Electric pump

Abstract

An electric pump includes: a motor rotor having a cylindrical yoke; a pump portion having outer and inner rotors; a shaft transmitting a rotational force from the motor rotor to the pump portion; a motor housing in which a coil portion is fixed to an inner peripheral surface and the motor rotor is housed on the inside of the coil portion; and a pump main body housing the pump portion, wherein the pump main body has a bearing portion supporting a portion of the shaft between the motor rotor and the inner rotor, and the inner rotor has a first recessed portion of a diameter greater than that of the shaft on a side facing the bearing portion and a part of the bearing portion is inserted into the first recessed portion to be disposed.

What is claimed is: 
     
         1 . An electric pump comprising:
 a motor rotor that has a cylindrical yoke and is rotated by an electromagnetic force;   a pump portion that has an outer rotor and an inner rotor;   a shaft that transmits a rotational force from the motor rotor to the pump portion by fixing the motor rotor on one side and fixing the inner rotor on the other side;   a motor housing in which a coil portion is fixed to an inner peripheral surface and the motor rotor is housed on the inside of the coil portion; and   a pump main body that houses the pump portion,   wherein the pump main body has a bearing portion that supports a portion of the shaft between the motor rotor and the inner rotor, and   wherein the inner rotor has a first recessed portion of a diameter greater than that of the shaft on a side facing the bearing portion and a part of the bearing portion is inserted into the first recessed portion to be disposed.   
     
     
         2 . The electric pump according to  claim 1 ,
 wherein the motor rotor has a second recessed portion of a diameter greater than that of the shaft on a side facing the bearing portion and a part of the bearing portion is inserted into the second recessed portion to be disposed.   
     
     
         3 . The electric pump according to  claim 2 ,
 wherein the yoke includes a first yoke that is positioned on an inner peripheral side of the coil portion and a second yoke that is provided continuously to the first yoke and protrudes on a side opposite to the pump portion with respect to the first yoke in an axial direction of the yoke, and   wherein a hole portion capable of fixing the shaft is formed in the second yoke and the second recessed portion is formed on a side facing the bearing portion in the first yoke.   
     
     
         4 . The electric pump according to of  claim 1 ,
 wherein an end portion of the shaft protruding from the pump portion is journaled by the pump main body.   
     
     
         5 . The electric pump according to of  claim 2 ,
 wherein an end portion of the shaft protruding from the pump portion is journaled by the pump main body.   
     
     
         6 . The electric pump according to of  claim 3 ,
 wherein an end portion of the shaft protruding from the pump portion is journaled by the pump main body.   
     
     
         7 . The electric pump according to  claim 1 ,
 wherein the shaft and the bearing portion are formed of a ferrous material.   
     
     
         8 . The electric pump according to  claim 2 ,
 wherein the shaft and the bearing portion are formed of a ferrous material.   
     
     
         9 . The electric pump according to  claim 3 ,
 wherein the shaft and the bearing portion are formed of a ferrous material.   
     
     
         10 . The electric pump according to  claim 4 ,
 wherein the shaft and the bearing portion are formed of a ferrous material.   
     
     
         11 . The electric pump according to  claim 1 ,
 wherein the cylindrical yoke includes magnetic bodies that are laminated so that a through-hole continuous along the axial direction of the yoke is formed and a resin portion with which the through-hole is filled.   
     
     
         12 . The electric pump according to  claim 2 ,
 wherein the cylindrical yoke includes magnetic bodies that are laminated so that a through-hole continuous along the axial direction of the yoke is formed and a resin portion with which the through-hole is filled.   
     
     
         13 . The electric pump according to  claim 3 ,
 wherein the cylindrical yoke includes magnetic bodies that are laminated so that a through-hole continuous along the axial direction of the yoke is formed and a resin portion with which the through-hole is filled.   
     
     
         14 . The electric pump according to  claim 4 ,
 wherein the cylindrical yoke includes magnetic bodies that are laminated so that a through-hole continuous along the axial direction of the yoke is formed and a resin portion with which the through-hole is filled.   
     
     
         15 . The electric pump according to  claim 5 ,
 wherein the cylindrical yoke includes magnetic bodies that are laminated so that a through-hole continuous along the axial direction of the yoke is formed and a resin portion with which the through-hole is filled.