JPS6046013A - Electric apparatus - Google Patents

Abstract

PURPOSE:To miniaturize dimensions of a packing type to enable assembly in a factory and transportation under that state without changing the installation angle of a bushing by biasing the center line of a pocket where the bushing is errected and the center line of the bushing installed obliquely on the wall of the tank of electric equipment such as a transformer, etc. CONSTITUTION:The angle theta' between the center line of a pocket 7 where a bushing 5 is housed and the center line of an iron core 1 is made smaller than the angle theta between the center line of the iron core 1 and that of the bushing 5. In this construction, the pocket 7 not always requires to secure a redius R concentrically with the bushing 5. The point of intersection C between the center line of the bushing 5 and that of the pocket 7, is made as a position which secures an insulation distance (d) between the lower shield 5a of the bushing 5 and the pocket 7. Consequently, a portion B can be brought nearer to the center side of a transformer and the equipment can be housed within the dimensions of transportation limit whereby transportation of the apparatus is facilitated without separating the pocket 7. Since the volume within the transformer can be made smaller, quantity of the insulation oil enclosed in the transformer can also be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to electrical equipment such as transformers, and particularly to the structure of bushings thereof.

[Background of the invention]

FIG. 1 shows the conventional structure of a power plant transformer in which a bushing is connected to a cable. In the figure, winding 2 is attached to iron core 1.
is wound and stored in a tank 3, and the upper part of the tank 3 is hermetically sealed with a cover 4. The bushing 5 is connected to the winding 2 via a lead wire 6,
This bushing 5 is established in a pocket 7 attached to the side surface of the tank 3 at an attachment angle of θ with respect to the center line of the iron core 1. One end of a lead wire 8 is fixed to the upper end of the bushing 5, and the other end of the lead wire 8 is connected to a cable 10 via a cable head 9. Shields 5a are provided at the upper and lower ends of the bushing 5, respectively, and the shields 5a are at the same potential as the lead wire 6 and reduce the electric field between the bushing 5 and the pocket 7 on the ground side. are doing. That is, the shield 5a and the pocket 7 are configured to maintain a constant insulation distance di.

FIG. 2 is a view taken along the line A-A in FIG. It forms a semicircle with radius R concentrically with the center of 5.

For electrical equipment such as transformers, it is desirable to transport accessories such as tanks to the site as assembled at the factory as much as possible from the viewpoint of electrical reliability and to facilitate on-site assembly work. However, there are restrictions on dimensions such as height and width in packaging during transportation, and the product must be packed so that the dimensions in packaging fall within these limits. In FIG. 1, the width is the widest and the upper part B of the pocket 7 exceeds the limit dimension, so there is a drawback that the pocket 7 may have to be separated and changed to a structure that can be transported separately.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to reduce the packaging dimensions so that electrical equipment such as transformers can be transported assembled at the factory without changing the mounting angle of the bushings. Our goal is to provide electrical equipment such as transformers that can be made smaller.

[Summary of the invention]

The present invention achieves this by making the center line of a bushing installed diagonally on the tank wall of an electrical device such as a transformer eccentric to the center line of a pocket in which the bushing is established.
It was designed to achieve the intended purpose.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electrical device according to the present invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of the present invention. In this figure, parts that are the same as those shown in FIG. 1 are designated by the same numbers. 1st
The only difference from the conventional example shown in the figure is the position of the center line of the pocket 7 that establishes the bushing 5, and the other parts are exactly the same as in FIG. With respect to the angle θ of the center line of the bushing 5 with respect to the center line of the iron core 1, the angle θ' of the center line of the pocket 7 that accommodates the bushing 5 with respect to the center line of the iron core 1.
is getting smaller.

According to this embodiment configured in this way, the bushing 5
Since the sleeve 5b constituting the sleeve 5b has a grounding potential like the pocket 7, there is no need to ensure an electrically insulating distance between the pocket 7 and the bushing 5 in the portion close to the sleeve 5b.

That is, the pocket 7 does not necessarily have to have a radius hole concentrically with the bushing 5. However, the intersection C between the center line of the bushing 5 and the center line of the pocket 7 is located at a position that ensures the insulation distance d between the lower shield 5a of the bushing 5 and the pocket 7.

As described above, according to this embodiment, part B can be brought closer to the center of the transformer, and the equipment can be accommodated within the transport limit dimensions, so that the pocket 7 can be transported without being separated. Furthermore, since the internal volume of the transformer can be reduced, the amount of insulating oil sealed in the transformer can also be reduced. In this case, the inclination angle θ' of the pocket 7 may be made as small as possible without causing the sleeve 5b to abut against the pocket 7.

In this embodiment, a pocket having a semicircular cross section has been described, but the same effect can be obtained with a pocket having a box-shaped cross section.

〔Effect of the invention〕

As described above, according to the present invention, the installation angle of the pocket for establishing the bushing of electrical equipment such as a transformer is reduced, so the equipment can be transported with the pocket assembled.
Reducing the amount of insulating oil, which improves the reliability of equipment.
The effect is significant because it has become possible to reduce on-site assembly costs.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the structure of a conventional transformer, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a side sectional view showing an embodiment of the transformer according to the present invention. be.

Claims (1)

[Claims] 1. A tank for storing the iron r□ around which the winding is wound, a pocket formed in the tank, and a bushing connected to the lead wire end of the winding in the pocket and inclined with respect to the iron core. An electrical device according to the present invention, wherein the angle of inclination of the pocket with respect to the iron core is smaller than the angle of inclination of the bushing with respect to the iron core.