JPH10126995A - Insulation method for stator core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation method for stator core of a motor in which reliability is enhanced by protecting the corner part of stator core against crack. SOLUTION: Substantially I-shaped teeth 3a are arranged at constant intervals from the yoke part 2 of a stator core 1 and substantially U-shaped symmetric teeth 3b are arranged on the opposite sides of every other substantially U-shaped teeth while extending from the base end thereof. Inner and outer slots 4a, 4b are made, respectively, on the inside and outside of the substantially U-shaped teeth and the stator core is subjected to insert molding of resin at least except the forward end of the teeth 3d. In this regard, the stator core is impregnated, at first, with polyester varnish of heat resistant varnish 7 and dried and then a slot insulation layer 5 is formed in the slot and an end plate 6 is formed integrally at the end of the stator core.

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 for insulating a stator core in an electric motor, as shown in FIG. 6, substantially I-shaped teeth 3a are provided at equal intervals from a yoke 2 of a stator core 1. Symmetrical substantially U-shaped teeth 3b are provided on both sides of every other base end of the substantially I-shaped teeth, and inner grooves 4a are formed inside and outside the substantially U-shaped teeth, respectively. An outer groove 4b is formed, and except for at least the tip of the tooth portion, insert molding is performed with resin to cover the stator core, and as shown in FIG. 7, the groove insulating layer 5 of the stator core and the end plate are formed. 6 was integrally formed.

In this case, there is a problem that stress is generated due to thermal expansion / contraction and the like, and stress is concentrated at a corner portion serving as a boundary between the groove insulating layer 5 and the end plate 6 to cause cracks. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of the above-described problems. It is intended to provide an insulation method.

[0005]

In order to achieve the above object, a plurality of teeth protruding from a yoke of a stator core are provided, and grooves are formed between the teeth, and at least the teeth are formed. In the method of insulating a stator core that covers the stator core by insert molding with a thermoplastic resin except for a tip of the stator core, the stator core may have a heat-resistant varnish rounded at a corner of the stator core. After applying and heating and drying,
Insert molding with resin.

[0006] The varnish is applied so as to round the corners of the stator core.

Further, the varnish is a solvent type or a non-solvent type type E or higher electrically insulating varnish. The electrical insulating varnish is a polyester varnish.

On the other hand, after winding the stator core,
Avoid varnish treatment. On the other hand, the resin is
It should be a thermoplastic resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of teeth protruding from a yoke of a stator core are provided, grooves are formed between the teeth, and insert molding is performed with a resin except for at least the tips of the teeth. In the method for insulating a stator core covering the stator core, a heat-resistant varnish is applied to the stator core so as to round the corners of the stator core, and after drying by heating, the resin is heated. Insert molding.

[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 an insulated stator core according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view of a main part showing a stator core subjected to a varnish treatment in a first step. Is
FIG. 3 is an enlarged sectional view of a main part corresponding to AA ′ in FIG. 2. Also,
FIG. 4 is an enlarged sectional view of a main part showing a stator core formed with an end plate and a groove insulating layer in the second step, and FIG. 5 is an enlarged sectional view of a main part corresponding to BB 'in FIG.

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

First, the varnish process is performed first, and this will be described with reference to FIGS.

In this step, a polyester varnish of a heat-resistant varnish 7, which is a solvent-type or solvent-free type E or higher varnish, is coated on the stator core 1 except for at least the tip of the tooth portion. And heat drying.

Next, a step of forming a groove insulating layer and an end plate by insert molding with a resin is performed.
This will be described below. Here, a groove insulating layer 5 is formed in the inner groove 4a and the outer groove 4b, and end plates 6 are formed at both ends of the stator core by insert molding of PBT (polybutylene terephthalate) which is a thermoplastic resin. After the stator core 1 is wound, no varnish treatment is performed.

In this way, by forming the insulating layer in the above step, even if stress is generated due to the thermal expansion and contraction or the like, the corner at the boundary between the groove insulating layer and the end plate is subjected to the varnish treatment. Thus, the stress can be absorbed.

Since the stator core 1 is preliminarily subjected to varnish treatment, there is no fear of rusting, and the varnish treatment after winding can be omitted.

Furthermore, cracks are unlikely to occur because a thermoplastic resin is used. The thermoplastic resin is PPS
(Polyphenylene sulfide) or PET (polyethylene terephthalate) may be used.

[0018]

As described above, in the present invention, a plurality of teeth projecting from the yoke of the stator core are provided, grooves are formed between the teeth, and at least the tips of the teeth are formed. Except for the method of insulating the stator core by insert molding with resin and covering the stator core, the stator core is coated with a heat-resistant varnish so as to round the corners of the stator core, After heating and drying, insert molding was performed using a resin.

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

[Brief description of the drawings]

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

FIG. 2 is a main part enlarged plan view showing a stator core subjected to a varnish treatment in a 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 plan view of a main part showing a stator core formed with a groove insulating layer and 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 core subjected to insulation treatment.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator iron core 2 Yoke part 3a Substantially I-shaped tooth part 3b Substantially U-shaped tooth part 4a Inner groove 4b Outer groove 5 Groove insulating layer 6 End plate 7 Varnish

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Kawai 1116 Suenaga, Takatsu-ku, Kawasaki City Inside Fujitsu General Co., Ltd. (72) Inventor Yuji Soma 1116 Suenaga, Takatsu-ku Kawasaki City Inside Fujitsu General Co., Ltd.

Claims (5)

[Claims] A plurality of teeth protruding from a yoke portion of a stator core are provided, grooves are formed between the teeth, and at least a tip of the teeth is removed and insert-molded with a resin. In a method of insulating a stator core covering a stator core, a heat-resistant varnish is applied to the stator core so as to round the corners of the stator core, dried by heating, and then inserted with a resin. A method of insulating a stator core, which is formed by molding. 2. The method according to claim 1, wherein the varnish is a solvent type or a solventless type.
The method for insulating a stator core according to claim 1, wherein the insulating varnish is at least one kind. 3. The method for insulating a stator core according to claim 2, wherein the electrical insulating varnish is a polyester varnish. 4. The stator core insulating method according to claim 1, wherein a varnish treatment is not performed after the stator core is wound. 5. The method according to claim 1, wherein the resin is a thermoplastic resin.