JPS61185015A - Flexible bus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a flexible busbar used in gas-insulated switchgear for absorbing thermal expansion displacement and installation difference.

[Technical background of the invention and its problems] A conventional flexible busbar will be explained with reference to FIGS. 2 and 3. FIG. 2 shows a flexible busbar for absorbing installation dimensional errors, in which a central conductor 3.4.5 with slide contact parts 1, 2 is connected to a tank 6.7 and a flexible tank 8 arranged on the same axis. It is inserted inside. Further, the tank 6.7 and the flexible tank 8 are fastened to each other by bolts (not shown) at seven flanges 6a, 7a, 8a1, 8a2 provided respectively.

Here, the installation dimensional error is slide contact part 1.2
After assembly, the flexible tank 8 is fastened and fixed between its flanges 8at and 882 using studs 9 and nuts 10°11, 12, and 13.

Figure 3 shows a flexible bus bar for absorbing installation dimensional errors and thermal expansion displacement.The configuration is almost the same as the flexible bus bar in Figure 2, but studs are used to absorb thermal expansion displacement after installation. One side of the nut 9 has a double nut structure in which a gap is provided between the nut 10.11 and the flange 16 so that the nut 10.11 can slide, and a nut 14.15 is added to prevent the nut 10.11 from moving.

In this configuration, when the busbars on both sides (not shown) are displaced due to thermal expansion, the flexible tank 8 expands and contracts and the center conductor 3.4
．． The displacement is absorbed by the sliding movement of the slide contact portion 1°2 of 5. In addition, with this configuration, dimensional errors during installation can be absorbed as in Fig. 2, but for those used for long busbars, both the installation dimensional error and the amount of thermal expansion displacement are large. As shown in FIG. 4, when the flexible generatrix expands and contracts, the stress generated in the bellows increases, and the repeated stress when absorbing thermal expansion displacement shortens the service life.

In order to improve this problem, a configuration can be considered in which both a flexible bus bar that absorbs thermal expansion displacement and a flexible bus bar that absorbs installation dimensional errors are provided, but the space for installing the flexible bus bar will be large, and the flange connection part will be too large. There is a disadvantage that the reliability of airtightness decreases as the number increases.

[Object of the invention] The present invention has been made to eliminate the above-mentioned drawbacks, and
The purpose of this project is to provide a flexible bus bar that effectively absorbs dimensional errors during installation and thermal expansion displacement without increasing the number of flange connections, reduces the repetitive stress of the bellows, and extends its life. do.

[Summary of the Invention] In order to achieve the above object, according to the present invention, the bellows portion is divided into two to provide seven intermediate flange, and the space between one end flange and the intermediate flange is fixed with a stud. The structure is characterized in that the structure is used to absorb dimensional errors during installation, and there is no restraint between the other end flange and the intermediate flange, which is used to absorb thermal expansion displacement.

[Embodiment of the Invention] A flexible busbar of the present invention will be described with reference to an embodiment shown in FIG. That is, in FIG. 1, the center conductor 3°4.5 with the slide contact part 1.2 is connected to the tank 6.7 and the flexible tank 1 arranged on the same axis.
It is inserted into 7. Furthermore, the tanks 6.7 and the flexible tank 17 are each fastened at their flange portions with bolts (not shown).

The flexible tank 17 has two bellows 18°19
The intermediate flange 20 and the flanges 21 and 22 on both sides are integrally welded. A hole through which the stand 23 passes is provided on the outer periphery of the middle 7 flange 20 and the flanges 21 and 22 on both sides, and the stud 23 is inserted into the nut 10.
．． The flange 21 and the intermediate flange 20 are fixed by 11.12.13. Further, a nut 24.25 is provided with a gap between the nut 24.25 and the flange 22 so that the 7 flange 22 can slide against the stud 23, and a nut 26.2 is provided to prevent them from moving.
It has a double nut structure with 7 added.

Next, the operation of the embodiment configured as described above will be explained. That is, in this configuration; during installation, the bellows 18 are used so that the studs 23 and nuts 12 and 13 absorb installation errors.
expand and contract. Further, when the busbars on both sides are displaced due to thermal expansion after installation, the bellows 19 expands and contracts to absorb the displacement.

As for the conductor, both the installation dimensional error and thermal expansion displacement are absorbed by the sliding of the slide contact portion.

As explained above, according to this embodiment, the bellows 18 absorbs installation dimensional errors and the bellows 19 absorbs thermal expansion displacement.
As shown in FIG. 5, the stress of the bellows 18 for absorbing installation dimensional errors, where stress occurs only a few times, is set to a large value, and the stress of the bellows 19, for absorbing thermal expansion displacement, where stress occurs repeatedly many times, is set to a large value. This makes it possible to set the generated stress to the maximum value determined by the number of repetitions and the required life, and by minimizing the number of bellows ridges to the necessary and sufficient minimum. A reduced flexible busbar can be obtained.

Also, compared to the case where the flexible bus bar for absorbing installation dimensional errors and the flexible bus bar for absorbing thermal expansion are used separately,
The number of flange connection parts is reduced, which improves airtight reliability, and at the same time, the intermediate flange 20 and studs 23 can be shared, resulting in effects such as simpler structure, lower cost, and smaller size.

The present invention is not limited to the above embodiments, but can be implemented with various modifications without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the present invention, both ends have flanges for communicating with a gas insulated switchgear, a bellows portion is provided between the end flanges, and the bellows portion is divided into two. The one end flange and the intermediate flange are fixed with studs, and the other end flange and the intermediate flange are free of restraint so that the distance changes during operation. Because of this structure, it is possible to effectively absorb dimensional errors during installation and thermal expansion displacement without increasing the number of flange connections, and the flexible bus bar is designed to reduce the repetitive stress of the bellows and extend its life. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the flexible bus bar according to the present invention, FIGS. 2 and 3 are sectional views showing conventional flexible bus bars, and FIG. 4 is a conventional flexible bus bar for absorbing thermal expansion displacement. FIG. 5 is a characteristic diagram showing the stress generated in the bellows when the dimensional error during installation is also absorbed. FIG. 5 is a characteristic diagram showing the stress generated in the bellows in the flexible bus bar of the embodiment shown in FIG. 1.2... Slide contact, 3.4.5... Center conductor, 6, 7... Tank, 10, 11, 12゜13
... Nut, 17 ... Flexible tank, 18゜19 ... Bellow, 20 ... Intermediate flange, 21.2
2...Flange, 23...Stud, 24, 25,
26°27...Natsuto. Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] It has flanges at both ends for communication with a gas insulated switchgear, a bellows part between the end flanges, and an intermediate flange dividing the bellows part into two, the one end flange and the above A flexible bus bar characterized in that the space between the intermediate flanges is fixed with a stud, and the space between the other end flange and the intermediate flange is not restrained so that the distance changes during operation.