System and method for retaining wedges in a rotor

• US 20030048015A1
• Filed: 09/07/2001
• Published: 03/13/2003
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Tornquist, G.E., Xu, Ming, Lengel, James D., Borden, Raymond W., Chen, WuenFar L., Doherty, Kieran P.J., McDowall, Gregor J.S.
• Granted Patent: US 6,791,230 B2
• Time in Patent Office: Days
• US Class Current: 310/103
• CPC Class Codes: H02K 3/527 applicable to rotors only

Abstract

A rotor with wedges and a method of retaining wedges in a rotor are disclosed. The rotor includes a shaft, first and second poles extending radially from the shaft, and first and second coils of windings respectively wrapped around the first and second poles. Each coil includes a respective outer face including two end portions and two side portions, and a respective inward-facing edge including two end sections and two side sections. The rotor further includes a first outer wedge positioned between neighboring side portions of the first and second coils, and a first inner wedge positioned between neighboring side sections of the first and second coils. The first inner wedge is coupled to the first outer wedge so that the first outer wedge is at least partly retained from moving radially outward away from the shaft.

Claims

1. A rotor comprising:

a shaft extending along an axis through the rotor;

first and second poles extending radially from the shaft;

first and second coils of wire windings respectively wrapped around the first and second poles, wherein each coil includes a respective outer face including two end turn portions and two side portions, and a respective inward-facing edge including two end turn sections and two side sections;

a first outer wedge positioned between a first of the side portions of the first coil and a first of the side portions of the second coil; and

a first inner wedge positioned between a first of the side sections of the first coil and a first of the side sections of the second coil;

wherein the first inner wedge is coupled to the first outer wedge and provides support thereto so that the first outer wedge is at least partly retained from moving radially outward away from the shaft.

2. The rotor of claim 1, wherein at least one of the first outer wedge and the first inner wedge includes at least one passage through which coolant can flow.

3. The rotor of claim 2, wherein the first outer wedge includes a plurality of passages through which the coolant can flow.

4. The rotor of claim 3, wherein the coolant is cooling oil and, when the coolant flows through the plurality of passages, heat is transferred away from the first and second coils.

5. The rotor of claim 2, wherein the plurality of passages includes a first set of three passages positioned along a first side of the first outer wedge so that the three passages are proximate the first of the side portions of the first coil, a second set of three passages positioned along a second side of the first outer wedge so that the three passages are proximate the first of the side portions of the second coil, and a large interior passage.

6. The rotor of claim 1, wherein each of the first inner wedge and the first outer wedge has a respective short side, a respective long side, and two respective connecting sides that connect the respective short and long sides, such that each of the first inner and outer wedges has a substantially trapezoidal cross section.

7. The rotor of claim 6 wherein, although the first outer wedge has the substantially trapezoidal cross section, the long side of the first outer wedge is curved in cross section.

8. The rotor of claim 6, wherein the long side of the first outer wedge is further retained from moving radially outward by at least one of an end cap that has been shrunk fit onto the first outer wedge, flange extensions of the first and second poles, and a band around the rotor.

9. The rotor of claim 6, wherein the short side of the first outer wedge faces inward toward the shaft and additionally faces the short side of the first inner wedge.

10. The rotor of claim 9, wherein the short side of the first outer wedge is coupled to the short side of the first inner wedge.

11. The rotor of claim 6, wherein the long side of the first inner wedge is spaced apart from a core of the rotor by at least one jack screw, so that the two connecting sides of the first inner wedge are respectively pressed up tightly against the first of the side sections of the first coil and the first of the side sections of the second coil.

12. The rotor of claim 1, wherein the first outer wedge is coupled to the first inner wedge by at least one fastening device.

13. The rotor of claim 12, wherein the first outer wedge is coupled to the first inner wedge by a plurality of fastening devices spaced along the wedges in an axial direction, and wherein the plurality of fastening devices prevent flexure of the first outer wedge with respect to the first inner wedge during operation of the rotor.

14. The rotor of claim 12, wherein the at least one fastening device is selected from the group consisting of a bolt and a nut, an attachment screw, and an adhesive.

15. The rotor of claim 12, wherein the at least one fastening device can be adjusted to affect a spacing between an inner face of the first inner wedge and an inner face of the first outer wedge.

16. The rotor of claim 1, further comprising:

third and fourth poles extending radially from the shaft;

third and fourth coils of wire windings respectively wrapped around the third and fourth poles, wherein each of the third and fourth coils includes a respective outer face including two end turn portions and two side portions, and a respective inward-facing edge including two end turn sections and two side sections;

second, third and fourth outer wedges, wherein the second outer wedge is positioned between a second of the side portions of the first coil and a first of the side portions of the third coil, the third outer wedge is positioned between a second of the side portions of the second coil and a first of the side portions of the fourth coil, and the fourth outer wedge is positioned between a second of the side portions of the third coil and a second of the side portions of the fourth coil; and

second, third and fourth inner wedges, wherein the second inner wedge is positioned between a second of the side sections of the first coil and a first of the side sections of the third coil, the third inner wedge is positioned between a second of the side sections of the second coil and a first of the side sections of the fourth coil, and the fourth inner wedge is positioned between a second of the side sections of the third coil and a second of the side sections of the fourth coil.

17. The rotor of claim 16, wherein an end cap is shrunk fit over ridges on the first, second, third and fourth outer wedges so that a lip of the end cap limits movement of the outer wedges radially outward away from the shaft.

18. The rotor of claim 17, wherein coolant flows from the shaft via first channels to the outer wedges and flows from the outer wedges back to the shaft via second channels.

19. The rotor of claim 16, wherein fastening devices couple respective short sides of the first, second, third and fourth outer wedges to respective short sides of the first, second, third and fourth inner wedges, and wherein the fastening devices can be adjusted to determine respective spacings between the short sides of the outer wedges and the inner wedges in order to provide concentricity control.

20. A high speed generator comprising:

a stator; and

a rotor, wherein the rotor includes a shaft extending along an axis through the rotor;

a plurality of poles extending radially from the shaft;

a plurality of coils of wire windings, wherein each coil is wrapped around a respective one of the poles and wherein each coil includes

a respective outer face formed by a respective outermost layer of wire windings of the respective coil, wherein the respective outer face includes two end turn portions and two side portions, and

a respective pair of first and second edges, wherein the first edge faces inward toward the shaft and the second edge faces outward away from the shaft, and wherein each of the first and second edges includes two end turn sections and two side sections;

a plurality of outer wedges, wherein each outer wedge is positioned between a respective pair of the coils that neighbor one another so that the respective outer wedge is positioned between one of the side portions of a first coil of the respective pair and one of the side portions of a second coil of the respective pair; and

a plurality of inner wedges, wherein each inner wedge is positioned between a respective pair of the coils that neighbor one another so that the respective inner wedge is positioned between one of the side sections of the first edge of a first coil of the respective pair and one of the side sections of the first edge of a second coil of the respective pair; and

a means for coupling the respect inner wedges to the respective outer wedges.

21. An outer wedge for placement in a rotor assembly of a high speed generator, the outer wedge comprising:

a main body that is substantially trapezoidal in cross-section and hollow, wherein the main body further includes a pair of supports internal to the main body and respectively proximate each end of the main body; and

a pair of end pieces, also having a substantially trapezoidal cross-section, wherein the end pieces are coupled to the supports by axial screws and further include holes by which coolant can be conducted through the end pieces.

22. The wedge of claim 21, wherein pieces are coupled in between the end pieces and the supports, wherein each end piece has a ridge along a respective long curved side, and wherein the main body has a plurality of holes for receiving jack screws and attachment screws.

23. An inner wedge for placement in a rotor assembly of a high speed generator, the inner wedge comprising:

a main body having a substantially trapezoidal shape including a longer side, a shorter side, and two connecting sides,

wherein the main body is configured to be positioned between a pair of opposing side sections of a pair of coils of a pair of neighboring poles of the rotor assembly, and

wherein the main body is configured to be coupled to an outer wedge.

24. The inner wedge of claim 23, further comprising:

means for spacing the main body with respect to a core of the rotor assembly.

25. In a high speed generator including a rotor having coils of wire windings wrapped around respective poles of the rotor, each coil including a respective outer face having two end turn portions and two side portions, a method of adjusting concentricity of the rotor, the method comprising:

positioning inner wedges between opposing sides of the coils of neighboring poles, the inner wedges having one or more first threaded openings;

positioning outer wedges between opposing side portions of the coils of neighboring poles, the outer wedges having one or more second threaded openings collocated with the first threaded openings;

placing one or more threaded fasteners into collocated first and second threaded openings; and

adjusting concentricity of the rotor by adjusting the threaded fasteners.

27. The method of claim 25, further comprising:

tightening the inner wedges against the side sections with which the inner wedges are in contact by adjusting jack screws against a core of the rotor and thereby forcing the inner wedges radially outward away from the shaft;

adjusting the concentricity of the outer wedges by adjusting the fastening devices; and

shrink-fitting an end cap over ridges on outer sides of the outer wedges.

28. The method of claim 25, further comprising:

providing extensions onto the poles that provide further support for the outer wedges; and

positioning bands around the rotor, wherein the outer wedges are provided with internal channels through which coolant can flow.

26. A method of retaining wedges of a rotor from moving radially outwards away from a shaft of the rotor during rotation of the rotor, the method comprising:

wrapping coils of wire windings around respective poles of the rotor, wherein each coil includes a respective outer face including two end turn portions and two side portions, and further includes a respective inward-facing edge including two end turn sections and two side sections;

positioning inner wedges between opposing side sections of the coils of neighboring poles;

positioning outer wedges between opposing side portions of the coils of neighboring poles; and

coupling the outer wedges to the inner wedges through the use of fastening devices.