Electric pump

Abstract

An electric pump includes: a casing; a shaft member whose one end portion is fixed to the casing; first and second bearing portions disposed to an outer circumferential side of the shaft member at positions close to the one end portion of the shaft member and the other end portion of the shaft member, respectively; a rotor accommodated in the casing and integrally rotating with the first and second bearing portions; an impeller fixed to the rotor at a position close to the other end portion; an impeller housing connected to the casing in a state where the other end portion is inserted into the impeller housing and accommodating the impeller; and a slide-contacting member disposed between the impeller housing and the second bearing portion and coming into slide-contact with the second bearing portion.

What is claimed is: 
     
         1 . An electric pump comprising:
 a casing;   a shaft member whose one end portion is fixed to the casing;   a first bearing portion that is disposed to an outer circumferential side of the shaft member at a position close to the one end portion of the shaft member;   a second bearing portion that is disposed to the outer circumferential side of the shaft member at a position close to the other end portion of the shaft member;   a rotor that is accommodated in the casing and integrally rotates with the first bearing portion and the second bearing portion;   an impeller that is fixed to the rotor at a position close to the other end portion of the shaft member;   an impeller housing that is connected to the casing in a state where the other end portion of the shaft member is inserted into the impeller housing and that accommodates the impeller; and   a slide-contacting member that is disposed between the impeller housing and the second bearing portion and comes into slide-contact with the second bearing portion,   wherein the second bearing portion includes an outer circumferential portion that abuts onto an inner circumferential surface of the rotor in a state of being able to tilt with respect to a rotation axis of the rotor and a plane portion that comes into slide-contact with an end surface of the slide-contacting member.   
     
     
         2 . The electric pump according to  claim 1 ,
 wherein at least one of the inner circumferential surface of the rotor and the outer circumferential portion of the second bearing portion is configured as a curved surface.   
     
     
         3 . The electric pump according to  claim 1 ,
 wherein the first bearing portion is configured as a bearing member that is insert-molded into the rotor using resin, and   a resin portion that is exposed between the first bearing portion and the second bearing portion is positioned radially outward of inner circumferential surfaces of the first bearing portion and the second bearing portion.   
     
     
         4 . The electric pump according to  claim 2 ,
 wherein the first bearing portion is configured as a bearing member that is insert-molded into the rotor using resin, and   a resin portion that is exposed between the first bearing portion and the second bearing portion is positioned radially outward of inner circumferential surfaces of the first bearing portion and the second bearing portion.   
     
     
         5 . The electric pump according to  claim 1 ,
 wherein the first bearing portion abuts onto the inner circumferential surface of the rotor in a state of being able to tilt with respect to the rotation axis of the rotor.   
     
     
         6 . The electric pump according to  claim 2 ,
 wherein the first bearing portion abuts onto the inner circumferential surface of the rotor in a state of being able to tilt with respect to the rotation axis of the rotor.   
     
     
         7 . The electric pump according to  claim 1 ,
 wherein a discharging groove is formed on the plane portion of the second bearing portion to extend radially outwards from the shaft member.   
     
     
         8 . The electric pump according to  claim 2 ,
 wherein a discharging groove is formed on the plane portion of the second bearing portion to extend radially outwards from the shaft member.   
     
     
         9 . The electric pump according to  claim 1 ,
 wherein a plurality of rotation stopping projections are formed on the outer circumferential portion of the second bearing portion at regular intervals in a circumferential direction of the shaft member and rotation stopping groove portions that engage with the rotation stopping projections are formed on the inner circumferential surface of the rotor that abuts onto the outer circumferential portion.   
     
     
         10 . The electric pump according to  claim 2 ,
 wherein a plurality of rotation stopping projections are formed on the outer circumferential portion of the second bearing portion at regular intervals in a circumferential direction of the shaft member and rotation stopping groove portions that engage with the rotation stopping projections are formed on the inner circumferential surface of the rotor that abuts onto the outer circumferential portion.