JPH05184091A - Fabrication of winding for electric machine - Google Patents

Abstract

PURPOSE:To easily obtain an insulation layer having no void nor delamination. CONSTITUTION:In the fabrication of winding for electric machine wherein a main insulation layer 2 and a thermally shrinkable insulation layer(which is left as it is or subsequently removed) 3 are applied sequentially on a wound conductor 1 and impregnated with thermosetting resin which is subsequently set thermally, an insulating material having thermal shrinkage rate of 5-20% at the highest heating temperature of the thermosetting resin is employed as the thermosetting resin 3. Consequently, molding pressure in the range of 3-15kg/cm<2> is applied on the insulation layer at the time of thermal molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing electric equipment windings.

[0002]

2. Description of the Related Art A conventional method for manufacturing windings of electric equipment is disclosed in, for example, Japanese Utility Model Laid-Open No. 53-130484 and Japanese Patent Laid-Open No. 58-723.
48, JP-A-62-68030, JP-A-2
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. 128406, etc., a heat-shrinkable material is wound around the outside of the main insulating layer, and a pressing force due to the shrinkage of the heat-shrinkable material is used to obtain an electric device winding having a dense insulating layer. ..

However, since it is difficult to obtain a dense insulating layer even with such a heat-shrinkable material, a backing plate is used. That is, as shown in FIG. 2, the main insulating layer 2 is wound on the wound conductor 1 and the heat-shrinkable insulating layer 3 is wound on the outer side of the main insulating layer 2, followed by impregnation with a thermosetting resin. To do. When the thermosetting resin is subsequently heat-cured, as shown in the figure, the contact plate 4 is placed on the outer side of the heat-shrinkable insulating layer 3.
To heat-harden the impregnated resin, and tighten the backing plate 4 during the process of thermosetting the impregnated resin, and the pressing force of the backing plate 4 and the heat-shrinkable insulating layer 3 provides a rotating electric machine winding with a dense insulating layer. .. After the thermosetting resin is cured, the backing plate 4 is removed, but the heat-shrinkable insulating layer 3 may be left as it is or may be removed.

[0004]

A rotating electric machine, for example, a rotating electric machine for a vehicle, is more durable than a rotating electric machine for general industrial use under severe operating conditions such as vibration from a truck, a heat cycle due to load fluctuation, and moisture in rain or snow. In addition to high reliability, insulation with high heat resistance is required to achieve downsizing and weight reduction of equipment. In order to meet these requirements, it is necessary to eliminate voids, peeling, etc. in the insulating layer.

Therefore, in the conventional winding of electric equipment, the impregnating resin is heat-cured by applying a patch plate to be removed later to the outside of the winding having the heat-shrinkable insulating layer as described above.

Although the backing plate is used as described above, uniform pressure is applied to the electric equipment winding having a complicated shape, and the maximum temperature and pressure applied during heating of the thermosetting resin are taken into consideration. In some cases, a uniform insulating layer without voids or peeling in the insulating layer may not be formed.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing an electric device winding capable of easily obtaining an insulating layer free from voids or peeling in the insulating layer. It is what

[0008]

The above-mentioned object is to heat the heat-shrinkable insulating layer to a maximum heating temperature of 180 ° C. during heating of the thermosetting resin.
This is achieved by using an insulating material having a heat shrinkage ratio of 5 to 20% at ˜240 ° C.

[0009]

[Action] is provided with the above means, when heat molding, so applied molding pressure of 3kg / cm ² ~15kg / cm ² in the insulating layer.

The inventors of the present invention have various types of pressure (pressure applied to the insulating layer) at the time of molding the insulating layer impregnated with the thermosetting resin (at the time of thermosetting of the thermosetting resin) and occurrence of voids and peeling of the insulating layer. The molding pressure condition was examined. As a result, the molding pressure was 3 kg / cm at the maximum temperature of 180 ° C to 240 ° C during heating.
It has been found that a good insulating layer can be obtained at ^{2 to} 15 kg / cm ² .

In order to achieve this molding pressure by winding a shrinkable insulating material around the insulating layer, the relationship between the shrinkage rate of the shrinkable insulating material and the generated molding pressure was examined. As a result, the vertical axis shows the molding pressure applied to the insulating layer,
As shown in FIG. 4, which shows the relationship between the molding pressure applied to the insulating layer and the contraction rate of the insulating material by taking the contraction rate of the insulating material on the horizontal axis, Maximum temperature of 1
If 5% to 20% at 80 ° C. to 240 ° C., a molding pressure applied to the insulating layer was found to be a ^{3kg / cm 2 ~15kg / cm 2} .

Therefore, the shrinkable insulating material wound around the insulating layer is heated to a maximum temperature of 180 ° C. to 240 ° C.
It was confirmed that when the shrinkage was 0%, voids and peeling did not occur in the insulating layer without using a patch plate as in the conventional case.

Therefore, in the present invention, the heat-shrinkable insulating layer is made of an insulating material having a heat-shrinkage rate of 5 to 20% at the maximum heating temperature of 180 ° C. to 240 ° C. during heating of the thermosetting resin. By doing this, voids in the insulating layer,
It is possible to obtain a method for manufacturing an electric device winding that makes it possible to easily obtain an insulating layer without peeling.

[0014]

EXAMPLES Next, the present invention will be specifically described by way of examples.

[Embodiment 1] FIG. 1 shows an embodiment of the present invention. Note that the same parts as those of the related art are denoted by the same reference numerals, and the description thereof will be omitted. In this example, an insulating material having a heat shrinkage ratio of 5 to 20% at the maximum heating temperature of 180 ° C to 240 ° C during heating of the thermosetting resin was used. By doing so, during heat molding, the insulating layer has a pressure of 3 kg / cm ² to 1
By applying a molding pressure of 5 kg / cm ² , it is possible to obtain a method for manufacturing an electric device winding that makes it possible to easily obtain an insulating layer without voids or peeling in the insulating layer.

That is, as the conductor 1, a double glass winding was wound a plurality of times, and after the winding, the conductor 1 was molded to smooth the surface of the conductor 1. Next, a glass-backed mica tape is wound half-fold four times to form a main insulating layer 2, and a tetrafluoroethylene-based tape having heat shrinkability is formed on the outside thereof (for example, Nitflon Tape No. 920 manufactured by Nitto Denko Corporation). 2) was half-lapped and wound twice to form the heat-shrinkable insulating layer 3. After that, it is impregnated with epoxy type thermosetting resin for impregnation, 120 ° C / 10h + 220 ° C.
It was heat-cured at / 15h to form a field winding.

COMPARATIVE EXAMPLE 1 As shown in FIG. 3 as Comparative Example A, this example, conductor 1 (double glass winding is wound a plurality of times), main insulating layer 2 (glass-backed mica tape). The same procedure is applied for half-wrapping 4 times), and the outer insulating layer 5 is formed by wrapping a glass tape on the outside of the main insulating layer 2 instead of the heat-shrinkable insulating layer half-wrapping twice. Thereafter, as in the example, the thermosetting resin for epoxy impregnation was impregnated, and 120 ° C./10
It was heat-cured at h + 220 ° C./15 h to form a field winding.

[Comparative Example 2] FIG.
The one shown in was used. That is, the conductor, the main insulating layer, the heat-shrinkable insulating layer, and the like are the same as those in this example, but the impregnated epoxy-based impregnating thermosetting resin is 120 ° C./10 h + 220 ° C.
When heat-curing at / 15 h, a backing plate to be removed later was pressed and cured.

In order to investigate the occurrence of voids and peeling in the insulating layer of the field windings of Example H, Comparative Example A and Comparative Example B thus formed, the surface of the insulating layer was hit with a hammer to strike a sound. I investigated the quality of. Moreover, the temperature rise of the field winding was investigated by applying a constant direct current to the field winding.

The results of the tapping sound investigation are summarized in FIG. 5 as the ratio of the tapping defective portions to the entire surface area of the insulating layer. As is clear from the figure, in the present Example H, there were 1.
5%, which is significantly smaller than 12% of Comparative Example A, and of course, it is reduced to 0.5%, which is the same as that of Comparative Example B where a pad plate is used, which is a defective tapping sound. In this way, the voids and peeling in the insulating layer were reduced to the same level as in Comparative Example B using the backing plate because the tetrafluoroethylene tape wound around the outermost layer of the insulating layer was thermosetting for impregnation. By heating the resin (120 ° C / 10h + 220 ° C / 15h),
Since it contracted about 7%, the pressure on the insulating layer was 5 kg / cm.
^This is because ² was applied, and it was found that a field winding with less voids and peeling can be obtained by using only the heat-shrinkable insulating layer without using a contact plate.

FIG. 6 shows the result of investigation on the temperature rise of the field winding.
It was shown to. This figure shows the change in the temperature rise rate of the field winding depending on the energization time when an energization current of 500 A is applied. As is clear from this figure, this Example H is Comparative Example B
The temperature rise is the same as that of Comparative Example A and is about 20% lower than that of Comparative Example A. Thus, it goes without saying that this Example H has a smaller temperature rise than Comparative Example A, and shows the same characteristics as Comparative Example B only in the heat-shrinkable insulating layer without using a backing plate. It was found that the voids and peeling in the insulating layer of the field winding can be almost eliminated as in Comparative Example B, and the thermal conductivity of the insulating layer can be improved.

As described above, according to this embodiment, an insulating layer free from voids and peeling is provided in the insulating layer by a simple method of winding an insulating material which shrinks by 5 to 20% by heating during the curing process of the thermosetting resin. can do.

In this embodiment, the insulating layer of the field winding is formed by the main insulating layer and the heat-shrinkable insulating layer. However, the present invention is not limited to this, and the heat-shrinkable insulating layer may be formed later. May be removed. When the heat-shrinkable insulating layer is removed later, the tetrafluoroethylene tape to be used has a smooth surface. When it is not removed later and is left as an insulating layer as in this embodiment, an ethylene tetrafluoride tape having a roughened surface is used.

Further, in this embodiment, if the winding can be wound even if the winding has a complicated shape, it is possible to easily manufacture a winding without voids or peeling in the insulating layer.

[0025]

As described above, according to the present invention, the heat-shrinkable insulating layer is heated to a maximum temperature of 180 ° C. to 2 ° C. during heating of the thermosetting resin.
Since an insulating material having a heat shrinkage rate at 40 ° C. of 5 to 20% was used, 3 kg / cm ^{2 to} 15 k was applied to the insulating layer during heat molding.
Since a molding pressure of g / cm ² is applied, it is possible to obtain a method for manufacturing an electric device winding that makes it possible to easily obtain an insulating layer without voids or peeling in the insulating layer.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing a state at the time of manufacturing a winding according to an embodiment of a method for manufacturing an electric device winding of the present invention.

FIG. 2 is a vertical sectional side view showing a state at the time of manufacturing a winding by a conventional method for manufacturing a winding of an electric device.

FIG. 3 is a vertical cross-sectional side view showing a state at the time of manufacturing a winding according to another example of the conventional method for manufacturing a winding of an electric device.

FIG. 4 is a characteristic diagram showing a relationship between a molding pressure applied to an insulating layer and a shrinkage rate of an insulating material.

FIG. 5 is a characteristic diagram showing the tapping defect portion characteristics of the winding of one example of the present invention and the winding of the comparative example.

FIG. 6 is a characteristic diagram showing a relationship between a temperature increase ratio and an energization time when a constant current is energized between the winding of one example of the present invention and the winding of a comparative example.

[Explanation of symbols]

 1 ... Conductor, 2 ... Main insulating layer, 3 ... Heat-shrinkable insulating layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuo Yasuzawa 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory

Claims (5)

[Claims] 1. A wound conductor is formed, a main insulating layer and a heat-shrinkable insulating layer are provided in this order on the formed conductor, and then a thermosetting resin is impregnated, and the thermosetting resin is heat-cured. In the method for manufacturing an electric device winding, the heat-shrinkable insulating layer,
Maximum heating temperature during heating of the thermosetting resin 180 ° C. to 2
An insulating material having a heat shrinkage rate of 5 to 20% at 40 ° C. is used. 2. The method for manufacturing an electric device winding according to claim 1, wherein the insulating material is a fluorine resin tape and the surface of which is roughened. 3. The method for manufacturing an electric device winding according to claim 1, wherein the electric device winding is used for a field device of a rotary electric machine for a vehicle. 4. A wound conductor is formed, and a main insulating layer and a heat-shrinkable insulating layer to be removed later are sequentially provided on the formed conductor, which is then impregnated with a thermosetting resin, and the thermosetting is performed. In the method for manufacturing an electric device winding in which a thermosetting resin is heat-cured, the heat-shrinkable insulating layer has a heat shrinkage rate of 5 to 20% at a heating maximum temperature of 180 ° C to 240 ° C during heating of the thermosetting resin.
A method for manufacturing an electric equipment winding, characterized in that the above insulating material is used. 5. The method for manufacturing an electric equipment winding according to claim 4, wherein the insulating material is a fluorine resin tape and the surface of which is smoothed.