Integrated Motor-Pump

Abstract

An integrated motor-driven pump is proposed that reduces the part count of the assembly and addresses several tolerance and alignment issues by combining the outlet plate and retainer ring of the pump into a single component. The integrated motor-driven pump may also include an axial bushing for support of the motor shaft and inner gerotor, ensuring concentric rotation of these components. Combining one of the inlet or outlet plates with the retainer ring and including a central bushing eliminates the need for alignment pins and complex assembly procedures. The disclosure also combines one of the motor end plates with the disclosed integrated pump inlet or outlet plate, retainer ring and central bushing, eliminating the need for a separate motor end plate and bushing to support the motor shaft.

What is claimed: 
     
         1 . A motor-driven pump comprising:
 a motor having an exterior housing surrounding a stator and a rotor supported on a shaft, said motor having a first end plate with a first bushing supporting the shaft at a first end, and a second end plate having a second bushing supporting the shaft at a second end, said shaft passing through said second end plate, said second end plate including an integrally formed retainer ring and a central boss, both said central boss and said retainer ring projecting axially away from said motor to define a pump cavity, said retainer ring having an inside surface defined by a circle eccentric to an axis of rotation of said motor shaft, said central boss including an outside surface concentric with the axis of rotation of said motor shaft;   a pump rotor received in said pump cavity and seated on said central boss;   one or more pump components engaged with said retainer ring inside surface to produce differential pressures within said pump cavity during rotation of said pump rotor; and   a pump inlet plate secured to said retainer ring to retain said pump rotor and components in said pump cavity.   
     
     
         2 . The motor-driven pump of  claim 1 , wherein said pump rotor is the inner rotor of a gerotor pump and said one or more pump components are the outer gerotor of a gerotor pump. 
     
     
         3 . The motor-driven pump of  claim 1 , wherein said pump rotor includes radial slots and said components are roller vanes of a roller vane pump.