Stator winding having radial aligned wraps
View Patent ↗An electric machine stator having end loop segments includes a multi-phase stator winding having a plurality of radially aligned partial wraps, wraps, and wrap sets, that are adapted to be placed in a plurality of circumferentially spaced axially-extending core slots in a surface of a stator core. The stator winding includes a plurality of slot 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 loop segments include first and second sloped portions meeting at an apex portion. Each of the end loop segments includes a radial outward adjustment and a radial inward adjustment and forms a cascaded winding pattern.
1. A stator for an electric machine, comprising:
a generally cylindrically-shaped stator core having a plurality of circumferentially spaced and 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 having a plurality of phases, each of said phases comprising a plurality of partial wraps which are aligned in a radial direction;
said plurality of partial wraps having a plurality of slot segments disposed in said core slots, said slot segments alternately connected at said first and second ends of said stator core by a plurality of end loop segments; and
said plurality of partial wraps of at least one of said phases include at least one partial wrap having a first structure and at least one partial wrap having a second structure wherein said first structures alternate in the radial direction with said second structures;
said end loop segments of a particular partial wrap include a first sloped portion substantially co-radial with said slot segments of said particular partial wrap and a second sloped portion substantially non-co-radial with said slot segments of said particular partial wrap.
2. The stator of claim 1 wherein said first structure of said partial wraps having said first structure and having slot segments housed in a particular layer, creates a space in the same particular layer.
3. The stator of claim 2 , wherein a portion of said end loop segments of said partial wraps having said second structure extends into the space created in said particular layer.
4. The stator according to claim 1 wherein for at least one of said plurality of phases, said partial wrap having said first structure is shifted a predetermined number of slots from said partial wrap having said second structure such that in a particular circumferential location, said end loop segments of said first structure are on opposite axial ends of said stator core as said end loop segments of said second structure.
5. The stator according to claim 1 wherein at least three consecutive said slot segments of at least one of said partial wraps is housed at substantially the same radial distance from the central axis of said stator core.
6. The stator according to claim 1 wherein each of said core slots house an odd number of said slot segments.
7. The stator according to claim 1 wherein at least one of said phases includes an odd number of said partial wraps aligned n the radial direction.
8. The stator according to claim 1 wherein this plurality of said phases equals six.
9. The stator of claim 1 wherein said partial wraps having said first structure are wound around the stator core for one substantial revolution and said partial wraps having said second structure are wound around the stator core for one substantial revolution.
10. The stator of claim 9 wherein at least one of said wraps of at least one of said phases is formed from one continuous conductor.
11. The stator according to claim 9 wherein said wrap having said first structure and said wrap having said second structure, of at least one of said phases, are formed from a continuous conductor including a reversing end loop segment.
12. The stator according to claim 9 wherein at least one of said wraps having said first structure and at least one of said wraps having said second structure, of at least one of said phases, are individual conductors including a reversing end loop segment.
13. The stator according to claim 9 wherein at least two of said wraps having said first structure, of at least one of said phases, are individual conductors including a transition end loop segment.
14. The stator according to claim 9 wherein at least two of said wraps having said first structure, of at least one of said phases, are formed from a continuous conductor including a transition end loop segment.
15. The stator according to claim 1 wherein said second structure and said first structure of said partial wraps are comprised of substantially similar pre-forms and one of said pre-forms is rotated 180 degree around at least one axis prior to insertion into the core.
16. The stator of claim 1 wherein the number of said partial wraps which are aligned in the radial direction is greater than three.
17. The stator of according to claim 1 wherein said slot segments of at least one of said partial wraps have a rectangular cross section.
18. The stator according to claim 17 wherein said stator core slots have a substantially rectangular cross section.
19. The stator according to claim 17 wherein the width of said slot segments, including any insulation, fit closely to the width of said core slots, including any insulation.
20. The stator according to claim 1 wherein said slot segments housed in said core slots are aligned in at least one radial row.
21. The stator according to claim 1 wherein said winding includes at least one wrap set comprised of a plurality of said partial wraps, having each of sold slot segments of said plurality or said partial wraps being housed in substantially the same layer.
22. The stator according to claim 1 wherein a plurality of said end loop segments include at least two radial adjustments per end loop segment.
23. The stator according to claim 1 wherein said plurality of partial wraps are cascaded.
24. The stator according to claim 1 wherein at least one of said partial wraps is formed of a continuous conductor having a substantially constant width and thickness and therefore substantially constant cross sectional area.
25. A stator for an electric machine, comprising:
a generally cylindrically-shaped stator core having a plurality of circumferentially spaced and 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 having a plurality of phases, each of said phases comprising a plurality of wraps having a plurality of slot segments disposed in said core slots, said slot segments alternately connected at said first and second ends of said stator core by a plurality of end loop segments, each of said slot segments of a particular wrap being a substantially same radial distance from a central axis of said stator core;
said plurality of wraps including at least one wrap having a first structure and at least one wrap having a second structure wherein said first structures alternate in the radial direction with said second structures;
said wrap having said first structure of each phase being shifted a predetermined number of slots from said wrap having said second structure of the same phase such that in a particular circumferential location, said end loop segments of said first structure are on opposite axial ends of said stator core as said end loop segments of said second structure;
wherein said end loop segments of each particular layer include a first sloped portion, a second sloped portion, said first and second sloped portions connected by an apex portion thereof; and
wherein at least half of said end loop segments include a radial outward adjustment and a radial inward adjustment.
26. The stator according to claim 25 wherein said outward radial adjustment is a first radial extension at said apex portion and said radial inward adjustment is a second radial extension adjacent one of said slot segments.
27. The stator according to claim 25 wherein the conductors are substantially aligned in one radial row in at least half of said slots.
28. The stator according to claim 25 wherein a portion of said end loop segments of said conductors lay radially outward by one substantial conductor width for an outermost layer.
29. The stator according to claim 25 wherein said plurality of wraps are cascaded.
30. A stator for an electric machine, comprising:
a generally cylindrically-shaped stator core having a plurality of circumferentially spaced and 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 having a plurality of phases, each of said phases comprising a plurality of partial wraps which are aligned in a radial direction;
said plurality of partial wraps having a plurality of slot segments disposed in said core slots, said slot segments alternately connected at said first and second ends of said stator core by a plurality of end loop segments;
wherein at least one of said plurality of partial wraps includes at least three consecutive slot segments disposed in substantially a first layer and at least one other of said plurality of partial wraps includes at least three consecutive slot segments disposed in substantially a second layer;
said plurality of partial wraps of at least one of said phases include at least one partial wrap having a first structure and at least one partial wrap having a second structure wherein said first structures alternate in the radial direction with at sold second structures; and
said plurality of said end loop segments include at least two radial adjustments per end loop segment and wherein said plurality of end loop segments of a particular one of said partial wraps having slot segments housed in a particular layer, include a portion which is substantially co-radial with the slot segments of a different layer.
31. The stator according to claim 30 wherein said end loop segments of a particular partial wrap include a sloped portion which is substantially co-radial with said slot segments of a different layer.
32. The stator according to claim 30 wherein at least one of said partial wraps is formed of a continuous conductor having a substantially constant width and thickness and therefore substantially constant cross sectional area.
33. The stator according to claim 30 wherein for at least one of said plurality of phases, said partial wrap having said first structure is shifted a predetermined number of slots from said partial wrap having said second structure such that in a particular circumferential location, said end loop segments of said first structure are on opposite axial ends of said stator core as said end loop segments of said second structure.
34. The stator according to claim 30 wherein said plurality of end loop segments are formed such that said plurality of partial wraps are cascaded.