Stator winding having cascaded end loops and increased cooling surface area

• US 6,750,582 B1
• Filed: 05/22/2003
• Issued: 06/15/2004
• Est. Priority Date: 12/19/2002
• Status: Expired due to Fees

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Neet, Kirk E.
• Primary Examiner(s): LE, DANG D
• Application Number:
  US10/443,650
• Publication Number:
  US 20040119360A1
• Time in Patent Office: 390 Days
• Field of Search: 310/198-208, 296/05, 296/06
• US Class Current: 310/208
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors

Abstract

A dynamoelectric machine stator winding having cascaded end loops and increased cooling surface area is adapted to be placed in a plurality of circumferentially spaced axially-extending core slots in a surface of a generally cylindrically-shaped stator core. The stator winding includes a plurality of straight segments alternately connected at the first and second ends of the stator core by a plurality of end loop segments to form the winding. The end loops include first and second sloped sides meeting at an apex portion. The first and second sloped sides include at least one body portion offset in opposite radial directions to form a cascaded winding pattern and providing increased cooling surface area for the winding.

Claims

1. A stator for a dynamoelectric machine, comprising:

a generally cylindrically-shaped stator core having a plurality of circumferentially spaced axially-extending core slots in a surface thereof, said core slots extending between a first and a second end of said stator core; and

a stator winding including at least one layer of conductors having a plurality of phases,

wherein said at least one layer of said phases includes substantially straight segments disposed in a plurality of said core slots that are located at the same radial distance from the central axis of the stator core having end loop portions connecting two straight segments of said phase,

wherein said end loop segments form a cascaded winding pattern while keeping said end loop segments substantially radially within their respective layer, and

wherein said straight segments have a circumferential width C1 and said end loop segments have a circumferential width C2 less than said circumferential width C1, and

wherein at least one of said phases is radially shifted.

2. The stator according to claim 1 wherein said end loop segments of said phases include a first sloped side and a second sloped side that meet at an apex portion.

3. The stator according to claim 2 wherein at least one of said sloped sides of said end loop segments includes an offset body portion.

4. The stator according to claim 3 wherein at least one of said offset body portions is offset in a first radial direction and at least another of said offset body portions is offset in a second radial direction opposite said first radial direction.

5. The stator according to claim 4 wherein at least one of said sloped sides includes a body portion with a first body section offset in said second radial direction and a second body section offset in said first radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of another phase.

6. The stator according to claim 5 wherein said stator winding includes a first phase, a second phase, a third phase, a fourth phase, a fifth phase and a sixth phase, and

wherein said sloped sides of said first phase each include a body portion offset exclusively in a first radial direction, and

wherein a one of said sloped sides of said second phase includes a body portion offset exclusively in said first radial direction, and wherein the other of said sloped sides of said second phase includes a body portion with a first body section offset in a second radial direction opposite said first radial direction and a second body section offset in said first radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of said first phase, and

wherein one of said sloped sides of said third phase includes a body portion offset exclusively in said first radial direction, wherein the other of said sloped sides of said third phase includes a body portion offset exclusively in said second radial direction,

wherein said end loop segments of said fourth phase are substantially identical to said end loop segments of said third phase, and

wherein one of said sloped sides of said fifth phase includes a body portion offset exclusively in said second radial direction, and wherein the other of said sloped sides of said fifth phase includes a body portion with a first body section offset in a first radial direction and a second body section offset in said second radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of a sixth phase, and

wherein said sloped sides of said sixth phase each include a body portion offset exclusively in said second radial direction.

7. The stator according to claim 1 wherein each of said straight segments has a first substantially rectangular cross-sectional shape, wherein each of said first sloped sides has a second substantially rectangular cross-sectional shape and wherein each of said second sloped sides has a third substantially rectangular cross-sectional shape.

8. The stator according to claim 7 wherein an area of said second cross-sectional shape area is equal to an area of said third rectangular cross-sectional shape.

9. The stator according to claim 7 wherein an area of said first cross-sectional shape is equal to said area of said second cross-sectional shape and said area of said third cross-sectional shape.

10. The stator according to claim 7 wherein a one of said second cross-sectional shape and said third cross-sectional shape is equal to substantially one half of said area of said first cross-sectional shape.

11. The stator according to claim 1 wherein said stator core slots have a generally rectangular volume.

12. The stator according to claim 1 wherein the width, including any insulation of said straight segments of said stator winding fit closely to the width, including any insulation, of said stator core slots.

13. The stator according to claim 1 wherein said stator winding includes at least two layers of conductors.

14. The stator according to claim 13 wherein said straight segments of said layers are positioned in one radial row in each slot.

15. A method for forming a winding a stator of a dynamoelectric machine, comprising the steps of:

a) providing a stator winding having at least three continuous phases, each of said phases of said stator winding being formed from a wire having a rectangular cross section,

b) forming a first phase wherein said first phase has straight segments connected by a plurality of end loops, wherein end loops of said first phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein said sloped side each include a body portion offset exclusively in a first radial direction;

c) forming a second phase wherein said second phase has straight segments connected by a plurality of end loops, wherein end loops of said second phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein one of said sloped sides includes a body portion offset exclusively in said first radial direction, and wherein the other of said sloped sides includes a body portion with a first body section offset in a second radial direction opposite said first radial direction and a second body section offset in said first radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of said first phase;

d) forming a third phase wherein said third phase has straight segments connected by a plurality of end loops, wherein end loops of said third phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein one of said sloped sides includes a body portion offset exclusively in said first radial direction, wherein the other of said sloped sides includes a body portion offset exclusively in said second radial direction;

e) providing a generally cylindrically-shaped stator core having a plurality of circumferentially spaced axially-extending core slots in a surface thereof, said core slots extending between a first and a second end of said stator core;

f) inserting said third phase in a plurality of said core slots beginning at a first core slot and incrementally around said stator core at a predetermined pitch;

g) inserting said second phase in a plurality of said core slots beginning at a second core slot and incrementally around said stator core at said predetermined pitch,

h) inserting said first phase in a plurality of said core slots beginning at a third core slot and incrementally around said stator core at said predetermined pitch, said phases forming a cascaded winding pattern, said stator winding providing increased cooling surface area, and wherein at least one of said phases is radially shifted.

16. The method according to claim 15 wherein in step b) said straight segments are formed having a first substantially rectangular cross-sectional shape and said end loops are formed having a second substantially rectangular cross-sectional shape.

17. The method according to claim 15 wherein in step b) each of said straight segments are formed having a first substantially rectangular cross-sectional shape, each of said first sloped sides are formed having a second substantially rectangular cross-sectional shape and each of said second sloped sides are formed having a third substantially rectangular cross-sectional shape.

18. The method according to claim 17 wherein in step b) an area of said first cross-sectional shape, an area of said second cross-sectional shape, and an area of said third cross-sectional shape are formed substantially equal.

19. The method according to claim 17 wherein an area of said second substantially rectangular cross section formed in step b) is substantially one half of an area of said first substantially rectangular cross section.

20. The method according to claim 17 wherein in step b) said stator winding is formed in at least two layers of conductors.

21. A dynamoelectric machine, comprising:

a housing;

a shaft rotatably supported by said housing;

a rotor supported by and adapted to rotate with said shaft; and

a stator fixedly disposed in said housing adjacent said rotor, said stator comprising;

a generally cylindrically-shaped stator core having a plurality of circumferentially spaced axially-extending core slots in a surface thereof, said core slots extending between a first and a second end of said stator core; and

a stator winding including at least one layer of conductors having at least six phases,

wherein a first phase has straight segments disposed in a plurality of said core slots beginning at a first slot and incrementally around said stator core at a predetermined pitch, wherein end loops of said first phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein said sloped sides each include a body portion offset exclusively in a first radial direction, and

wherein a second phase has straight segments disposed in a plurality of said core slots beginning at a second slot and incrementally around said stator core at said predetermined pitch, wherein end loops of said second phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein one of said sloped sides includes a body portion offset exclusively in said first radial direction, and wherein the other of said sloped sides includes a body portion with a first body section offset in a second radial direction opposite said first radial direction and a second body section offset in said first radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of said first phase, and

wherein a third phase has straight segments disposed in a plurality of said core slots beginning at a third slot and incrementally around said stator core at said predetermined pitch, wherein end loops of said third phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein one of said sloped sides includes a body portion offset exclusively in said first radial direction, wherein the other of said sloped sides includes a body portion offset exclusively in said second radial direction, and

wherein a fourth phase has straight segments disposed in a plurality of said core slots beginning at a fourth slot and incrementally around said stator core at said predetermined pitch and includes end loops substantially identical to said end loops of said third phase, and

wherein a fifth phase has straight segments disposed in a plurality of said core slots beginning at a fifth slot and incrementally around said stator core at said predetermined pitch, wherein end loops of said fifth phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein one of said sloped sides includes a body portion offset exclusively in said second radial direction, and wherein the other of said sloped sides includes a body portion with a first body section offset in a first radial direction and a second body section offset in said second radial direction, a radial transition between said first and second body sections being placed in response to a crossing point of a sixth phase, and

wherein said sixth phase has straight segments disposed in a plurality of said core slots beginning at a sixth slot and incrementally around said stator core at said predetermined pitch, wherein end loops of said sixth phase are substantially identical and include first and second sloped sides meeting at an apex portion, wherein said sloped sides each include a body portion offset exclusively in said second radial direction

wherein each of said end loops form a cascaded winding pattern and keeping said end loops radially within their respective layer, and

wherein at least one of said phases is radially shifted and said stator winding exhibits improved cooling by providing increased cooling surface area.

22. The dynamoelectric machine according to claim 21 wherein said stator core slots have a generally rectangular volume.

23. The dynamoelectric machine according to claim 21 wherein the width, including any insulation of said straight segments of said stator winding fit closely to the width, including any insulation, of said stator core slots.

24. The dynamoelectric machine according to claim 21 wherein said stator winding includes at least two layers of conductors.

25. The dynamoelectric machine according to claim 24 wherein said straight segments of said layers are positioned in one radial row in each slot.