Hairpin winding electric machine
An electric machine includes a stator core defining slots and a single-layer winding disposed in the core and having first and second parallel paths. Each path includes hairpins interconnected to form a continuous circuit between a terminal and a neutral. The hairpins of the first path include a first type of hairpins each having a first leg, a second leg, a crown connecting between the legs, an outwardly extending twist joined to the first leg, and an inwardly extending twist joined to the second leg, wherein the legs are spaced apart by a span of five slots, and a second type of hairpins each having a first leg, a second leg, a crown connecting between the legs, an inwardly extending twist joined to the first leg, and an outwardly extending twist joined to the second leg, wherein the legs are spaced apart by a span of seven slots.
1. An electric machine comprising:
a stator core defining slots; and
a single-layer winding disposed in the core and having first and second parallel paths each including hairpins interconnected to form a continuous circuit between a terminal and a neutral, wherein the hairpins of the first path include:
a first type of hairpins (first hairpins) each having a first leg, a second leg, a crown connecting between the legs, an outwardly extending twist joined to the first leg, and an inwardly extending twist joined to the second leg, wherein the legs are spaced apart by a span of five slots, and
a second type of hairpins (second hairpins) each having a first leg, a second leg, a crown connecting between the legs, an inwardly extending twist joined to the first leg, and an outwardly extending twist joined to the second leg, wherein the legs are spaced apart by a span of seven slots.
2. The electric machine of claim 1 , wherein the hairpins of the first path further include a third type of hairpins (third hairpins) each having first and second legs spaced apart by a span of six slots.
3. The electric machine of claim 2 , wherein each of the third hairpins further includes a first inwardly extending twist joined to the first leg and a second inwardly extending twist joined to the second leg.
4. The electric machine of claim 1 , wherein the slots have a plurality of radial positions, and wherein the legs of the first hairpins are disposed in a first of the positions, and the legs of the second hairpins are disposed in a second of the positions.
5. The electric machine of claim 4 , wherein the first radial position is nearest an outer diameter of the stator core, and the second radial position is nearest an inner diameter of the stator core.
6. The electric machine of claim 1 , wherein the slots have a plurality of radial positions including an inner-most position, an outer-most position, and intermediate positions therebetween, and wherein, both of the legs of the first hairpins are disposed in the outer-most positions and both of the legs of the second hairpins are disposed in the inner-most positions, and wherein the hairpins of the first path further include a third type of hairpins (third hairpins) each having first and second legs spaced apart by a span of six slots and disposed in the intermediate positions.
7. The electric machine of claim 6 , wherein, for each of the third hairpins, the first and second legs are disposed in different ones of the intermediate positions.
8. The electric machine of claim 1 , wherein the hairpins of the second path also include the first hairpins and the second hairpins.
9. The electric machine of claim 8 , wherein the slots have a plurality of radial positions including an inner-most position and an outer-most position, wherein the legs of the first hairpins of the first path and the legs of the second hairpins of the second path are disposed in the inner-most position, and the legs of the second hairpins of the first path and the legs of the first hairpins of the second path are disposed in the outer-most position.
10. The electric machine of claim 1 , wherein, for each of the first hairpins, the inwardly and outwardly extending twists have a same slot span, and, for each of the second hairpins, the inwardly and outwardly extending twists have a same slot span.
11. The electric machine of claim 10 , wherein the twists of the first hairpins have a same slot span as the twists of the second hairpins.
12. An electric machine comprising:
a stator core defining slots having a plurality of radial positions; and
a plurality of hairpins each having legs disposed in corresponding ones of the slots and twists extending from the legs, wherein the hairpins are inserted into the stator core with corresponding ones of the twists connected to form
a three-phase winding having end turns, wherein each of the end turns configured with a single-bent portion that define a vertex, wherein, for each of the radial positions, all of the twists of that radial position extend from their respective legs in a same circumferential direction of the stator core.
13. The electric machine of claim 12 , wherein the twists disposed in adjacent ones of the radial positions extend from their respective legs in opposite circumferential directions of the stator core.
14. The electric machine of claim 12 , wherein the plurality of radial positions includes eight positions, wherein the twists of even ones of the positions extend from their respective legs in a first circumferential direction of the stator core, and the twists of odd ones of the positions extend from their respective legs in a second circumferential direction of the stator core that is opposite the first.
15. The electric machine of claim 12 , wherein each phase of the three-phase winding includes at least two parallel paths that each extend between a terminal and a neutral.
16. An electric machine comprising:
a stator core defining slots; and
a winding disposed in the core and having at least two parallel paths including hairpins interconnected to form at least two continuous circuits between a terminal and a neutral, wherein the hairpins of each path include:
a first type of hairpins (first hairpins) each having first and second legs spaced apart by a span of five slots, and each further having an outwardly extending twist joined to the first leg and an inwardly extending twist joined to the second leg, and
a second type of hairpins (second hairpins) each having first and second legs spaced apart by a span of seven slots.
17. The electric machine of claim 16 , wherein each of the second hairpins further has an outwardly extending twist joined to the first leg and an inwardly extending twist joined to the second leg.
18. The electric machine of claim 16 , wherein the slots have a plurality of radial positions, and wherein the legs of the first hairpins are disposed in a first one of the positions, and the legs of the second hairpins are disposed in a second one of the positions.
19. The electric machine of claim 16 , wherein the hairpins of each path further includes a third type of hairpins (third hairpins) each having first and second legs spaced apart by a span of six slots.