JPS59162749A - Insulating method of fully impregnated-coil of rotary electric machine - Google Patents

Abstract

PURPOSE:To preferably insulate by forming a sheath insulating layer with thermosetting resin on the entire part exposed from a core of a coil, then immersing insulating varnish and thermosetting the varnish. CONSTITUTION:An insulating layer 6 is formed by winding a mica tape or sheet entirely on a slot 1 of a coil 5, a coil end 2, a noise unit 3 and a lead unit 4. The coil 5 is then inserted into the slot of a core 7, and the lead unit 4 and a phase ring 8 are connected. Then, the entire end 2 projected from the core 7 is dipped in a fluid dipping tank, and an insulating layer 11 is formed entirely on the end 2, the nose unit 3, the lead unit 4 and the ring 8. Eventually, the overall stator is filled in the tank, insulating varnish is immersed in vacuum or under pressure, thermally cured in a dry furnace to form the insulating layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for insulating a fully impregnated coil of a rotating electric machine.

In general, the fully impregnated coil insulation method for rotating electric machines involves wrapping the entire circumference of the coil in a hexagonal shape with insulating tape, inserting it into the slot of the iron core, connecting the leads, etc., and then insulating the connected part. Wind the tape. Thereafter, a widely used method is to vacuum-heat and impregnate the entire structure with insulating varnish in an impregnating tank, and heat and harden it in a drying oven to form an insulating layer.

This fully impregnated coil insulation layer method consists of a slot part (1), a coil end part (2), a nose part (
3) and a lead part (4).
When used alone, the slot part (1) and the coil end part (
2), the nose part (3), and the lead part (11) are all wrapped with mica tape, and an insulating layer (6
) to form.

Thereafter, as shown in Figure 2, the coil (5) is inserted into the groove of the iron core (7), the lead part (4) and the phase ring (8) are connected, and then this connection part is covered with an insulating layer (mica tape insulation). 6), and a spacer (9) is inserted between the coil end portions (2) to support the coil end portions (2).
Also, a place ring (1o) is attached to the outer periphery of the tip of the coil end portion (2). Next, the whole is loaded into an impregnating tank, and after being impregnated with insulating varnish under vacuum pressure, it is heated and cured in a drying oven to form an insulating layer (6).

However, in the above conventional method, the insulating varnish impregnated into the insulating layer (6) flows out between the time when the stator is taken out from the impregnating tank and carried into the heating drying oven until the insulating varnish polymerizes. 6) There was a drawback that voids were generated within the film and good electrical characteristics could not be obtained after curing.

This invention was made in view of the above-mentioned drawbacks of the conventional products, and includes an outer insulating layer made of thermosetting resin to prevent insulating varnish from flowing out over the entire part of the coil (5) exposed from the iron core (7). An object of the present invention is to provide a method for insulating a fully impregnated coil of a rotating electrical machine, in which the coil is impregnated with an insulating varnish under vacuum pressure and cured by heating.

The thermosetting resin insulation coating layer can be formed by powder coating, electrophoresis,
There is a dipping method using a thixotropic resin, and the drawings will be explained using powder coating as an example of an embodiment of the present invention.

First, when the coil (5) is used as a single unit, as shown in FIG. )
When used alone, the slot part (1) and the coil end part (
2) Wrap mica tape or mica sheet around all of the nose portion (3) and the IJ-shaped portion (4) to form an insulating layer (6).

Thereafter, as shown in Figure 3, the coil (5) is inserted into the groove of the iron core (7), and the lead part (4) and phase ring (8) are inserted into the groove.
The coil end section (
2), a spacer (9) and a place ring (1) are used to hold the
0).

After the above work is completed, the entire stator is preheated to ensure good powder coating, and once fully heated, the stator is placed upright and the entire coil end portion (2) protruding from the iron core (7) is heated. The coil end (2), nose (3), lead (4), and phase ring (8) are all coated with powder coating insulation. Finally, the entire stator is impregnated with insulating varnish under vacuum pressure in an impregnating tank, and then heated and cured in a drying oven to form an insulating layer.

FIG. 4 is a comparison diagram of tan δ characteristics between the conventional method and the method of the present invention, where the horizontal axis shows the applied voltage (XV) and the vertical axis shows tan δ ((6). In the figure, E is The rated voltage (XV) is shown.As is clear from Fig. 4, the characteristic of the method of the present invention (
13) has better tan δ characteristics.

FIG. 5 shows the AC short-time dielectric breakdown voltage values of coils insulated by the conventional method and the method of the present invention by the rapid rise method in a 5% NaO4 solution. That's t
As shown at 1100, an insulated coil (5) is placed in a container (15) containing a 5% NaO' solution (14).
), and the AC voltage of the AC power supply (16) is rapidly increased, the average value X of the AC short-time dielectric breakdown voltage of the coil (5) insulated by the conventional method is set as 100%, and the vertical axis is The dielectric breakdown voltage ((6) is taken, and the horizontal axis shows the conventional method and the method B of the present invention.As is clear from FIG. 6, the characteristics (17) of the conventional method It can be seen that the insulating layer according to the characteristic (18) of method B shows superior characteristics.This is due to the improved reliability of the entire insulating layer.In addition, in Fig. 6, For the average value of AC short-time dielectric breakdown voltage, ±3σ indicates a value three times the variation of the upper and lower limits.

In addition, although powder coating was described in the above embodiments, electrophoresis and dipping with chicken tropic resin were used to coat the coil end (2), nose (3), and lead (4) with each other as well as with the lead (2). It goes without saying that the same effect can be obtained by forming the insulating layer (11) at the connection portion between the phase ring (8) and the phase ring (8).

Furthermore, in the above embodiment, the insulating layer (11) made of thermosetting resin was formed only on the protruding part that protruded from the iron core (7), but the insulating layer (11) made of thermosetting resin was formed on the entire stator including the iron core (7). A similar effect can be obtained by forming (11).

As described above, according to the present invention, there is an effect that good insulation treatment can be performed without the insulating varnish flowing out.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional plan view showing a rotating electric machine coil insulated by a conventional method, and Fig. 2 is a local cross-sectional view showing the vicinity of the coil end of a rotating electric machine coil insulated by a conventional method with the iron core inserted. , FIG. 3 is a local sectional view showing the vicinity of the coil end with the iron core inserted in a rotary electric machine coil insulated using the method of the present invention, and FIG. 4 is a comparison diagram of tan δ characteristics between the conventional method and the method of the present invention. , FIG. 5 is a comparison diagram of dielectric breakdown voltage in a solution of 5% NaO according to the conventional method and the method of the present invention, and FIG. 6 is an electrical wiring diagram showing the dielectric breakdown test state. In the figure, (1) is the slot part, (2) is the coil end part, (3) is the nose part, (4) is the lead part, (5) is the coil, (6) is the insulating layer, and (7) is the iron core. , (8) is a phase ring, (9) is a spacer, (10) is a place ring,
(11) is an insulating layer. Note that the same reference numerals in each figure indicate the same parts.

Claims (1)

[Scope of Claims] 1. A first step of wrapping the entire circumference of the hexagonal coil with mica tape or mica sheet; A second step of connecting the hexagonal coils after inserting them into the grooves of the iron core and holding the coil end portions of the hexagonal coils with spacers and place rings; a third step of forming an insulating layer of thermosetting resin on the surface of the protrusion including the surface of the stator core; and a fourth step of impregnating the entire stator with insulating varnish under vacuum pressure and then curing it by heating. A method for insulating a fully impregnated coil of a rotating electric machine, which is characterized by comprising the steps of: 2. The fully impregnated coil insulation method for a rotating electric machine according to claim 1, wherein the insulating layer is formed by powder coating. 3. The fully impregnated coil insulation method for a rotating electric machine according to claim 1, wherein the insulating layer is formed by electrophoretic coating. 4. The fully impregnated coil insulation method for a rotating electrical machine as claimed in the claims, wherein the insulating layer is formed by dip coating with chicken tropic resin.