Seals for intermittent and partially rotating and translating shafts

Abstract

To provide a gas insulated switchgear with more excellent cost efficiency.SOLUTION: A gas insulated switchgear includes: a gas-tight housing; at least one shaft extending through an opening in the gas-tight housing, and partially rotatable and translatable; and sealing means disposed in the opening for sealing the shaft relative to the gas-tight housing. The sealing means includes a sealing bellows having a first mounting rim on one axial end, a second mounting rim on the other axial end, and a bellows body between the first and second mounting rims. A mounting ring is mounted coaxially to the shaft. The sealing bellows is disposed around the shaft, the first mounting rim is disposed to the housing, and the second mounting rim is disposed to the mounting ring.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a gas-insulated switchgear such as a circuit breaker and a disconnector, an airtight housing; - at least one shaft extending through an opening in the gas-tight housing, the shaft being partially rotatable and / or translatable; - sealing means arranged in the opening for sealing the shaft against the gas-tight housing.

[0002] In gas-insulated switchgear, there is an airtight tank containing a gas, such as air, sulfur hexafluoride, or another electrical insulating gas, that is expected to be sealed for a lifespan typically exceeding 30 years.

[0003] Typically, switchgear devices have both static and dynamic seals. Dynamic seals allow axial and / or rotational movement of the shaft extending from the housing while maintaining the housing's airtightness. All of these seals have stringent requirements for preventing gas leakage.

[0004] In known gas-insulated switchgear, lip seals are used that allow the shaft to move axially and rotate relative to the lip seal while maintaining gas tightness, however, due to stringent requirements such lip seals must meet high standards and are therefore costly.

[0005] It is an object of the present invention to provide a preferably more cost-effective alternative.

[0006] For this purpose, the sealing means comprises a sealing bellows having a first mounting rim at one axial end, a second mounting rim at the other axial end, and a bellows body between the first and second mounting rims; This is achieved according to the invention by using a gas-insulated switchgear according to the preceding sentence, characterized in that the mounting ring is coaxially mounted on the shaft, the sealing bellows is arranged around the shaft, the first mounting rim is arranged on the housing and the second mounting rim is arranged on the mounting ring.

[0007] The sealing bellows allows axial and rotational movement of the shaft relative to the housing without any sliding between the parts, especially the seals. The mounting ring can be attached to the shaft and remain fixed relative to it, while the sealing bellows accommodates relative movement by deformation of the bellows body. Also, by twisting the bellows body, the bellows body can accommodate partial rotation of the shaft.

[0008] In the gas insulated switchgear according to the invention, there is no relative sliding on the sealing interface, as is the case with lip seals, which allows for a single component design which is cost effective.

[0009] In a preferred embodiment of the gas-insulated switchgear according to the invention, the bellows body is conical and made of a flexible material, in particular a soft polymer, to allow twisting, compression and expansion of the bellows body around the shaft.

[0010] The conical bellows body can easily accommodate axial displacement, rotational movement, or both. The conical walls of the bellows body bend inward or stretch when the shaft is displaced axially.

[0011] In a further preferred embodiment of the gas-insulated switchgear according to the invention, the bellows body has an undulating or undulating wave shape for guiding or causing twisting, compression and expansion of the bellows body.

[0012] The use of undulating corrugations allows the bellows body to deform in a controlled manner.

[0013] Preferably, the undulations extend along the surface of the bellows body and have tangential and axial components, in particular a helical component.

[0014] Such undulations allow the bellows body to twist in a controlled manner when the shaft is axially displaced or rotated. A further advantage is that the bellows body can be designed to have additional strength in locations around the bellows body that are subjected to more pressure than other locations around the bellows body.

[0015] In another embodiment of the gas-insulated switchgear according to the invention, the mounting ring is provided with a circumferential groove arranged on the inner edge of the mounting ring, and a seal, in particular an O-ring, is arranged in the circumferential groove and is in sealing contact with the shaft.

[0016] By placing the mounting ring with an O-ring on the shaft, good sealing of the mounting ring to the shaft is obtained, while the sealing means can be easily disassembled.

[0017] In a further embodiment of the gas-insulated switchgear according to the invention, the first clamping ring is mounted on the gas-tight housing, and the first mounting rim is arranged between the gas-tight housing and the first clamping ring.

[0018] Preferably, a seal, in particular an O-ring, is arranged between the first mounting rim and the gas-tight housing and radially inside some of the mountings, such as bolts, of the first clamping ring.

[0019] The first clamping ring contributes to easy assembly and disassembly of the sealing means, and also ensures that an evenly distributed clamping force is applied by the first clamping ring to the first mounting rim, contributing to a reliable hermetic opening and closing device.

[0020] In yet another embodiment of the gas-insulated switchgear according to the invention, a second clamping ring is attached to the mounting ring, and the second mounting rim is arranged between the mounting ring and the second clamping ring.

[0021] It is also preferred here if a seal, in particular an O-ring, is arranged between the second mounting rim and the mounting ring and radially inward of some of the mounting fixtures, such as bolts, of the second clamping ring.

[0022] The second clamping ring also contributes to easier assembly and disassembly of the sealing means of the gas-insulated switchgear.

[0023] These and other features of the present invention will be described in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0024] [Figure 1] 1 shows a perspective view of an embodiment of a gas-insulated switchgear according to the present invention; [Figure 2] 2 shows a cross-sectional view of the embodiment of FIG. 1. [Figure 3] 2 shows a more detailed view of the sealing bellows of the embodiment of FIG. 1;

[0025] 1 shows a first embodiment of a gas-insulated switchgear according to the present invention. The first embodiment has a gas-tight housing 2 with a shaft 3 that is axially movable and can rotate over a small angle, for example, between 0° and 180°.

[0026] A mounting ring 4 is fixedly positioned on the shaft 3 and a sealing bellows 5 is mounted between the housing 2 and the shaft 3 to allow rotational and axial movement of the shaft 3 while maintaining an airtight seal.

[0027] Figure 2 shows a cross section of embodiment 1 according to Figure 1. Mounting ring 4 has a circumferential groove located on the inner edge of mounting ring 4, with O-ring 6 positioned therein. O-ring 6 provides a seal between mounting ring 4 and shaft 3, ensuring that mounting ring 4 remains fixed relative to shaft 3.

[0028] The sealing bellows 5, shown in more detail in Figure 3, has a first mounting rim 7 at one end, a second mounting rim 8 at the other end and a bellows body 9 between both mounting rims.

[0029] The first mounting rim 7 is clamped between a first clamping ring 10 and the housing 2 by means of several bolts 11. An O-ring 12 is provided between the first mounting rim 7 and the housing 2 to ensure reliable gas tightness.

[0030] The second mounting rim 8 is clamped between the second clamping ring 13 and the mounting ring 4 by means of bolts 14. An O-ring 15 is provided between the second mounting rim 8 and the mounting ring 4 to ensure tightness at this end.

[0031] The sealing bellows 5 has a helical shape and has undulations or undulations 16 extending along the periphery of the wave-shaped bellows body 9 .

Claims

1. A gas-insulated switchgear (1), - an airtight housing (2), - at least one shaft (3) extending through an opening in said gas-tight housing (2), said at least one shaft (3) being partly rotatable and / or translatable; a sealing bellows (5) having a first mounting rim (7) at one axial end and a second mounting rim (8) at the other axial end, and a bellows body (9) connecting said first and second mounting rims (7, 8), said sealing bellows (5) being at least partially within said opening; - a mounting ring (4) coaxially mounted on said at least one shaft (3); Equipped with The sealing bellows (5) is disposed around the at least one shaft (3), the first mounting rim (7) is attached to the inner surface of the airtight housing (2), and the second mounting rim (8) is attached to the mounting ring (4). A gas-insulated switchgear (1).

2. 2. The gas-insulated switchgear (1) according to claim 1, wherein the bellows body (9) is conical and made of a flexible material, in particular a soft polymer, to allow twisting, compression and expansion of the bellows body (9) around the shaft.

3. 3. The gas-insulated switchgear (1) according to claim 2, wherein the bellows body (9) has a corrugated shape with undulations (16) for guiding the torsion, compression, and expansion of the bellows body (9).

4. Gas-insulated switchgear (1) according to claim 3, wherein the undulations (16) extend along the surface of the bellows body (9) and have tangential and axial components, in particular helical components.

5. 5. The gas-insulated switchgear (1) according to claim 1, wherein the mounting ring (4) is provided with a circumferential groove arranged on an inner edge of the mounting ring, and a seal (6), in particular an O-ring, is arranged in the circumferential groove and is in sealing contact with the shaft (3).

6. 6. The gas-insulated switchgear (1) according to claim 1, wherein a first clamping ring (10) is attached to the gas-tight housing (2), and the first mounting rim (7) is arranged between the gas-tight housing (2) and the first clamping ring (10).

7. 7. The gas-insulated switchgear (1) according to claim 6, wherein a seal (12), in particular an O-ring, is arranged between the first mounting rim (7) and the gas-tight housing (2) and radially inside some of the mountings, such as bolts (11), of the first clamping ring (10).

8. 8. The gas-insulated switchgear (1) according to claim 1, wherein a second clamping ring (13) is attached to the mounting ring (4), and the second mounting rim (8) is arranged between the mounting ring (4) and the second clamping ring (13).

9. 9. The gas-insulated switchgear (1) according to claim 8, wherein a seal, in particular an O-ring (15), is arranged between the second mounting rim (8) and the mounting ring (4) and radially inside some mountings, such as bolts (14), of the second clamping ring (13).

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