Electric machine with stator having phase shift windings

Patent metadata

Field	Value
Publication number	US-10581292-B2
Application number	US-201715652507-A
Country	US
Kind code	B2
Filing date	Jul 18, 2017
Priority date	Jul 28, 2016
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

A multi-phase electric machine having plurality of windings are mounted on the stator core that define a plurality of phases wherein, for each phase, the windings include at least two parallel windings, each winding comprising a pair of continuous wires which are connected in series. For each pole, the parallel windings fill one or more central slots and two outer slots. Each winding fills each central slot twice the number of times that the winding fills each outer slot to thereby define a slot fill ratio of 2:1 between central slots and outer slots and wherein each wire of the wire pair forming a winding fills the slots in a ratio that differs from the slot fill ratio. Each of the parallel windings include a phase shift end loop that shift the windings from one outer slot to the other outer slot.

First claim

What is claimed is:

1. A multi-phase electric machine comprising:
a stator operably coupled with a rotor wherein the rotor is rotatable relative to the stator;
the stator including a stator core defining a central opening and a plurality of axially extending slots which circumscribe the central opening;
a plurality of windings mounted on the stator core wherein the plurality of windings define a plurality of phases and wherein, for each phase, the plurality of windings include:
at least two parallel windings, each winding comprising a pair of continuous wires which are connected in series and are disposed in an equal number of slots; wherein, for each pole, the parallel windings are disposed in at least one central slot and two outer slots disposed on opposite sides of the central slots; each winding disposed in each of the central slots an equal number of times and disposed in each of the outer slots an equal number of times and wherein each winding is disposed in each central slot twice the number of times that the winding is disposed in each outer slot to thereby define a slot fill ratio of 2:1 between central slots and outer slots and wherein each wire of the wire pair is disposed in the slots in a ratio that differs from the slot fill ratio;
the stator assembly defining a standard pitch between each pole of each phase, the pitch being a common circumferential spacing between corresponding slots of each pole;
and wherein each wire includes a phase shift end loop having a pitch that differs from the standard pitch by one slot; each of the parallel windings having the phase shift end loop at the same pole locations whereby the phase shift end loops shift the parallel windings from one of the outer slots to the other outer slot.

2. The electric machine of claim 1 wherein each wire extends for a plurality of wraps about the stator.

3. The electric machine of claim 1 wherein the stator assembly defines first and second oppositely disposed axial ends, each of the windings defining leads connectable to an external circuit member, the leads being disposed at the first axial end and the phase shift loops being disposed at the second axial end.

4. The electric machine of claim 1 wherein the phase shift end loops are disposed at a location where the wire transitions from one layer to another layer.

5. The electric machine of claim 1 wherein, the phase shift end loops each define a pitch one slot greater than the standard pitch.

6. The electric machine of claim of claim 1 wherein each phase includes at least three windings connected in parallel.

7. The electric machine of claim 6 wherein each phase includes three parallel windings, each central slot being filled with at least six segments of wire and each outer slot being filled with at least three segments of wire.

8. The electric machine of claim 7 wherein each pole includes two central slots and two outer slots.

9. The electric machine of claim 8 wherein, for each pole of each phase, a first one of the outer slots is disposed on the counterclockwise side of the central slots and a second one of the outer slots is disposed on the clockwise side of the central slots and wherein the wires disposed in one of the first and second outer slots are disposed in radially outermost layers and the wires in the other one of the first and second outer slots are disposed in radially innermost layers whereby each outer slot is filled with wires from two separate phases.

10. The electric machine of claim 9 wherein the electric machine is a three phase electric machine.

11. The electric machine of claim 10 wherein the phase shift end loops are disposed at a location where the wire transitions from one layer to another layer.

12. The electric machine of claim 11 wherein, the phase shift end loops each define a pitch one slot greater than the standard pitch.

13. The electric machine of claim 1 wherein the stator assembly defines first and second oppositely disposed axial ends, each of the windings defining leads connectable to an external circuit member, the leads being disposed at the first axial end and the phase shift end loops being disposed at the second axial end and wherein each wire extends for a plurality of wraps about the stator.

14. The electric machine of claim 13 wherein each wire is a continuous wire that extends for a plurality of wraps about the stator without any breaks in the continuous wire that require a connection.

15. The electric machine of claim 14 wherein, for each pole, each central slot is filled with at least six segments of wire and each outer slot is filled with at least three segments of wire.

16. The electric machine of claim 15 wherein the phase shift end loops are disposed at a location where the wire transitions from one layer to another layer.

17. A multi-phase electric machine comprising:
a stator operably coupled with a rotor wherein the rotor is rotatable relative to the stator;
the stator including a stator core defining a central opening and a plurality of axially extending slots which circumscribe the central opening;
a plurality of windings mounted on the stator core wherein the plurality of windings define a plurality of phases and wherein, for each phase, the plurality of windings include:
at least two parallel windings, each winding comprising a pair of continuous wires which are connected in series and are disposed in an equal number of slots; wherein, for each pole, the parallel windings are disposed in at least one central slot and two outer slots disposed on opposite sides of the at least one central slot;
the stator assembly defining a standard pitch between each pole of each phase, the pitch being a common circumferential spacing between corresponding slots of each pole;
and wherein each wire includes a phase shift end loop having a pitch that differs from the standard pitch by one slot; each of the parallel windings having the phase shift end loop at the same pole locations whereby the phase shift end loops shift the parallel windings from one of the outer slots to the other outer slot wherein the stator assembly defines first and second oppositely disposed axial ends, each of the windings defining leads connectable to an external circuit member, the leads being disposed at the first axial end and the phase shift end loops being disposed at the second axial end.

18. The electric machine of claim 17 wherein each wire extends for a plurality of wraps about the stator.

19. The electric machine of claim 17 wherein, for each pole, each central slot is filled with at least six segments of wire and each outer slot is filled with at least three segments of wire.

20. The electric machine of claim 17 wherein the phase shift end loops are disposed at a location where the wire transitions from one layer to another layer.

Assignees

• Borgwarner Inc

Inventors

• Neet Kirk E
• Lee Seong Taek

Classifications

• H02K3/14

  with transposed conductors, e.g. twisted conductors · CPC title

• H02K3/12

  arranged in slots · CPC title

• H02K3/48

  in slots · CPC title

• H02K1/165 Primary

  Shape, form or location of the slots · CPC title

• H02K3/28 Primary

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title