JPS59127562A - Forming method of insulator of high voltage coil for rotary electric machine - Google Patents

Abstract

PURPOSE:To moderate the stress concentration to corners of a coil by inserting an inorganic material having durability against corona of specific thickness into the interior of an inner insulating layer in the degree of covering the corners of both side faces continued to the upper and lower sections of a coil conductors and heat pressing it. CONSTITUTION:After coil conductors 1 are shaped in a stator coil shape, a mica bonding material 3 made of inorganic material having durability against corona of 0.1-0.5mm. in thickness is contacted in the degree of covering the corners of both side faces continued to the upper and lower sections of the coil conductors, prepreg mica tape is then wound as an insulating layer 2, heat-pressed, molded and hardened. In this manner, the stress concentration to the corners can be moderated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a thermosetting resin is pre-impregnated into laminated mica, glass fiber, etc., and the resultant resin is made into a Grigreg state by heat treatment.
After wrapping the grip or leg insulating tape or sheet around a coil conductor, especially the coil conductor of a high-voltage stator coil of an AC rotating electric machine, an insulating layer is formed using a heat press machine.
The present invention relates to a method for forming insulation of a high-voltage coil for a rotating electric machine to be cured.

Hereinafter, the content of the present invention will be explained in detail using the drawings.

Figure 1 is a cross-sectional view of an example of a high-voltage stator coil for a rotating electric machine. For example, after a coil conductor l, which is a double glass winding, is formed into the shape of a stator coil, the outer periphery of this coil conductor bundle is insulated with prepreg. After winding the tape or sheet, the insulating layer 2 is formed and cured by heat pressing so as not to leave any voids inside.

The stator coil thus completed is used by being inserted into the slot of the stator core, but when a high voltage is applied, the electric field distribution applied to the insulating layer 2 is distributed at four locations as shown in Figure 1. It is easy to concentrate on the corner a, and the deterioration progresses from the corner a even during long-term cosena deterioration.

In addition, in the case of a so-called resin-rich insulation method in which GriGreg mica is wound as the main insulation and then heated and pressurized using a heat press device, the insulation layer 2 is usually compressed by 20730% due to heating and pressure. be.

FIG. 2 is a cross-sectional view showing the stator coil set in the heat press device. When heat pressing is performed, the straight portion of the stator coil to be inserted into the slot is set in the heat press device 4. The heat press device 14 consists of a hot plate 7.8 in which a heater 9 and a cooling pipe 10 are embedded, and a press liner 5.6, and presses the top and bottom of a bundle of coil conductors 1 around which an insulating layer 2 is wound. The liners 5 and 6 are placed in close contact with each other, and there are heating plates 8°9 on the left and right.
are brought into close contact with each other, and the heater 9 is energized and heated with almost no pressure applied. The prepreg insulation is heated directly from the hot plate 7.8 and via the press liners 5, 6, and is once softened. At this point of softening, pressure is applied from above and below and from left and right as shown by arrows P in FIG. 2 to form and harden the material. The cooling pipe IO is for cooling after the heat pressing operation is completed. FIG. 3 is a partial cross-sectional view of the stator coil showing the insulating layer formed and cured by a conventional method. When heat pressing is performed by the conventional method as described above, the compressive strain of the insulating layer 2 is concentrated at the corners of the conductor, as shown in FIG. 3, and this often results in defects in the insulation.

The present invention has been made to compensate for these drawbacks, and will be described below with reference to drawings of an embodiment.

FIG. 4 is a cross-sectional view of a stator coil according to an embodiment of the present invention. After forming the coil conductor l into the shape of a stator coil, apply peel-off mica bonding material 3 with a thickness Q of 5 mm to the upper and lower parts of the coil conductor and to the following both side parts to cover the corners. Then, a prepreg assembly of mica chives is wound to form the insulating layer 2, which is then heat pressed to form and harden so as not to leave any voids inside.

In this way, the corners are covered with a material with strong corona resistance, which is a peelable mica bonding material that is similar to a single-piece sheet material, which prevents deterioration in areas with high electric field strength, and also provides a resin-rich insulation method. Compressive strain caused by the heat press work is avoided from concentrating on the corners, and the compressive strain is created on the sides of the coil where the electric field strength is relatively low, which alleviates stress concentration at the corners. It is something that can be done.

In the above example, a peelable mica bonded material was used as the inorganic material with high scratch resistance, but the material is not limited to this, and other inorganic materials with high scratch resistance may be used. Any material may be used. Moreover, the thickness may be appropriately selected within the range of 0.1 to 0.5 mm depending on the size of the coil cross section and the difference in the common voltage.

Furthermore, in the above example, an inorganic material with strong corona resistance was inserted into the bottom layer before winding the prepreg insulating tape, but it may also be inserted into the middle layer. Needless to say, a Gripreg insulating sheet may be used instead.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an example of a high-voltage stator coil for a rotating electrical machine, Fig. 2 is a cross-sectional view showing the stator coil set in a heat press machine, and Fig. 3 is a cross-sectional view of a high-voltage stator coil for a rotating electrical machine. a partial cross-sectional view of the stator coil showing the hardened insulation layer;
FIG. 4 is a cross-sectional view of a stator coil according to an embodiment of the present invention. l... Coil conductor, 2... Insulating layer, 3...
...Peelable mica bonding material, 4...
... Heat press device, 5, 6 ... Press liner, 7.8 ... Heat plate, 9 ... Heater, lO
・・・・・・Cooling pipe. Patent applicant Toyo Denki Seizo Co., Ltd. Representative Atsushi Doi Figure 1 Broom, 3 fertilizers: jbze Mu 4 necessary

Claims (1)

[Claims] In high-voltage coils for rotating electric machines in which prepreg insulating tape or sheet is wound on a coil conductor and an insulating layer is formed by heat pressing, a thickness of 0.1 is applied to the upper and lower parts of the coil conductor and to the following both side parts to the extent that the corners are covered. ~0.5
A method of forming insulation for a high-voltage coil for a rotating electrical machine, characterized by inserting an inorganic material having a strong corona resistance of mm into the main insulating layer and performing heat pressing.