Electric pump

Abstract

An electric pump includes: a case; a shaft member fixed to the case; a cylindrical bearing inserted on the outside of the shaft member; a rotor configured as a member separate from the bearing, and configured to rotate integrally with the bearing; and an impeller fixed to one end of the rotor, wherein a discharge path is formed between the bearing and the rotor along an axial direction, and allows fluid to return to the impeller therethrough, the fluid flowing from the outer circumference of the impeller into the case, and circulating in the case.

What is claimed is: 
     
         1 . An electric pump comprising:
 a case;   a shaft member fixed to the case;   a cylindrical bearing inserted on the outside of the shaft member;   a rotor configured as a member separate from the bearing, and configured to rotate integrally with the bearing; and   an impeller fixed to one end of the rotor,   wherein a discharge path is formed between the bearing and the rotor along an axial direction, and allows fluid to return to the impeller therethrough, the fluid flowing from the outer circumference of the impeller into the case, and circulating in the case.   
     
     
         2 . The electric pump according to  claim 1 ,
 wherein an outlet of the discharge path is provided closer to the center of the shaft member than blade members of the impeller.   
     
     
         3 . The electric pump according to  claim 1 ,
 wherein the rotor is made of a resin material into which the bearing is insert-molded, and   wherein a portion of the discharge path passes through an inside portion of the rotor while not being in contact with the external surface of the bearing along the axial direction.   
     
     
         4 . The electric pump according to  claim 2 ,
 wherein the rotor is made of a resin material into which the bearing is insert-molded, and   wherein a portion of the discharge path passes through an inside portion of the rotor while not being in contact with the external surface of the bearing along the axial direction.