JP2016048989A - Stator for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability in fixing a coil to a stator core.SOLUTION: An expansion material 28 which has insulation and foaming properties and is foamed by heating to expand the volume is provided only between coils 22 which are adjacent in a circumferential direction of a stator and the expansion material 28 is not provided between teeth 24 and the coil 22, such that a pressure to act on the coil 22 by expanding the expansion material 28 acts only at one side where the coil 22 is pressed to the teeth 24. Therefore, the coil 22 can be prevented from being displaced from a desired position by varying a shape after the expansion of the expansion material 28 or varying the pressure caused by the expansion.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a stator for a rotating electric machine, and more particularly to a stator in which a coil is wound in concentrated winding on teeth of a stator core.

  In the stator of the rotating electrical machine described in Patent Document 1, when the coil is wound around the teeth of the stator core by concentrated winding, the insulating material has an insulating property on both the surface where the insulator and the teeth are in contact and between adjacent concentrated winding coils. And the coil is fixed by expansion of the expansion material. This eliminates the need for fixing the coil with a resin mold or varnish while ensuring the insulation of the coil.

JP 2014-93893 A JP 2002-112488 A

  In Patent Document 1, since the expansion material is provided on both the surface where the insulator and the tooth are in contact with each other and between the adjacent concentrated winding coils, the pressing force due to the expansion of both expansion materials is applied from both sides of the coil. At this time, if a variation occurs in the pressing force due to expansion of both of the expansion materials, the coil may be displaced from a desired position.

  The stator of the rotating electrical machine according to the present invention aims to improve the reliability when the coil is fixed to the stator core.

  The stator of the rotating electrical machine according to the present invention employs the following means in order to achieve the above-described object.

  The stator of the rotating electrical machine according to the present invention has a stator core in which a plurality of teeth are arranged at intervals in the circumferential direction, a coil wound in concentrated winding around each tooth, and has insulating properties and foamability. An expansion material that expands in volume when heated, and the expansion material is provided between coils adjacent in the circumferential direction, and is not provided between the teeth and the coil.

  According to the present invention, the expandable material that has insulating properties and foamability and expands in volume when heated is provided between the coils adjacent in the circumferential direction, and is not provided between the teeth and the coils. The pressing force acting on the coil due to the expansion of the expansion material is only on one side for pressing the coil against the teeth, and the coil can be securely fixed to the teeth. As a result, the reliability when fixing the coil to the stator core can be improved.

It is sectional drawing which shows the structural example of the stator which concerns on embodiment of this invention. It is an enlarged view of the A section of FIG. It is a figure explaining the force which acts on the coil 22, when the expansion material 28 is provided between the coils 22 adjacent to the stator circumferential direction and between the teeth 24 and the coils 22. FIG. 3 is a diagram illustrating a configuration example in which an expansion material is integrated with a base material. It is a figure which shows the structural example which made the expansion material 28 the bellows shape.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1 and 2 are diagrams showing a schematic configuration of a stator of a rotating electrical machine according to an embodiment of the present invention. FIG. 1 is a sectional view as seen from the stator axial direction, and FIG. 2 is an enlarged view of a portion A in FIG. The stator includes a stator core 21 and a coil 22 wound around the stator core 21. The stator core 21 includes an annular yoke 23 that extends along the circumferential direction of the stator, and a plurality of teeth 24 that protrude from the inner circumferential surface of the yoke 23 to the inside in the stator radial direction (the rotor side not shown). The plurality of teeth 24 are arranged at regular intervals (equal intervals) in the stator circumferential direction. Slots 25 are formed between teeth 24 adjacent in the stator circumferential direction, and a plurality of slots 25 are arranged at regular intervals (equal intervals) in the stator circumferential direction. Each tooth 24 and each slot 25 extends along the stator axial direction. The coil 22 is wound around each tooth 24 through the slot 25 in a concentrated manner. In the example of FIG. 2, an insulator 26 having an insulating property is attached to each tooth 24, and a coil 22 is attached to each tooth 24 via the insulator 26.

  In the present embodiment, an expansion material 28 that has insulating properties and foaming properties and expands in volume when heated is provided in each slot 25. The expansion material 28 is provided between the coils 22 adjacent to each other in the circumferential direction of the stator, and between the teeth 24 and 22 between the coils 22 adjacent to each other in the circumferential direction of the stator. Not. The expansion material 28 between the adjacent coils 22 extends along the stator axial direction. As the material of the expansion material 28, for example, a foamable resin such as foamable polyurethane, foamable polystyrene, and foamable polyolefin can be used. The expansion material 28 may be a plate-shaped material that may be heated, foamed, and expanded, but may be filled with a fluid expansion material 28 and then heated, foamed, and expanded.

  When fixing the coil 22 to the stator core 21, the coil 22 is wound around each tooth 24 by concentrated winding, and then the expansion material 28 is inserted between the coils 22 adjacent in the stator circumferential direction, and the expansion material 28 is heated. . The expansion material 28 is foamed by heating and expands in volume, so that the space between the adjacent coils 22 is filled with the expansion material 28, and the coil 22 is pressed toward the teeth 24 as shown by an arrow a in FIG. 2. . Insulation between adjacent coils 22 is secured by the expansion material 28 whose volume has expanded, and the coils 22 are fixed to the teeth 24 via insulators 26. As a result, the fixing process of the coil 22 by a resin mold or varnish becomes unnecessary. As the insulation between the coils 22 improves, the space between the coils 22 can be shortened to improve the space factor in the slot 25.

  Here, considering the case where the expansion material 28 is provided between the coils 22 adjacent to each other in the circumferential direction of the stator and between the teeth 24 and the coil 22, as shown by arrows a and b in FIG. A pressing force due to the expansion of 28 is applied from both sides of the coil 22. At that time, if the inflated material 28 has a variation in the shape after expansion and the pressing force due to the expansion, the coil 22 may be displaced from a desired position.

  In contrast, in the present embodiment, the expansion material 28 is not provided between the tooth 24 and the coil 22, and the expansion material 28 is provided only between the coils 22 adjacent in the stator circumferential direction. The pressing force that acts on the coil 22 due to the expansion is only on one side that presses the coil 22 against the tooth 24 as shown by an arrow a in FIG. Therefore, it is possible to prevent the coil 22 from being displaced from a desired position due to variation in shape of the expansion material 28 after expansion and variation in pressing force due to expansion, and reliability when the coil 22 is fixed to each tooth 24. Can be improved.

  Furthermore, the strength at the time of fixing the coil 22 to each tooth | gear 24 can further be improved by using the resin material which has adhesiveness for the material of the expansion material 28. FIG. Further, by inserting the expansion material 28 between the coils 22 after the coils 22 are mounted on the teeth 24, the expansion material 28 is prevented from being damaged when the expansion material 28 is disposed and then the coil 22 is mounted. be able to.

  In the present embodiment, for example, as shown in FIG. 4, a base material 30 for defining a coil interval can be provided between the coils 22 adjacent in the stator circumferential direction. Here, FIG. 4 shows a cross-sectional view viewed from the inside in the stator radial direction. The base material 30 is disposed at a central position between the coils 22 adjacent to each other in the circumferential direction of the stator, and is connected to a plate portion 31 extending along the stator axial direction and one end of the plate portion 31 in the stator axial direction. A protrusion 32 that protrudes from both sides of the stator 31 in the circumferential direction of the stator 31 and is connected to the other end of the plate 31 in the stator axial direction, and protrudes from the plate 31 to both sides of the stator in the circumferential direction. And a protrusion 33. For example, an insulating material such as a resin can be used as the material of the base material 30. The expansion material 28 is integrated with the base material 30 and is provided in a space 34 formed between the plate portion 31 and the coil 22 in the circumferential direction of the stator and between the protrusion portions 32 and 33 in the stator axial direction. Yes. However, FIG. 4 shows a state before the expansion material 28 is expanded (before heating), and the expansion material 28 expands as shown by an arrow c in FIG. According to the configuration example of FIG. 4, the expansion material 28 can be prevented from expanding in the stator axial direction by the protrusions 32 and 33, and the expansion ratio (expansion ratio) of the expansion material 28 can be controlled. Further, it is possible to prevent turning-up when inserting the expansion material 28 between the adjacent coils 22.

  Further, in the present embodiment, for example, as shown in FIG. 5, the expansion material 28 disposed between the coils 22 adjacent in the stator circumferential direction is formed into a bellows shape extending in the stator radial direction while undulating in the stator circumferential direction. It is also possible. Here, FIG. 5 corresponds to an enlarged view of a portion A in FIG. According to the configuration example of FIG. 5, even if the expansion ratio (expansion ratio) due to heating of the expansion material 28 is small, the expansion of the expansion material 28 ensures that the coil 22 is moved toward the teeth 24 as indicated by the arrow a in FIG. 5. It can be pressed and fixed. Furthermore, by using a resin material having adhesiveness as the material of the expansion material 28, the expansion material 28 can be reliably bonded to the coil 22 even if the expansion ratio of the expansion material 28 is small. In addition, the bellows-shaped expansion material 28 is preferably formed into a bellows shape in advance and then heated after being inserted. Moreover, in order to maintain a bellows, you may insert the expansion | swelling material 28 which provided the core material and formed the expansion | swelling material in the front and back both surfaces, and may heat after that.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

  21 Stator core, 22 coils, 23 yoke, 24 teeth, 25 slots, 26 insulator, 28 expansion material, 30 base material, 31 plate part, 32, 33 protrusion part, 34 space.

Claims (1)

A stator core in which a plurality of teeth are spaced apart from each other in the circumferential direction;
A coil wound around each tooth in concentrated winding;
An insulative and foaming material that expands by heating and expands in volume;
With
The said expansion | swelling material is a stator of a rotary electric machine provided between the coils adjacent to the circumferential direction, and is not provided between the teeth and the coils.

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