JPH0686491A - Manufacture of winding of rotating electric machine - Google Patents

Abstract

PURPOSE:To provide the winding for a rotating electric machine, which prevents the outflow of resin from a lead branching part, and whose insulating characteristic and workability are improved. CONSTITUTION:An expanding fiber sheet 7, which is expanded when resin is impregnated, is applied between lead insulating layers at the lead branching part of a coil. Then, a lead insulating part 6 is covered with a ground insulating layer 4. Thereafter, hardening resin is compressed and impregnated in the vacuum state at normal temperature, and the expanding fiber sheet 7 is expanded. Thus, the outflow of the resin at normal temperature is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding outlet branch portion of a rotary electric machine, and more particularly to a method of manufacturing a winding for preventing impregnated resin from flowing out in a vacuum pressure impregnation insulation method.

[0002]

2. Description of the Related Art In a conventional rotary electric machine winding, for example, a mica tape is wound a specified number of times on the lead wire of the coil and the coil conductor, and further outer layer insulation is applied to form ground insulation. After that, the coil is housed in an iron core, a lead wire is connected to the coil to insulate the coil, and then epoxy resin is impregnated under a vacuum pressure and cured by heating to manufacture a final rotary electric machine winding.

Generally, the impregnated resin has a low viscosity (about 0.5 to 5 poises) in order to improve the impregnation property into the insulating layer.
It has become. Therefore, in the course of curing the resin, the resin flows out from the outlet branching portion with a decrease in viscosity due to the temperature characteristic of the resin. As a result, a gap is created in the area between the output insulating layer and the coil loop insulating layer at the output branching portion to connect the coil conductor and the outside, and as a result, moisture and dust enter from the output branching portion to insulate the coil conductor. The characteristics are deteriorated, which leads to dielectric breakdown.

In order to prevent this, conventionally, (1) a method of previously winding a thermosetting semi-cured resin tape around the outlet insulating layer (for example, Japanese Patent Publication No. 57-21935), (2) winding outlet branching portion A rubber compound, a prepreg sheet, or the like (for example, JP-A-58-39234), (3) a method in which the entire connecting portion is pre-cast with an epoxy resin, (4)
There is a method in which a small amount of a curing accelerator that reacts with the resin in the process of heat curing is put in the adhesive of the mica tape wound on the conductor.

[0005]

SUMMARY OF THE INVENTION In a method for manufacturing a rotary electric machine winding by vacuum pressure impregnation, the gap between the lead-out branch portions is to allow the gap between the coil conductors and the ground insulating layer to be impregnated with resin easily in a short time. Is an important impregnation route. However, in these methods, the method (2) closes the resin impregnation path at the branching point of the mouth, impedes impregnation property and prolongs impregnation time, which causes incomplete impregnation. The method (3) cannot impregnate the resin from the branching part of the mouth. In addition, since the outlet branch portion and the coil end are wrapped with resin, the heat dissipation is deteriorated and the heating tends to occur. Further, a mold type is also required, which increases the manufacturing cost. In the method of (1) or (4), after impregnating the winding with the resin and heating and curing, the impregnated resin is branched before the curing accelerator or the like reacts with the impregnated resin due to a decrease in the viscosity of the resin. Outflow from the department.
As described above, the conventional method for preventing the outflow of the impregnated resin has the above-mentioned drawbacks in terms of its operation effect, man-hours, and cost. SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the drawbacks of the prior art, to prevent resin outflow from the outlet branch portion, and to provide a rotary electric machine winding having improved insulation characteristics and workability.

[0006]

According to the present invention, an expandable fiber sheet that expands when a resin is impregnated is applied between a lead insulating layer and a coil loop insulating layer in a lead branch portion of a coil.
Next, the outlet insulation is covered with a ground insulation layer. After that, the curable resin is impregnated under vacuum at room temperature to expand the expansive fiber sheet and prevent the resin from flowing out at room temperature.

[0007]

According to the rotary electric machine winding having such a structure, when the winding is impregnated with the impregnating resin in the manufacturing method by vacuum pressure impregnation, the impregnating resin is evacuated in advance in the impregnating tank. inject. Therefore, the pressure in the winding and the pressure in the tank resin are the same. Therefore, since the impregnated resin does not come into contact with the entire expandable fiber sheet, the expandable fiber sheet does not expand. Impregnation of the resin into the gap between the coil conductors and the ground insulation is performed during the pressure treatment. Therefore, the expandable fiber sheet does not hinder the resin impregnation into the ground insulation. Further, even when the expansive fiber sheet is expanded by the impregnated resin, it is easy to supply the resin to the gap between the coil conductors because it is fibrous and the pressure difference is large.

After the pressure treatment is completed or during the treatment, the expandable fiber sheet is impregnated with the resin and expanded. As a result, there is no gap at the outlet branch portion at room temperature. Therefore, even if the viscosity of the resin is lowered in the process of heating and curing the resin, the resin does not flow out in the winding insulating layer, particularly in the coil conductor gap.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the coil conductor 1 formed in a hexagonal shape, as a first step, the mica tape 3 is wound on the coil loop portion 2 in a ½ stack for a specified number of times to form a ground insulation 4. As the second step, 1/2 the mica tape 3 on the lead wire 5
The lead insulation 6 is formed by winding a specified number of times in layers. As a third step, an expandable fiber sheet 7 that expands when the resin is impregnated is applied between the outlet insulation 6 and the ground insulation 4 of the coil loop portion 2 at the outlet branch portion of the coil. Although the thickness of the expansive fiber sheet may be changed depending on the coil cross-sectional shape,
It is preferably about 5 to 2 mm. Further, the width is preferably about the coil width after insulation, and the length is preferably about 2 mm or more, but since the sheet expands, it is not necessary to be particular about dimensions.

Next, the output insulation 6 is attached to the mica tape 3 by 1 /
Two layers are formed so as to be wound a specified number of times and covered with the ground insulation 4. As the fourth step, the coil is put in an iron core and the lead wire 5
After connecting and insulating the connecting portion, a thermosetting resin is impregnated under vacuum at room temperature under vacuum pressure to be cured by heating to obtain a rotating electric machine winding.

Impregnation of the resin into the gaps between the coil conductors 1 and the ground insulation 4 is carried out during the pressure treatment. Therefore,
The expansive fiber sheet 7 does not hinder the impregnation of the ground insulation 4 with the resin. Further, even when the expansive fiber sheet 7 is expanded by the impregnated resin, it is easy to supply the resin to the gap of the coil conductor 1 because it is fibrous and the pressure difference is large. After the pressure treatment is completed or during the treatment, the expandable fiber sheet 7 is impregnated with the resin and expands. This allows
There is no gap at the outlet branch at room temperature.

According to the constitution of the above-mentioned embodiment, in the vacuum pressure impregnation treatment at room temperature, there is no impediment to the resin impregnation of the coil, and the branching of the outlet after the pressure treatment is completed or during the treatment. Since the gap between the portions can be eliminated, even if the viscosity of the resin decreases in the process of heating and curing the resin, the resin does not flow out in the winding insulating layer, particularly in the gap of the coil conductor 1.

As described above, the resin impregnated in the gap between the coil conductor 1 or the four layers of ground insulation does not flow out from the outlet branching portion, so that no void is generated in the vicinity of the coil conductor 1 and the ground insulation layer 4, and the resin shown in FIG. As described above, the tan δ-voltage characteristic is significantly improved as compared with the conventional insulation. In addition, since there is a sealing effect on the branching portion of the outlet, there is no reduction in insulation resistance due to flooding as shown in FIG. Therefore, the environmental resistance is also greatly improved.

[0014]

As described above, according to the present invention, voids do not occur near the coil conductor and the ground insulating layer, and tan δ
-Significantly improved voltage characteristics compared to conventional insulation. In addition, since there is also a sealing effect on the branching portion of the outlet, the insulation resistance does not decrease due to water immersion, and the environmental resistance is greatly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotary electric machine coil according to the present invention in the vicinity of a lead-out branch portion,

FIG. 2 is a tan δ-voltage characteristic comparison diagram between the winding of the present invention and a conventional one;

FIG. 3 is a comparison diagram of water resistance characteristics of the winding of the present invention and a conventional one.

[Explanation of symbols]

 1 …… Coil conductor 2 …… Coil loop part 3 …… Mica tape 4 …… Ground insulation 5 …… Lead wire 6 …… Lead insulation 7 …… Expandable fiber sheet

Claims (1)

[Claims] 1. In a rotary electric machine winding including a lead branch portion of a coil conductor, an expansive fiber sheet that expands when impregnated with resin is applied to a portion between the lead insulating layer and the coil loop insulating layer of the coil conductor, A method for manufacturing a winding of a rotary electric machine, wherein the lead-out insulating layer is covered with a ground insulating layer, and a thermosetting resin is impregnated under a vacuum to heat-harden the resin.