Internal gear pumps

摘要

An internal gear pump includes in a pump housing an outer rotor including an internal gear portion on the inner periphery, and an inner rotor being eccentrically disposed with respect to the outer rotor and including an external gear portion on the outer periphery that is engaged with the internal gear portion of the outer rotor. A side plate is integrated with the outer rotor to abut on a side of the inner rotor that fails to be in slide contact with the housing. A holding device is mounted to the pump housing to restrict a position of the outer rotor with respect to the housing.