JPH09285053A - Insulating method for stator core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable insulating method for a stator core by preventing a crack in a corner part of the stator core in a motor. SOLUTION: A yoke part 2 of a stator core 1 has I-shaped tooth parts 3a at equal intervals and a pair of symmetrical C-shaped tooth parts 3b from base ends of the tooth parts 3a on both sides, while an inner groove 4a and an outer groove 4b are formed on inner or outer sides of the C-shaped tooth parts 3b. The stator core 1 is covered in an insulated state by resin insert molding except for an end part of the tooth parts 3a opposing to a rotor. In this case, a groove insulating layer 5 is formed in the grooves 4a and 4b in a first step. An edge plate 6 is formed at an edge face of the stator core 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for insulating a stator core, and more particularly, to a method and a process for forming a groove insulating layer and an end plate.

[0002]

2. Description of the Related Art Conventionally, as an example of a method of insulating a stator core in an electric motor, as shown in FIG. 6, a substantially I-shaped tooth portion 3a is provided from a yoke portion 2 of a stator core 1 at equal intervals. Symmetrical substantially U-shaped tooth portions 3b are provided on both sides of every other base end of the substantially I-shaped tooth portions, and inner grooves 4a are provided inside and outside the substantially U-shaped tooth portion, respectively. The outer groove 4b is formed, and at least the tips of the tooth portions facing the rotor are removed, and the stator core is covered by insert molding with a resin to cover the stator core, as shown in FIG. The insulating layer 5 and the end plate 6 were integrally molded.

In this case, stress is generated due to thermal expansion and contraction and the like, and at the corner portion which becomes the boundary between the groove insulating layer 5 and the end plate 6,
There is a problem that stress concentration may occur and cracks may occur.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. Insulation of a stator core is achieved by preventing cracks in the corners of the stator core of an electric motor and improving reliability. It is intended to provide a way.

[0005]

In order to achieve the above object, a plurality of tooth portions protruding from a yoke portion of a stator iron core are provided, and grooves are formed between the tooth portions to form at least a rotor and a rotor. Except for the tips of the tooth portions facing each other, in a method for insulating a stator core insert-molded with resin to cover the stator core, a groove insulating layer is formed in the groove as a first step, and as a second step, The end plate is formed on the end surface of the stator core.

The groove insulating layer is projected from both end faces of the stator core. Further, the protruding length of the groove insulating layer is at least 2 mm. Further, the thickness of the end plate is at least 2 mm. After a while
The thickness of the end plate is smaller than the protruding length of the groove insulating layer.

On the other hand, the material of the resin is a thermoplastic resin. And, the thermoplastic resin is PBT
(Polybutylene terephthalate) or PPS (polyphenylene sulfide) or PET (polyethylene terephthalate).

Further, the coefficient of thermal expansion of the resin material of the groove insulating layer and that of the resin material of the end plate are made substantially the same.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of tooth portions projecting from a yoke portion of a stator core are provided, grooves are formed between the tooth portions, and at least the tips of the tooth portions facing the rotor are excluded. In a method of insulating a stator core by insert molding with a resin to cover the stator core, a groove insulating layer is formed in the groove as a first step, and an end plate is formed on an end surface of the stator core as a second step. I will do it.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, the same reference numerals are used for the same parts as in the related art. FIG. 1 is a plan view showing a stator core that has been subjected to an insulation treatment according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part showing a stator core formed with a groove insulating layer in the first step. 3 is
FIG. 3 is an enlarged sectional view of a main part corresponding to AA ′ in FIG. 2. Also,
FIG. 4 is an enlarged cross-sectional view of an essential part showing a stator core formed by molding an end plate in the second step, and FIG. 5 is an enlarged cross-sectional view of an essential part corresponding to BB ′ in FIG.

In this embodiment, substantially I-shaped tooth portions 3a are provided at equal intervals from the yoke portion 2 of the stator iron core 1, and the substantially I-shaped tooth portions are provided on both sides of the base end of every other tooth portion. A symmetrical substantially U-shaped tooth portion 3b is provided, and an inner groove 4a and an outer groove 4b are formed inside and outside the substantially U-shaped tooth portion 3b, respectively. The present invention is not limited to this stator core.

First, the groove insulating layer which is the first step is first applied, which will be described with reference to FIGS. 2 and 3.

In this step, the groove insulating layer 5 corresponds to the electrical appliance control method, and at least 2 from both end surfaces of the stator core.
In order to form a protrusion 5a having a length ts that protrudes by mm, insert molding is performed using PBT (polybutylene terephthalate), which is a thermoplastic resin, except at least the tips of the teeth that face the rotor.

Next, a step of the end plate, which is a second step, is performed. This step will be described with reference to FIGS. 4 and 5. Here, the thickness t of the end plate 6 also corresponds to the electrical appliance control method, is at least 2 mm, is smaller than the protruding length of the groove insulating layer, and is the same as the material of the groove insulating layer. Insert molding is performed using PBT (polybutylene terephthalate) which is a thermoplastic resin.

By thus forming the groove insulating layer and the end plate in the first and second steps, the boundary between the groove insulating layer and the end plate is generated even if stress is generated due to the thermal expansion and contraction. The corner portions to be formed can absorb stress due to the gap between the groove insulating layer and the end plate.

Further, even if the deviation occurs, the thickness is at least 2 mm, which corresponds to the electrical appliance control method.
Further, since the thermoplastic resins having substantially the same thermal expansion coefficient are used, the deviation is minute.

The thermoplastic resin may be PPS (polyphenylene sulfide) or PET (polyethylene terephthalate). Further, different thermoplastic resins having substantially the same thermal expansion coefficient as the resin material of the groove insulating layer and the end plate may be used.

[0018]

As described above, in the present invention, a plurality of tooth portions projecting from the yoke portion of the stator core are provided, and grooves are formed between the tooth portions, respectively, and at least face the rotor. In a method of insulating a stator core, which covers the stator core by insert molding with a resin, excluding the tip of the tooth portion,
As a first step, a groove insulating layer is formed in the groove, and as a second step, an end plate is formed on an end surface of the stator core.

As a result, it is possible to provide a stator core insulation method that prevents cracks at the corners of the stator core of the electric motor and improves reliability.

[Brief description of drawings]

FIG. 1 is a plan view showing an insulated stator core according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part showing a stator core formed with a groove insulating layer in the first step of the present invention.

FIG. 3 is an enlarged sectional view of a main part corresponding to AA ′ of FIG. 2;

FIG. 4 is an enlarged sectional view of an essential part showing a stator core formed by molding an end plate in a second step of the present invention.

FIG. 5 is an enlarged sectional view of a main part corresponding to BB ′ in FIG. 4;

FIG. 6 is an enlarged plan view of an essential part showing an example of a conventional stator iron core subjected to an insulation treatment.

FIG. 7 is an enlarged sectional view of a main part corresponding to CC ′ in FIG. 6;

[Explanation of symbols]

 1 Stator core 2 Yoke part 3a Approximately I-shaped tooth part 3b Approximately U-shaped tooth part 4a Inner groove 4b Outer groove 5 Groove insulation layer 5a Projection 6 End plate insulation layer ts Projection length t Thickness of insulating layer of end plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kawai 1116 Suenaga, Takatsu-ku, Kawasaki City, Fujitsu General Ltd. (72) Inventor Yuji Soma 1116 Suenaga, Takatsu-ku, Kawasaki City, Fujitsu General

Claims (8)

[Claims] 1. A resin core is provided with a plurality of tooth portions projecting from a yoke portion of a stator core, grooves are formed between the tooth portions, and at least the tips of the tooth portions facing the rotor are removed. In a method of insulating a stator core by insert molding to cover the stator core, a groove insulating layer is formed in the groove as a first step, and an end plate is formed on an end surface of the stator core as a second step. A method for insulating a stator core, comprising: 2. The method for insulating a stator core according to claim 1, wherein the groove insulating layer is projected from both end surfaces of the stator core. 3. The method of insulating a stator core according to claim 2, wherein the protruding length of the groove insulating layer is at least 2 mm. 4. The method of insulating a stator core according to claim 1, wherein the end plate has a thickness of at least 2 mm. 5. The thickness of the end plate is smaller than the protruding length of the groove insulating layer.
Insulation method for the stator core described. 6. The method of insulating a stator core according to claim 1, wherein the resin material is a thermoplastic resin. 7. The insulation method for a stator core according to claim 6, wherein the thermoplastic resin is PBT (polybutylene terephthalate), PPS (polyphenylene sulfide) or PET (polyethylene terephthalate). 8. The method of insulating a stator core according to claim 1, wherein the groove insulating layer and the resin material of the end plate have substantially the same thermal expansion coefficient.