Multistage oil pump

Abstract

Conventional multistage oil pumps could not have been used in an application where the pressure and the temperature are high. A multistage oil pump including two rotors that are connected in series in the direction of the rotation axis, wherein the respective rotors are accommodated in a rotor case separately across a spacer, the inside thereof being partitioned by the spacer part. The rotor case is in the form of an integral cylindrical part, and the spacer is integral with the rotor case. The rotors and the rotor case are made of a ferrous material, and the rotor case is fixed to a housing by positioning pins.

1 . A multistage oil pump, two rotors being connected in series in the direction of the rotation axis, said respective rotors being accommodated in a rotor case separately across a spacer, the inside thereof being partitioned by the spacer part, said rotor case being in the form of an integral cylindrical part, and said spacer part being integral with said rotor case. 
     
     
         2 . The multistage oil pump according to  claim 1 , wherein said rotors and said rotor case are made of a ferrous material. 
     
     
         3 . The multistage oil pump according to  claim 1 , wherein said rotor case is fixed to a housing by positioning pins. 
     
     
         4 . The multistage oil pump according to  claim 2 , wherein said rotor case is fixed to a housing by positioning pins.