Cam locked air gap baffle assembly for a dynamoelectric machine

• US 20050151430A1
• Filed: 01/09/2004
• Published: 07/14/2005
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Westinghouse Power Corporation
• Inventors: Lowther, Gary R.
• Granted Patent: US 6,987,337 B2
• Time in Patent Office: Days
• US Class Current: 310/58
• CPC Class Codes: H02K 2201/03 Machines characterised by aspects of the air-gap between rotor and stator
• CPC Class Codes: H02K 9/10 by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing

Abstract

A baffle system for routing cooling fluids through a dynamoelectric machine. The baffle system may include a locking cam mechanism for releaseably attaching a baffle to a stator assembly to substantially eliminate an annular air gap between a rotor assembly and a stator assembly. The baffle system may include a locking strip attached to a stator slot wedge to seal the locking cam mechanism and baffle to the stator assembly. In other embodiments, the baffle system may include a friction pad for sealing the locking cam mechanism and baffle to the stator assembly. The baffle system may also include a locking tool for simultaneously, or individually, moving the locking cam mechanism from an unlocked position to a locked position, or vice versa.

Claims

1. A barrier system for air gaps between stators and rotors in dynamoelectric machines, comprising:

at least one air gap baffle adapted to be positioned between a stator assembly and a rotor assembly;

at least one locking cam assembly configured to be coupled to the at least one air gap baffle and having at least one cam for receiving a locking tool including an inner cavity extending through the cam and at least one keyway in an inner wall of the inner cavity for receiving a key of the locking tool, wherein the at least one cam is movable between a first position in which the cam has a first diameter and a second position in which the cam has a second diameter that is greater than the first diameter; and

at least one locking strip coupled to a stator slot wedge in a position to contact the cam.

2. The barrier system of claim 1, further comprising at least one friction pad coupled to the at least one locking strip.

3. The barrier system of claim 2, wherein the at least one friction pad comprises at least two layers.

4. The barrier system of claim 3, wherein the at least two layers comprises a first layer formed from a porous cloth adapted to receive a resin and a second layer formed from a TEFLON coated cloth.

5. The barrier system of claim 3, wherein the at least two layers comprises a first layer formed from a porous cloth adapted to receive a resin and a second layer formed from rubber.

6. The barrier system of claim 1, wherein the at least one keyway comprises at least two keyways positioned generally on opposite sides of the inner surface from each other and aligned generally parallel with a longitudinal axis of the at least one cam.

7. The barrier system of claim 1, wherein the inner cavity in the at least one cam is adapted to receive a locking tool having a generally cylindrical cross-section and includes at least one key extending from an outer surface of the locking tool.

8. The barrier system of claim 1, wherein the at least one locking strip is comprised of glass laminates.

9. The barrier system of claim 1, wherein the at least one air gap baffle comprises a plurality of air gap baffles and the at least one locking cam assembly comprises a plurality of locking cam assemblies having a plurality of cams, and wherein the plurality of cams are positioned along a substantially straight axis enabling a locking tool to be inserted through the plurality of cams to rotate the cams substantially simultaneously to locked positions.

10. A barrier system for air gaps between stators and rotors in dynamoelectric machines, comprising:

at least one air gap baffle adapted to be positioned between a stator assembly and a rotor assembly;

at least one locking cam assembly configured to be coupled to the at least one air gap baffle and having at least one cam for receiving a locking tool including an inner cavity extending through the cam and at least one keyway in an inner wall of the inner cavity for receiving a key of the locking tool, wherein the at least one cam is movable between a first position in which the cam has a first diameter and a second position in which the cam has a second diameter that is greater than the first diameter; and

at least one friction pad coupled to a stator slot wedge in a position to contact the cam.

11. The barrier system of claim 10, wherein the at least one friction pad comprises at least two layers.

12. The barrier system of claim 11, wherein the at least two layers comprises a first layer formed from a porous cloth adapted to receive a resin and a second layer formed from a TEFLON coated cloth.

13. The barrier system of claim 11, wherein the at least two layers comprises a first layer formed from a porous cloth adapted to receive a resin and a second layer formed from rubber.

14. The barrier system of claim 10, wherein the at least one keyway comprises at least two keyways positioned generally on opposite sides of the inner surface from each other and aligned generally parallel with a longitudinal axis of the at least one cam.

15. The barrier system of claim 10, wherein the inner cavity in the at least one cam is adapted to receive a locking tool having a generally cylindrical cross-section and includes at least one key extending from an outer surface of the locking tool.

16. The barrier system of claim 10, further comprising at least one locking strip coupled to the stator slot wedge.

17. The barrier system of claim 16, wherein the at least one locking strip is comprised of glass laminates.

18. The barrier system of claim 10, wherein the at least one air gap baffle comprises a plurality of air gap baffles and the at least one locking cam assembly comprises a plurality of locking cam assemblies having a plurality of cams, and wherein the plurality of cams are positioned along a substantially straight axis enabling a locking tool to be inserted through the plurality of cams to rotate the cams substantially simultaneously to locked positions.

19. A barrier system for air gaps between stators and rotors in dynamoelectric machines, comprising:

at least one air gap baffle adapted to be positioned between a stator assembly and a rotor assembly and including at least one slot;

at least one locking cam assembly configured to be positioned in the at least one slot of the at least one air gap baffle and having at least one cam including an inner cavity extending through the cam and at least one keyway in an inner wall of the inner cavity for receiving a locking tool, wherein the at least one cam is movable between a first position in which the cam has a first diameter and a second position in which the cam has a second diameter that is greater than the first diameter; and

at least one locking tool having a substantially cylindrical shaft with at least one key extending from an outer surface of the shaft and adapted to be received in the at least one keyway in the at least one cam;

wherein the at least one locking tool is capable of moving a plurality of locking cam assemblies to locked positions substantially simultaneously.

20. The barrier system of claim 19, further comprising at least one locking strip coupled to a stator slot wedge.

21. The barrier system of claim 20, wherein the at least one locking strip is comprised of glass laminates.

22. The barrier system of claim 19, further comprising at least one friction pad coupled to a stator slot wedge.

23. The barrier system of claim 22, wherein the at least one friction pad comprises at least two layers.

24. The barrier system of claim 19, wherein the at least one keyway comprises at least two keyways positioned generally on opposite sides of the inner surface from each other and aligned generally parallel with a longitudinal axis of the at least one cam.

25. The barrier system of claim 19, wherein the inner cavity in the at least one cam is adapted to receive a locking tool having a generally cylindrical cross-section and includes at least one key extending from an outer surface of the locking tool.

26. The barrier system of claim 19, wherein the at least one air gap baffle comprises a plurality of air gap baffles and the at least one locking cam assembly comprises a plurality of locking cam assemblies having a plurality of cams, and wherein the plurality of cams are positioned along a substantially straight axis enabling a locking tool to be inserted through the plurality of cams to rotate the cams substantially simultaneously to locked positions.

27. The barrier system of claim 19, wherein the at least one key comprises two keys positioned about 180 degrees apart.

28. The barrier system of claim 27, wherein the at least one locking tool comprises a plurality of pairs of keys positioned along the length of the locking tool to engage keyways in cams in a dynamoelectric machine.

29. A method of sealing air gaps between stators and rotors in dynamoelectric machines, comprising:

positioning at least one air gap baffle between a stator assembly and a rotor assembly;

positioning at least one locking cam assembly between the stator and rotor assemblies, wherein the at least one cam includes an inner cavity extending through the cam and at least one keyway in an inner wall of the inner cavity for receiving a locking tool, and wherein the at least one cam is movable between a first position in which the cam has a first diameter and a second position in which the cam has a second diameter that is greater than the first diameter;

positioning at least one locking strip proximate to the at least one air gap baffle;

inserting a portion of at least one locking tool having at least one key extending from an outer surface of the at least one locking tool into the inner cavity of the at least one cam; and

rotating the at least one locking tool which causes the cam to rotate and hold the at least one air gap baffle in position.

30. The method of claim 29, further comprising positioning at least one friction pad between the at least one locking strip and a stator slot wedge.

31. The method of claim 39, wherein positioning at least one locking cam assembly comprises positioning a plurality of air gap baffles and a plurality of locking cam assemblies axially in a dynamoelectric machine, and inserting at least one locking tool through the cams of the locking cam assemblies so that keys on the locking tool mate with keyways in the cams, and the at least one locking tool is rotated so that the plurality of locking cam assemblies are locked substantially simultaneously.