

Claim Text:
1. An oil pump, comprising: a pump body; an outer rotor; and an inner rotor, the pump body including a rotor chamber having an inner circumferential support wall on an inner circumferential side, an inlet port and an outlet port formed in the rotor chamber, an inlet passage communicating with said inlet port, an outlet passage communicating with said outlet port, a relief valve allowing oil to flow from the outlet passage to said inlet passage by relieving pressure, a relief chamber formed on a discharge side of the relief valve, and an oil return passage formed from said relief chamber to said inlet passage; the outer rotor being supported by the inner circumferential support wall of said rotor chamber; and the inner rotor being arranged on an inner circumferential side of the outer rotor, wherein said oil return passage is formed in said inner circumferential support wall as a groove-like recess and opens along an outer circumferential surface of said outer rotor.