JPH0823651A - Stator coil for rotating electric machine - Google Patents

Abstract

PURPOSE:To prevent the flowing out of the impregnating resin through gaps between coil insulation electric wires when the coils are impregnated with the resin and the resin is thermally cured by a method wherein a sheet with a nonwoven fabric film stuck thereto is wound around the straight parts of a hexagonal body of coils in such a way that the nonwoven fabric side of the sheet is in contact with the coil insulation electric wires, and a mica tape is wound around the whole coils to cover the insulation-against-earth layer therewith. CONSTITUTION:A sheet to which a nonwoven fabric film is stuck is wound flatwise around the linear section of coils formed in a hexagonal shape in such a way that the nonwoven fabric 3 side is in contact with the coil insulation electric wires. Then a layer 7 for insulation against the earth is formed by winding a dry mica tape around the hexagonal body of coils. as a result, when a thermosetting resin which is injected into the gaps between the electric wires 5 by evacuation and pressurization after the coils are connected to each other and insulated is cured by heating, the resin does not flow out from the insulating layer 7. Therefore, no void is made in the layer 7 and the tandelta-voltage characteristic of the layer is remarkably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine coil and, more particularly, to a highly reliable stator coil which prevents the impregnated resin from flowing out in the vicinity of an insulated wire in a vacuum pressure impregnation insulation method.

[0002]

2. Description of the Related Art A conventional stator coil will be described with reference to FIGS. FIG. 8 shows a conventional manufacturing process of a stator coil. The rectangular insulated wire 5 is wound around a winding die (not shown) a specified number of times to form a groove-shaped coil 25 having a predetermined shape as shown in FIG. After that, as shown in FIG. 8B, the insulated wire and the catamaran coil 25 are formed to form a hexagonal shape.
For example, the heat-resistant film tape 10 is spirally wound around the outer circumference of the coil 25 so as not to collapse. Next, FIG.
As shown in (c), the hexagonal coil 35 is formed by a forming machine. Furthermore, dry mica tape 6 is attached to the hexagonal coil 35.
Is laminated in half and wound in multiple layers to have a specified thickness to form the ground insulating layer 7. FIG. 9 shows a vertical section of a straight portion (a portion I-I in FIG. 8) of the stator coil of the rotating electric machine in this state. In addition, external insulation is applied. After such a coil is housed in an iron core and a lead wire is connected and insulated, an epoxy resin is impregnated under vacuum pressure and heat-cured to form a final stator winding.

In general, the impregnating resin usually has a low viscosity (about 0.5 to 5 poise) in order to improve the impregnation property into the insulating layer. The width of the dry mica tape 6 is also narrow (for example, about 19 mm width) in order to improve the impregnation property of the ground insulating layer 7 of the impregnated resin. For this reason, in the process of curing the impregnated resin, the impregnated resin flows out from the overlapping portion of the mica tape wound around the ground insulating layer 7 with a decrease in viscosity due to the temperature characteristic of the resin. When the resin impregnated in this way flows out from the insulating layer, a gap 8 is formed at the corner curvature portion of the coil insulated wire 5. When an insulating layer in such a state is formed and a voltage is applied to the ground, a partial discharge is generated in the gap 8 at the corner curvature portion of the coil insulated wire 5, and the insulated wire 5 is likely to be deteriorated and damaged.

In order to prevent this, conventionally, (1) a method of burying a semi-cure resin filler containing an inorganic filler between coil insulated wires (Actual Development Sho 64-12462), (2) a mica tape wound on a conductor A method of putting a small amount of a curing accelerator that reacts with the impregnated resin in the process of heat curing in the adhesive of (3), spirally winding a tape that fills the gap created by the curved portion of the corner of the insulated wire and so on.

[0005]

In the method for manufacturing a stator winding by vacuum pressure impregnation, the gap 8 between the insulated wires due to the corner curvature portion of the coil insulated wire 5 is the gap 8.
It is also an important impregnation route for easily impregnating the ground insulating layer 7 with the resin in a short time. However, in these methods, the method (1) impairs impregnation because the gap 8 between the coil insulated wires, which is an important impregnation path, is filled. In the method of (2), when the corner curvature portion of the coil insulated wire 5 is large, the coil length is long, and the gap 8 between the coil insulated wires 5 becomes large, in the process of impregnating the winding with resin and heat curing. As the viscosity of the impregnated resin decreases before the curing accelerator or the like reacts with the impregnated resin, the impregnated resin flows out of the ground insulating layer 7 and the gap 8 cannot be completely filled with the resin. The method (3) has a high effect, but since a step is formed at the tape portion, it affects the voltage application life. This is for the following reason.

In an insulation method of winding an insulating tape,
The width of the tape is an important point that determines the insulation performance. The wider the tape width, the better the insulation performance, especially the withstand voltage characteristics. Fig. 5 shows the relationship between the tape width of the insulated coil by the vacuum pressure impregnation method and the applied voltage life (Source:
IEEE Trans. EI-12,237-248
(1977) Statistical Analysis
sis on the Electrical Fail
ure Properties of the For
m-Wound Epoxy M-icaceous
Insulating Systems for Ro
tating Machines: H.M. mitsui
and Y. Ino-ue). As is clear from this figure, the wider the insulating tape width, the longer the voltage application life. This is because the tape stitches dominate the dielectric breakdown characteristics, and the smaller this portion, the better the dielectric breakdown characteristics.

As described above, the conventional impregnating resin outflow preventing method has the above-mentioned drawbacks in terms of its operation effect, man-hours, and cost. The present invention eliminates the drawbacks of the prior art, provides a stator winding that prevents the impregnated resin from flowing out from the gap between the coil insulated wires due to the corner curvature portion of the coil insulated wire, and improves the insulation performance. The purpose is to

[0008]

According to the present invention, a non-woven fabric film-attached sheet or a non-woven fabric mica film as set forth in the claims of the present invention is provided on a straight portion of a coil obtained by winding a flat insulated wire around a winding form a specified number of times and removing the coil from the winding form. The pasting sheet is wound by a flat winding method with the non-woven fabric side on the coil insulated wire side and then formed into a hexagonal coil, and dry mica tape is wound on the entire coil to cover the ground insulating layer. Alternatively, the rectangular insulated wire is wound a specified number of times around the winding form, and the coil removed from the winding form is shaped into a hexagonal coil, and the non-woven film pasted sheet or non-woven mica film pasted sheet is coil-insulated on the non-woven side on the straight part of the coil. After winding on the wire side by the flat winding method, dry mica tape is wound around the entire coil to cover the ground insulating layer. In such a state, the gap between the coil insulated wires due to the corner curvature portion of the coil insulated wire is partially or entirely filled with the nonwoven fabric. After that, the coil is placed in an iron core, wedged, connected and insulated to form a stator winding state, and impregnated resin is impregnated under vacuum pressure to form a gap between the coil insulated wires due to the corner curvature portion of the insulated wire. Also impregnate the impregnating resin. After that, the impregnated resin is heated and cured in a drying furnace.

[0009]

According to the above-mentioned means, when the winding is impregnated with the impregnated resin, since the case is made of only the non-woven fabric or the non-woven fabric coated with the resin, the gap between the coil-insulated electric wires due to the corner curvature portion of the coil-insulated electric wire It is never completely filled.
Therefore, the gap between the insulated wires can sufficiently secure a path through which the impregnated resin passes, and the gap between the coil insulated wires and the ground insulating layer can be easily impregnated with the resin in a short time. By the way, the gap formed by the corner curvature portion of the coil insulated wire is considered to be a kind of long tube when viewed in the length direction of the coil. In this case, the outflow property of the resin impregnated in the long pipe portion is related to the surface tension T of the impregnated resin and the cross-sectional area S of the gap between the coil insulated wires due to the corner curvature portion of the insulated wire. , T / S, that is, the larger the cross-sectional area S, the easier the impregnating resin flows.

However, according to the structure of the present invention, the non-woven fabric fills the gaps between the coil insulated wires due to the corner curvature portions of all the insulated wires of the coil straight portion corresponding to the iron core portion of the rotary electric machine winding. There is. Therefore, the cross-sectional area S of the gap between the coil-insulated electric wires due to the corner curvature portion of the insulated electric wire becomes small, and the configuration becomes like a collection of long tubes having a small cross-sectional area S. For this reason, T / S becomes large as a whole, and the impregnated resin is less likely to come out. Therefore, even if the viscosity of the resin decreases during the process of heat-curing the impregnated resin,
The resin impregnated in the gap formed by the curved portion at the corner of the coil-insulated electric wire does not flow out from the ground insulating layer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment corresponding to claim 1 of the present invention will be described below with reference to FIGS. 1, 3 and 4. FIG.
FIG. 3 is a vertical cross-sectional view of a non-woven fabric film-attached sheet 1 that is flatly wound around a straight portion of a stator coil of the present invention. The nonwoven fabric film-attached sheet 1 has the film 2 and the nonwoven fabric 3 attached thereto. This non-woven film sticking sheet 1 has a constitution in which a non-woven fabric 3 is adhered to one side of a base film 2 with a resin such as acrylic or epoxy, and the base film 2 has a thickness of 0.025 to 0.005 (mm), for example. Polyester, PP
There are materials such as S and PEN. The non-woven fabric 3 is preferably a felt-like one in which fibers are entangled, for example, a thickness of 0.
Materials such as polyester and aromatic polyamide fibers having a weight of 5 to 2 (mm) and a weight of 100 (g / m ² / mm) are available.

First, the insulated electric wire 5 is wound around a winding mold (not shown) to form a groove-shaped coil having a predetermined shape as shown in FIG. 3 (a). After that, it is formed into a hexagonal shape as shown in FIG. Next, as shown in FIG. 3 (c), the non-woven fabric film-attached sheet 1 is flat-wound with the non-woven fabric 3 side being the insulated electric wire 5 side by a length corresponding to the straight line portion of the coil formed in the hexagonal shape. The sheet may be wound with a film adhesive tape or the like. The number of windings may be one or more so that the sheets overlap each other. Further, dry mica tape 6 or the like is wound around the hexagonal coil to form the ground insulating layer 7. FIG. 4 shows a vertical cross section of the stator coil of the rotating electric machine in this state. Then, a large number of hexagonal coils are placed in an iron core, the coils are connected and insulated, and then thermosetting resin is impregnated under vacuum under pressure and heat cured to obtain a final stator winding.

The operation of the configuration of the above embodiment will be described with reference to FIG. FIG. 4 is a vertical cross-sectional view of the straight portion of the coil after the ground insulation is applied to the hexagonal coil of FIG. 3 (c). When the non-woven fabric film-attached sheet 1 is flatly wound on the straight part of the tortoise shell coil with the non-woven fabric 3 side being the insulated electric wire 5 side, the gap 8 between the curved corner portions of the insulating structure 5 is formed by the non-woven fabric base material 2. Filled with 3. However, in the manufacture of the rotary electric machine coil by vacuum pressure impregnation, when impregnating the winding with the impregnating resin, the non-woven fabric fills the gap 8. The gap 8 between them is not filled, and even if the coil straight line is long, it can be transmitted through the layer of the nonwoven fabric 3 in the length direction of the straight line portion, and a sufficient path for the impregnated resin to pass through to the ground insulating layer 7 can be secured. Therefore, as in the conventional case, the resin can be easily impregnated into the gap 8 between the insulated electric wires 5 and the ground insulating layer 7 due to the curved portion of the corners of the insulated electric wire 5 in a short time.

Next, in the step of heating and hardening the stator winding impregnated with the impregnated resin by vacuum pressure impregnation, the insulated wire 5
The non-woven fabric 3 is filled in the gap 8 between the insulated electric wires 5 due to the curved portion of the corner. Therefore, the impregnated impregnated resin is
Since T / S (T is the surface tension of the resin and S is the cross-sectional area of the gap) is large, it is difficult to come out. Further, since this portion is covered with the film sheet, even if the viscosity of the resin is lowered in the process of heating and curing the impregnated resin, the coil insulated wire 5
The resin impregnated in the gap 8 formed by the curved portion of the corner portion does not flow out from the ground insulating layer 7.

According to the configuration of the above embodiment, the gap 8 between the insulated wires 5 due to the corner curvature portion of the insulated wire 5 is formed.
Since the impregnated resin does not flow out in the ground insulating layer 7, voids do not occur, and as shown in FIG.
-Significantly improved voltage characteristics compared to conventional insulation. In addition, as shown in FIG. 3, at an important point that determines the insulation performance, the wider the tape width is, the better the voltage application life becomes. Therefore, by applying the flat winding as in the present invention, the service life is significantly extended as shown in FIG. Furthermore, the breakdown voltage has increased 1.3 times that of the conventional one.

(Second Embodiment) An embodiment corresponding to claim 2 will be described. In the coil of the first embodiment, the non-woven fabric film sticking sheet 1 is replaced with the non-woven fabric mica film sticking sheet 4 shown in FIG. This mica layer 9 is an integrated mica. With this configuration, since the mica has excellent corona resistance, the electric charging life of the stator coil is further extended.

(Third Embodiment) An embodiment corresponding to claim 3 will be described. In the coil of the first embodiment, after winding an insulated electric wire in a predetermined shape on a coil winding form, a non-woven fabric film-attached sheet is placed on the coil side with the non-woven fabric side attached to the portion corresponding to the straight line portion of the coil when the coil is formed into a hexagonal shape. After winding, the coil is shaped like a turtle shell. In this method, the non-woven fabric film-attached sheet can prevent the coil insulated wires from being displaced from each other, thus eliminating the need for a wire mold for fixing the insulated wires necessary for forming the coil in a hexagonal shape.

(Fourth Embodiment) An embodiment corresponding to claim 4 will be described. In the coil of the third embodiment, instead of the non-woven film sticking sheet 1, the non-woven mica film sticking sheet 4 shown in FIG. 2 is used. This mica layer shall be an integrated mica. With this configuration, since the mica has excellent corona resistance, the electric charging life of the stator coil is further extended.

(Fifth Embodiment) An embodiment corresponding to claim 5 will be described. In the coils of Examples 1 to 4, the non-woven fabric film-attached sheet and the non-woven fabric layer of the non-woven fabric mica film-attached sheet are previously treated with a catalyst that accelerates the curing speed of the impregnated resin. By doing this, in addition to the winding effect of the non-woven film sticking sheet and the non-woven mica film sticking sheet, the resin impregnated in the insulating layer can be used even if the viscosity of the resin decreases in the process of heating and curing the impregnated resin. Example 1
Since the curing of the resin progresses faster than that, the resin impregnated in the gap 8 formed by the corner curvature portion of the coil insulated wire 5 does not flow out. Furthermore, it will prevent the resin from flowing out.

(Sixth Embodiment) An embodiment corresponding to claim 6 will be described. In the coils of Examples 1 to 4, the films of the non-woven film sticking sheet and the non-woven mica film sticking sheet are made heat-shrinkable. With this configuration, since the sheet does not wrinkle during flat winding, the insulation characteristics such as the service life are further improved.

(Seventh Embodiment) An embodiment corresponding to claim 7 will be described. In the coils of Examples 1 to 6, after the ground insulation is applied, a film tape is wound around the outermost layer. By doing so, in addition to the rolling effect of the non-woven fabric film-attached sheet and the non-woven fabric mica film-attached sheet, it also leads to prevention of resin outflow.

[0022]

As described above, according to the present invention, the impregnating resin does not flow out, and therefore voids do not occur in the vicinity of the coil-insulated wire and the ground insulating layer. improves. In addition, since the tape step difference, which is a weak point, is reduced in the vicinity of the conductor, the service life is significantly extended. Therefore, since insulation deterioration due to discharge does not occur, a highly reliable stator winding can be provided.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a non-woven fabric film-attached sheet that is wound flat on a rotating electric machine coil of the present invention,

FIG. 2 is a vertical cross-sectional view of a sheet of a non-woven mica film stuck on a rotating electric machine coil in a flat winding,

FIG. 3 is a manufacturing process diagram of the rotating electric machine coil of the present invention;

FIG. 4 is a longitudinal sectional view of a stator coil of a rotating electric machine coil according to the present invention,

FIG. 5 is a diagram showing the relationship between the tape width of the insulated coil and the life of charging.

FIG. 6 is a tan δ of the present invention and a conventional rotating electric machine coil.
-Voltage characteristics,

FIG. 7: Charging life characteristics of the present invention and conventional rotary electric machine coils,

FIG. 8 is a conventional stator coil manufacturing process,

9 is a vertical cross-sectional view taken along the line I-I of FIG.

[Explanation of symbols]

1 ... Nonwoven film sticking sheet, 2 ... Film, 3 ... Nonwoven cloth, 4 ... Nonwoven mica film sticking sheet, 5 ... Insulated wire, 6 ...
Dry mica tape, 7 ... Ground insulation layer, 8
… Gap, 9… Mica layer, 10… Heat-resistant film tape.

Claims (7)

[Claims] 1. A method for manufacturing a rotating electrical machine coil formed in a hexagonal shape, wherein an insulating electric machine is wound in a predetermined shape, and a non-woven fabric film-attached sheet is wound on the straight side of the hexagonal coil with the non-woven fabric side being the coil side. After rotating, the stator coil of the rotating electric machine is characterized in that the whole coil is insulated with a mica tape to the ground and impregnated with a thermosetting resin under vacuum pressure to heat cure. 2. The stator coil for a rotating electric machine according to claim 1, wherein the non-woven fabric film-attached sheet is a non-woven fabric mica film-attached sheet and is wound with the non-woven fabric side being the coil side. 3. A rotary electric machine coil manufactured in a hexagonal shape, the portion corresponding to the straight portion of the coil when the insulated electric wire is wound in a predetermined shape on the coil winding form and then formed in the hexagonal shape. The non-woven fabric film-attached sheet is wound on the non-woven fabric side with the non-woven fabric side as the coil side, and then the coil is formed into a hexagonal shape, and then the whole coil is insulated with ground by mica tape and impregnated with a thermosetting resin under vacuum pressure. A stator coil for a rotating electric machine, characterized by being heat-cured. 4. The stator coil of a rotating electric machine according to claim 3, wherein the non-woven fabric film-attached sheet is a non-woven mica film-attached sheet, and is wound with the non-woven fabric side being the coil side. 5. The stator coil of a rotating electric machine according to claim 1, wherein the non-woven fabric film-attached sheet and the non-woven fabric mica film-attached sheet have a configuration in which a non-woven fabric layer is subjected to a catalyst treatment in advance. 6. The stator coil of a rotating electric machine according to claim 1, wherein the films of the non-woven film sticking sheet and the non-woven mica film sticking sheet are heat-shrinkable. 7. The stator coil of a rotating electric machine according to claim 1, wherein a film tape is wound on the outermost layer after ground insulation.