Internal gear pump and an inner rotor of such a pump

摘要

An inner motor is structured to increase the discharge rate of an internal gear pump by making it possible to freely adjust the eccentricity e between the inner and outer rotors. Each tooth of the inner rotor includes a tooth bottom defined by hypocycloidal curves, an engaging portion to be brought into engagement with the outer rotor and defined by involute curves, and a tooth top defined by a predetermined curve such as a part of a circle or an oval or an epicycloidal curve.