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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical section through an electric pump according to a first representative embodiment;

FIG. 2 is a view showing the bottom surface of the bearing of an electric pump according to the first representative embodiment;

FIG. 3 is a vertical section when viewed from the side of an electric pump according to a second representative embodiment;

FIG. 4 is a plan view of the bearing in an electric pump according to the second representative embodiment; and

FIG. 5 is a plan view showing another example of the bearing in an electric pump according to the second representative embodiment.

Claims

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; anda 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; anda 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; anda 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.