Rotor-type oil pump installed on motorcycle crank case

The utility model discloses a rotor-type oil pump installed on a motorcycle crank case. The rotor-type oil pump installed on the motorcycle crank case comprises an inner rotor (1), an outer rotor (2), an oil pump shaft (3) and the crank case (4), wherein the components formed by the inner rotor (1), the outer rotor (2) and the oil pump shaft (3) are installed in a cavity which is correspondingly formed in the crank case (4) and are positioned through an oil pump cover (5) arranged on the outer side of the cavity, the axis of the oil pump shaft (3) is perpendicular to a main oil duct (4a), and an oil inlet hole (4b) and an oil outlet hole (4c) which are communicated with the main oil duct (4a) are formed in the cavity; the inner rotor (1) is fixed to the oil pump shaft (3), the outer rotor (2) rotates along with the inner rotor (1), the inner rotor (1) and the oil pump shaft (3) are coaxially arranged, and an eccentric distance is formed between the outer rotor (2) and the inner rotor (1). The rotor-type oil p