JPS59218708A - Coil for electromagnet - Google Patents

Abstract

PURPOSE:To contrive improvement in mechanical strength, heat-resisting property and weatherability of the titled coil by a method wherein the gap located between wire materials is filled up with an elastic insulating material, and the outer surface is formed into the cross-sectional structure wherein it is covered by a fiber-reinforced plastic outer skin, thereby enabling to prevent the generation of cracks on the filling material, the propagation of cracks to the skin and the generation of cracks on the skin itself. CONSTITUTION:After an enamel-covered wire material 1 has been wound around the prescribed number of turns, the gap between the wire materials 1 is molded by an elastic insulating material 3', and the outside of which is formed into the cross-sectional structure wherein a fiber-reinformed plastic crust 5' such as glass fiber reinforced silicon varnish and the like is coated. By the filling of the elastic insulating material 3' into the gap of the wire material 1 as above-mentioned, the generation of cracks on the filled part and the propagation of ctacks to the outer skin 5' can be prevented, and the deterioration both in mechanical strength, due to generation of cracks, and the characteristics due to the infiltration of moisture can also be stopped. Especially, as cracks are hardly generated on the filled part even when there is a major degree of rise in temperatue on the coil, the heat resisting property of the coil can be improved substantially.

Description

[Detailed description of the invention] The present invention relates to an electromagnetic coil.

Conventionally, the cross-sectional structure of a coil used in magnetic levitation electromagnets and various high current density electromagnets is as shown in Figure 1.
In some cases, the gap between the hindlimb wires obtained by winding the enamel-coated wire 1 a predetermined number of times is filled and fixed with varnish impregnation or epoxy resin mold 3, or as shown in Fig. 2, the outside of the structure shown in Fig. 1 is further coated with epoxy. A material coated and reinforced with impregnated glass tape 5 is used. However, the former type has poor weather resistance because it does not have a protective layer on the outer surface, and because the filling material between the wire gaps is made of a material that lacks elasticity, it often cracks due to thermal stress and reduces mechanical strength. Moreover, when such cracks occur, moisture enters through the cracks, which tends to lead to deterioration of characteristics.

In addition, although the latter has a protective layer on the outer surface, the protective layer and the filling material between the wire gaps still lack elasticity, so similar to the former, cranks occur in the filling material part,
Since the cranks become buds and easily spread to the resin in the epoxy-impregnated glass tape on the outer surface, there is a drawback that, like the former, it tends to cause a decrease in mechanical strength and properties.

The present invention has been made to eliminate the above-mentioned conventional drawbacks.
For this reason, the electromagnetic coil according to the present invention has a cross-sectional structure in which the gaps between the wires are filled with an elastic insulating material and the outer surface is covered with a fiber-reinforced plastic sheath, thereby preventing the occurrence of cracks in the filling material between the wire gaps. It is characterized by preventing the propagation of cranks to the outer skin and the occurrence of cranks in the outer skin itself, thereby improving mechanical strength, heat resistance, and weather resistance, and preventing deterioration of properties.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 shows an embodiment of the present invention, in which the enamel-covered wire 1 is wound a predetermined number of times and then
It has a cross-sectional structure in which the gap is molded with an elastic insulating material 3' such as silicone rubber, and the outside thereof is further covered with a fiber-reinforced plastic outer skin 5' such as glass fiber-reinforced silicone varnish.

By filling the gap between the wire rods 1 with the elastic insulating material 3' as described above, it is possible to prevent the occurrence of cracks in the filled portion and the propagation of the cranks to the outer skin 5'. It is possible to prevent a decrease in mechanical strength due to propagation and a decrease in properties due to moisture intrusion. With this structure, cranking is difficult to occur in the filled portion even if there is a large temperature rise in the coil, so the heat resistance of the coil can be considerably improved. Further, the outer skin 5' is made of fiber-reinforced plastic, and since the outer skin itself is less prone to cranking, mechanical strength and weather resistance can be further improved.

The coil according to the present invention can be applied to magnetic levitation electromagnets and various types of high current density electromagnets.

As described above, the present invention provides an electromagnetic coil that has excellent mechanical strength, weather resistance, and heat resistance, and can prevent deterioration of characteristics.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing an example of the structure of a conventional coil, and FIG. 3 is a cross-sectional view showing an example of the structure of a coil according to the present invention. 1...Enamel coated wire 3'...Elastic insulating material 5'...Fibre-reinforced glass outer skin Patent applicant Sumitomo Electric Industries, Ltd. (4 others) Melon/''/ Hole 3U-. b

Claims (3)

[Claims] (1) An electromagnetic coil having a cross-sectional structure in which the gaps between fIM materials are filled with an elastic insulating material and the outer surface is covered with a fiber-reinforced plastic jacket. (2) The coil according to item 1, wherein the elastic insulating material is made of silicone rubber. (3) The coil according to item 1, wherein the outer cover is made of glass fiber reinforced silicone rubber.