VARIABLE DISPLACEMENT PUMP

摘要

A variable displacement pump includes a housing having a pair of end wall surfaces; an annular outer rotor guide swingably disposed between the pair of end wall surfaces; a cylindrical outer rotor; an inner rotor provided radially inward of the outer rotor and configured to rotate integrally with a drive shaft at a location eccentric relative to the outer rotor; and a plurality of coupling plates coupling the inner rotor and the outer rotor. The outer rotor is rotatably fitted into an outer rotor supporting surface of the outer rotor guide. A space between the inner rotor and the outer rotor is partitioned into a plurality of chambers by the plurality of coupling plates. A concave portion is formed in the outer rotor supporting surface such that the concave portion exists over an entire axial range between the both end surfaces of the outer rotor guide.

主权项

1. A variable displacement pump comprising:
a housing including a pair of end wall surfaces through which a drive shaft passes, wherein a suction port and a discharge port are formed in at least one of the pair of end wall surfaces; an annular outer rotor guide swingably disposed between the pair of end wall surfaces such that both end surfaces of the outer rotor guide are in close contact with the pair of end wall surfaces, wherein the outer rotor guide includes an outer rotor supporting surface given in a cylinder-surface shape, the drive shaft passing radially inward of the outer rotor supporting surface; a cylindrical outer rotor including an outer circumferential surface given in a cylinder-surface shape, the outer rotor being rotatably fitted into the outer rotor supporting surface; an inner rotor provided radially inward of the outer rotor and configured to rotate integrally with the drive shaft at a location eccentric relative to the outer rotor; and a plurality of coupling plates coupling the inner rotor and the outer rotor such that rotational force is transmitted from the inner rotor to the outer rotor, wherein a space between the inner rotor and the outer rotor is partitioned into a plurality of chambers by the plurality of coupling plates, and a concave portion is formed in the outer rotor supporting surface such that the concave portion exists over an entire axial range between the both end surfaces of the outer rotor guide.