JPH0341446Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field to which the idea belongs]

This invention mainly relates to the structure of a connecting lead between windings of an oil-feed cooled stationary induction electric appliance such as a transformer.

[Prior art and its problems]

Generally, when connecting two windings of an electric appliance using a lead, it is desirable to make the lead the shortest possible size to make the electric appliance smaller. Especially in the case of an oil-feed cooling type, this is even more strongly desired since there is little room inside the appliance. As the voltage and capacity of electrical appliances increases, the cross-sectional area or outer diameter of the lead wire that connects two windings becomes larger in terms of its current capacity or electric field strength, and its insulation thickness also becomes thicker. Therefore, it becomes necessary to connect the winding core wires not directly, but through copper wires or round copper wires. 4 and 5 show the conventional structure in this case, FIG. 4 is a sectional view of the lead, and FIG. 5 shows the relationship between the lead and the winding. In the figure, one end of a lead wire 41 made of round copper is connected to a winding 51, and the other ends are brazed to each other. In this case, in order to prevent the insulating material 42 of the lead wire 41 from deteriorating due to the influence of heat caused by this brazing, the brazed portion 41a and the insulating material 42 are
A so-called burnt margin 43 is required between the ends of the insulating material 42, and in order to increase the creepage insulation distance 44 of the connection part, the end of the insulating material 42 is made conical, and additional insulation 45 is provided between the conical parts. It is performed. Therefore, lead 4
6 becomes longer, the lead 46 protrudes from the outer diameter part of the winding 51 as shown in FIG. It became.

[Purpose of invention]

This invention was made in view of the above-mentioned drawbacks of the conventional method, and its purpose is to reduce the size and weight of electrical appliances by shortening the connecting leads between the windings.

[Key points of the idea]

The above object is achieved according to the invention by configuring the connecting lead between the two windings as follows. That is, the connecting lead has a connecting core part that extends the core wires at the ends of the two windings and connects them to each other between the windings, and a cooling medium such as insulating oil is circulated inside the connecting core part. a metal shield that surrounds the metal shield in the axial direction and can be divided in the circumferential direction with room for consisting of additional insulation. By configuring the connection lead between two windings as described above, since the core wire is often made up of multiple strands, it is easy to connect individual strands by brazing, etc. be. Further, since the insulation thickness of the strands is thin and the cross-sectional area is small, the connecting portion can be made small. Since the cooling medium flows around the core wire, there is no need to increase its cross section. Furthermore, by surrounding the connecting core wire with a shield that can be divided in the circumferential direction and insulating the top with an additional insulator, the electric field in the shield portion is relaxed, so that the insulation distance to other parts may be small.

[Example of idea]

Figures 1 to 3 are illustrations of an embodiment of this invention. Figure 1 is a longitudinal cross-sectional view of the lead 1, Figure 2 is a cross-sectional view of the lead, and Figure 3 is a diagram of the relationship between the winding 51 and the lead 1. It is. Two windings 51 formed by winding the core wire 2 extend the end core wire 2 and are connected between the windings 51 . A metal shield 5 surrounds the connecting core wire portions 3 that are connected to each other in the axial direction, leaving room for a cooling medium 4 such as insulating oil to flow therein, and can be divided into two in the circumferential direction (divided into two in the figure). is provided. A power supply lead 6 is provided inside the shield 5 to connect the shield 5 and the connecting core portion 3 to have the same potential, and additional insulation 7 is provided in contact with the outside of the shield 5 to insulate the shield. ing. The lead 1 is supported by an oil guide insulator 9 provided around the outer periphery of the winding 51. The lead 1 is manufactured by extending the core wire 2, which is generally made up of a plurality of wires 2a, from the ends of the windings, connecting each wire 2a to each other, covering the axial periphery with a shield 5, and further shielding. Additional insulation 7 is applied on top of the lead 1 to complete the lead 1.

[Effect of the idea]

By configuring the lead 1 that connects the two windings 51 as described above, since the connecting core wire portion 3 has a small cross-sectional area, connection by brazing or splicing is easy and the length thereof can be shortened. In addition, since the cooling medium flows around it, the cooling efficiency is good and there is no need to increase the cross-sectional area as in the conventional case. Connection lead 3
Even if the cross-sectional area of the lead 1 is small, the electric field on the surface of the lead 1 can be alleviated by covering the outside with a large-diameter metal shield 5, making this the same potential as the connecting lead 3, and providing additional insulation 7. The insulation distance from other parts can be shortened. Because of this and because the connection lead 3 is short, the lead 1 fits between the two windings 51, and the distance from the container 52 is also small, requiring less materials including insulating oil, resulting in an overall smaller and cheaper electrical appliance. It will be done.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a connection lead between windings, Figure 2 is a cross-sectional view of Figure 1, Figure 3 is a diagram of the relationship between the windings and the connection lead, and Figures 4 and 5 are respectively conventional FIG. 3 is a vertical cross-sectional view of the lead and a relationship diagram between the winding wire and the lead. 1: Connection lead between windings, 2: Core wire, 3: Connection core portion, 4: Cooling medium, 5: Metal shield, 6: Power supply lead, 7: Additional insulation, 51: Winding wire.

Claims (1)

[Scope of utility model registration request] A lead that connects two windings cooled by a cooling medium, including a connecting core portion that extends the core wires of the two windings and connects the windings to each other, and a space for the cooling medium to flow. a shield formed to surround the connecting core wire in the axial direction and to be divisible in the circumferential direction while leaving the connecting core wire; a power supply lead that brings this shield to the same potential as the connecting core wire; An inter-winding connection lead, characterized in that it comprises an additional insulator provided.