Patent ID: 6896500
Filing Date: 2005-05-24
Classification: F04C

Abstract:
1. A gear pump in which an inner rotor which is coupled to a rotating shaft and which has external teeth on an outer periphery thereof, and an outer rotor having internal teeth on an inner periphery thereof that are meshed with the external teeth are rotatably housed between a housing and a cover, and inter-teeth chambers are created between the external teeth and the internal teeth, an intake port is formed facing a region in which the inter-teeth chambers expand as rotation of both rotors advances, and a discharge port is formed facing a region in which the inter-teeth chambers contract as rotation of both rotors advances, characterized in that a sloped bottom surface provided on a bottom portion of the intake port is formed of a plane that is inclined so as to approach a side surface of the internal teeth and the external teeth from the upstream side to the downstream side in the rotational direction of both rotors, and a downstream end segment of the sloped bottom surface is inclined such that an end of the downstream end segment of the sloped bottom surface which is farther from a rotational axis of the inner rotor is positioned upstream of an end which is closer thereto.