JPH0464443B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a water-cooled winding used in an electromagnetic stirring device.

[Prior art] Since electromagnetic stirring devices are installed in narrow spaces,
It is necessary to design the size to be compact. In addition, since there are cases where a large current is passed through the device, it is necessary to cool parts that become overheated, such as the windings, that is, the coil. In the case of an electromagnetic stirring device whose coil is cooled by air cooling, it can generally be used at a maximum current density of about 3 to 5 A/ ^mm2 , but if the maximum current density exceeds 10A/ ^mm2, cannot be used. Therefore, in such cases, an electromagnetic stirring device with a water-cooled coil is used.

FIG. 1 is a cross-sectional view of the winding part in the water-cooled electromagnetic stirring device of the present invention, and FIG. 2 is an enlarged cross-sectional view of the coil in the device of FIG. The configuration of the wire section is the same as that of the winding section in the water-cooled electromagnetic stirring device described in the prior art, for example, Japanese Patent Publication No. 53-25235, so the winding section in the water-cooled electromagnetic stirring device described in this publication is The description will also be given with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 denotes a coil constituting a winding in which electric wire is wound into an oval shape. An iron core 2 is inserted into this coil 1, and is fixed to the iron core 2 with wedges 3 and spacers 4. The coil 1 fixed to the iron core 2 is integrally impregnated with resin for insulation.

In FIG. 2, 5 is a conductor formed of necessary turns, for example, a rectangular electric wire. This conductor 5
For example, a polyimide film is wound several times in a half-overlap manner on the surface of the turn insulating layer 6.
Further, on the upper layer of the turn insulating layer 6, for example, a glass tape is wound around the conductor 5 in two and a half turns to form an insulating layer 7 as a main insulating layer.

In the case of a conventional water-cooled electromagnetic stirrer, the turn insulating layer 6 must be made of an insulating material with good water resistance, and in the case of air cooling, the turn insulating layer 6 must also serve as the main insulating layer. is necessary. Therefore, in this case the insulating layer 7 covers each turn conductor 5.
The role of the insulating layer is changed so that it plays the role of bundling the turn insulating layer 6 and also covers the role of main insulation, that is, water-resistant insulation, which is also performed by the turn insulating layer 6.
This increases the burden on the turn insulating layer.

[Problems to be solved by the invention] In the winding of the conventional electromagnetic stirring device as described above,
The turn insulating layer 6 is water resistant and needs to play the role of not only insulating between coil turns but also insulating the entire coil turn (main insulation), so its thickness becomes thicker and the coil as a whole becomes larger. There was a drawback. Furthermore, since the wire is formed into a coil by winding multiple layers of film to form an insulating layer, it is susceptible to processing deterioration, resulting in a shortened lifespan of the coil 1. On the other hand, when the turn insulating layer 6 is applied after forming the electric wire, the work is complicated and requires a large number of man-hours, which is disadvantageous economically.

This invention was made to solve this problem, and the finished size of the coil is small.
In addition, it has superior water resistance compared to conventional equipment.
The purpose of the present invention is to obtain a water-cooled winding for an electromagnetic stirring device that has a long life and excellent mechanical rigidity.

[Means for Solving the Problems] The water-cooled winding for an electromagnetic stirrer according to the present invention includes a winding of a rectangular electric wire around which a backing laminated mica tape is wound as a turn insulating layer. A porous polyamide fiber that can be impregnated with a resin is wound as a layer, and this winding is further impregnated with an epoxy resin.

[Function] In this invention, porous polyamide fibers that are easily impregnated with resin are wound around a rectangular electric wire wound with a backing laminated mica tape. is impregnated and hardened, so it has strong mechanical rigidity.
It has excellent water resistance and can achieve a long life.

As the backing material used in this invention, glass cloth, polyimide film such as NOMEX (trade name of DuPont, USA), or polyester nonwoven fabric can be used.

The polyamide fiber used in this invention preferably has an air permeability of 25 to 20 seconds/100 cm ³ -air. If the ventilation rate exceeds 25 seconds/100cm ³ -air, the resin retention will be poor and the resin will leak, which is not preferable. Also, this polyamide fiber has a thickness
0.08 mm (3 mils) with an area factor of 40-60 g/m ² or a thickness of 0.13 mm (5 mils) with an area factor of 70-90 g/m ²
Polyamide paper can also be used. For example, NOMEX paper #424 (trade name of DuPont, USA) is suitable.

As the epoxy resin to be impregnated into the winding wire, an epoxy resin consisting of a bisphenol type epoxy, a reactive diluent such as a diglycidyl ether type reactive diluent, and an amine type curing agent can be suitably used.

[Example] In Fig. 1, a rectangular electric wire is used as the conductor 5, and a laminated mica tape with a finished thickness of 0.13 mm backed with a polyester film is wrapped once in a half-wound manner around the rectangular electric wire to form a turn insulating layer. It was set at 6. The conductor 5 was wound into a coil the required number of times and formed into the desired shape. Next, the main insulating layer 7 is made of polyamide paper having a density of less than 25 seconds/100 cm ³ - air (ASTM D726A method) with an area coefficient of 81.4 g/m ² and a width of 19 mm (0.13 mm).
The tape was wrapped around the above coil four and a half times. The iron core 2 shown in FIG. 1 was inserted into this coil 1, fixed using wedges 3, spacers 4, etc., and wired. Turn insulation and main insulation are applied to this connection section in the same manner as above, and this coil 1 is impregnated with vacuum pressure and pressure using an epoxy resin consisting of bisphenol type epoxy, reactive diluent, and amine hardener. The impregnated resin was polymerized and cured while drying.

Experiments were conducted to determine the deterioration characteristics of the coils fabricated in this manner. In this experiment, when a coil is immersed in water and a voltage is applied, the deterioration characteristics are determined from the relationship between the applied voltage and the time until the coil becomes punctured. The results thus obtained are shown in FIG. In the figure, curve A is for the coil according to the present invention, and curve B is for the conventional coil. From this figure, it can be seen that the deterioration characteristics of the coil according to the present invention are far superior to those of conventional coils. This is because the main insulating layer 7 of the present invention is very dense.
It is thought that the water resistance and deterioration due to electrical charging have been significantly improved. Therefore, compared to the conventional structure in which each turn insulating layer 6 has water resistance, it has far superior reliability.

In the above example, an epoxy resin consisting of bisphenol epoxy, a reactive diluent, and an amine curing agent was used as the impregnating resin, but a porous resin with an air flow rate of 25 seconds/100 cm ³ -air or less was used as the main insulating layer. As long as polyamide paper is used, similar results can be obtained using other epoxy resins.

[Effects of the Invention] As explained above, the present invention has a winding of a rectangular electric wire in which a laminated mica tape with a backing material as a backing is wound as a turn insulation.
sec/100cm ³ - A polyamide fiber of less than air is wound as the main insulation, and the winding with the main insulation is impregnated with an epoxy resin consisting of bisphenol epoxy, a reactive diluent, and an amine curing agent, and hardened. By doing so, it is possible to obtain an inexpensive water-cooled winding for an electromagnetic stirrer which has a strong turn insulating layer and excellent water resistance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a winding part in a water-cooled electromagnetic stirring device according to an embodiment of the present invention, and at the same time, a sectional view of a winding part in a conventional water-cooled electromagnetic stirring device, and FIG. 2 is a sectional view of a coil in the device of FIG. FIG. 3 is an enlarged cross-sectional view of FIG. 3, which is a diagram showing the deterioration characteristics of a coil used in an embodiment of the present invention or a conventional water-cooled electromagnetic stirrer when applied with electricity in water. In the figure, 1 is a coil, 2 is an iron core, 3 is a wedge, 4 is a spacer, 5 is a conductor, 6 is a turn insulating layer, and 7 is a (main) insulating layer.

Claims (1)

[Claims] 1. Polyamide fiber with an air flow rate of 25 seconds/100cm ³ -air or less is wound as the main insulation around a winding of a rectangular electric wire in which a laminated mica tape with a backing material as a backing is wound as a turn insulation. 1. A water-cooled winding for an electromagnetic stirrer, characterized in that the winding provided with main insulation is impregnated and cured with an epoxy resin consisting of bisphenol epoxy, a reactive diluent, and an amine curing agent. 2. The water-cooled winding for an electromagnetic stirring device according to claim 1, wherein the backing material is glass cloth, polyimide film, or polyester nonwoven fabric.