JPH033610A - Gas insulated equipment - Google Patents

Abstract

PURPOSE:To prevent an insulator from being broken due to thermal stress concentrated on the insulator by retaining the insulator with a free bearing mechanism always within allowed temperature change. CONSTITUTION:Between the flanges 5, 6 of closed vessels 9a, 9b, an external metal ring 3 is retained, and inside the ring 3, an internal metal ring 2 is supported. In a recessed section formed with the flange section 3a of the external metal ring 3 and the flange section 2a of the internal metal ring 2, the outer periphery of an insulator 1 is set, and at a section confronted with the direction of the diameters of the insulator 1 and the internal metal ring 2, a gap G2 is formed. The gap G2 is sealed with an O ring 10. Also at a section confronted with the insulator 1 and a flange section 3b, a gap G4 is formed. At a section confronted with the external metal ring 3 and the internal metal ring, a gap G3 is set, and at a section confronted with the internal metal ring 2 and a flange 5, a gap G1 is set, and is sealed with an O ring 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to gas insulated equipment, and more particularly to a gas insulated equipment constructed by sandwiching an insulating spacer supporting a center conductor between flanges of a closed container.

[Prior Art] Generally, in gas insulated equipment such as gas insulated switchgear, an insulating spacer is sandwiched between the flanges of a sealed container in order to support a center conductor and form a gas section within the sealed container. have.

Conventional gas insulated equipment using this type of insulating spacer is
Special Publication No. Sho 60-13371, Special Publication No. Sho 60-1337
It is constructed as shown in Publication No. 2 and Japanese Patent Laid-Open No. 62-201013, etc., and this is shown in FIG.

A convex support portion 26 is formed on the outer periphery of the insulator 30 that supports the center conductor at the center, and metal rings 22.2 are positioned on the outer periphery of the insulator 30 and sandwich the support portion 26 from both sides.
3 is provided, and the metal rings 22 and 23 are sandwiched between the flanges 5 and 6 of a pair of closed containers 9. One of the metal rings 23 is formed with a penetrating female threaded portion 23a, into which the male threaded portion of the stud bolt 17 is screwed. However, the flanges 5 and 6 through which the stud bolt 17 penetrated and the metal ring 22 have blank holes, so they do not have a threaded relationship with the stand bolt 17. Also, the flange 5 of the metal ring 22
A counterbore 25 in which the nut 19b is housed is formed on the side. Nut 19b stored in this counterbore 25
and the nut 1 screwed onto both sides of the stud bolt 17.
Both metal rings 22 and 23 are clamped and held between flanges 5 and 6 by 9a and 19c. Further, as shown in the figure, by making the outer diameter of the M edge member 30 larger than the inner diameter of the flanges 5 and 6.

A portion held between the flanges 5 and 6 is formed in the insulator 30, and an O-ring 21 is disposed in the same portion to form a seal portion.

[Problems to be Solved by the Invention] A gas insulated device using a conventional insulating spacer is constructed as described above, and the insulator 30 is generally cast with epoxy resin, the metal rings 22 and 23 are made of aluminum, Further, the flange 5.6 is made of iron, stainless steel, etc. from the viewpoint of mechanical strength, but the insulator 30 has a large amount of thermal expansion and contraction due to temperature changes, and the metal ring 22.2
There was a risk that stress would be concentrated at the contact area with No. 3, especially at the corners, causing cracking.

An object of the present invention is to provide a gas insulated device that prevents stress concentration on the insulator of an insulating spacer caused by a difference in coefficient of thermal expansion.

[Means for Solving the Problems] In order to achieve the above object, a gas insulated device according to the present invention includes an inner metal ring and an outer metal ring that sandwich the outer periphery of an insulator by a free support structure.

The inner metal ring is disposed around the outer periphery of the insulator with a radial gap and an O-ring that seals the gap, and the outer metal ring has a radial gap around the outer periphery of the inner metal ring and an O-ring that seals the gap. Placed with an O-ring,
It is characterized in that the inner metal ring is held by the outer metal ring which is held between flanges of the sealed container.

[Function] Since the gas insulated equipment according to the present invention has the above-described configuration, even if the insulator expands and contracts due to temperature changes, the gap formed between the inner metal ring and the insulator prevents stress concentration due to the difference in coefficient of thermal expansion. Since the inner metal ring is placed between the outer metal ring and the insulator, the outer diameter of the insulator can be made smaller than before, and the inner and outer metal rings are made of different metals. This makes it possible to achieve various effects as described below.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a gas insulated device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.

An outer metal ring 3 is sandwiched between the flanges 5 and 6 of the closed containers 9a and 9b, and a female thread is formed in the through hole 3a of the outer metal ring 3. Each flange 5°6 at a position opposite to this through hole 3a has a blank hole 5a.
, 6a are formed, and both ends of the stud bolt 17 are screwed into female threads formed in the through hole 3a of the outer metal ring 3.
Idiot hole 5a.

6a. A washer 16 and a nut 1 were installed at both ends of this drawn-out stud bolt 17.
9, the outer metal ring 3 is clamped between the flanges 5 and 6. Flange 5 and outer metal ring 3
O-rings 12, 13, 14.1 are provided at the opposing contact portion between the flange 6 and the outer metal ring 3, respectively.
5 are arranged to form a seal portion.

On the flange 6 side of the outer metal ring 3, there is a flange portion 3b extending so as to have an inner diameter approximately equal to the inner diameter of the flange 6.
The inner metal ring 2, which has a flange portion 2a forming a pair with the flange portion 3b, has a gap G at a portion facing the outer flange 3 in the radial direction, and a gap G at a portion facing the flange 5 in the axial direction. It is supported by the flange portion 3b of the outer metal ring 3 by the bolt 7 in a state having G□. A circle ring 11 is placed between the metal rings 2 and 3 to close the gap G3. Therefore, gas communication via the gap G between the closed containers 9a and 9b having flanges 5 and 6, respectively, is cut off by the O-ring 11. The head of the bolt 7 mentioned above is accommodated in the counterbore 26 formed in the flange 3b, and does not have any adverse effect on the seal between the flange 6 and the outer metal ring 3.

The outer peripheral portion of the insulator 1 is disposed in the recess formed by the flange portions 2a and 3b, and a gap G2 is formed between the insulator 1 and the inner metal ring 2 at the radially opposing portion. The sealed container 9a is inserted through this gap G2.

Gas communication between the insulators 1 and 9b is prevented by arranging the circle ring 10 in the space obtained by removing the corners of the insulator 1. Further, a gap G4 is also formed in the opposing portion between the insulator 1 and the flange portion 3b of the outer metal ring 3.

In this way, an insulating spacer is obtained in which the insulator 1 is held by the metal rings 2 and 3 by a free support structure that does not apply much contact pressure.

The insulator 1 is cast with epoxy resin, the inner metal ring 2 is made of aluminum or its alloys, etc. whose coefficient of thermal expansion is similar to that of the insulator 1, and the outer metal ring 3 is made of the same material as the flanges 5 and 6. It is better to make it with If such a material is selected, the thermal contraction of the insulator 1 and the inner metal ring 2 is approximately the same, so that the gap G2 between them can be maintained approximately constant. When actually selecting the gap G2, it is preferable that a substantial gap is formed even at the maximum allowable temperature difference between the sealed containers 9a, 9b and the center conductor (not shown). Other gaps G1. It is preferable to select G, , G4 under similar conditions.

According to such a configuration, even if a permissible temperature change occurs, the insulator 1 can always be held in a free support structure,
It is possible to prevent damage caused by stress concentration as in the conventional case. In addition, the holding portion with the radial length F formed on the outer periphery of the insulator 1 is
Since it only needs to have sufficient strength against the maximum pressure difference that can act on the A side and the 8th side of the Therefore, the outer diameter of the insulator 1 is the same as that of the closed containers 9a, 9.
b or the inner diameter of the flanges 5 and 6. Therefore, as in the conventional insulator 30 shown in FIG.
No electric field concentration occurs at the inner diameter of 6.
With flanges 5 and 6 made of the same material and outer metal ring 3,
Since the seal part is made up of the O-rings 12, 13, 14, and 15, there is no possibility of electrical corrosion caused by the flow of current due to the difference in ionization tendency between different metals as in the conventional case, and the sealing part of the flanges 5 and 6 is prevented. Rainwater that has entered through the holes 5a, 6a, etc. is prevented from entering by the seals of the O-rings 12, 13, 14, and 15, so there is no chance that the rainwater that has entered will freeze and damage #@the edges like in the past. Nor.

The above-mentioned drawbacks of conventional gas insulated equipment arise when the diameter and thickness of the insulating spacer is increased by changing from a phase-separated type to a three-phase finger type, and when adopted for ultra-high voltage and ultra-super high voltage classes. This becomes more and more noticeable when the diameter and thickness of the insulating spacer are increased, so the structure of this embodiment is particularly effective in such usage.

Part 3 is a cross-sectional view of a main part of a gas insulated device according to another embodiment of the present invention. Parts equivalent to those in Fig. 1 are given the same reference numerals, and only the different parts will be explained.

In this embodiment, a counterbore 27 is formed on the inner surface of the flange 6, and the head of the bolt 7 connecting the outer metal ring 3 and the inner metal ring 2 is housed in the counterbore 27. . This configuration also has the same effect as the previous embodiment.6 Figure 4 is a cross-sectional view of the main parts of a gas insulated device according to a further different embodiment of the present invention, and the same reference numerals are given to the same parts as in Figure 1. Only the different parts will be explained.

In the previous embodiment, a stud bolt 17 is inserted between the flanges 5 and 6.
In contrast to the previous method, each flange 5, 6 is tightened with a dedicated bolt 18. With this configuration, one sealed container can be dismantled while maintaining its gas-tightness. can do.

5 and 6 are a sectional view of a main part of a gas insulated device according to still another embodiment of the present invention, and a sectional view taken along the line VI-VI in FIG. 5. The difference from the embodiment shown in FIG. 1 described above is that a rotation prevention means is provided between the inner metal ring 3 and the insulator 1.

This rotation prevention means is composed of a female threaded metal fitting 13 embedded in the radial direction of the insulator 1 and a bolt 8 screwed into the female threaded metal fitting 13 with its head positioned in a counterbore 28 formed in the inner metal ring 2. has been done.

The female screw fitting 13 is l! It is made of aluminum or the like having a coefficient of thermal expansion similar to that of material 1.

According to this embodiment, the insulator 1 and the inner metal ring 2 are connected by the bolt 8, and the inner metal ring 2 and the outer metal ring 3 are connected by the bolt 7, so that the rotation of the insulator 1 is prevented. It can be prevented. Although the bolt 8 and the female threaded fitting 13 can be placed at any arbitrary position along the outer periphery of the insulator 1, it is preferable to select a position where the electric field is weak.

FIG. 7 is a sectional view of a main part of a gas insulated device according to still another embodiment of the present invention, and FIG. 8 is a sectional view taken along the line 1--2 in FIG.

This embodiment shows a different configuration of the rotation prevention means from the embodiment shown in FIG. 5 above. In this embodiment, in order to configure the rotation prevention means without using bolts, a partial convex portion 1a is formed on the outer periphery of the insulator 1 and protrudes in the radial direction, and a convex portion 1a is formed on the opposing portion of the inner metal ring 2. A recess 2b is formed to fit into the recess 2b. Therefore, the insulator 1 is prevented from rotating in the circumferential direction by the convex portion 1a fitted into the inner metal ring 2, and since the bolt 8 extending toward the center conductor is not used as shown in FIG. 5, it has little effect on the electric field. not give.

FIG. 9 is a sectional view of a main part of a gas insulated device according to yet another embodiment of the present invention, and FIG. 10 is a sectional view taken along the line X--X.

This embodiment also shows a different configuration example of the rotation prevention means described above, in which partial recesses 1b and 2c are formed in the opposing parts of the insulator 1 and the inner metal ring 2, spanning both.
, 2c, and the connecting fittings 32 are fixed to the inner metal ring 2 with bolts 29.

Therefore, the connecting fitting 32 can prevent the rotation of the insulator 1 by engaging with the recess 1b of the insulator 1. At this time, there is a first
Since the same gap G4 as in the case shown in the figure is formed, the insulator 1 can always be held in a free support structure, and the insulator 1 can be prevented from being damaged due to stress concentration caused by the difference in thermal expansion coefficients as in the conventional case. can be prevented.

[Effects of the Invention] As explained above, in the present invention, since the insulator 1 is always held in a free support structure within an allowable temperature change, stress is concentrated on the insulator 1 due to the difference in thermal expansion coefficient. In addition, since the inner metal ring 2 is disposed between the outer metal ring 3 and the insulator 1 which are sandwiched between the flanges 5 and 6 of the sealed containers 9a and 9b, the sealed containers can be prevented from being damaged. 9a.

A gas insulated device having an insulating spacer using an insulator 1 having a diameter smaller than that of the conventional insulator 9b can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part of a gas insulated device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIGS. 3, 4, and 5. 6 is a longitudinal sectional view of a main part of gas insulated equipment according to other different embodiments of the present invention, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. 7 is a further embodiment of the present invention. A longitudinal sectional view of the main parts of gas insulated equipment as an example,
FIG. 8 is a sectional view taken along the line ■-■ in FIG. - Sectional view along the X-ray, 1st
FIG. 1 is a longitudinal cross-sectional view of the main parts of a conventional gas insulated device. 1... Insulator, 2... Inner metal ring, 3... Outer metal ring, 5, 6...
Flange, 9a. 9b... Sealed container, 12-15...0
Ring, G1-G4...Gap. Figure 3 Figure 4 9a, 9b: Closed fF wing Gf, G2vGstG4: Yami Figure 2 - Figure 6 Figure 7 ■'' Figure 8 Figure 9

Claims (1)

[Claims] 1. In a gas insulated device comprising a metal ring sandwiched between flanges of a closed container filled with an insulating gas, and an insulator supporting a center conductor being supported inside the metal ring. , the metal ring is composed of an inner metal ring and an outer metal ring, the inner metal ring is arranged around the outer periphery of the insulator with a gap therebetween, and the insulator is supported by a free support structure; A gas insulated device characterized in that the outer metal ring is disposed on the outer periphery of the metal ring with a gap therebetween and is sandwiched between the flanges. 2. The gas insulated device according to claim 1, further comprising a rotation prevention means provided between the inner metal ring and the insulator. 3. The gas insulated device according to claim 1, wherein the flange and the outer metal ring are made of the same material. 4. The gas insulated device according to claim 1, wherein the inner metal ring is formed of a metal having a coefficient of thermal expansion closer to that of the insulator than the outer metal ring. 5. The gas insulated device according to claim 1, further comprising an O-ring for sealing each of the gaps, and an O-ring for sealing between each of the flanges and the outer metal ring.