JPH0211003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to cellulose-free transformer coils;
In particular, it concerns multilayer resin insulation along the edges of the coil windings.

PRIOR ART Although the concept of celluloseless isolation transformers is known, efforts are currently being made to improve upon it. As part of the cellulose-free coil concept, liquid resin is applied and cured on-site during coil winding. This concept was used to improve the coil structure in the radial direction by reducing the insulation in the radial direction, applying a thin resin film between the layers,
A cellulose-free structure is obtained by repeatedly curing a thin resin film to form high-low spaces.

Structure of the Invention According to the present invention, there is provided a tubular coil having a first metal winding made of a plurality of layers including an inner layer and an outer layer, and a first metal winding made of a resin material between the layers of the first metal winding.
a coating, a second coating of resin material on the outer layer of the first metal winding, and a second coating of resin material provided on the second layer of resin material;
A second metal winding made of a plurality of layers, and a third coating of a resin material between the layers of the second metal winding, each coating of the resin material covering the first metal winding and the second metal winding. A cellulose-free transformer coil is obtained having an overlapping portion extending continuously over the opposing edges of the wire and overlapping portions of the previously formed layers of resin material to form a multilayer coating of high dielectric strength.

Further, according to the present invention, the steps include: (a) providing a winding mandrel so as to be repeatedly rotated through a resin application section and a resin hardening section; (b) applying at least one resin coating on the mandrel; (c) a step of spirally winding multiple layers of metal windings on the resin coating, (d) a step of applying a resin coating on each of the metal winding layers, and (e) a step of (c) above. (f) applying at least one resin coating on the outer layer of the applied metal winding; (f) threading a long conductor layer across and over the resin coating applied in step (e) above; (g) applying a resin coating on each turn of each layer of the long conductor applied in step (f) above, and applying a resin coating on both opposite edges of the previously applied resin coating; A method of manufacturing a cellulose-free transformer coil is also provided, comprising the step of flowing the respective resin coating.

An advantage of the transformer coil and method of manufacturing the same of the present invention is that a cellulose-free transformer coil structure is obtained that results in dielectric breakdown rather than dielectric creep along the layer extension surface during operation of the transformer coil. Multiple resin coatings on the edges of the coil layer have a higher dielectric strength than one applied in one layer to the same thickness. Therefore, damage to the insulation in the event of an accident is minimized and less likely to occur.

EXAMPLES According to the present invention, a method for manufacturing a cellulose-free transformer coil consists of the following steps.

(a) providing a winding mandrel adapted to be repeatedly rotated through the resin coating and resin hardening sections; (b) applying at least one resin coating on the mandrel; (c) providing a metal winding on the mandrel. (d) Step of applying a resin coating on each layer of the metal winding wire; (e) Step of applying a large number of resin coatings on the metal winding layer; (f) The step of (e) above. (g) applying at least one additional resin coating over the outer layer of the elongated conductor; h) flowing each resin coating over opposite edges of the layer of metal winding and the previously applied resin coating to form a multilayer coating on the edges of the coil structure;

In FIG. 1, the transformer coil 3 is a tubular member formed by continuously applying a metal winding as a conductor and a resin coating on a mandrel 5 rotating around a center line 7. When the mandrel rotates in the direction of arrow 9 (FIG. 2), the mandrel
1. Pass through a working section including a winding section 13 for applying a winding conductor such as a wire 15 to the coil 3, and a resin curing section for curing the resin while rotating the mandrel through 360 degrees as shown by arrow 9. Rotate. The method of manufacturing the coil 3 described here can be changed as necessary.

As shown in FIG. 1, the coil 3 includes the following parts in the order in which they are applied. That is, coating 1 of resin material
9, a first metal winding consisting of a plurality of layers 21 including an inner layer and an outer layer, a first coating 23 of a resin material between the layers 21 of the first metal winding, and an outer layer of the first metal winding. A second coating 25 of resin material on 21 and a plurality of layers 27, 2 provided on the second layer 25 of resin material.
a second metal winding consisting of layers 9 and 31;
29, a resin coating 35 between the layers 29 and 31 (constituting a third coating together with the resin coating 33), and an outer resin coating 37. The transformer coil 3 further comprises laminated covers (multilayer coatings) 39, 41 on opposite edges of the several layers and coatings, which overlap when each resin coating is applied in place. It is a part.

The resin coating 19 (FIG. 1) is applied by any suitable method, such as by spraying or using a resin applicator 11 such as a paint roller. in fact,
Coating 19 consists of multiple layers applied repeatedly to cover any holes, cavities or undesirable contaminants that would weaken the dielectric strength of the coating.
For this purpose, 5 to 30 coatings, each approximately 0.05 mm (approximately 2.0 mils) thick, are applied. The coating is applied in a spiral manner by rotating the mandrel 4, and each coating is cured in a resin curing section 17. Preferably, the resin is a high temperature cross-linkable resin material. The resin can be, for example, a mixture of acrylated epoxies, acrylated epoxy novolacs, acrylated hydantoin epoxies, and acrylated urethanes in acrylate monomers that can be cured by ultraviolet radiation. Each resin coating is approximately 0.0127mm to approx.
There can be from 5 to 100 turns up to a thickness of 0.102 mm (about 0.0005 in. to 0.0040 in.), or about 0.102 mm (4 mils) per turn. The resin is applied in one or more thin layers and cured, depending on the dielectric strength required.

If the layer of winding (i.e. the first metal winding) 21 includes a pre-insulated surface, the coating 1
3 and 23 can be omitted. The resin curing section 17 is equipped with a suitable radiation device such as infrared rays. For this purpose, an ultraviolet irradiation device or an electron beam device is satisfactory. Ultraviolet irradiation appears to be practical.

After applying the coating 19, a conductor winding or layer 21 is applied. The winding is a continuous metal strip of copper or aluminum. Layer 21 may have an insulating coating, such as enamel, on its outer surface, in which case continuous winding of the layer can be applied without intervening resin coating 23. Generally, layer 21 will be the low voltage winding of transformer coil 3.

After the formation of the winding layer 21 is completed, a plurality of turns of the coating 25 are applied, e.g. about 4 mils per turn.
Approximately 5 to 100 turns of up to 100 turns are applied in the same manner as for coating 19.

After applying the required number of coatings 25, the winding layers (ie the second metal windings) 27, 29, 31 are applied. The winding is preferably a continuous conductor, such as copper or aluminum, and preferably has an insulating coating, such as enamel. As the mandrel 4 rotates, a winding layer 27 is applied by the wire 15. wire 15
moves along the outer surface of the insulating coating 25 to a position 15a indicated by a broken line in FIG. Winding layer 27
As the wire is wound into position, a resin coating roller or resin applicator 11 is advanced along with the wire to apply a resin coating 33 onto each turn. As the rotation continues in this manner, the first coating 33 passes through the resin hardening portion 17 and hardens. When the next winding layer 27 is applied, it is also covered with a resin coating 33, and the previous coating 33 is also covered with the next resin coating. Finally, the resin coating 33
is equal to the number of turns of the winding, and a wedge-shaped insulator consisting of a plurality of separately cured resin coatings 33 is formed.

Next, a winding layer 29 is applied by rotating the mandrel while advancing the wire 15 in the opposite direction to that for the previous winding layer 27. Similarly, for each turn of the winding, the resin applicator is advanced from the dashed line position 11 in FIG. 2 to apply a separate resin coating 35 until the wire 15 reaches the left end of the coil as shown in FIG. is cured and coated with multiple resin coatings. In this way, a wedge-shaped insulator consisting of a plurality of resin coatings 35 is completed.

Thereafter, the same process as in the case of the winding layer 27 is performed to form the winding layer 31. If the winding layer 31 is the last layer, the outer coating 37 is applied by the resin applicator 11. First, after all the windings of the winding layer 31 are made, the mandrel 4 is rotated and all the windings are coated with the resin coating 37 by the resin applicator 11.

As shown in FIG. 1, the resin coating 33, which is a wedge-shaped insulator, is tapered so that the thick end is on the left and the thin end is on the right. On the contrary, the resin coating 35 is arranged in opposite directions, with the thick end on the right and the thin end on the left. Since the winding layers 27, 29, 31 are high voltage windings, wedge-shaped resin coatings 33, 35 are desirable. However, the structure and method of the present invention also applies when the intermediate winding layers, such as winding layer 29, are not sloped and are parallel to the inner and outer winding layers 27, 31, as shown in FIG. It is possible.

According to the invention, each time a resin coating is applied, the overlap extending beyond the ends of the winding layer flows onto the ends of the previously applied core component. For example, when the winding layer 21 is applied close to the resin coating 19, the overlapping portion of the opposite end of the winding layer is
A resin coating 23 is applied over the opposite edge of and flowing over the resin coating 19. Next winding layer 21
is similarly coated with another resin coating 23, the overlapping portion likewise flowing onto the opposite end of the winding layer 21 and onto the overlapping portion of the previously applied resin coating 23.

Similarly, as each resin coating 25 is applied, the overlapping portion extends over and covers the opposite edge of the winding layer and the previously applied resin coating 23. As each resin coating 33 is applied, the overlapping portion extends downwardly over the previously applied winding layer 27 and over the overlapping portion of the resin coatings 23, 25, as shown by the laminated cover 41. Similarly, as each resin coating 35 is applied, the overlapping portion extends downwardly over the end of the coil 3 to completely cover the overlapping portion of the previously applied resin coatings 23, 25. Finally, the resin coating 37 is
As part of the laminated covers 39 and 41, there are overlapped portions extending downward on both sides.

Effects of the Invention According to the cellulose-free transformer coil of the present invention, a multilayer resin coating is obtained at the edges of the coil, where a greater dielectric strength is required than that obtained with the same thickness of resin formed in a single layer. . The advantage of this multilayer resin coating is that the possibility of dielectric breakdown in the event of an accident can be minimized or virtually eliminated.
Also, because the resin coating is multilayered, breakdown voltage occurs during operation of the transformer rather than insulation creep along the plane in which the layers extend.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a winding layer and a resin coating thereon, and FIG. 2 is a schematic perspective view showing one method of forming the coil structure of FIG. 1. 3... Coil, 21... First metal winding (winding layer) consisting of multiple layers, 23... First coating (resin coating), 2
5...Second coating (resin coating), 27, 29, 31...
a second metal winding (winding layer) consisting of a plurality of layers, 33;
35...Third coating (resin coating), 39, 41...Multilayer coating (laminated cover).

Claims (1)

[Scope of Claims] 1. A tubular coil having a first metal winding made of a plurality of layers including an inner layer and an outer layer; a first coating of a resin material between the layers of the first metal winding; 1 of the resin material on the outer layer of the metal winding.
a second metal winding provided on the second layer of resin material and consisting of a plurality of layers; and a third coating of resin material between the layers of the second metal winding, each of the resin material an overlapping portion in which the coating extends continuously over opposing edges of the first metal winding and the second metal winding and overlapping portions of the previously formed layers of resin material to form a multilayer coating with high dielectric strength; A cellulose-free transformer coil comprising: 2. Claim 1, wherein the resin material is a mixture of acrylated epoxy, acrylated epoxy novolak, acrylated hydantoin epoxy, and acrylated urethane dissolved in an acrylate monomer that is UV curable.
Cellulose-free transformer coil as described in Section 1. 3. Claim 1, wherein the third layer of resin material is wedge-shaped, being thin at one edge of the adjacent pair of layers of the second metal winding and thick at the other edge of the pair of layers.
Cellulose-free transformer coil as described in Section 1. 4. (a) preparing a winding mandrel for repeated rotation through the resin coating and resin curing sections; (b) spirally winding multiple layers of metal winding onto the mandrel; and (c) a step of applying a large number of resin coatings on the layer of metal winding applied in step (b) above, and (d) a step of winding at least one long conductor layer in a spiral shape across the resin coating and on top of the resin coating. (e) applying at least one additional resin coating on the outer layer of the long conductor, each resin coating flowing over opposite edges of the resin coating to form a multilayer coating on the edges of the coil structure; A method of manufacturing a cellulose-free transformer coil, comprising: 5. The method of manufacturing a cellulose-free transformer coil according to claim 4, wherein at least one resin coating is applied on the mandrel before step (b).