Streamlined body wedge blocks and method for enhanced cooling of generator rotor

• US 20070236100A1
• Filed: 04/05/2006
• Published: 10/11/2007
• Est. Priority Date: 04/05/2006
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Parsania, Nishant, Salamah, Samir
• Granted Patent: US 7,541,714 B2
• Time in Patent Office: Days
• US Class Current: 310/270
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 2205/12 Machines characterised by means for reducing windage losses or windage noise
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 3/51 applicable to rotors only

Abstract

Body wedge blocks are provided adjacent the end of the rotor body that have a forward facing axial end that is aerodynamically streamlined. Thus, between adjacent body wedge blocks a flow passage for cooling air is created that allows gradual contraction of the flow from the endwinding region toward the subslot ducts, thereby reducing pressure losses.

Claims

1. A gas cooled dynamoelectric machine, comprising:

a rotor having a body portion, said rotor having axially extending coils and end turns defining a plurality of endwindings extending axially beyond at least one end of said body portion; and

at least one body wedge block located between adjacent said coils adjacent an axial end of said body portion, said body wedge block having first and second sidewall portions generally parallel to the axis of the rotor that engage said adjacent coils, an upstream wall, and a downstream wall, said upstream wall of said body wedge block having an aerodynamic contour having a gradually increasing width from a leading end edge thereof to said sidewall portions.

2. The dynamoelectric machine of claim 1, wherein said upstream wall has an apex and first and second inclined wall portions extending from said apex to said sidewall portions.

3. The dynamoelectric machine of claim 2, wherein said apex is disposed at a substantial lateral midpoint of said upstream wall.

4. The dynamoelectric machine of claim 2, wherein said inclined wall portions are each substantially planar.

5. The dynamoelectric machine of claim 1, wherein said body wedge block is comprised of a generally rectangular main body portion and a leading end portion, said main body portion defining said downstream wall and said sidewall portions, and said leading end portion defining said upstream wall.

6. The dynamoelectric machine of claim 5, wherein said upstream wall has an apex and first and second inclined wall portions extending from said apex to said sidewall portions.

7. The dynamoelectric machine of claim 6, wherein said apex is disposed at a substantial lateral midpoint of said upstream wall.

8. The dynamoelectric machine of claim 5, wherein said inclined wall portions are each substantially planar.

9. The dynamoelectric machine of claim 5, wherein said leading end portion is integrally formed with said main body portion.

10. A gas cooled dynamoelectric machine, comprising:

a rotor having a spindle and a body portion;

a rotor winding comprising axially extending coils disposed on said body portion and spaced, concentric endwindings extending axially beyond at least one end of said body portion, said endwindings and said spindle defining an annular space therebetween;

a plurality of body wedge blocks located between adjacent said coils, adjacent said rotor body portion; and

each said body wedge block having first and second sidewall portions engaging said adjacent coils, an upstream wall, and a downstream wall, said upstream wall of at least one of said body wedge blocks having an aerodynamic contour thereby to reduce pressure losses when cooling flow enters cooling passages beneath said coils in the rotor body portion.

11. The dynamoelectric machine of claim 10, wherein said upstream wall has an apex and first and second inclined wall portions extending from said apex to said sidewall portions.

12. The dynamoelectric machine of claim 11, wherein said apex is disposed at a substantial lateral midpoint of said upstream wall.

13. The dynamoelectric machine of claim 11, wherein said inclined wall portions are each substantially planar.

14. The dynamoelectric machine of claim 10, wherein said at least one body wedge block is comprised of a generally rectangular main body portion and a leading end portion, said main body portion defining said downstream wall and said sidewall portions, and said leading end portion defining said upstream wall.

15. The dynamoelectric machine of claim 14, wherein said upstream wall has an apex and first and second inclined wall portions extending from said apex to said sidewall portions.

16. The dynamoelectric machine of claim 15, wherein said apex is disposed at a substantial lateral midpoint of said upstream wall.

17. The dynamoelectric machine of claim 15, wherein said inclined wall portions are each substantially planar.

18. The dynamoelectric machine of claim 14, wherein said leading end portion is integrally formed with said main body portion.

19. A method of cooling a generator rotor having a spindle, a body portion, and a rotor winding comprising axially extending coils disposed on said body portion and spaced, concentric endwindings extending axially beyond at least one end of said body portion, said endwindings and said spindle defining an annular space therebetween, the method comprising:

disposing a plurality of body wedge blocks between adjacent said coils, adjacent said rotor body portion, each said body wedge block having first and second sidewall portions engaging said adjacent coils, an upstream wall, and a downstream wall, said upstream wall having an aerodynamic contour; and

directing cooling air to flow into said annular space and past said body wedge blocks into subslot ducts defined in said rotor body below said coils,

wherein said aerodynamic contour of said upstream walls of said body wedge blocks gradually contracts said flow into said subslot ducts, thereby to reduce pressure losses.

20. The method of claim 19, wherein said upstream wall has an apex and first and second inclined wall portions extending from said apex to said sidewall portions.