Insulating material and electrical coil

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an electric winding of a rotary electric machine. Further, the present invention relates to an insulating material for forming an insulating coating of an electric winding.

【0002】

[Conventional technology]

Conventionally, the insulating coating of an electric winding used in a rotary electric machine has been formed by using, for example, an insulating material as described in Japanese Patent Application Laid-Open No. 63-110929. That is, an insulating material having a mica layer, a reinforcing material layer, and a filler layer having a filler having a high thermal conductivity and containing a resin in each layer was used. Then, this insulating material was wound around the outer peripheral portion of the winding conductor, and the resin in the insulating material was cured while applying pressure to the insulating material to form an insulating coating for the electric winding.

【0003】

[Problems to be Solved by the Invention]

There was no problem when the electric winding whose insulating coating was formed by using the above-mentioned insulating material was used for a rotary electric machine operated at a low voltage. However, when it is used for a rotating electric machine operated at a high voltage such as a commercial generator or a high-voltage electric motor, there is a tendency for electrical defects to occur, and there is a dislike that the electrical characteristics deteriorate.

【0004】

In view of this problem, the inventor of the present invention has investigated the cause of the tendency for electrical defects to occur. As a result, it was found that the cause was as follows. That is, when forming the insulating coating of the electric winding, some of the minute bubbles contained in the mica layer, the filler layer and the contained resin are not discharged together with a part of the contained resin. It was found that the cause was that it remained in the insulating material. This is because the amount of resin in each layer of the mica layer and the filler layer is not maintained at an appropriate content, and therefore, when forming the insulating coating of the electric winding, in the pressurizing process. , It was found that the flow of the impregnated resin contained was insufficient.

【0005】

An object of the present invention is to provide an electric winding having an insulating coating having excellent electrical characteristics. Another object of the present invention is to provide an insulating material capable of obtaining an insulating coating of an electric winding having excellent electrical characteristics.

【0006】

[Means for solving problems]

The insulating material according to the present invention has a mica layer, a reinforcing material layer, and a filler layer, and the amount of resin in each layer of the mica layer and the filler layer is 10 to 25% by weight of the entire insulating material.

【0007】

The mica layer is a layer having mica foil. The reinforcing material layer is a layer having a reinforcing material, for example, a glass cloth. The filler layer is a layer having a filler having a thermal conductivity of at least 5 W / m · K, for example, alumina. The insulating material is a laminate in which each of these layers is laminated in the order of mica layer, reinforcing material layer, and filler layer, or in the order of filler layer, mica layer, and reinforcing material layer.

【0008】

Further, the insulating material contains a resin, for example, an epoxy resin. The total amount of resin contained in the insulating material is 20 to 50% by weight of the entire insulating material, and the amount of resin contained in each layer of the mica layer and the filler layer is 10 to 25% of the total amount of the insulating material. It is% by weight.

【0009】

Here, the amount of resin in each layer of the mica layer and the filler layer is set to 10% by weight or more of the entire insulating material when forming the insulating coating of the electric winding, and the mica layer and the filler are filled in the pressurizing process. This is because it is necessary to contain at least 10% by weight of the total amount of resin in each layer of the mica layer and the filler layer in order to discharge the minute bubbles contained in each layer of the material layer.

【0010】

Further, the amount of resin in each layer of the mica layer and the filler layer is set to 25% by weight or less of the total insulating material because the amount of resin in each layer of the mica layer and the filler layer exceeds 25% by weight of the entire insulating material. This is because when the insulating material is applied to the winding conductor, the workability is lowered and the insulating material is wrinkled.

【0011】

Further, in the insulating material according to the present invention, the difference between the amount of resin in the mica layer and the amount of resin in the filler layer is 10% by weight or less.

【0012】

Here, the difference between the amount of resin in the mica layer and the amount of resin in the filler layer is 10% by weight or less because the difference between the amount of resin in the mica layer and the amount of resin in the filler layer is 10% by weight. If it exceeds%, when forming the insulating coating of the electric winding, a part of the resin containing minute bubbles to be discharged to the outside in the pressurizing process is from the layer with a large amount of resin to the amount of resin with a small amount. This is because it penetrates into the layer and remains.

【0013】

The electric winding according to the present invention has a withstand voltage layer, a reinforcing material layer, and a heat conductive layer, and is insulated with the amount of resin in each of the withstand voltage layer and the heat conductive layer set to 10 to 25% by weight of the entire insulating material. An insulating coating is formed using a material.

【0014】

The withstand voltage layer is a mica layer having mica foil. The reinforcing material layer is a layer having a reinforcing material, for example, a glass cloth. The heat conductive layer is a filler having a thermal conductivity of at least 5 W / m · K, for example, alumina.

【0015】

Each layer contains a resin, for example, an epoxy resin. The total amount of resin is 20 to 50% by weight of the entire insulating material, and the amount of resin contained in each layer of the mica layer and the filler layer is 10 to 25% by weight of the entire insulating material. The difference between the amount of resin in the mica layer and the amount of resin in the filler layer is 10% by weight or less.

【0016】

Here, adjusting the amount of resin in each layer of the mica layer and the filler layer so as to be 10 to 25% by weight of the entire insulating material has desired electrical characteristics, for example, AC insulation of 26.5 to 29.0 kV / mm. This is to obtain a breakdown voltage.

【0017】

The insulating coating of the electric winding is formed as follows by using an insulating material. First, the insulating conductor is wound a plurality of times to form a wound conductor. After that, either the mica layer or the filler layer is applied to the outer peripheral portion of the winding conductor as the winding conductor side. After that, a mold release material is applied to the outer peripheral portion of the insulating material applied to the winding conductor. After that, a molding jig is attached, and an external force is applied from the outer surface through the molding jig. Then, the minute bubbles contained in the insulating material are discharged together with a part of the resin in the insulating material and heated at a predetermined temperature to cure the resin in the insulating material to form an insulating coating.

【0018】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, examples of the present invention will be described with reference to the drawings.

【0019】

Explaining the material structure of the high thermal conductive insulating tape 1 (high thermal conductive prepreg tape) of the embodiment of the present invention with reference to FIG. 1, the high thermal conductive insulating tape 1 is a mica layer 3 (withstanding voltage layer) having an aggregated mica foil 2. It has a laminated body in which a reinforcing material layer 5 having a glass cloth 4 and a high thermal conductive filler layer 7 (thermal conductive layer) having an alumina particle body 6 are laminated in this order. The laminated body may be laminated in the order of the high thermal conductive filler layer 7, the mica layer 3, and the reinforcing material layer 5.

【0020】

Further, the high thermal conductive insulating tape 1 contains resin 8 in each of the mica layer 3, the reinforcing material layer 5, and the high thermal conductive filler layer 7, and the total amount of the contained resin 8 is the high thermal conductive insulating tape 1. It is 31.4% by weight of the whole. The amount of resin 8 contained in the mica layer 3 is 12.9% by weight of the entire high thermal conductive insulating tape 1, and the amount of resin 8 contained in the high thermal conductive filler layer 7 is 15.0 of the entire high thermal conductive insulating tape 1. Weight%.

【0021】

This high thermal conductive insulating tape 1 was manufactured as follows. First, aggregated mica foil 2 (weight 165 g / m) produced by making mica particles dispersed in water with a paper machine.²), Glass cloth 4 (Weight 35g / m)²), And BF for 100 parts by weight of novolak type epoxy resin₃Resin 8 (impregnation amount 85 g / m) made by adding 3 parts by weight of monoethylamine²) Was impregnated and adhered to obtain an assembled mica sheet (a laminate of mica layer 3 and reinforcing material layer 5).

【0022】

After that, BF was added to 1,300 parts by weight of the alumina particle body 6, novolak type epoxy resin.₃Resin 8 made by adding 3 parts by weight of monoethylamine is mixed so that the weight ratio of alumina particle body 6 and resin 8 is 2: 1 and 10% by weight of methyl ethyl ketone is added thereto to reinforce the aggregated mica sheet. Layer 5 side surface coated with roll coater 256g / m²It was painted so that it would be. After that, methyl ethyl ketone was volatilized and removed in a drying oven to obtain a high thermal conductive insulating sheet.

【0023】

After that, the high thermal conductive insulating sheet was slit to a width of 30 mm with a slitter to obtain a high thermal conductive insulating tape 1.

【0024】

Next, the structure of the electric winding 9 according to the embodiment of the present invention will be described with reference to FIG. 2. The electric winding 9 is formed by winding a plurality of insulating conductors 10a. It has a high thermal conductive insulation coating 11 formed on the outer peripheral portion.

【0025】

This electric winding 9 was manufactured as follows. First, as shown in FIG. 2, a plurality of insulating conductors 10a are wound a plurality of times to form a wound conductor 10. After that, the high thermal conductive insulating tape 1 shown in FIG. 1 was partially overlapped and wound around the outer peripheral portion of the winding conductor 10. At this time, in the high thermal conductive insulating tape 1, either side of the mica layer 3 or the high thermal conductive filler layer 7 may be the winding conductor 10 side, but in this embodiment, the mica layer 3 side is the winding conductor 10. On the side, the high thermal conductive insulating tape 1 was wound around the outer peripheral portion of the winding conductor 10. After that, the release tape 12 was wrapped around the outer peripheral portion of the high thermal conductive insulating tape 1. The reason why the release tape 12 is wrapped around the outer peripheral portion of the high thermal conductive insulating tape 1 in this way is to prevent adhesion between the molding jig and the high thermal conductive insulating tape 1, which will be described later.

【0026】

After that, as shown in FIG. 3, a molding jig 13 was attached, and an external force was applied from the outer surface through the molding jig 13. Then, the minute bubbles contained in the high thermal conductive insulating tape 1 are discharged together with a part 14 of the resin in the high thermal conductive insulating tape 1 and heated at a predetermined temperature to heat the resin of the high thermal conductive insulating tape 1. 8 was cured to form a high thermal conductive insulating coating 11, and an electric winding 9 was obtained.

【0027】

The electric winding 8 of the present embodiment manufactured in this way is housed in an iron core slot of a rotating electric machine such as a generator or a motor.

【0028】

Next, the AC dielectric breakdown voltage test results of the electric winding of this example and the electric winding of the comparative example will be described with reference to Table 1. As the electric winding of the comparative example, an electric winding having high thermal conductive insulation formed by the high thermal conductive insulating tape manufactured as follows was used. The production of the high thermal conductive insulating tape is as follows.

【0029】

First, aggregated mica foil 2 (weight 165 g / m) produced by making mica particles dispersed in water with a paper machine.²), Glass cloth 4 (Weight 35g / m)²), And BF for 100 parts by weight of novolak type epoxy resin₃Resin made by adding 3 parts by weight of monoethylamine (impregnation amount 40 g / m)²) Was impregnated and adhered to obtain an assembled mica sheet (a laminate of mica layer 3 and reinforcing material layer 5).

【0030】

After that, BF for 100 parts by weight of alumina particles and novolak type epoxy resin₃The resin made by adding 3 parts by weight of monoethylamine is mixed so that the weight ratio of the alumina particles to the resin is 3.5: 1, and 10% by weight of methyl ethyl ketone is added thereto, and the resin is rolled on the side surface of the reinforcing material layer of the assembled mica sheet. The amount of coating with a coater is 230 g / m²It was painted so that it would be. After that, methyl ethyl ketone was volatilized and removed in a drying oven to obtain a high thermal conductive insulating sheet.

【0031】

After that, the high thermal conductive insulating sheet was slit to a width of 30 mm with a slitter to obtain a high thermal conductive insulating tape 1.

【0032】

In the high thermal conductive insulating tape of the comparative example produced in this way, the total amount of resin in the tape was 19.3% by weight of the entire high thermal conductive insulating tape. The amount of resin in the mica layer was 7.1% by weight of the entire high thermal conductive insulating tape, and the amount of resin in the high thermal conductive filler layer was 10.4% by weight of the entire high thermal conductive insulating tape.

【0033】

After that, an electric winding was manufactured using the high thermal conductive insulating tape manufactured as described above. The manufacturing method is the same as that of this embodiment, and the description thereof will be omitted.

【0034】

In the AC insulation breakdown voltage test, an aluminum foil is wound around the outer circumferences of the electric windings of this example and the electric windings of the comparative example to form electrodes, and AC is used between the aluminum electrodes of each electric winding and the winding conductor. A voltage was applied and the AC insulation breakdown voltage was measured. The results are shown in Table 1.

【0035】

[table 1]

<img file="JPH11250737A_D0001.tif" />【0036】

As is clear from Table 1, the electric winding of this example had a higher AC dielectric breakdown voltage than the electric winding of the comparative example. This is because the high heat conductive insulation coating of the electric winding was formed using the high heat conductive insulating tape in which the amount of resin in each layer of the mica layer and the high heat conductive filler layer was within the range of 10 to 25% by weight of the whole material. Yes, when forming the high thermal conductive insulation coating of the electric winding, in the pressurizing process, minute bubbles contained in the high thermal conductive insulating tape are sufficiently discharged together with a part of the resin in the high thermal conductive insulating tape. It was because it was possible.

【0037】

Therefore, since the electric winding of this embodiment has a dense high thermal conductive insulation coating having excellent electrical characteristics, it is possible to provide high reliability for a rotating electric machine operated at a high voltage.

【0038】

[Effect of the invention]

According to the insulating material according to the present invention, the amount of resin in each layer of the mica layer and the filler layer is set to 10 to 25% by weight of the entire insulating material. In the process, minute bubbles contained in the insulating material can be sufficiently discharged together with a part of the resin in the insulating material, and an insulating coating of an electric winding having excellent electrical characteristics can be obtained. ..

【0039】

Further, if the amount of the resin is within this range, when the insulating material is applied to the winding conductor, the workability is lowered and the insulating material can be prevented from wrinkling. It is possible to prevent the formation of voids that become electrical defects, and it is possible to obtain an insulating coating of an electric winding having excellent electrical characteristics.

【0040】

Further, according to the insulating material according to the present invention, the difference between the amount of resin in the mica layer and the amount of resin in the filler layer is set to 10% by weight or less. In the pressurizing process, it is possible to prevent a part of the resin containing minute bubbles to be discharged to the outside from infiltrating from the layer having a large amount of resin to the layer having a small amount of resin and remaining, and it has electrical characteristics. It is possible to obtain an excellent insulating coating for electric windings.

【0041】

According to the electric winding according to the present invention, the insulating coating is formed by using an insulating material in which the amount of resin contained in each layer of the mica layer and the filler layer is 10 to 25% by weight of the entire insulating material. Therefore, when forming the insulating coating of the electric winding, in the pressurizing process, minute bubbles contained in the insulating material can be sufficiently discharged together with a part of the resin in the insulating material, and electricity can be obtained. It is possible to obtain a highly reliable electric winding which has an insulating coating having excellent physical characteristics and whose electrical characteristics do not deteriorate even when used in any rotary electric machine.

【0042】

Further, if the insulating coating is formed by using an insulating material in the range of this resin amount, the workability of the insulating material is lowered when the insulating material is applied to the winding conductor, and the insulating material can be prevented from wrinkling. Therefore, it is possible to prevent the formation of voids that become electrical defects in the insulation coating of the electric winding, and it has an insulation coating with excellent electrical characteristics, and even if it is used in any rotating electric machine, the electrical characteristics are good. It is possible to obtain a highly reliable electric winding that does not deteriorate. Further, according to the electric winding according to the present invention, the insulating coating is formed by using an insulating material in which the difference between the amount of resin in the mica layer and the amount of resin in the filler layer is 10% by weight or less. Therefore, when forming the insulating coating of the electric winding, a part of the resin containing minute bubbles to be discharged to the outside penetrates from the layer having a large amount of resin to the layer having a small amount of resin in the pressurizing process. To obtain a highly reliable electric winding that can be prevented from remaining and has an insulating coating with excellent electrical characteristics, and whose electrical characteristics do not deteriorate even when used in any rotating electric machine. Can be done.

[Simple explanation of drawings]

[Figure 1]

The cross-sectional view which showed the material structure of the high thermal conductive insulating tape of the Example of this invention.

[Figure 2]

The perspective view which showed the structure of the electric winding of the Example of this invention.

[Fig. 3]

The perspective view for demonstrating one manufacturing process of the electric winding of the Example of this invention.

[Explanation of symbols]

1 ... High thermal conductivity insulating tape, 2 ... Assembled mica foil, 3 ... Mica layer, 4 ... Glass cloth, 5 ... Reinforcing material layer, 6 ... Alumina particles, 7.. High thermal conductivity filler layer, 8 ... resin, 9 ... electric winding, 10 ... winding conductor, 11 ... high thermal conductive insulation coating, 12 ... release tape, 13 ... Molding jig, 14 ... Part of resin.