| 摘要 |
PROBLEM TO BE SOLVED: To provide an oil pump excellent in pump efficiency and capable of reducing friction between a housing and the oil pump.SOLUTION: An oil pump 1 comprises: a gear rotor 2 including external teeth and rotated by a drive shaft; and a rotating body including teeth mating with the external teeth (ring gear 3 including inner teeth). Furthermore, the oil pump 1 comprises: a plurality of concave portions 20, 30 provided on a surface of at least one of the gear rotor 2 and the ring gear 3 orthogonal to an axial direction of the drive shaft; and flat portions 22, 32 provided continuously in circumferential edge-side regions 220, 320 in which the external teeth of the gear rotor 2 and the inner teeth of the ring gear 3 approach one another on both of the orthogonal surface of the gear rotor 2 and the orthogonal surface of the ring gear 3 along circumferential edges (an outer circumferential edge 2o and an inner circumferential edge 3i) of the circumferential edge-side regions 220, 320.SELECTED DRAWING: Figure 1 |
