Electric pump

Abstract

An electric pump may comprise a pump case ( 110, 150 ) having a pump chamber. An impeller 143 may be rotatably disposed within the pump chamber. The impeller 143 may include a magnetized cylindrical portion 145 . A stator 133 may be disposed opposite to the cylindrical portion 145 of the impeller 143 . The stator 133 may drive the impeller 143 by applying magnetic forces to the cylindrical portion 145 of the impeller 143 . A shaft 146 may be formed integrally with the impeller 143 . One end of the shaft 143 may be rotatably supported with respect to the pump case.

1 . An electric pump, comprising:
 a pump case having a pump chamber;   an impeller rotatably disposed within the pump chamber, the impeller having a magnetized cylindrical portion;   a stator disposed opposite to the cylindrical portion of the impeller, the stator driving the impeller by applying magnetic forces to the cylindrical portion of the impeller; and   a shaft fixed to the impeller, wherein the shaft is rotatably supported with respect to the pump case.   
   
   
       2 . The electric pump according to  claim 1 , further comprising a first bearing for supporting a top end of the shaft and a second bearing for supporting a lower end of the shaft. 
   
   
       3 . The electric pump according to  claim 2 , wherein the stator is compartmentalized from the impeller by a first wall of the pump case, a first clearance is formed between the first wall and the impeller, and fluid within the pump chamber can flow in the first clearance. 
   
   
       4 . The electric pump according to  claim 3 , wherein the shaft is disposed penetrating the center of the stator, the shaft is compartmentalized from the stator by a second wall of the pump case, a second clearance is formed between the second wall and the shaft, and fluid within the pump chamber can flow in the second clearance. 
   
   
       5 . The electric pump according to  claim 4 , wherein the shaft has a hollow portion, and the fluid within the pump chamber can flow in the hollow portion of the shaft. 
   
   
       6 . The electric pump according to  claim 5 , wherein the second bearing that supports the lower end of the shaft is arranged to receive radial loads and thrust loads. 
   
   
       7 . The electric pump according to  claim 6 , wherein the impeller and the shaft are formed integrally by insert forming. 
   
   
       8 . An electric pump, comprising:
 a pump case having a pump chamber;   a shaft disposed within the pump chamber, wherein a lower end of the shaft is fixed to the pump case;   an impeller rotatably disposed within the pump chamber, the impeller comprising a magnetized cylindrical portion, and a bearing into which the shaft is inserted, wherein a plurality of grooves are formed in a lower end surface of the bearing; and   a stator disposed opposite to the cylindrical portion of the impeller, the stator driving the impeller by applying magnetic forces to the cylindrical portion of the impeller.   
   
   
       9 . The electric pump according to  claim 8 , further comprising a circuit board that provides electrical power to the stator, and a temperature sensor that detects temperature of the stator, wherein the temperature sensor is separated from the circuit board and is disposed in a position close to the stator. 
   
   
       10 . An electric pump, comprising:
 a pump case having a pump chamber;   a shaft disposed within the pump chamber, wherein a lower end of the shaft is fixed to the pump case;   an impeller rotatably disposed within the pump chamber, the impeller comprising a magnetized cylindrical portion, and a bearing into which the shaft is inserted;   a stator disposed opposite to the cylindrical portion of the impeller, the stator driving the impeller by applying magnetic forces to the cylindrical portion of the impeller; and   a washer disposed between the pump case and a lower end surface of the bearing.   
   
   
       11 . The electric pump according to  claim 10 , further comprising a circuit board that provides electrical power to the stator and a temperature sensor that detects temperature of the stator, wherein the temperature sensor is separated from the circuit board and is disposed in a position close to the stator.