EXPANSION SHEET FOR ROTARY ELECTRIC MACHINE, STATOR FOR ROTARY ELECTRIC MACHINE USING THE SAME, AND MANUFACTURING METHOD OF STATOR FOR ROTARY ELECTRIC MACHINE

• US 20130300248A1
• Filed: 04/30/2013
• Published: 11/14/2013
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ishida, Takeshi, Tsukamoto, Takahiro
• Granted Patent: US 9,537,364 B2
• Time in Patent Office: Days
• US Class Current: 310/214
• CPC Class Codes: H02K 15/10 Applying solid insulation to windings, stators or rotors
• CPC Class Codes: H02K 15/105 to the windings
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 3/345 between conductor and core, e.g. slot insulation
• CPC Class Codes: H02K 3/40 for high voltage, e.g. affording protection against corona discharges
• CPC Class Codes: H02K 3/48 in slots

Abstract

In an expansion sheet for a rotary electric machine that has a thermal expansion property and is to be arranged between a core and a coil conductor in a slot in the rotary electric machine, in which the coil conductor is housed in the slot formed in the core, the expansion sheet has a first surface and a second surface and includes: a first surface-side portion; and a second surface-side portion that is closer to the second surface than the first surface-side portion, wherein an amount of volume increase, caused by heating, of the first surface-side portion is higher than an amount of volume increase, caused by the heating, of the second surface-side portion.

Claims

1. An expansion sheet for a rotary electric machine that has a thermal expansion property and is to be arranged between a core and a coil conductor in a slot in the rotary electric machine, in which the coil conductor is housed in the slot formed in the core, the expansion sheet having a first surface and a second surface and comprising:

a first surface-side portion; and

a second surface-side portion that is closer to the second surface than the first surface-side portion, wherein

an amount of volume increase, caused by heating, of the first surface-side portion is higher than an amount of volume increase, caused by the heating, of the second surface-side portion.

2. The expansion sheet according to claim 1, wherein

the first surface is a surface to be positioned on a side, on which the coil conductor is located, and

the second surface is a surface to be positioned on a side, on which the core is located.

3. The expansion sheet according to claim 1, wherein

the first surface-side portion of the expansion sheet includes a first surface-side expansion layer having a sheet center portion and a sheet edge portion that is provided at an outer periphery of the sheet center portion, and

an amount of volume increase, caused by the heating, of the sheet edge portion is lower than an amount of volume increase, caused by the heating, of the sheet center portion.

4. The expansion sheet according to claim 3, wherein

the sheet edge portion is portions that correspond to two sides of the expansion sheet that are arranged along an axial direction of the rotary electric machine when the expansion sheet is inserted in the slot.

5. The expansion sheet according to claim 3, wherein

the sheet edge portion is portions that correspond to two sides of the expansion sheet that are arranged at both axial end surfaces of the core when the expansion sheet is inserted in the slot.

6. The expansion sheet according to claim 1, wherein:

the first surface-side portion of the expansion sheet includes a first surface-side layer having a sheet center portion and a sheet edge portion that is provided at an outer periphery of the sheet center portion of the expansion sheet;

an amount of volume increase, caused by the heating, of the sheet center portion is higher than an amount of volume increase, caused by the heating, of the second surface-side portion of the expansion sheet; and

the sheet edge portion does not have the thermal expansion property.

7. The expansion sheet according to claim 6, wherein

the sheet edge portion is portions that correspond to two sides of the expansion sheet that are arranged along an axial direction of the rotary electric machine when the expansion sheet is inserted in the slot.

8. The expansion sheet according to claim 6, wherein

the sheet edge portion is portions that correspond to two sides of the expansion sheet that are arranged at both axial end surfaces of the core when the expansion sheet is inserted in the slot.

9. The expansion sheet according to claim 1, wherein

the expansion sheet has a second surface-side expansion layer and a first surface-side expansion layer that is closer to the first surface.

10. The expansion sheet according to claim 9, further comprising

an insulating layer that is arranged between the second surface-side expansion layer and the first surface-side expansion layer of the expansion sheet and contains insulating material.

11. The expansion sheet according to claim 9, wherein

the first surface-side expansion layer is thicker than the second surface-side expansion layer.

12. The expansion sheet according to claim 9, wherein

at least one of the second surface-side expansion layer and the first surface-side expansion layer includes a felt-like sheet base material that is impregnated with insulating resin material.

13. The expansion sheet according to claim 1, wherein

the expansion sheet has a second surface-side joining layer on a second surface side, and a first surface-side joining layer on a first surface side.

14. The expansion sheet according to claim 1, wherein

the expansion sheet is configured such that an amount of volume increase caused by the heating increases gradually in a direction from the second surface toward the first surface.

15. The expansion sheet according to claim 1, wherein

the expansion sheet is configured such that an amount of volume increase caused by the heating increases stepwise in a direction from the second surface toward the first surface.

16. The expansion sheet according to claim 1, wherein

the expansion sheet contains an epoxy resin and an expansion filler.

17. A stator for a rotary electric machine, comprising:

a stator core in which a slot is formed;

a coil conductor that is housed in the slot; and

the expansion sheet according to claim 1 that is arranged between the stator core and the core conductor with the first surface facing the coil conductor and with the second surface facing the stator core, wherein

the coil conductor is fixed to the stator core by the expansion sheet.

18. A manufacturing method of a stator for a rotary electric machine, comprising:

inserting the expansion sheet according to claim 1 into a slot in a stator core with the second surface facing the stator core;

tentatively adhering;

to an inner wall surface of the slot, the second surface of the expansion sheet that has been inserted into the slot;

housing the coil conductor in the slot; and

adhering an outer peripheral surface of the coil conductor to the first surface of the expansion sheet, and adhering the inner wall surface of the slot to the second surface of the expansion sheet, by expanding and curing the expansion sheet by heating the expansion sheet.

19. A manufacturing method of a stator for a rotary electric machine, comprising:

limiting expansion of an edge portion of the expansion sheet according to claim 1 by laser processing the edge portion of the expansion sheet, and then inserting the expansion sheet into the slot of the stator core with the second surface facing the stator core;

tentatively adhering, to an inner wall surface of the slot, the second surface of the expansion sheet that has been inserted into the slot;

housing the coil conductor in the slot; and

adhering an outer peripheral surface of the coil conductor to the first surface of the expansion sheet, and adhering the inner wall surface of the slot to the second surface of the expansion sheet, by expanding and curing the expansion sheet by heating the expansion sheet.