JPH06237559A - Coil insulation of rotating electric machine - Google Patents

Abstract

PURPOSE:To provide the coil insulation o a rotating ellectric machine where the heat resistance improves and the electric performance is favorable. CONSTITUTION:A polyimide tape 6 and mica paper are stuck together by silicon adhesive vanish 10, and it is wound on a coil as a polyimide composite mica tape 5, and it is impregnated with thermosetting resin composition consisting of epoxy resin imide resin compound and an acid anhydride hardener so as to harden it. Further, it is to be desired that the quantity of silicon adhesive vanish 10 should be 3.5-20wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to coil insulation of a rotating electric machine used for a vehicle driving main electric motor, for example.

[0002]

2. Description of the Related Art Recent rotary electric machines are required to increase the capacity of a single machine by improving the heat resistance of coil insulation, reduce the size and weight, and make maintenance free. Conventionally, for materials of class H (220 ℃) or higher, which are used for coil insulation,
Examples include an aramid paper, a polyimide film, a polyamide film, and an integrated mica tape in which films are attached to mica paper. Since these are also extremely excellent in withstand voltage, they also greatly contribute to the thinning of the insulation thickness. Further, as the impregnating resin combined with these,
Polyester, epoxy resin, etc. are available.

On the other hand, the adhesive varnish for bonding the laminated mica tape and the impregnated resin do not have heat resistance higher than H type, and are peeled off between insulating layers or between the coil insulation and the iron core slot due to thermal stress, electromagnetic force, vibration, etc. during operation. Progresses and the thermal conductivity decreases. As a result, the life of the rotating electric machine is shortened due to defects in insulation resistance due to a rise in coil temperature, deterioration in water resistance and moisture resistance, and partial discharge deterioration.

Therefore, as a result of studying the winding material for the main insulation and the impregnating resin, as a resin for impregnating
-17532 was developed a heat resistant resin containing an epoxy resin and an imide resin, and it was confirmed that the heat resistance was H or higher.

[0005]

However, it has been found that the desired performance cannot be obtained by simply using such a heat resistant resin for coil insulation. That is, the type of adhesive varnish and the amount of adhesive required for laminating the mica paper and the film of the laminated mica tape in which the mica paper is lined with a film have a great influence, and the heat resistance and the electrical performance are significantly reduced. An object of the present invention is to provide coil insulation of a rotary electric machine that is excellent in heat resistance and electrical performance.

[0006]

In order to achieve the above object, the inventors of the present invention examined the type of adhesive varnish and the amount of adhesive as described above.

As for the type of adhesive varnish, polyester type adhesive varnish, epoxy type adhesive varnish, and silicone type adhesive varnish were examined. Silicone type adhesive varnish has the best heat resistance and heat resistance of 220 ° C or higher. It turned out that the sex can be obtained.

On the other hand, it has been found that heat resistance and electrical performance can be further improved depending on the amount of adhesive. In other words, when the amount of adhesive is too large and the adhesive varnish stains on the surface of the mica paper of the laminated mica tape,
At the time of ½ lap winding, interlayer adhesion occurs between the upper layer mica paper and the lower layer substrate film, impeding the impregnation property of the impregnated resin. On the other hand, when the amount of the adhesive is too small, the film and the mica paper are not sufficiently adhered to each other, resulting in uneven stacking margins and defective winding. In the former case, the dielectric loss tangent value rises and the partial discharge inception voltage decreases, and in the latter case, the dielectric breakdown voltage decreases and the coil size is not uniform.

Therefore, the amount of the adhesive is 3.5 to 28% by weight in consideration of the coiling property and the impregnating property of the mica paper and the heat resistant film with a silicone adhesive varnish.
By winding the laminated mica tape of the above in a coil and further impregnating and thermosetting a thermosetting resin composition consisting of an epoxy resin, an imide resin compound and an acid anhydride curing agent, heat resistance and electrical performance are improved. Can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a coil-insulated polyimide mica tape for coil insulation of a rotary electric machine of the present invention, FIG. 2 is an external view of coil insulation of a rotary electric machine of the present invention, and FIG. 3 is a coil insulation of a rotary electric machine of the present invention. It is a figure which shows an insulation structure.

In these figures, the stator coil 1 is as follows. That is, a polyimide tape or glass roving is wound, and a conductor 2 coated with a varnish and coated with an insulating coating 3 is molded and combined into a shape like a coil insulation 8 shown in FIG. For this purpose, the glass tape 4 is wound, and the linear portion is impregnated with epoxy resin or the like and cured.

On the other hand, depending on the voltage class, for example, 1500 (V)
In the case of a class induction motor, 3.5 to 28% by weight of the total weight is required for bonding polyimide tape 6 and mica paper 11 described later.
The polyimide adhesive mica tape 5 using the silicone adhesive varnish 10 (862HDT, Japan Mica Mfg. Co., Ltd.) whose adhesive amount was adjusted so that A glass tape 7 for holding the impregnated resin and securing the strength is wound around it once.

After that, the wound coil insulation 8 is inserted into the slot of the stator and preheated at about 120 ° C. to remove water and improve impregnation, and the compound of epoxy resin and imide resin and acid are added. Vacuum impregnation is performed with an impregnating resin consisting of an anhydride curing agent at a vacuum degree of about 70 (Pa) and a pressure of about 0.5 (MPa). The impregnating resin is cured at about 180 ° C. for 15 hours to obtain 1500 (V) class induction motor stator coil insulation according to the present invention.

For the coil insulation 8 thus obtained, a polyimide-bonded mica tape using a silicone-based adhesive varnish 10 of this embodiment and a conventional epoxy-based adhesive varnish (RDS-039 manufactured by Toshiba Chemical) was used. Coil insulation (referred to as Comparative Example 1) was produced, and both were subjected to heat deterioration and moisture absorption deterioration at 310 ° C. to measure the dielectric breakdown voltage (BDV), and heat resistance was evaluated (Table 1). In addition, the polyimide-bonded mica tape in which the compounding amount of the silicone-based adhesive varnish 10 is changed (the silicone-based adhesive varnish 10 is
Using 1.0 wt% and 30 wt%), coil insulation (Comparative Examples 2 and 3) was made in the same manner as above, and the dielectric loss tangent, the dielectric breakdown voltage, and the winding of the polyimide mica tape were respectively wound. The roundness was evaluated (Table 2).

As is clear from Table 1, in this example and the comparative example 1, it is understood that the example has a higher dielectric breakdown voltage after deterioration and is excellent in heat resistance. Regarding the winding property, there was no problem in the manual winding, but when the winding tension was increased, the cutting of the mica paper was observed in the latter.

Further, looking at Table 2, in Comparative Example 2, the amount of the bonding adhesive was extremely small, so that winding failure occurred. Compared to the example, the comparative example 2 is 1/2
Since there is a gap between the top and bottom of the stacked tapes, the impregnation property is good and the dielectric loss tangent value is small.
The breakdown voltage is reduced because the tape overlaps are uneven. In Comparative Example 3, since the amount of the adhesive was large, impregnation failure occurred due to interlayer adhesion between the mica paper of the upper layer tape and the polyimide film that is the base tape of the lower layer tape that were ½ stacked, and the dielectric loss tangent value was also determined in Example. It is much higher than the above, and there is a decrease in performance.

[0018]

[Table 1]

[0019]

[Table 2]

The coil insulation 8 of this embodiment is used as an adhesive varnish for laminating laminated mica tape, which is one of the constituent members,
It is characterized by using the above-mentioned heat-resistant resin as the impregnating resin to be combined with the silicone-based adhesive varnish that has excellent heat resistance by replacing the conventionally used epoxy-based adhesive varnish, but the superiority of withstand voltage after heat deterioration Basically, it depends largely on the heat resistance of the silicone adhesive varnish. The silicone-based adhesive varnish is characterized in that, when compared with the epoxy-based adhesive varnish in terms of dielectric breakdown voltage value and adhesive strength, the initial value is low, but the characteristic deterioration after thermal deterioration is small. Therefore, it is expected that the heat resistance can be improved by increasing the proportion of the silicone adhesive varnish, but the amount is regulated due to the coil insulation manufacturing process. Also,
Although the silicone-based adhesive varnish has excellent heat resistance, the cured product thereof has a characteristic of slightly poor adhesion. That is, the adhesive surface is peeled off due to vibration or thermal stress during vehicle operation, which causes a decrease in the partial discharge inception voltage, which shortens the life of the insulator and increases the dielectric pressure contact value.

However, when the heat-resistant impregnating resin disclosed in JP-B-58-17532 is combined, the adhesiveness is relatively good. Regarding the adhesive strength when the heat-resistant impregnating resin is impregnated on the film of the base material of the laminated mica tape using the silicone-based adhesive varnish of the present example, a comparative test with the conventional epoxy adhesive Was performed (Table 3). As is clear from Table 3, it can be seen that it is at the same level as the conventional one in the region of H type (220 ° C. including the ambient temperature) or higher.

[0022]

[Table 3]

[0023]

As described above, according to the present invention, a polyimide laminated mica tape obtained by bonding mica paper and a polyimide film with a silicone adhesive varnish is wound around a coil, and an epoxy resin, an imide resin compound and an acid anhydride are used. Since the thermosetting resin composition composed of the physical curing agent is impregnated and cured, heat resistance can be improved. Furthermore, the electrical performance can be improved by optimizing the amount of the silicone adhesive varnish.

[Brief description of drawings]

FIG. 1 is a diagram showing a coil-insulated polyimide laminated mica tape for a rotating electric machine according to the present invention.

FIG. 2 is an external view of coil insulation of the rotating electric machine of the present invention.

FIG. 3 is a diagram showing an insulating configuration of coil insulation of the rotating electric machine of the present invention.

[Explanation of symbols]

 5 ... Polyimide laminated mica tape 8 ... Coil insulation 10 ... Silicone adhesive varnish

Claims (2)

[Claims] 1. A thermosetting resin comprising an epoxy resin, an imide resin compound and an acid anhydride curing agent, which is obtained by winding a polyimide laminated mica tape obtained by bonding a mica paper and a polyimide film with a silicone adhesive varnish around a coil. Coil insulation for a rotating electric machine, characterized by being impregnated with a composition and curing. 2. The amount of the silicone adhesive varnish is 3.5.
The coil insulation of the rotating electric machine according to claim 1, wherein the coil insulation is about 28% by weight.