Patent ID: 6116878
Filing Date: 2000-09-12
Classification: F04C

Abstract:
An oil pump apparatus comprising:a housing defining therein a generally cylindrical space;an outer rotor having a substantially cylindrical outer peripheral surface disposed in rotatably sliding contact with an inner peripheral surface of the cylindrical space, the outer rotor further having an inner peripheral surface formed thereon with a plurality of circumferentially equally spaced gear teeth;a shaft rotatably mounted in the housing; andan inner rotor having a plurality of projections for supporting the outer peripheral surface of the shaft and disposed facing inwardly on the inner peripheral surface of the inner rotor, the inner rotor being disposed in the substantially cylindrical space in the housing and having an outer peripheral surface formed thereon with a plurality of circumferentially equally spaced gear teeth disposed in partial meshing engagement with the gear teeth of the outer rotor so as to define a plurality of working chambers between the gear teeth of the inner rotor and the outer rotor.