Stator assembly for belt alternator starter motor generator for hybrid vehicles
View Patent ↗A stator assembly comprises a stator defining S slots. First and second windings are arranged in each of the S slots. The two windings have a width in a radial direction and a thickness in a direction perpendicular to the radial direction. A ratio of the width to the thickness is between 3.0:1 and 4.5:1.
1. A 3-phase electric machine comprising:
a stator assembly comprising:
a stator having 72 slots; and
first and second windings that are arranged in each of said 72 slots,
the first and second windings each having a width in a radial direction and a thickness in a direction perpendicular to said radial direction,
wherein a ratio of said width to said thickness is between 3.0:1 and 4.5:1;
wherein the 72 slots include 8 different groups of 9 adjacent slots, each of the 8 different groups of 9 adjacent slots including:
a first set of the first and second windings that are connected to a first one of three phases and that are arranged in first, second, and third adjacent ones of the 9 adjacent slots;
a second set of the first and second windings that are connected to a second one of the three phases and that are arranged in fourth, fifth, and sixth adjacent ones of the 9 adjacent slots; and
a third set of the first and second windings that are connected to a third one of the three phases and that are arranged in seventh, eighth, and ninth adjacent ones of the 9 adjacent slots; and
a rotor assembly including a plurality of slots.
2. The 3-phase electric machine of claim 1 wherein the rotor assembly includes 8 different groups of slots, each of the 8 different groups of slots including:
a first “V”-shaped slot;
a second “V”-shaped slot arranged radially outside of the first “V”-shaped slot; and
a permanent magnet material that is disposed within the first and second “V”-shaped slots.
3. The 3-phase electric machine of claim 1 wherein each of the 72 slots of the stator assembly includes insulation that insulates the first and second windings from the stator assembly and that includes multiple layers.
4. The 3-phase electric machine of claim 3 wherein the insulation includes a Mylar layer disposed between layers of Nomex.
5. The 3-phase electric machine of claim 1 wherein the stator assembly further includes a plurality of stacked laminations that are made of a magnetic material.
6. The 3-phase electric machine of claim 5 wherein the magnetic material includes M19 steel.
7. The 3-phase electric machine of claim 5 wherein the stacked laminations include a lamination coating.
8. The 3-phase electric machine of claim 7 wherein the lamination coating includes one of a C5 coating and a C6 coating.
9. The 3-phase electric machine of claim 1 wherein the first and second windings are coated with a winding coating.
10. The 3-phase electric machine of claim 9 wherein the winding coating includes one of varnish and polyamideimide.
11. The 3-phase electric machine of claim 1 wherein the rotor assembly includes a plurality of rotor laminations that are made of a magnetic material.
12. The 3-phase electric machine of claim 11 wherein the magnetic material includes M19 steel.
13. The 3-phase electric machine of claim 11 wherein the rotor laminations are coated with a coating.
14. The 3-phase electric machine of claim 13 wherein the coating includes one of a C5 coating and a C6 coating.
15. The 3-phase electric machine of claim 13 wherein the first and second windings comprise wave windings with substantially rectangular conductors.
16. The 3-phase electric machine of claim 13 wherein:
the width of said first winding plus the width of the second winding is approximately equal to a width of the slots; and
the thickness of said first and second windings is approximately equal to a thickness of the slots.