JPS5847806B2 - butsing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil-filled bushing that is used in a horizontal position, in which a shield plate and a heat-generating connecting pipe are provided between a mounting flange and an insulating pipe surrounding a center conductor, and a heat-generating connection is provided. The feature is that the oil is caused to convect along the central conductor by utilizing the density difference caused by the temperature difference between the inner oil and the outer oil.

As shown in Fig. 1, in the conventional type, an insulating tube 2 is provided around a center conductor 1, a mounting flange 3 is placed in the center on the outer periphery, guides 4 and 5 are placed on both sides, and an insulating tube 2 is provided at one end. Terminal fitting 6
An expansion chamber 7 is provided at the other end, and a strong compression coil spring 8 is disposed inside the expansion chamber 7, and a compression force is applied to the guy tubes 4, 5 and the mounting flange to provide mechanical strength.

At the end of the expansion chamber 7, a bellows 9 is used to securely seal the expansion chamber 7 and the center conductor 1 so that a completely sealed structure can be maintained even if each part expands and contracts due to temperature changes in the bushing. It is configured so that it can be done.

In such bushings, since an insulating tube is attached around the center conductor that serves as a heat source, there is little heat radiation in the radial direction, and it is difficult to expect oil convection along the center conductor.

Therefore, the temperature rise of the center conductor increases, and in order to keep the temperature rise below a specified value, a conductor with a large diameter (d) must be used, and the size of the bushing also becomes large.

The present invention provides a shielding plate and a heat-generating connecting pipe between the mounting flange and the insulating pipe, so that oil convects along the center conductor,
This is an attempt to eliminate the drawbacks of the conventional ones mentioned above.

An embodiment of this invention is shown in FIG.

In the figure, reference numeral 1 denotes a tubular center conductor that forms an oil flow passage in the hollow part, and holes 15a and 15 for liquid insulating medium flow are formed at both ends where the insulating tube 2 surrounding the outer periphery cannot be attached.
b is open.

3 is a mounting flange, 4 and 5 are guy tubes, 6 is a terminal metal, 7 is an expansion chamber, and 10 is a conservator.

11 is a shielding plate that divides the interior of the bushing into left and right halves.

Reference numeral 12 denotes a heat-generating connecting pipe made of a metal annular pipe arranged around the insulating tube and concentric with the center conductor so that heat is generated by electromagnetic induction when current flows through the center conductor; Holes 14a, 14b at the top and bottom as shown in figure a=e
One hole 14b opens to the expansion chamber side in the pushing that is divided into two parts, and the other hole 14a passes through the shield plate and opens to the terminal metal side in the bushing. It connects the two halves of the bushing.

Reference numeral 13 denotes a heat insulating material wrapped around the heat generating connecting pipe to prevent the heat generated in the heat generating connecting pipe from escaping toward the outer circumference of the pipe.

The operation of the present invention will be explained.

When a current flows through the center conductor, a magnetic field is generated around the center conductor due to electromagnetic induction, and when the magnetic flux of the magnetic field passes through the annular/hoop cross-section of the heat-generating connecting pipe and its inner hollow part,
A current flows in the circumferential direction within the cross section of the annular pipe in a direction that cancels out this magnetic flux, and heat is generated due to the electrical resistance V (1) of the metal of the annular pipe.

This amount of heat increases the temperature of the oil inside the heat-generating connecting pipe, causing convection due to the density difference between the oil and the oil outside the heat-generating connecting pipe.

Oil flows from the hole 14b of the heat-generating connecting pipe, and the oil flows into the heat-generating connecting pipe 12.
It flows out of the heat generating connecting pipe 12 through the hole 14a.

After that, it flows horizontally through the space between the insulating tube 5 and the insulating tube 2, flows into the center conductor 1 through the hole 15b of the center conductor, flows horizontally inside the center conductor 1, and flows through the hole 15b into the center conductor 1.
leak outside.

Then, it flows horizontally through the space separated by the insulating pipe 4 and the insulating pipe 2, reaches the hole 14b of the heat-generating connecting pipe, and repeats the above flow.

The flow of oil is indicated by arrows in the figure.

According to this invention, since the oil flows along the center conductor, the center conductor can be cooled by convection, and an increase in the temperature of the center conductor can be suppressed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional pushing, Fig. 2 is a cross-sectional view of a bushing according to the present invention, Fig. 3 a, b, and C show the configuration of a heat-generating connecting pipe, and Fig. 3 a is a front view thereof. , FIG. 3b is a cross-sectional view along line mb-lIIb towards FIG. 3a,
Figure 3C is line III c - III in Figure 3a.
FIG. The same reference numerals indicate the same parts. In the figure, 1 is the center conductor, 2 is the insulating tube, 3 is the mounting 7 lunge,
11 is a shielding plate, and 12 is a heat generating connecting pipe.

Claims (1)

[Claims] 1. In a pusher filled with a liquid insulating medium that is used in a horizontal position, a shielding plate is provided between the mounting flange and the insulating tube that surrounds the pipe-shaped center conductor to divide the inside of the pusher into two, and to prevent the current flowing through the center conductor. A heat-generating connecting pipe that generates heat by electromagnetic induction is provided, and the interior of the footing is connected by the connecting pipe with the shielding plate, so that a liquid insulating medium is convected within the connecting pipe and the center conductor. Butsuthing to do.