Rotating electric machine and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-9705372-B2
Application number	US-201214117778-A
Country	US
Kind code	B2
Filing date	May 21, 2012
Priority date	May 27, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A rotating electric machine includes: a stator including a stator core, slots provided in the stator core at equal intervals along the circumferential direction, and coils placed in the stator slots and configured to generate a rotating magnetic field; and a rotor rotatably provided with a predetermined rotation gap between the stator core and the rotor, wherein the rotating electric machine further includes a first varnish applied between the slots in the stator core and the coils for impregnation, and a second varnish applied directly onto enamel coating of the coils outside of the slots in the axial direction, the first varnish is a thermosetting varnish having a shear bond strength of a flat wire between the coils and the varnish is higher than that of the second varnish, and the second varnish is a thermosetting varnish having a glass transition temperature of approximately 104° C. or lower and the glass transition temperature of the second varnish by the Dynamic Mechanical Analysis (DMA) method is lower than that of the first varnish.

First claim

The invention claimed is:

1. A rotating electric machine comprising:
a stator including a stator core, slots provided in the stator core at equal intervals along the circumferential direction, and coils placed in the stator slots and configured to generate a rotating magnetic field; and
a rotor rotatably provided with a predetermined rotation gap between the stator core and the rotor, wherein
the rotating electric machine further comprising a first varnish applied between the slots in the stator core and the coils for impregnation, and a second varnish applied directly on enamel coating of the coils outside of the slots in the axial direction,
the first varnish is a thermosetting varnish having a shear bond strength of a flat wire between the coils and the varnish is higher than that of the second varnish, and
the second varnish is a thermosetting varnish having a glass transition temperature of approximately 104° C. or lower and the glass transition temperature of the second varnish by a Dynamic Mechanical Analysis (DMA) method is lower than that of the first varnish.

2. The rotating electric machine according to claim 1 , wherein a contact part of the first varnish and the second varnish has two layers in the radial direction.

3. The rotating electric machine according to claim 1 , wherein the varnish applied to coil ends outside of the stator core includes one varnish from inside of the stator core to an insulating paper end, two varnishes from an insulating paper end to an end of a layered part of the first varnish and the second varnish, and one varnish from the end of the layered part of the first varnish and the second varnish to extreme ends of the coil ends.

4. The rotating electric machine according to claim 1 , wherein the second varnish is a varnish applied to the coils outside of the slots in the axial direction before the first varnish.

5. The rotating electric machine according to claim 1 , wherein the first varnish is a varnish having polymer components different from those of the second varnish.

6. The rotating electric machine according to claim 1 , wherein the first varnish is varnished with epoxy varnish.

7. The rotating electric machine according to claim 1 , wherein the second varnish is unsaturated polyester varnish.

8. The rotating electric machine according to claim 1 , wherein the second varnish is a varnish of the same polymer components as the first varnish, and a polymer having flexible chains is added to the second varnish to lower the glass transition temperature of the second varnish.

9. A method of manufacturing a rotating electric machine including: a stator including a stator core, slots provided in the stator core at equal intervals along the circumferential direction, and coils placed in the stator slots and configured to generate a rotating magnetic field; and a rotor rotatably provided with a predetermined rotation gap between the stator core and the rotor, wherein the rotating electric machine further comprising a first varnish applied between the slots in the stator core and the coils for impregnation, and a second varnish applied directly on enamel coating of the coils outside of the slots in the axial direction, the first varnish is a thermosetting varnish having a shear bond strength of a flat wire between the coils and the varnish is higher than that of the second varnish, and the second varnish is a thermosetting varnish having a glass transition temperature Tg of approximately 104° C. or lower and the glass transition temperature of the second varnish by a Dynamic Mechanical Analysis (DMA) method is lower than that of the first varnish, the method comprising:
immersing the stator in which the coils are inserted in a vessel containing the second varnish outside of the stator core up to an insulating paper end and heat curing the second varnish, and then, also immersing the opposite side of the stator up to an insulating paper end and heat curing the second varnish.

10. The method of manufacturing a rotating electric machine according to claim 9 , wherein the second varnish is applied onto the surfaces of the coils outside of the stator core with a brush from an insulating paper end outside of the stator core outward in the axial direction outward and heat cured.

11. The method of manufacturing a rotating electric machine according to claim 9 , wherein the first varnish is dripped into openings of the slots in the stator core for impregnation and heat cured while the stator to which the second varnish is applied is rotated with the axis being in the horizontal direction.

Assignees

• Kurahara Yoshimi
• Obata Koji
• Hagiwara Shuya
• Hitachi Automotive Systems Ltd

Inventors

• Kurahara Yoshimi
• Obata Koji
• Hagiwara Shuya

Classifications

• H02K15/12

  Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines · CPC title

• Y10T29/49012

  Rotor · CPC title

• H02K3/34

  between conductors or between conductor and core, e.g. slot insulation · CPC title

• H02K3/30 Primary

  Windings characterised by the insulating material · CPC title

• H02K15/02

  of stator or rotor bodies · CPC title