JPH02136046A - Insulation structure and insulation processing method for electrical rotating machine coil - Google Patents

Abstract

PURPOSE:To improve the heat resistance of insulation by applying a strand insulation and an insulation to the earth by means of polyimide film tape or sheet constituted by a specific chemical structure and by impregnating said insulations with a resin compound composed of a main agent constituted by polyimide resin and epoxy resin, and acid anhydride curing agent and curing them to form the insulation of a coil. CONSTITUTION:A hexagonal strand coil conductor having a length l of e.g., 200mm in the linear part, in which conductor strands 3 obtained by applying a strand insulation 2 to a flat copper wire 1 (1.8X5.0mm) are bundled in 2 and 3 stages, is wound three times in a half-lap manner by a polyimide film having a chemical structure expressed by a formula 1 and one time in a half-lap manner by a glass tape having a thickness of 0.13mm as an armoring insulation to form an insulation 4 to the earth. Then, after a vacuum deaeration in a vacuum vessel, at 100 deg.C and for 4 hours, a resin compound mixing an acid anhydride curing agent with a main agent composed of polyimide resin and epoxy resin used to apply a vacuum pressurized impregnation. In a curing treatment, a precure at 150 deg.C for 16 hours and further an aftercure at 200 deg.C for 12 hours ae conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulating structure and an insulating treatment method for rotating electric machine coils having excellent heat resistance.

B. Summary of the Invention The present invention forms at least a part of the wire insulation and ground insulation with a film tape or sheet mainly made of polyimide having a specific chemical structure, and furthermore, a mixed resin of polyimide resin and epoxy ml is used. The heat resistance of the insulation is improved by impregnating and curing a resin compound consisting of a main ingredient consisting of the following and an acid anhydride curing agent to insulate the coils of rotating electric machines.

C9 Conventional technology There is a demand for smaller and lighter rotating electrical equipment from the perspective of energy and resource conservation.In particular, for vehicle electric motors, smaller size and lighter weight are paramount from the perspective of improving interlocking performance. ing. And, the small size and size of such rotating electrical equipment
One way to reduce weight is to improve the heat resistance of the coil insulation.

Insulating materials include inorganic materials and organic materials.
Although the former is superior in terms of heat resistance, organic materials are generally used in terms of workability and functionality. For high heat resistance grade equipment, polyimide resin is used, which is one of the most heat resistant and workable materials.

-S, in the insulation of rotating electric coils, film tapes or sheets are wound around the coil conductor for wire insulation and ground insulation, and gaps between these film tapes or sheets are filled with impregnated resin to prevent heat radiation and mechanical damage. It has a structure that improves strength and environmental resistance and prevents the occurrence of partial discharge, but in the heat-resistant grade, polyimide film material and polyimide 4!1 resin for impregnation are used as the film and impregnating resin.

D. Problems to be Solved by the Invention However, there are various types of polyimide resins. For example, for impregnation resins, the pot life and viscosity must be adjusted to improve workability. Currently, it is difficult to obtain satisfactory heat resistance properties because various functions are required for each resin used and mutual compatibility must be taken into consideration.

In view of these circumstances, the present invention aims to provide an electrical equipment insulation and insulation treatment method that has excellent heat resistance and good workability.

E. Means for Solving the Problems The insulating structure of the rotating electric machine coil of the present invention that achieves the above object is such that at least a part of the strands mm and the ground insulation are formed mainly from polyimide represented by the general formula. The impregnated resin insulation is made by curing a resin compound consisting of a base resin mixed with polyimide resin and epoxy resin and an acid anhydride curing agent. The processing method is based on the above general formula (
1) A base material made of a mixture of polyimide resin and epoxy resin in a rotating electrical machine coil that forms at least part of the wire insulation and ground insulation using a film tape or sheet mainly composed of polyimide represented by 1), and provides ground insulation. It is characterized by being impregnated with a resin compound consisting of and an acid anhydride curing agent and curing.

F. Function When a film tape or sheet mainly made of polyimide having the chemical structure represented by the above general formula (1) is combined with an impregnating resin containing a polyimide resin and an epoxy resin, the impregnation work It has good properties and compatibility, and also prevents deterioration of the film due to gases generated at high temperatures, greatly improving heat resistance.

G. Example The present invention will now be described based on preferred embodiments.

As shown in Figure 1 (a3, (b)), the rectangular [tl(
1.8X 5. A tortoise-shell-shaped strand coil conductor with a straight length l of 200 mm is made by bundling 3 rows of 2 tiers of strands 3 with strands R2 made of enamel and polyimide resin on Om),
A polyimide film (Upilex R; manufactured by Ube Industries, Ltd.) having a chemical structure represented by the general formula (1) is wound three times in a half-wrap manner, and a glass tape with a thickness of 0.13 ooa is further applied over the film as exterior insulation. It was wound once in a half wrap to provide ground insulation of 4. Model slots 4 made of iron plate with a length of 180 WI are placed on the straight parts on both sides of this coil.
was placed in close contact with the coil surface. After vacuum degassing treatment at 100°C for 4 hours in a vacuum container, vacuum pressure impregnation treatment is performed using a resin compound that is a mixture of polyimide resin and epoxy resin and an acid anhydride curing agent. was applied. As for the curing treatment, precure was performed in a drying oven at 150°C for 16 hours, and further,
After-cure was performed at 200°C for 12 hours.

For comparison, as a polyimide film, the following general formula (
Insulation treatment was performed in the same manner except that Kapton (manufactured by DuPont) having the chemical structure 2) was used.

−δ of the above-mentioned Examples and Comparative Examples. -The temperature characteristics are shown in Figure 2. The figure shows -δ with only ground insulation applied before resin impregnation. -Temperature characteristics are also shown.

As shown in FIG. 2, before impregnation, both values were small and no major difference was observed, but after impregnation, -δo(+1) in the high temperature region was significantly higher only in the comparative example.

On the other hand, -δ when the impregnated resin is made into a plate with a thickness of 2 mm. - When the temperature characteristics were investigated, as shown in Fig. 3, it was about 5% at 200°C, which was not a bad value.

From these results, it can be seen that the polyimide film represented by the general formula (1) used in the present invention has extremely good compatibility with the impregnating resin made of polyimide and epoxy resin.

Figure 4 shows the rate of decrease in dielectric breakdown strength after deterioration relative to the dielectric breakdown strength in the initial state when the model coils of the above-mentioned examples and comparative examples were thermally degraded in a constant temperature bath at 270°C. It is. Note that this dielectric breakdown strength was measured separately for the model slot portion S and the coil end portion e (see FIG. 1). As shown in the figure, it can be seen that in the model coil of the comparative example, the dielectric breakdown strength decreased in a short period of time, and the deterioration was severe. It can also be seen that the rate of decline is particularly high in the slot portion. In contrast, in the model coil of the example, the deterioration was gradual, and no difference was observed between the slot portion S and the end portion e.

From the results of Part B, it is clear that when the stator coil of an electric motor is installed in close contact with the slot part of the iron core and is integrally impregnated and has a high degree of sealing, in other words, the dielectric breakdown strength of the slot part of the comparative example is high. It can be seen that in cases where the deterioration is significant, the insulation of the present invention is extremely effective.

Next, a case where a film tape made of polyimide of the above general formula (1) (Upilex R; manufactured by Ube Industries, Ltd.) was used for wire insulation (Test Example 1).

Thermal deterioration of insulation was compared when used for ground insulation (Test Example 2) and when used for strand insulation and ground insulation (Test Example 3). In addition, Kapton (DuPont fM) was used for parts other than polyimide in general formula (1), and for comparison, a comparison was also made when Kapton was used for wire insulation and ground insulation (Comparative Example 1). did.

The insulation treatment was performed as follows.

Bare rectangular copper wire (size 1.8 mm x 5.0 +nm
), a film tape with a thickness of 0.05 mm and a width of 121 m+ is wound once in a half-wrap manner to form strand insulation, and the strands are bundled in 2 rows in 4 tiers to form a tortoiseshell-shaped element with a straight length of 200 mm. Formed into a wire coil conductor with a thickness of 0.05
mm, vAl A 9-cylinder film tape is wound three times in a half-wrap, and then a 0.5mm thick film tape is wrapped as an exterior insulation layer on top of the half-wrap film tape.
A 13m+n glass woven tape was wound once with eight flaps to provide ground insulation. Then, model slots made of iron plate with a length of 180 mm and a thickness of 5 mm were attached to the straight parts on both sides of the coil so as to be in close contact with the coil surface, and then polyimide resin and epoxy resin were added in the same manner as in the above embodiment. The mixture was impregnated with a mixture of the above and hardened in the same manner.

Regarding these Test Examples 1 to 3 and the control example,
The insulating wave*#4 force between the bare glands and the ground was measured after forced heating and deterioration at 85° C. for 12 days. In addition, the value of O (y) is expressed as residual insulation wave fs proof strength (%) with respect to the average value before deterioration, and is shown in Table 1.

Table 1 As shown in Table 1, wire insulation and ground insulation using a film made of polyimide shown in the above general formula (1) are as follows:
It shows an average yield strength of 60% or more. In this way, if the polyimide of general formula (1) is used for either wire insulation or ground insulation, or both, and is impregnated and cured with a mixed resin of polyimide and epoxy, heat resistance can be obtained as in the above example. It was found that there was a significant improvement.

Ho As described in detail of the invention, in the present invention, a film tape or sheet made of polyimide having a specific chemical structure is used for at least a part of the wire insulation and the ground insulation, and a polyimide resin, an epoxy resin, and an acid anhydride are used. By impregnating and curing a resin compound consisting of a hardening agent to form coil insulation, workability is good, and heat resistance is significantly improved due to improved compatibility between the film and the impregnated resin. be able to. Therefore, when applied to, for example, a vehicle electric motor, the driving performance of the vehicle can be improved and manufacturing costs can be reduced.

[Brief explanation of drawings]

Figure 1 (al, (bl) is a plan view and cross-sectional view of the model coil of the example, Figure 2 is a graph of -δA characteristic of the coil of the example, and Figure 3 is -δ of the resin plate. Figure 4 is a graph showing the temperature characteristics and the thermal deterioration time vs. dielectric breakdown strength characteristics of the model coil of the example. 4 is ground insulation, 5 is a model slot. (b) Figure tan δ0 temperature characteristic temperature, C) Procedural amendment September 8, 1989

Claims (1)

[Claims] 1) At least a part of the wire insulation and the ground insulation are made of a film tape or sheet mainly made of polyimide represented by the general formula, ▲numerical formula, chemical formula, table, etc.▼ An insulating structure for a rotating electric machine coil, characterized in that the impregnated resin insulation is made by curing a resin compound consisting of a main resin mixed with a polyimide resin and an epoxy resin and an acid anhydride curing agent. 2) A rotating electric machine with ground insulation formed by forming at least a part of the wire insulation and ground insulation with a film tape or sheet mainly made of polyimide represented by the general formula, ▲Mathematical formula, chemical formula, table, etc.▼ A method for insulating a coil of a rotating electric machine, which comprises impregnating a coil with a resin compound consisting of a base resin mixed with a polyimide resin and an epoxy resin and an acid anhydride curing agent and curing the coil.