JP2011193626A - Motor stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor stator which prevents the formation of a microgap lowering a partial discharge start voltage between a first insulating sheet and a coil. <P>SOLUTION: The motor stator includes a stator core having a yoke and teeth, insulators attached to both axial ends of the stator core to cover both ends, a first insulating sheet of which axial both ends are held between the stator core and the insulators and which covers the axial central part of the stator core not covered with the insulator, a second insulating sheet of which the entire surface is joined to the first insulating sheet and which is disposed on the axial central part of the stator core not covered with the insulator, and an enamel coil which is wound around the teeth to cover the insulator and first and second insulating sheets and is so supported that a micro air gap minimizing a partial discharge start voltage is not created between the coil and the first insulating sheet due to the thickness of the second insulating sheet. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor stator, and more particularly to an insulation structure that improves the insulation performance between a stator core and a coil winding.

  Conventionally, an insulator formed by an iron core, a main body portion, and a U-shaped pressing portion that is provided in the main body portion and extends along the teeth portion of the iron core; and is mounted on the teeth portion of the iron core, and the insulator An insulating sheet fixed to the tooth portion and a winding wound around the tooth portion provided with the insulating sheet fixed by the insulator, and a plurality of the iron cores are joined in a ring shape A stator of a rotating electrical machine, wherein the insulating sheet is formed by a mounting portion that is mounted on the teeth portion and an extension portion that extends from both ends of the mounting portion, and the mounting portion is a shaft of the iron core. Installed between the thin portions of the pressing portion of the insulator installed at both ends in the direction, and the extension portion overlaps the winding that is exposed to the opening side of the insulator in a doubled manner. Stator of location has been rotating electric machine is disclosed (for example, see Patent Document 1).

  The insulating sheet includes a first insulating sheet and a second insulating sheet overlapped with a central portion of the mounting portion of the first insulating sheet and having a central portion welded to the central portion of the first insulating sheet. The length of the second insulating sheet in the direction parallel to the axial direction of the iron core is shorter than the length of the first insulating sheet in the direction parallel to the axial direction of the iron core. In the stator of this rotating electrical machine, the step between the end of the pressing portion of the insulator and the mounting portion of the first insulating sheet is filled with the second insulating sheet.

  A core having a tooth portion; a winding body formed by winding a winding around the tooth portion; and a surface between the tooth portion surface and the inner peripheral portion of the winding body. A split stator for an electric motor comprising: an insulating spacer member that holds an inner peripheral portion of the winding body from the surface of the tooth portion with a gap; and a high thermal conductive resin filler filled in the gap. It is disclosed (for example, see Patent Document 2).

  Further, in a method of manufacturing a synchronous machine stator having at least one of a structure for connecting a teeth part and a yoke part, or a structure for forming the teeth part or the yoke part as a connecting body of a plurality of pieces. A connecting step of connecting the teeth portion and the yoke portion or the element piece, and a winding step of winding the sheet material impregnated or coated with the crosslinked precursor resin, including the connecting portion, A winding step of winding a coil wire around a winding region of the stator coil, and a heating step of heating the synchronous machine stator around which the coil wire is wound under conditions in which the crosslinked precursor resin is melted and thermoset. Is disclosed (for example, see Patent Document 3). The method for manufacturing a synchronous machine stator includes a swing restraining step in which a splint-like regulating member that restrains swing caused by the connecting portion is provided between both members beyond the connecting portion. Yes.

JP 2009-171720 A JP 2008-283730 A JP 2004-242414 A

  However, according to the conventional technique described in Patent Document 1, the first insulating sheet and the second insulating sheet are only welded at the center, and the first insulating sheet and the second insulating sheet There is a slight air gap between the insulating sheet. For this reason, there is a problem that the insulation in the air gap, particularly the partial discharge start voltage is lowered. In addition, since only the central portions of the first and second insulating sheets are welded, each insulating sheet floats and breaks at the tip portion disposed in a U shape, and the winding is wound around the iron core. In addition, there is a problem that the winding enters between the separated first and second insulating sheets, and the winding is damaged, or the insulating sheet is caught by the winding and broken.

  Moreover, according to the conventional technique described in Patent Document 2, a high thermal conductivity resin filler is filled in the gap between the inner peripheral portion of the winding body and the surface of the tooth portion. Therefore, the boundary surface between the insulating spacer member and the high thermal conductive resin filler becomes a creeping surface on insulation, and a creeping surface that is perpendicular between the winding body and the tooth portion is generated. Therefore, it is necessary to increase the creepage length in order to ensure insulation, and as a result, there is a problem that the insulation distance between the winding body and the tooth portion, that is, the interval must be increased.

  Further, according to the conventional technique described in Patent Document 3, the distance of the air gap generated between the stator coil and the tooth portion by the sub-tree-like regulating member is small at the axial end portion of the tooth portion. Thus, there is a problem that a minute gap in which the partial discharge start voltage is lowered is generated, and the insulating property is lowered.

  The present invention has been made in view of the above, and there is no reduction in the partial discharge start voltage due to the minute air gap between the first and second insulating sheets, and the interval between the winding and the tooth portion is reduced. An object of the present invention is to obtain a motor stator in which a minute gap in which the partial discharge start voltage is reduced does not occur between the first insulating sheet and the winding.

  In order to solve the above-described problems and achieve the object, the present invention provides a stator core having a yoke portion and a tooth portion, and an insulator that is attached to both end portions in the axial direction of the stator core and covers the both end portions. And a first insulating sheet that is sandwiched between the stator core and the insulator at both axial ends, and covers the axial center of the stator core that is not covered by the insulator, A second insulating sheet that is bonded to the entire surface of the insulating sheet and disposed at the axially central portion of the stator core that is not covered with the insulator, and the insulator and the first and second insulating sheets from above. Wrapped around the tooth portion, and supported by the thickness of the second insulating sheet so that a minute air gap that minimizes the partial discharge start voltage does not occur between the first insulating sheet and the first insulating sheet. Characterized in that it comprises the enameled windings, the.

  According to the present invention, there is no reduction in the partial discharge start voltage due to the minute air gap between the first and second insulating sheets, the interval between the winding and the tooth portion can be reduced, and the first insulating sheet and There is an effect that a minute gap in which the partial discharge start voltage decreases does not occur between the windings.

FIG. 1 is a partial cross-sectional view perpendicular to the rotation axis showing Embodiment 1 of the stator of the motor of the present invention. FIG. 2 is a view taken along the line AA of FIG. FIG. 3 is a perspective view showing the insulating sheet of the first embodiment. 4 is a cross-sectional view taken along line BB in FIG. FIG. 5 is a diagram illustrating the relationship between the gap length between the enamel winding and the first insulating sheet and the partial discharge start voltage (standardized value). FIG. 6 is a longitudinal sectional view of a tooth portion of the stator of the motor according to the second embodiment, and is the same view as FIG. 4. FIG. 7 is a perspective view showing the insulating sheet of the second embodiment. FIG. 8 is a perspective view showing the insulating sheet of the third embodiment.

  Embodiments of a motor stator according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a partial cross-sectional view perpendicular to the rotational axis showing Embodiment 1 of the stator of the motor of the present invention, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. It is a perspective view which shows the insulating sheet of Embodiment 1, and FIG. 4 is sectional drawing which follows the BB line of FIG.

  As shown in FIG. 1, the stator 91 of the motor according to the first embodiment has a substantially cylindrical shape formed by connecting a plurality of substantially T-shaped split cores 10 each having a yoke portion 11 and a teeth portion 12. An iron core 20 is provided. The split iron core 10 is formed by laminating electromagnetic steel plates. A slot 13 for accommodating an enamel winding 50 described later is formed so as to be surrounded by the yoke portion 11 and the tooth portion 12. The motor of the first embodiment is a concentrated winding motor.

  As shown in FIG. 2, insulators 30 that cover and insulate both ends and both ends of each slot 13 are attached to both ends in the axial direction of the stator core 20. A central portion in the axial direction of the slot 13 of the stator core 20 that is not covered by the insulator 30 is covered and insulated by a first insulating sheet 41. As shown in FIG. 4, both axial end portions of the first insulating sheet 41 are sandwiched between the stator core 20 and the insulator 30.

  As shown in FIGS. 3 and 4, the second insulating sheet 42 is a single (one) insulating sheet, and is formed at the axial center of the slot 13 of the stator core 20 that is not covered with the insulator 30. The entire surface is bonded to the first insulating sheet 41 by adhesion or welding. The first and second insulating sheets 41 and 42 are bonded in close contact so that air does not enter the bonding surfaces. The first insulating sheet 41 and the second insulating sheet 42 bonded thereto constitute an insulating sheet 40.

  As shown in FIGS. 1, 2, and 4, an enamel winding 50 that forms a coil winding is wound on the tooth portion 12 from above the insulator 30 and the first and second insulating sheets 41, 42, Due to the thickness of the second insulating sheet 42, the second insulating sheet 42 is supported so as not to generate a minute air gap between which the partial discharge start voltage is minimized.

  Since the first and second insulating sheets 41 and 42 are adhered or welded in close contact so that air does not enter the joint surfaces, the enamel winding 50 is wound around the tooth portion 12 without being peeled off. In this process, the enamel winding 50 does not enter between the first and second insulating sheets 41 and 42, and the winding is damaged or the first and second insulating sheets 41 and 42 are enameled. There is no possibility of getting caught by the line 50 and breaking. In addition, since a minute air gap does not occur between the first and second insulating sheets 41 and 42, there is no decrease in partial discharge start voltage due to the minute air gap, and insulation reliability is high.

  As shown in FIG. 4, the enamel at the step portion between the insulator 30 and the first insulating sheet 41 attached to both axial ends of the stator core 20 is caused by winding tightening in the winding process. When the winding 50 is pushed into the stepped portion (concave portion), a minute air gap is generated between the enamel winding 50 and the first insulating sheet 41, and the partial discharge start voltage may be lowered depending on conditions. .

  The second insulating sheet 42 is disposed in close contact with the first insulating sheet 41 at the axially central portion of the slot 13 of the stator core 20 that is not covered with the insulator 30, so that the gap shown in FIG. The length d is secured. The thickness of the second insulating sheet 42 is set such that the partial discharge start voltage at this portion does not decrease. In the air gap portion 60, the axial distance c between the end portion of the second insulating sheet 42 and the end portion of the insulator 30 is preferably 0.1 mm to several mm.

  As the material of the first and second insulating sheets 41 and 42, for example, an organic insulator such as polyethylene terephthalate (abbreviation: PET), polyphenylene sulfide (abbreviation: PPS), Nomex (trademark), Kapton (trademark), or the like is used. . A material having an electrical relative dielectric constant of about 2.5 to 3.5 may be used alone, or a plurality of materials may be used in combination.

  Further, as the enamel winding 50, a wire having an electrical relative dielectric constant of about 3.0 to 4.0 such as a polyesterimide wire, a polyester wire, a polyamideimide wire, or a polyurethane wire is used.

  FIG. 5 is a diagram showing the relationship between the gap length between the enamel winding 50 and the first insulating sheet 41 and the partial discharge start voltage (standardized value). As shown in FIG. 5, the partial discharge start voltage has a characteristic that the gap length d becomes a minimum value in the range of 0.02 mm to 0.1 mm. The electric field analysis is performed with the configuration and material properties of the insulating material used for the stator 91 of the motor according to the first embodiment, the calculation result of the electric field strength (voltage difference generated per spatial distance) of the minute air gap, By comparing the spark start voltage according to the law and the relational expression of the gap length, it was found that the partial discharge start voltage can be calculated in the space surrounded by the insulator. With regard to the electrical properties and material thickness of the material used in Embodiment 1, the range in which the partial discharge start voltage is minimized is found to be the above-described gap length in the range of 0.02 mm to 0.1 mm. It was.

  Even if the above-mentioned gap length is shorter or longer than this range, the partial discharge start voltage becomes high, it becomes difficult for discharge to occur, and the partial discharge start voltage rises rapidly. That is, in order not to minimize the partial discharge start voltage, the thickness of the second insulating sheet 42 is adjusted so that the gap length is not in the range of 0.02 mm to 0.1 mm, and the gap length is set. Need to be adjusted. If the thickness of the second insulating sheet 42 is made thicker than 0.1 mm so that the gap length is not in the range of 0.02 mm to 0.1 mm, the insulation reliability can be improved.

Embodiment 2. FIG.
6 is a longitudinal sectional view (similar to FIG. 4) of a tooth portion of the stator of the motor according to the second embodiment, and FIG. 7 is a perspective view showing an insulating sheet according to the second embodiment. Since the motor stator 92 of the second embodiment is different from the motor stator of the first embodiment only in the shape of the second insulating sheet, only this portion will be described, and the other portions will be described. Omitted.

  As shown in FIGS. 6 and 7, the second insulating sheet 43 of the second embodiment has a plurality of (four shown in FIG. 6 are shown in FIG. 7) arranged at intervals (a constant interval e). 5 shows a strip-shaped insulating sheet, and is arranged in the axial center of the slot 13 of the stator core 20 not covered with the insulator 30, and the entire surface thereof is the first insulating sheet 41. Are bonded to each other by adhesion or welding. The first and second insulating sheets 41 and 43 are bonded in close contact so that air does not enter the bonding surfaces.

  As shown in FIG. 6, the enamel winding 50 forming the coil winding is wound on the tooth portion 12 from above the insulator 30 and the first and second insulating sheets 41 and 43, and the second insulating sheet 43. The thickness is supported so that a minute air gap that minimizes the partial discharge starting voltage is not generated between the first insulating sheet 41 and the first insulating sheet 41.

  Since the first and second insulating sheets 41 and 43 are bonded in close contact so that air does not enter the bonding surfaces, the first and second insulating sheets 41 and 43 are not peeled off, and the step of winding the enamel winding 50 around the teeth portion 12 is performed. The enamel winding 50 does not enter between the first and second insulating sheets 41 and 43, and the winding is damaged or the first and second insulating sheets 41 and 43 are enameled winding 50. There is no such thing as being caught and torn. Moreover, since a minute air gap does not occur between the first and second insulating sheets 41 and 43, the partial discharge start voltage does not decrease due to the minute air gap, and the insulation reliability is high.

  Since the second insulating sheet 43 is composed of a plurality of strip-shaped insulating sheets arranged at intervals (a constant interval e), the amount of material used is smaller than that of the second insulating sheet 42 of the first embodiment. Can be reduced.

  As in the first embodiment, the gap length depending on the thickness of the second insulating sheet 43 of the second embodiment is less than 0.02 mm or greater than 0.1 mm, so that the partial discharge start voltage is minimized. It can be avoided. The material of the second insulating sheet 43 is the same as that of the first embodiment.

Embodiment 3 FIG.
FIG. 8 is a perspective view showing the insulating sheet of the third embodiment. Since the motor stator of the third embodiment is different from the motor stator of the first embodiment only in the shape of the second insulating sheet, only this part will be described, and the description of the other parts will be omitted. To do.

  As shown in FIG. 8, the second insulating sheet 44 of the third embodiment is provided with punch holes 44a having a diameter e or mesh-like holes at intervals in a single (one) insulating sheet. ing. The second insulating sheet 44 is disposed in the center portion in the axial direction of the slot 13 of the stator core 20 that is not covered with the insulator 30, and the entire surface thereof is bonded to the first insulating sheet 41 by adhesion or welding. The first and second insulating sheets 41 and 44 are bonded in close contact so that air does not enter the bonding surfaces.

  An enamel winding 50 forming a coil winding is wound on the teeth portion 12 from above the insulator 30 and the first and second insulating sheets 41, 44, and the punch hole depends on the thickness of the second insulating sheet 44. 44a or even if a mesh-like hole is formed, the enamel winding 50 and the first insulating sheet 41 are supported so that a minute air gap that minimizes the partial discharge start voltage does not occur. .

  Since punch holes 44a or mesh-shaped holes are provided in the second insulating sheet 44, the amount of material used can be reduced compared to the second insulating sheet 42 of the first embodiment. By making the gap length the same as that of the first embodiment, the insulation reliability can be improved.

Embodiment 4 FIG.
The second insulating sheet of the fourth embodiment is obtained by converting the second insulating sheet 42 of the first embodiment into an insulating sheet made of a nonwoven fabric, and the shape thereof is the same as that shown in FIG. As the nonwoven material, polyester fiber, polyphenylene sulfide fiber, cellulose fiber, polyethylene fiber or the like is used.

  The nonwoven fabric has an electrical relative dielectric constant of about 2.5 to 3.5. When such a non-woven fabric is used, even if the enamel winding 50 is pressed against the stator core 20 side, the non-woven fabric itself is shrinkable, and the surface of the electric wire is scratched by the enamel winding 50 being pressed. Generation and damage to the coating layer can be minimized.

  Since the nonwoven fabric is manufactured by superposing without weaving minute fibers, the nonwoven fabric contains a large number of minute air layers. Therefore, even if the enamel winding 50 is pressed and compressed to reduce the thickness, the thickness of the nonwoven fabric is set to be greater than 0.1 mm. By doing so, there is no gap that minimizes the partial discharge start voltage, and the insulation reliability is improved.

  As described above, the stator of the motor according to the present invention has high insulation reliability and is useful.

DESCRIPTION OF SYMBOLS 10 Divided iron core 11 Yoke part 12 Teeth part 13 Slot 20 Stator iron core 30 Insulator 40 Insulating sheet 41 1st insulating sheet 42, 43, 44 2nd insulating sheet 44a Punch hole 50 Enamel winding 60 Air gap part 91, 92 Motor stator

Claims (6)

A stator core having a yoke portion and a teeth portion;
An insulator attached to both ends of the stator core in the axial direction and covering the both ends;
A first insulating sheet that is sandwiched between the stator core and the insulator in both axial ends, and covers the axial center of the stator core that is not covered by the insulator;
A second insulating sheet disposed at the axially central portion of the stator core that is joined to the first insulating sheet and is not covered with the insulator;
The partial discharge start voltage is minimum between the first insulating sheet and the insulator wound around the teeth portion from above the insulator and the first and second insulating sheets, depending on the thickness of the second insulating sheet. Enamel winding supported so as not to generate a micro air gap,
The stator of the motor characterized by comprising.   2. The motor stator according to claim 1, wherein the second insulating sheet is formed of an organic insulator having a thickness greater than 0.1 mm.   The stator of the motor according to claim 1, wherein the second insulating sheet is formed of a single insulating sheet.   The motor stator according to claim 3, wherein the second insulating sheet is provided with a plurality of holes.   3. The motor stator according to claim 1, wherein the second insulating sheet is composed of a plurality of strip-shaped insulating sheets arranged at intervals. 4.   The motor stator according to claim 1, wherein the second insulating sheet is formed of a nonwoven fabric.

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