JPS62178144A - Insulation treating method for stator coil - Google Patents

Abstract

PURPOSE:To improve mechanical and electrical characteristic, by forming a hair-setting sheet on leaf material for catalyst treatment, and by inserting an insulating coil wound up with them into a slot to be impregnated with resin. CONSTITUTION:An insulating coil 1 with the outer peripheral surface wound up with a hair-setting sheet 12 is inserted into the slot 4 of a stator coil 3, and is fixed with a wedge 5. After the coil 3 is vacuum-pressure-impregnated with a specified resin component, the coil 3 is heated and hardened. The hair- setting sheet 12 is organized with short fibers 12c bonded to leaf material 12a with bonding agent 12b. In this case, before the insulating coil 1 is wound up, the catalyst treatment of the resin component for impregnation is executed on the hair-setting sheet 12. Then, the impregnation-retained resin starts to be hardened from the external side by resin catalyst. As a result, resin contained in a space section 4a is also prevented from leaking, and the stator coil 3 of good quality is obtained.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method for insulating a stator coil of a rotating electric machine, and particularly to a method for insulating a stator coil of an AC motor. [Technical background of the invention and its problems] Recently, there has been an increasing demand for increased single machine capacity, smaller size and lighter weight, and maintenance-free design for rotating electric machines, but these can be met with advances in thin-sheet materials and manufacturing technology. It has become to. In particular, thin materials such as aramid paper and polyimide film have a heat resistance of class H or higher, and are also extremely excellent in voltage resistance, so they are of great help in reducing the insulation thickness to 'A9'. Also, in impregnated resin,
Solvent-free epoxy resins, polyimide resins, etc., which have heat resistance of 11 or more types, have low viscosity, and are easily impregnated, have become commercially available. On the other hand, manufacturing methods include the conventionally known prepreg method, in which resin-rich tape is wound for insulation, and dry tape, which is laminated with a very small amount of adhesive (for example, glass cloth and mica paper are laminated together). There is a method in which a film is laminated with mica paper, etc., and the adhesive layer is limited to a few to 10% of the vehicle m ratio) and is wound and impregnated with resin. There are three methods: a single impregnation method in which the coil with main insulation is impregnated with resin, and a total impregnation method in which the coil is incorporated into the core and then impregnated with resin. Figure 5 shows the conventional total impregnation method. For example, a film-like slot insulation 2 is wound around the outer surface of the insulation coil 1, and this is wrapped around the stator coil 3.
established in

[The method used is to insert it into the slot 4, fix it with a wedge 5, and then impregnate it with resin. Does this include? 1, the stator including the coil connections can be impregnated in one piece, so it has excellent resistance to environments such as moisture and dust, and contributes to maintenance-free operation. In order to take advantage of this total impregnation, the material used for the main insulation of the coil also takes into consideration the impregnability, and in addition to using the dry tape, heat shrink tape is wrapped around the outermost layer of the main insulation. Alternatively, a method can be adopted to prevent resin leakage from the main insulating layer, such as by applying seal varnish. Since the total impregnation method has many advantages, it has become the mainstream insulation treatment method for stator coils, but a film is often used for the slot insulation 2, and this film has good retention of resin. Unfortunately, since the resin tends to flow out, there remains a problem in filling the gap 4a between the insulated coil 1 and the slot 4 with the resin. In other words, due to the heat capacity of the stator, it takes a considerable amount of time to heat the resin to the temperature required for the curing reaction, and for this reason, the impregnated resin is required to have a long pot life, and in many cases, Due to the fact that it contains a latent curing agent that exhibits a catalytic effect at high temperatures, the viscosity of the impregnated resin decreases significantly before the curing reaction occurs. Therefore, the resin filled in the gap 4a between the insulated coil 2 and the slot 4 is more likely to flow out, resulting in voids. These voids prevent the conductor from dissipating heat, weaken the adhesive force between the iron core and the insulated coil 1 in the slot 4, make it easier for moisture and dust to enter, and make it easier for corona discharge to occur, resulting in poor electrical insulation performance. This is not preferable because it reduces the [Objective of the Invention] The present invention was made in view of the current situation, and it completely fills the gap between the insulated coil and the slot with resin to eliminate voids, and significantly improves the heat dissipation effect and corona deterioration characteristics. It is an object of the present invention to provide a method for insulating a stator coil. [Summary of the Invention] The present invention involves performing flocking processing on a thin leaf material to form a flocked sheet (1), treating this flocked sheet with a catalyst that promotes a resin composition, and then forming a flocked sheet treated with the catalyst. is wound around the outer circumferential surface of an insulated coil with the flocked surface facing outward, and is inserted into a slot provided in the stator coil, followed by vacuum pressure impregnation using the resin composition, followed by heat curing. 6 is characterized in that voids are not generated in the gap between the insulated coil and the slot. [Embodiments of the Invention] An example of embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of the stator coil, and reference numeral 1 in the figure indicates an insulated coil. This insulated coil 1 is inserted into a slot 4 of a stator coil 3 with a flocked sheet 12 wound around its outer peripheral surface with the flocked surface facing outward, and is fixed with a mold 5. Thereafter, the stator coil 3 is impregnated with a predetermined resin composition under vacuum pressure, and then heated and cured. The flocked sheet 12 is made of a thin sheet material 1 as shown in FIG.
The flocked sheet 12 is made up of a fluff 1ff 112c which is processed on one surface of the fluffy material 12a with an adhesive 12b, and is wound around the insulating coil 1 with the fluff 1ff 12c on the outside. It has become. The λ leaf material 12a may be made of polyimide, polynisdel films, or aramid paper. A sheet material such as glass cloth is used, and the adhesive 12b is a polyester-based material such as TVB20.
2 varnish (product name: Toshiba Chemical Corporation) was used,
Further, for the section I112c, a wholly aromatic polyamide-based material such as Cornex (trade name: Mitsuyuri Co., Ltd.) is used, and its fiber length is set to 0.2 #llll+. Although it is related to the size of the gap 4a between the coil 1 and the slot 4 and the flocking density, it is usually set to be equal to or about 1.5 times the size of the gap 4a. , rayon, and nylon are typical, but when heat resistance is required, polyester is used, and when even higher heat resistance is required, for example, for heat resistance class H or higher, use other than the above-mentioned Conex. Asbestos, glass, rock wool, etc. are used for this method.Various types of hair transplanting methods are used, such as the blowing method using a spray gun, the sonic method, and the mechanical vibration method. The flocked sheet 12 configured in this way has an insulated coil 1
Prior to winding, the impregnating resin composition is subjected to a catalyst treatment, that is, a catalyst treatment that promotes the resin composition. In this case, an appropriate catalyst is selected from the viewpoints of the type of impregnating resin, workability, reactivity, etc. For example, when the impregnating resin is an epoxy resin, amines such as diethylenetriamine and benzyldimethylamine, metal salts of carboxylic acids such as zinc octoate, cobalt(II)-acetylacetonate, metal-acetylacetonates, and imidazoles are used. Are suitable. Next, a method for insulating the stator coil will be described. For the insulation treatment, first, the catalytically treated flocked sheet 12 is wound around the outer peripheral surface of the insulated coil 1 with the section 1ft12c facing outward, and then this is inserted into the slot 4. and wedge 5
Fix it by. Next, this stator coil 3 is impregnated with epoxy resin under vacuum pressure, and this stator coil 3 is
is heated and cured in a heating furnace while being rotated by a rotating device (not shown). Therefore, the impregnated resin is retained by the section 11t12c in the gap between the flocked sheet 12, the void 4a of the slot 4, and the gap under the pattern 5, and hardening is started from the outside by the resin catalyst. Therefore, not only the impregnated resin inside the main insulation but also the resin filled in the cavity 4a is prevented from flowing out.
A stator coil 3 with good characteristics is obtained. Fig. 3 shows the dielectric loss tangent-voltage characteristics of an AC motor of 140 to - in comparison with a conventional example, where the symbol A in the figure indicates the characteristic curve according to the present invention, and B indicates the characteristic curve of the conventional example. . In addition, Figure 4 shows that the model was subjected to a cold cycle test at a high temperature of 160°C (the average temperature of the winding wire according to the resistance method) and at room temperature, and the starting voltage for each 100 cycles was checked. The results are shown in comparison with the conventional example, in which symbol C indicates the result according to the present invention, and D indicates the result of the conventional example. As is clear from FIG. 4, in the conventional stator coil 3 in which the cavity 4a is insufficiently filled with resin, the initial corona start voltage is low, and the rate of decrease after 1500 heat cycles is approximately 25%. This has decreased to 75%. On the other hand, in the stator coil 3 subjected to the insulation treatment of the present invention, no defects or abnormalities were observed even after 2400 cycles, indicating that the present invention is superior in terms of characteristics not shown in Fig. 3. . [Effects of the Invention] As explained above, the present invention involves performing flocking processing on a thin leaf material to form a flocked sheet, treating the flocked sheet with a catalyst that promotes the resin composition, and then applying the catalyst-treated material to the flocked sheet. The flocked sheet was wound around the outer peripheral surface of the insulating coil with the flocked side facing outward, and this was inserted into a slot provided in the stator coil, and then vacuum pressure impregnation was performed using the resin composition. Because it is heated and hardened, no voids are generated in the gap between the insulated coil and the slot, and the thermal conductivity from the insulated coil to the iron core is improved, improving the heat dissipation effect. It also becomes more robust and its electrical characteristics can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a stator coil showing an example of an embodiment of the present invention, FIG. 2 is a sectional view showing the structure of a flocked sheet, and FIG. 3 is a graph showing dielectric loss tangent-voltage characteristics in comparison with a conventional example.
FIG. 4 is a graph comparing the rate of decrease in corona starting voltage with the conventional example, and FIG. 5 is a diagram corresponding to FIG. 1 showing the conventional example. 1... Insulated coil, 3... Stator coil, 4...
- Slot, 4a...Gap, 12...Flocked sheet, 12a...Thin leaf material, 12b...Adhesive, 12c
...Short fiber. Applicant's agent Sato - Yuai Figure 1, Figure 2

Claims (1)

[Scope of Claims] 1. A flocked sheet is formed by flocking on a thin leaf material, and this flocked sheet is treated with a catalyst that promotes the resin composition, and then the catalyst-treated flocked sheet is attached to an insulating coil. A flocked surface is wound outwardly around the outer peripheral surface of the stator coil, and the flocked surface is inserted into a slot provided in the stator coil.Then, the resin composition is impregnated with vacuum pressure, and then heated and cured. Stator coil insulation treatment method. 2. The method for insulating a stator coil according to claim 1, wherein the stator coil is heated and hardened while rotating the stator coil.