SYSTEMS AND METHODS FOR COOLING AND LUBRICATION OF ELECTRIC MACHINES

• US 20120049668A1
• Filed: 08/25/2010
• Published: 03/01/2012
• Est. Priority Date: 08/25/2010
• Status: Active Grant

• Current Assignee: Clean Wave Technologies, Inc.
• Original Assignee: Clean Wave Technologies, Inc.
• Inventors: Garriga, Ruldolph, Kubic, Michael
• Granted Patent: US 8,427,019 B2
• Time in Patent Office: Days
• US Class Current: 310/59
• CPC Class Codes: F16C 2380/26 Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators in general H02K
• CPC Class Codes: F16C 33/6659 Details of supply of the liquid to the bearing, e.g. passages or nozzles
• CPC Class Codes: F16C 35/042 Housings for rolling element bearings for rotary movement
• CPC Class Codes: F16C 37/007 of rolling bearings
• CPC Class Codes: H02K 5/203 specially adapted for liquids, e.g. cooling jackets
• CPC Class Codes: H02K 9/12 wherein the cooling medium circulates freely within the casing
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Abstract

The invention provides systems and methods for cooling and lubrication of high power density electric machines with an enhanced fluid injection system. Multiple fluid flow passages may be provided within the electric machine, which may comprise a stator fluid flow pathway, a rotor fluid flow pathway, and a bearing fluid flow pathway. The fluid within the electric machine may be used to cool and/or lubricate internal components of the electric machine.

Claims

1. An electric machine comprising:

a rotor fixed to a rotatable shaft and supported by means of one or more bearings;

a stator stationary in relation to the rotatable rotor and shaft with a gap between the rotor and the stator;

a housing surrounding all or part of the machine; and

a plurality of fluid flow passages within the machine, wherein the fluid flow passages include;

one or more stator fluid flow pathways between the stator and the housing;

one or more rotor fluid flow pathways along the rotatable shaft toward the rotor and stator; and

one or more bearing fluid flow pathways contacting at least one bearing.

2. The electric machine of claim 1 wherein a stator fluid flow pathway comprises a circumferential or perimetrical groove on the internal surface of the housing, wherein the groove forms a cavity between an outside surface of the stator and an inside surface of the housing.

3. The electric machine of claim 2 wherein a fluid is directed to flow circumferentially or perimetrically around the stator through the cavity between the outside surface of the stator and the inside surface of the housing.

4. The electric machine of claim 3 wherein the fluid directly contacts the outside surface of the stator.

5. The electric machine of claim 1 wherein a rotor fluid flow pathway comprises a fluid injector nozzle, wherein the injector nozzle surrounds the rotatable shaft and forms a gap between the injector nozzle and the shaft.

6. The electric machine of claim 5 wherein a fluid is directed to flow along the rotatable shaft through the gap between the injector nozzle and the shaft toward the rotor.

7. The electric machine of claim 6 wherein the fluid exits the injector nozzle through a gap between the injector nozzle and a surface of the rotor.

8. The electric machine of claim 7 wherein the fluid that exits the injector nozzle is directed to flow over the surface of the rotor, then over and around an end ring of the rotor, and then toward the stator by centrifugal force.

9. The electric machine of claim 1 wherein at least one fluid flow passage leads to a junction wherein the fluid flow passage splits into a bearing fluid flow pathway to contact a bearing and into a rotor fluid flow pathway to contact the rotor.

10. The electric machine of claim 9 further comprising a metering device between the bearing fluid flow pathway and rotor fluid flow pathway, wherein the metering device is configured to determine the relative amount of fluid that flows to contact the bearing and fluid that flows to contact the rotor.

11. The electric machine of claim 1 wherein all or part of the housing is fluid-sealed, such that fluid is prevented from entering or exiting the machine except at designated inlet and outlet ports.

12. A method for cooling and lubricating an electric machine comprising:

providing a rotor fixed to a rotatable shaft;

providing a stator stationary in relation to the rotatable rotor and shaft with a gap between the rotor and the stator;

providing a housing surrounding all or part of the machine; and

providing a plurality of fluid flow passages within the machine, wherein the fluid flow passages include;

one or more stator fluid flow pathways between the stator and the housing;

one or more rotor fluid flow pathways along the rotatable shaft toward the rotor and stator; and

one or more bearing fluid flow pathways contacting at least one bearing.

13. The method of claim 12 wherein a stator fluid flow pathway comprises providing a circumferential or perimetrical groove on the internal surface of the housing, wherein the groove forms a cavity between an outside surface of the stator and an inside surface of the housing.

14. The method of claim 13 further comprising flowing a fluid circumferentially or perimetrically around the stator through the cavity between the outside surface of the stator and the inside surface of the housing.

15. The method of claim 14 wherein the fluid directly contacts the outside surface of the stator and allows heat to transfer from the stator to the fluid, thereby cooling the stator.

16. The method of claim 12 wherein a rotor fluid flow pathway comprises providing a fluid injector nozzle, wherein the injector nozzle surrounds the rotatable shaft and forms a gap between the injector nozzle and the shaft.

17. The method of claim 16 further comprising flowing a fluid along the rotatable shaft through the gap between the injector nozzle and the shaft toward the rotor.

18. The method of claim 17 wherein the fluid exits the injector nozzle through a gap between the injector nozzle and a surface of the rotor.

19. The method of claim 18 wherein the fluid that exits the injector nozzle flows over the surface of the rotor, then over and around an end ring of the rotor, and then toward the stator by centrifugal force.

20. The method of claim 19 wherein the fluid directly contacts the surface of the rotor, the end ring of the rotor, and the stator and allows heat to transfer from the rotor to the fluid and from the stator to the fluid, thereby cooling the rotor and stator.

21. The method of claim 12 wherein at least one fluid flow passage comprises providing a junction wherein the fluid flow passage splits into a bearing fluid flow pathway to contact a bearing and into a rotor fluid flow pathway to contact the rotor.

22. The method of claim 21 further comprising flowing a fluid through the bearing fluid flow pathway wherein the fluid directly contacts the bearing and flows through the bearing.

23. The method of claim 22 wherein the fluid provides lubrication for the bearing and allows heat to transfer from the bearing to the fluid, thereby cooling the bearing.

24. The method of claim 12 wherein all or part of the housing is fluid-sealed, such that fluid is prevented from entering or exiting the machine except at designated inlet and outlet ports.