JP2003111328A - Slot liner for rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high insulation by improving the strength of a slot liner for insulating a section between a core and a coil of a rotating electric machine, and to improve the radiation of heat generated at the coil. SOLUTION: This slot liner 18 is disposed so as to run along the inner periphery of a slot in the core of the rotating electric machine and to be interposed between the core 10 and a coil 32. The slot liner 18 includes a main insulating sheet 28, and a reinforcing sheet 30 for reinforcing the main insulating sheet 28. The reinforcing sheet 30 is positioned between the main insulating sheet 28 and the core 10 and arranged near the end face of the core in the axial direction of the rotating electric machine without being arranged therebetween. Thus, heat runs to the core 10 from the coil 32 without passing through the reinforcing sheet 30, thereby ensuring the radiation of the coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a slot liner arranged in a slot of a core of a rotating electric machine such as an electric motor or a generator to insulate the core from the coil conductor.

[0002]

2. Description of the Related Art A rotary electric machine such as an electric motor or a generator has a core having a plurality of arranged teeth, and a coil wire is housed in a space between the teeth, that is, a slot. In order to ensure insulation between the coil conductor and the core, a sheet-shaped insulating material called a slot liner is arranged between them.

In a rotary electric machine used in a high temperature environment, the insulating material also needs to have sufficient heat resistance.
As such an insulating material, one using mica is known. The sheet-shaped insulating material using mica is vulnerable to bending and the like, and in particular, there is a problem in that a portion of the coil protruding from the core end portion, that is, a so-called coil end portion is easily subjected to a load and damaged. When this damage is a problem, conventionally, a sheet of a material having a relatively high mechanical strength, such as a resin, of the same size as the insulating material is laminated on the insulating material using mica, and the slot is formed. Made up the liner.

[0004]

The above-mentioned layer of the reinforcing resin for the slot liner is interposed between the coil and the core. Under high temperature conditions, the resin expands and is peeled from the core due to deformation and is generated in the coil. There is a problem in that the heat generated is hindered from being transferred to the core, and the heat dissipation of the coil is reduced.

The present invention has been made in consideration of the above problems, and an object thereof is to secure the strength of a slot liner of a rotary electric machine, prevent dielectric breakdown, and improve heat dissipation of a coil. .

[0006]

In order to solve the above-mentioned problems, in the slot liner of the rotary electric machine according to the present invention,
Reinforcing sheets are separately arranged on both ends of the sheet separately from each other. That is, the reinforcing sheet is arranged in the slot so as to extend in the axial direction of the rotating electric machine and near the end of the main insulating sheet that insulates the coil from the core. The reinforcing sheet reinforces the main insulating sheet near the end of the core, and receives a part of the load received from the coil by the main insulating sheet due to, for example, the treatment of the coil end to ensure insulation. Further, the reinforcing sheet does not exist except the end portion of the slot liner, and therefore, the reinforcing sheet does not peel off and hinder the heat transfer from the coil to the core.

The reinforcing sheet needs to be considered with respect to the usage environment of the rotating electric machine, particularly the temperature. When a resin material is used, if carbonization occurs at high temperature, the insulating property decreases, so it is necessary to select a material that is suitable for the temperature conditions.
If polyimide is used as the resin material, heat resistance of at least 400 ° C. can be obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. Figure 1
FIG. 3 is a cross-sectional view of a stator of a rotary electric machine such as an electric motor or a generator. The core 10 of the stator has a substantially cylindrical shape, and teeth 12 are arranged at predetermined intervals in the circumferential direction on the inner circumference, that is, the surface facing the rotor. Inside the slot 14, which is the space between the teeth 12, there is arranged a conductor 16 forming a coil.

FIG. 2 is an enlarged view of one slot 14. Between the conductor 16 of the coil and the core 10, a slot liner 18 as an insulating material is arranged along the inner circumference of the slot. Slot liner 18
Is composed of three mica insulating sheets 20, 22, 24 at the central portion in the axial direction. Slot 1
A wedge 25 is arranged in the opening portion of No. 4.

FIG. 3 is a sectional view of the stator of the electric motor as viewed in the direction orthogonal to the axis. The slot liner 18 extends in the axial direction of the electric motor, its length is longer than that of the core 10, and both ends project from the core end surface 26. The slot liner 18
Further, it includes a main insulating sheet 28 consisting of the above three layers of mica insulating sheet and extending over the entire length thereof, and a reinforcing sheet 30 arranged only at both ends. As shown in the figure, one reinforcing sheet 30 is arranged on the outer side of the main insulating sheet 28 at the position of the core end surface 26 and the left and right positions thereof. That is, it is interposed between the main insulating sheet 28 and the core 10.

A coil end 34, which is a portion of the coil 32 housed in the core, extending from the end face of the core, is formed so as to be bent outward in the radial direction of the rotating electric machine as shown in the figure after forming the coil. At this time, the portion of the slot liner 18 protruding from the core end surface 26 is pushed, and a bending load is generated. In particular, high stress is generated at the corners of the core end surface 26. The reinforcing sheet 30 disperses this stress and reduces the stress generated in the main insulating sheet 28. As a result, the mechanically weak insulating sheet made of mica is prevented from being damaged and the insulating property is secured.

The reinforcing sheet 30 is made of polyimide resin. The heat resistance of the polyimide resin is very high. For example, Kapton (registered trademark) manufactured by DuPont has a heat resistance of about 400 ° C. Since it has such high heat resistance, it does not carbonize even in a high temperature environment, and it is possible to ensure insulation.

As shown in FIG. 3, the slot liner 1
The reinforcing sheet 30 does not exist in portions other than both end portions of 8. Therefore, the heat generated by the current flowing through the conductor of the coil does not pass through the reinforcing sheet 30 and
Transmitted to 0. That is, the reinforcing sheet 30 does not hinder the heat transfer in the central portion of the core, and high heat dissipation characteristics are obtained. Further, although the polyimide resin does not carbonize at 400 ° C., it shrinks at a temperature higher than this.
If the adhesion between the core and the reinforcing sheet deteriorates due to this shrinkage, there is a problem that heat transfer is hindered. From this aspect as well, the reinforcing sheet 30 is arranged only at the end portion of the slot liner 18. That is, even if the reinforcing sheet is shrunk, if it is arranged only at both ends, heat transfer in the central portion is not hindered and heat dissipation is secured.

FIG. 4 is a view showing another structure of the end portion of the slot liner. The main insulating sheet 40 has the same configuration as the main insulating sheet 28 described above. Main insulation sheet 40
At both end portions of the core, that is, near the end surface of the core, the reinforcing sheet 4
2 are arranged. The reinforcing sheet 42 is folded,
The folds at this time are made to extend along the edges of the main insulating sheet 40, and are thereby arranged so as to cover the edges of the main insulating sheet 40. Thereby, the end portion of the main insulating sheet 40 can be reinforced more strongly.

[Brief description of drawings]

FIG. 1 is a schematic axial cross-sectional view of a stator core of an electric motor.

FIG. 2 is an enlarged view of a slot portion of the stator core of FIG.

FIG. 3 is a schematic cross-sectional view including a shaft of a stator core.

FIG. 4 is a perspective view showing another example of a reinforcing sheet.

[Explanation of symbols]

10 stator cores, 12 teeth, 14 slots, 18
Slot liner, 26 core end face, 28,40 main insulating sheet, 30,42 reinforcing sheet.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Ogura             2-16-2 Noguchi-cho, Higashimurayama-shi, Tokyo Sun             Kiso Co., Ltd. Higashimurayama Works (72) Inventor Maguchi Eguchi             2-16-2 Noguchi-cho, Higashimurayama-shi, Tokyo Sun             Kiso Co., Ltd. Higashimurayama Works F-term (reference) 5H604 AA02 CC05 CC14 DB26 PA07                       PB04 PC01 PD02 PD03

Claims (5)

[Claims] 1. A slot liner arranged in a slot of a core of a rotating electric machine, which is a slot liner for insulating a conductor housed in the slot from the core, the slot liner extending in an axial direction of the rotating electric machine. A main insulating sheet having a length equal to or greater than the core, and separately provided near both ends of the core, separately from each other, and overlapped with a portion of the main insulating sheet including the position of the core end surface. And a reinforcing sheet which is disposed at least between the core and the main insulating sheet and reinforces a load applied to the main insulating sheet. 2. The slot liner according to claim 1, wherein the reinforcing sheet is made of polyimide. 3. The slot liner according to claim 1, wherein the reinforcing sheet has heat resistance of 400 ° C. or higher. 4. The slot liner according to claim 1, wherein the reinforcing sheet is bent,
A slot liner whose folds correspond to the ends of the main insulating sheet and are arranged to cover the ends. 5. A rotating electric machine using the slot liner according to any one of claims 1 to 4.