Patent ID: 8585384
Filing Date: 2013-11-19
Classification: F04C

Abstract:
1. A rotary pump comprising: a shaft that is rotatable; a drive device that generates a rotational drive force to rotate the shaft; an inner rotor that includes a plurality of external teeth and is adapted to be rotated integrally with the shaft by the rotational drive force, which is received from the drive device; an outer rotor that includes a plurality of internal teeth meshed with the plurality of external teeth and is placed eccentric to the inner rotor on a radially outer side of the inner rotor, wherein the inner rotor and the outer rotor form a pressure chamber therebetween, and a volume of the pressure chamber is variable upon rotation of the inner rotor; a first housing that includes: an axial size of an axial clearance, which is formed between an axial end surface of the pump chamber and an axial end surface of the inner rotor, differs from an axial size of an axial clearance, which is formed between the axial end surface of the pump chamber and an axial end surface of the outer rotor; and the axial size of the axial clearance, which is formed between the axial end surface of the pump chamber and the axial end surface of the inner rotor, is smaller than the axial size of the axial clearance, which is formed between the axial end surface of the pump chamber and the axial end surface of the outer rotor.