Patent ID: 9404496
Filing Date: 2016-08-02
CPC Classification: F04C

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