ELECTRIC MACHINE WITH WINDINGS HAVING END LOOP ARRANGEMENT

• US 20170310169A1
• Filed: 04/21/2016
• Published: 10/26/2017
• Est. Priority Date: 04/21/2016
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: Remy Technologies LLC (BorgWarner Incorporated)
• Inventors: Neet, Kirk, Sailors, Timothy J.
• Granted Patent: US 9,979,242 B2
• Time in Patent Office: Days
• CPC Class Codes: H02K 1/165 Shape, form or location of the slots
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32

Abstract

An electric machine including a rotor and a stator and having a first winding. The stator slots define a plurality of layer positions wherein each of the layer positions is at a different radial distance from the axis. There is an odd number of select stator slots wherein for two slot segments disposed in different layer positions, a pair of end loops connect each of the slot segments with another slot segment in a different slot that is in the same layer position. In some embodiments, at least 60 percent of the end loops connect slot segments that are disposed in different layer positions. For some embodiments, only a single select stator slot is provided with the end loops being positioned to reduce spatial conflicts.

Claims

1. An electric machine comprising:

a rotor rotatable about an axis and operably coupled with a stator wherein the stator defines opposing first and second axial ends and a plurality of axially extending stator slots;

at least one winding defining at least one phase, the at least one winding including a first winding of a first phase wherein the first winding comprises;

a conductor extending from a first end to a second end wherein, between the first and second ends, the winding defines a plurality of slot segments and a plurality of end loops, each of the slot segments being disposed within one of the stator slots and each of the end loops connecting a pair of the slot segments disposed in different stator slots; and

wherein each of the stator slots define a plurality of layer positions, each of the layer positions being at a different radial distance from the axis whereby slot segments are positionable in the plurality of layer positions of each stator slot;

wherein at least 60 percent of the end loops defined by the first winding connect a slot segment disposed in one of the plurality of layer positions with another slot segment disposed in another one of the plurality of layer positions; and

wherein, for the first winding, the electric machine defines an odd number of select stator slots wherein, at each of the select stator slots, first and second slot segments disposed in the select stator slot are located in different layer positions, the first and second slot segments being respectively connected to first and second end loops wherein the first end loop connects the first slot segment with a third slot segment disposed in the same layer position as the first slot segment and the second end loop connects the second slot segment with a fourth slot segment disposed in the same layer position as the second slot segment.

2. The electric machine of claim 1 wherein the first and second ends of the first winding are disposed at the first axial end of the stator and the first and second end loops are disposed at the second axial end of the stator.

3. The electric machine of claim 2 wherein there is only one select stator slot.

4. The electric machine of claim 2 wherein the first and second ends of the first winding are connected with slot segments disposed in different layer positions.

5. The electric machine of claim 2 wherein the first winding comprises a plurality of hairpin segments wherein each hairpin segment defines an end turn connecting two legs, each of the two legs defining a slot segment with the distal portion of the legs defining a portion of an end turn and wherein distal portions of separate and adjacent hairpin segments are welded together to form the conductor defining the winding and wherein the welds are all disposed on the second axial end of the stator.

6. The electric machine of claim 1 wherein the first and second ends of the first winding and the first and second end turns are all disposed at the first axial end of the stator.

7. The electric machine of claim 6 wherein there is only one select stator slot.

8. The electric machine of claim 1 wherein there is only one select stator slot.

9. The electric machine of claim 1 wherein the first end loop defines a first pair of legs and a first central portion extending between the first pair of legs and a second end loop defines a second pair of legs and a second central portion extending between the second pair of legs, each of the legs of the first and second end loops being connected with a slot segment and wherein one of the first and second pair of legs are inclined in a clockwise direction and the other one of the first and second pair of legs are inclined in a counter-clockwise direction.

10. The electric machine of claim 1 wherein the electric machine defines a three phase electric machine and a second phase of the electric machine is defined, at least in part, by a second winding which comprises:

a second conductor extending from a third end to a fourth end wherein, between the third and fourth ends, the second winding defines a second plurality of slot segments and a second plurality of end loops, each of the second plurality of slot segments being disposed within one of the stator slots and each of the second plurality of end loops connecting a pair of the second plurality of slot segments disposed in different stator slots; and

wherein at least 60 percent of the second plurality of end loops defined by the second winding connect a slot segment disposed in one of the plurality of layer positions with another slot segment disposed in another one of the plurality of layer positions; and

wherein, for the second phase, the electric machine defines an odd number of second phase select stator slots wherein, at each of the second phase select stator slots, fifth and sixth slot segments disposed in the second phase select stator slot are located in different layer positions, the fifth and sixth slot segments being respectively connected to third and fourth end loops wherein the third end loop connects the fifth slot segment with a seventh slot segment disposed in the same layer position as the fifth slot segment and the fourth end loop connects the sixth slot segment with an eighth slot segment disposed in the same layer position as the sixth slot segment.

11. The electric machine of claim 10 wherein the first and second ends of the first winding and the third and fourth ends of the second winding are all disposed at the first axial end of the stator, and wherein the first, second, third and fourth end loops are all disposed at the second axial end of the stator and wherein the electric machine further comprises a neutral connection, the neutral connection being connecting with one of the first and second ends of the first winding and one of the third and fourth ends of the second winding, the neutral connection being formed by a conductor defining a segment of a circle that extends for less than 360 degrees and which is disposed at the same radial distance from the axis as one of the first and second slot segments at the first axial end of the stator.

12. The electric machine of claim 11 wherein the third phase is defined, at least in part, by a third winding which comprises:

a third conductor extending from a fifth end to a sixth end, the fifth and sixth ends being disposed at the first axial end of the stator and wherein, between the fifth and sixth ends, the third winding defines a third plurality of slot segments and a third plurality of end loops, each of the third plurality of slot segments being disposed within one of the stator slots and each of the third plurality of end loops connecting a pair of the third plurality of slot segments disposed in different stator slots; and

wherein, at the first axial end of the stator and for the stator slots within the circular segment defined by the neutral connection, the third plurality of end loops defined by the third winding connect a slot segment disposed in one of the plurality of layer positions with another slot segment disposed in another one of the plurality of layer positions.

13. The electric machine of claim 12 wherein:

at least 60 percent of the third plurality of end loops defined by the third winding connect a slot segment disposed in one of the plurality of layer positions with another slot segment disposed in another one of the plurality of layer positions; and

wherein, for the third phase, the electric machine defines an odd number of third phase select stator slots wherein, at each of the third phase select stator slots, ninth and tenth slot segments disposed in the third phase select stator slot are located in different layer positions, the ninth and tenth slot segments being respectively connected to fifth and sixth end loops wherein the fifth end loop connects the ninth slot segment with an eleventh slot segment disposed in the same layer position as the ninth slot segment and the sixth end loop connects the tenth slot segment with a twelfth slot segment disposed in the same layer position as the tenth slot segment.

14. The electric machine of claim 13 wherein there is only one select stator slot, there is only one second phase select stator slot, there is only one third phase select stator slot and wherein the fifth and sixth end loops are disposed at the first axial end of the stator.

15. An electric machine comprising:

a rotor rotatable about an axis and operably coupled with a stator wherein the stator defines opposing first and second axial ends and a plurality of axially extending stator slots;

at least one winding defining at least one phase, the at least one winding including a first winding of a first phase wherein the first winding comprises;

a conductor extending from a first end to a second end wherein, between the first and second ends, the winding defines a plurality of slot segments and a plurality of end loops, each of the slot segments being disposed within one of the stator slots and each of the end loops connecting a pair of the slot segments disposed in different stator slots; and

wherein each of the stator slots define a plurality of layer positions, each of the layer positions being at a different radial distance from the axis whereby slot segments are positionable in the plurality of layer positions of each stator slot;

wherein the first winding defines a series connection at the first axial end of the stator at the midpoint of the first winding and wherein the midpoint of the first winding is formed in an end loop connecting a pair of slot segments disposed in different layer positions; and

wherein, for the first winding, the electric machine defines an odd number of select stator slots wherein, at each of the select stator slots, first and second slot segments disposed in the select stator slot are located in different layer positions, the first and second slot segments being respectively connected to first and second end loops wherein the first end loop connects the first slot segment with a third slot segment disposed in the same layer position as the first slot segment and the second end loop connects the second slot segment with a fourth slot segment disposed in the same layer position as the second slot segment.

16. The electric machine of claim 15 wherein at least 60 percent of the end loops defined by the first winding connect a slot segment disposed in one of the plurality of layer positions with another slot segment disposed in another one of the plurality of layer positions.

17. The electric machine of claim 15 wherein the electric machine defines a three phase electric machine and a second phase of the electric machine is defined, at least in part, by a second winding which comprises:

a second conductor extending from a third end to a fourth end wherein, between the third and fourth ends, the second winding defines a second plurality of slot segments and a second plurality of end loops, each of the second plurality of slot segments being disposed within one of the stator slots and each of the second plurality of end loops connecting a pair of the second plurality of slot segments disposed in different stator slots;

wherein the second winding defines a series connection at the first axial end of the stator at the midpoint of the second winding and wherein the midpoint of the second winding is formed in an end loop connecting a pair of slot segments disposed in different layer positions; and

wherein, for the second phase, the electric machine defines an odd number of second phase select stator slots wherein, at each of the second phase select stator slots, fifth and sixth slot segments disposed in the second phase select stator slot are located in different layer positions, the fifth and sixth slot segments being respectively connected to third and fourth end loops wherein the third end loop connects the fifth slot segment with a seventh slot segment disposed in the same layer position as the fifth slot segment and the fourth end loop connects the sixth slot segment with an eighth slot segment disposed in the same layer position as the sixth slot segment.

18. The electric machine of claim 17 wherein the third phase is defined, at least in part, by a third winding which comprises:

a third conductor extending from a fifth end to a sixth end, the fifth and sixth ends being disposed at the first axial end of the stator and wherein, between the fifth and sixth ends, the third winding defines a third plurality of slot segments and a third plurality of end loops, each of the third plurality of slot segments being disposed within one of the stator slots and each of the third plurality of end loops connecting a pair of the third plurality of slot segments disposed in different stator slots;

wherein the second winding defines a series connection at the first axial end of the stator at the midpoint of the second winding and wherein the midpoint of the second winding is formed in an end loop connecting a pair of slot segments disposed in different layer positions; and

wherein, for the third phase, the electric machine defines an odd number of third phase select stator slots wherein, at each of the third phase select stator slots, ninth and tenth slot segments disposed in the third phase select stator slot are located in different layer positions, the ninth and tenth slot segments being respectively connected to fifth and sixth end loops wherein the fifth end loop connects the ninth slot segment with an eleventh slot segment disposed in the same layer position as the ninth slot segment and the sixth end loop connects the tenth slot segment with a twelfth slot segment disposed in the same layer position as the tenth slot segment.

19. The electric machine of claim 18 wherein the end loop containing the midpoint of the first winding, the end loop containing the midpoint of the second winding and the end loop containing the midpoint of the third winding are all shaped similar to immediately adjacent end loops and thereby nest with the immediately adjacent end loops.

20. The electric machine of claim 15 wherein the first end loop defines a first pair of legs and a first central portion extending between the first pair of legs and a second end loop defines a second pair of legs and a second central portion extending between the second pair of legs, each of the legs of the first and second end loops being connected with a slot segment and wherein one of the first and second pair of legs are inclined in a clockwise direction and the other one of the first and second pair of legs are inclined in a counter-clockwise direction.