Insulation component for an electric machine and method of assembly
View Patent ↗An electric machine includes a core with a plurality of teeth that extends between end faces of the core. Slots are defined in the core between adjacent teeth of the plurality of teeth. The slots each have a radial opening formed between end portions of the adjacent teeth. An insulation sheet is positioned on the core to obstruct the radial openings to the slots. The insulation has at least two spaced circumferential members that respectively overlap the end faces of the core. The insulation sheet also has a plurality of spaced axial members connected to the circumferential members. The axial members are positioned within the slots to obstruct the radial openings to the slots.
1. An electric machine comprising:
a core having a plurality of teeth that extend axially between end faces of the core, adjacent teeth of the plurality of teeth defining a slot with a radial opening formed between end portions of the adjacent teeth; and
an insulation sheet including at least two spaced side portions and a connecting portion connected to the side portions, the side portions overlapping a portion of the core to position the connecting portion in the slot to obstruct the radial opening.
2. The electric machine of claim 1 wherein the insulation sheet includes a plurality of spaced connecting portions connected to the side portions, each of the connecting portions positioned to obstruct respective radial openings formed between end portions of adjacent teeth.
3. The electric machine of claim 1 wherein each of the adjacent teeth has a radial face extending axially along a portion of the end portions of the adjacent teeth, the connection portion of the insulation sheet being offset from the radial faces of the adjacent teeth when the connecting portion is positioned to obstruct the radial opening.
4. The electric machine of claim 1 wherein:
the radial opening has a first width measured in a circumferential direction between the end portions of the adjacent teeth,
the slot at a position offset from the end portions has a second width measured in the circumferential direction between the adjacent teeth, and
the connecting portion of the insulation sheet has a third width measured in the circumferential direction, the first width being less than the second width and the third width being greater than the first width and one of greater than, less than, or equal to the second width.
5. The electric machine of claim 4 wherein the connecting portion of the insulation sheet at the connection of the connecting portion and at least one of the side portions has a fourth width measured in the circumferential direction, the fourth width being less than the third width to enable a portion of the connecting portion to bend or rotate.
6. The electric machine of claim 1 further comprising an insulation sleeve positioned in the slot to cover surfaces of the adjacent teeth that define the slot.
7. The electric machine of claim 6 wherein the insulation sleeve extends past at least one of the end faces of the core, at least one of the side portions of the insulation sheet being positioned to overlap a portion of the insulation sleeve that extends past the at least one end face.
8. The electric machine of claim 6 further comprising at least one electric conductor positioned in the slot, the insulation sleeve electrically insulating the at least one electric conductor from the surfaces of the adjacent teeth that define the slot.
9. The electric machine of claim 1 wherein the insulation sheet has a thickness of approximately 0.127 millimeters.
10. The electric machine of claim 1 wherein the insulation sheet is formed from flame-resistant aramid material.
11. The electric machine of claim 1 wherein the side portions and the connecting portion integrally form the insulation sheet.
12. An electric machine comprising:
a core having a plurality of teeth, adjacent teeth of the plurality of teeth defining a slot that extends axially between end faces of the core; and
an insulation sheet including a first circumferential member and an axial member connected to the first circumferential member, the first circumferential member overlapping a first portion of the core and the axial member positioned in the slot.
13. The electric machine of claim 12 wherein the insulation sheet includes a plurality of spaced axial members connected to the first circumferential member, each of the axial members positioned to radially obstruct respective slots defined by adjacent teeth of the plurality of teeth.
14. The electric machine of claim 12 wherein the insulation sheet further includes a second circumferential member spaced from the first circumferential member, the second circumferential member being connected to the axial member and overlapping a second portion of the core.
15. The electric machine of claim 14 wherein the first and second circumferential members extend substantially around the end faces and one of the plurality of axial members is positioned in each of the slots.
16. The electric machine of claim 12 wherein:
the adjacent teeth each have end portions that reduce a width of the slot at the end portions in a circumferential direction, and
the axial member has a first width in the circumferential direction that is greater than the width of the slot at the end portions such that the end portions of the adjacent teeth facilitate radial retention of the axial member within the slot.
17. The electric machine of claim 16 wherein the axial member of the insulation sheet at the connection of the axial member and the first circumferential member has a second width measured in the circumferential direction, the second width being less than the first width to enable a portion of the axial member to bend or rotate.
18. The electric machine of claim 12 wherein the core of the electric machine is a stator core.