Systems and methods for providing fluid for internal cooling and lubrication of electric machines

• US 8,432,076 B2
• Filed: 04/06/2011
• Issued: 04/30/2013
• Est. Priority Date: 08/25/2010
• Status: Expired due to Fees

• Current Assignee: Clean Wave Technologies, Inc.
• Original Assignee: Clean Wave Technologies, Inc.
• Inventors: Garriga, Ruldolph, Kubic, Mike
• Primary Examiner(s): Lam, Thanh
• Application Number:
  US13/080,979
• Publication Number:
  US 20120049666A1
• Time in Patent Office: 755 Days
• Field of Search: 310 52- 59, 310 61- 64
• US Class Current: 310/54
• 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 include one or more bearing fluid flow pathways and one or more rotor fluid flow pathways. The bearing fluid flow pathway may comprise one or more passages which may direct a fluid to contact one or more bearings. The rotor fluid flow pathway may comprise one or more passages which may direct a fluid along the rotatable shaft toward the rotor and stator. A method for cooling and lubricating the electric machine may include directing a fluid to flow through a bearing fluid flow pathway for lubrication and cooling of one or more bearings, and then sequentially flow through a rotor fluid flow pathway for cooling of the rotor and stator.

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; and

one or more liquid flow passages within the machine, wherein the one or more liquid flow passages comprise;

one or more bearing liquid flow pathways contacting one or more bearings; and

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

wherein a liquid is directed to flow in series through a bearing liquid flow pathway, and then sequentially flow through a rotor liquid flow pathway.

2. The electric machine of claim 1 wherein the liquid is first directed to flow to contact the one or more bearings, then flow through the one or more bearings, and then subsequently flow to contact the rotor.

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

4. The electric machine of claim 3 wherein the liquid is directed to flow along the rotatable shaft through the gap between the injector nozzle and the shaft toward the rotor.

5. The electric machine of claim 4 wherein the liquid exits the injector nozzle through a gap between the injector nozzle and a surface of the rotor.

6. The electric machine of claim 5 wherein the liquid that exits the injector nozzle is directed to flow over the surface of the rotor, then flow over and around an end ring of the rotor, and then flow toward the stator by centrifugal force.

7. The electric machine of claim 6 wherein the liquid that is directed to flow toward the stator by centrifugal force contacts the end turns of the stator.

8. The electric machine of claim 7 wherein the liquid that contacts the end turns of the stator is then directed to flow through a main internal cavity of the machine.

9. The electric machine of claim 8 wherein the liquid that is directed to flow through the main internal cavity of the machine is collected within an exhaust sump which is in fluid communication with at least one liquid outlet port.

10. The electric machine of claim 9 wherein the liquid that is collected within the exhaust sump exits the machine through one or more liquid outlet ports.

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

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

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

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

providing one or more liquid flow passages within the machine, wherein the one or more liquid flow passages comprise;

one or more bearing liquid flow pathways contacting one or more bearings; and

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

directing a liquid to flow in series through a bearing liquid flow pathway for cooling and lubrication of the one or more bearings, and then sequentially flow through a rotor liquid flow pathway for cooling of the rotor and stator.

13. The method of claim 12 wherein the liquid is first directed to flow to contact the one or more bearings, then flow through the one or more bearings, and then subsequently flow to contact the rotor.

14. The method of claim 12 wherein the liquid directly contacts the one or more bearings, thereby providing lubrication for the one or more bearings.

15. The method of claim 12 wherein the liquid directly contacts the one or more bearings, and allows heat to transfer from the one or more bearings to the liquid, thereby cooling the one or more bearings.

16. The method of claim 12 wherein the rotor liquid flow pathway comprises a liquid 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 directing the liquid to flow 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 liquid 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 liquid 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.

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

21. The method of claim 19 wherein the liquid that is directed to flow toward the stator by centrifugal force directly contacts the end turns of the stator, and allows heat to transfer from the stator end turns to the liquid, thereby cooling the stator.

22. The method of claim 21 wherein the liquid that contacts the end turns of the stator is then directed to flow through a main internal cavity of the machine.

23. The method of claim 22 wherein the liquid that is directed to flow through the main internal cavity of the machine is collected within an exhaust sump which is in fluid communication with at least one liquid outlet port.

24. The method of claim 23 wherein the liquid that is collected within the exhaust sump exits the machine through one or more liquid outlet ports, allowing the liquid to be cooled outside the electric machine.

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