Protection structure of corrugated pipe of vacuum arc-extinguishing chamber

Abstract

The protection structure comprises an inflation valve, the vacuum arc-extinguishing chamber comprises an arc-extinguishing chamber shell, a movable end cover plate, a movable conducting rod, the corrugated pipe and a conducting seat, the conducting seat comprises a medium-voltage cavity and an inflation connector, the conducting seat is fixed at the outer end of the movable end cover plate, an opening of the medium-voltage cavity faces the movable end cover plate, and the movable end cover plate is fixed on the movable end cover plate. The connection part of the conductive seat and the movable end cover plate comprises a sealing ring; the movable conducting rod penetrates through the medium-voltage cavity and the guide hole of the conducting seat, a conducting ring is arranged in an annular groove in the hole wall of the guide hole, and the inner wall of the conducting ring is in sliding contact with the movable conducting rod; the inflation connector is located on the outer wall of the conductive base and comprises an inflation hole, and the inflation valve is installed on the inflation connector. According to the utility model, the middle-pressure gas is filled into the middle-pressure cavity of the conductive seat, so that the pressure difference inside and outside the arc extinguishing chamber can be reduced. The corrugated pipe is uniform in stress, the mechanical life is prolonged, an additional static corrugated pipe does not need to be added, the structure is simplified, and the machining difficulty and cost are reduced.

Description

Technical Field

[0001] This utility model relates to vacuum switches, and more particularly to a protective structure for a bellows in a vacuum interrupter. Background Technology

[0002] Vacuum interrupters are the core components of medium- and high-voltage power vacuum switches. The main functions of vacuum switches are achieved through vacuum interrupters. With the increasing emphasis on environmental protection, switches using environmentally friendly gases as the insulating medium are gradually gaining popularity in power equipment. To ensure insulation performance, circuit breakers using environmentally friendly gases as the insulating medium require high gas pressure. When the vacuum interrupter is exposed to a high-pressure environment for extended periods, its internal bellows, in addition to bearing the operating forces of the circuit breaker and arc pressure, also endures the high pressure applied by the environmentally friendly gas. This high pressure from the environmentally friendly gas and the high vacuum of the vacuum interrupter creates a significant pressure difference, leading to fatigue failure of the bellows, reducing its mechanical life, and ultimately rendering the vacuum interrupter inoperable. This results in a failure of the entire power equipment. Therefore, the reliability of the bellows directly determines the service life of the equipment and the safety of the power grid. To address the problem of bellows easily breaking under high pressure, various manufacturers have developed different types of bellows for use in high-pressure gases. However, complex bellows have disadvantages such as high processing difficulty, high cost, and poor reliability.

[0003] The invention with application number 202011202751.3 discloses a protective structure and working method for a vacuum interrupter bellows under high gas pressure. The protective structure includes a conductive seat, a fixing screw, a connecting screw, an O-ring, a conductive spring, a static bellows, and connecting flanges welded to the upper and lower ends of the static bellows, all located at the lower end of the moving end cover plate of the vacuum interrupter. By setting up a static bellows sealing structure, this invention transforms the structure of the bellows in the interrupter of a tank-type fast vacuum circuit breaker that bears gas pressure into a two-stage gas chamber structure, ensuring that the pressure difference of the insulating gas on both sides of the bellows is reduced to one atmosphere, which can effectively improve the mechanical life of the vacuum interrupter bellows.

[0004] This invention employs a two-stage gas chamber structure (a high-pressure gas chamber and a standard atmospheric pressure gas chamber), reducing the pressure difference of the bellows to one atmosphere through a static bellows and a sliding sealing gas chamber. However, the structure relies on the static bellows and multiple sealing rings, making it difficult to manufacture and highly complex. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a simple protective structure for the bellows of a vacuum interrupter, so as to solve the problem of excessive internal and external pressure difference in the vacuum interrupter under high pressure conditions, reduce the pressure difference on the bellows, thereby improving the mechanical life of the bellows and ensuring the reliability of the vacuum interrupter under high pressure conditions.

[0006] To solve the above-mentioned technical problems, the present invention adopts a protective structure for a bellows of a vacuum interrupter, including an inflation valve. The vacuum interrupter includes an interrupter shell, a moving end cover plate, a moving conductive rod, a bellows, and a conductive seat. The conductive seat includes a medium-pressure chamber and an inflation connector. The conductive seat is fixed to the outer end of the moving end cover plate, and the opening of the medium-pressure chamber faces the moving end cover plate. The connection between the conductive seat and the moving end cover plate includes a sealing ring. The conductive seat includes a guide hole, through which the moving conductive rod passes. The wall of the guide hole includes an annular groove, in which a conductive ring is installed. The inner wall of the conductive ring slides in contact with the moving conductive rod. The inflation connector is located on the outer wall of the conductive seat and includes an inflation hole communicating with the medium-pressure chamber. The inflation valve is installed on the inflation connector.

[0007] The protective structure of the bellows of the vacuum interrupter described above includes a dynamic sealing frame, which is fixed on the bottom surface of the outer end of the conductive base; the joint between the dynamic sealing frame and the conductive base includes an end face sealing device; the dynamic sealing frame includes an axial hole, which is coaxial with the guide hole of the conductive base; the dynamic conductive rod passes through the axial hole of the dynamic sealing frame; and a radial sealing device is installed in the axial hole.

[0008] The protective structure of the bellows in the vacuum interrupter described above includes a pull rod for the moving conductive rod. The rear end of the moving conductive rod includes a threaded hole, and the front end of the pull rod includes a connecting stud. The front connecting stud of the pull rod is screwed into the threaded hole of the moving conductive rod. The pull rod passes through the axial hole of the dynamic sealing frame.

[0009] The protective structure of the bellows in the vacuum interrupter described above includes a dynamic sealing frame comprising a guide ring, a V-shaped sealing ring, and a pressing threaded sleeve. The moving conductive rod passes through the guide ring, the V-shaped sealing ring, and the pressing threaded sleeve sequentially from front to back. The axial hole of the dynamic sealing frame, from the inside to the outside, includes a guide ring bearing hole, a V-shaped sealing ring bearing hole, and a threaded hole. The guide ring is installed in the guide ring bearing hole, and an O-ring is installed between the outer diameter of the guide ring and the guide ring bearing hole. The inner hole of the guide ring slides with the moving guide rod. The V-shaped sealing ring is installed in the V-shaped sealing ring bearing hole, and the pressing threaded sleeve is screwed into the threaded hole of the dynamic sealing frame and presses on the V-shaped sealing ring. An O-ring and a dustproof sealing ring are installed from the inside to the outside in the inner hole of the pressing threaded sleeve.

[0010] The protective structure of the bellows in the vacuum interrupter described above, wherein the conductive ring is a spring contact finger or a watch strap contact finger.

[0011] The protective structure of the bellows in the vacuum interrupter described above includes a conductive base with an inflation port shielding cover. The inflation port shielding cover is fixed on the inflation connector and covers the inflation valve. The inflation valve is a one-way inflation valve.

[0012] The protective structure of the bellows in the vacuum interrupter described above includes a conductive base with a silver-plated interface for connecting to an external conductor.

[0013] The protective structure of the vacuum interrupter bellows described above includes a conductive seat shield, and the connection between the conductive seat and the moving end cover includes a connecting flange. The conductive seat shield is fixed on the outside of the connecting flange.

[0014] The protective structure of the bellows in this invention for a vacuum interrupter reduces the pressure difference between the inside and outside of the interrupter by filling the gas chamber with intermediate-pressure gas in the pressure cavity of the conductive base. This results in uniform stress distribution on the bellows, extending its mechanical lifespan. Furthermore, it eliminates the need for an additional static bellows, simplifying the structure and reducing processing difficulty and cost. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] Figure 1 This is a front view of the vacuum interrupter chamber according to an embodiment of this utility model.

[0017] Figure 2 This is a top view of the vacuum interrupter chamber according to an embodiment of this utility model.

[0018] Figure 3 This is a left view of the vacuum interrupter chamber according to an embodiment of this utility model.

[0019] Figure 4 This is a perspective view of the vacuum interrupter chamber according to an embodiment of this utility model.

[0020] Figure 5 yes Figure 1 AA section view in the image.

[0021] Figure 6 yes Figure 5 A magnified view of part I in the middle section. Detailed Implementation

[0022] The protective structure of the bellows in the vacuum interrupter of this utility model embodiment is as follows: Figures 1 to 6 As shown, the vacuum interrupter includes an interrupter ceramic shell 1, a moving end cover 2, a moving conductive rod 10, a bellows 3, a conductive base (outgoing conductor) 20, and a moving sealing frame 30.

[0023] The movable conductive rod 10 includes a pull rod 10A. The rear end of the movable conductive rod 10 includes a threaded hole 11, and the front end of the pull rod 10A includes a connecting stud 12. The front connecting stud 12 of the pull rod 10A is screwed into the threaded hole 11 of the movable conductive rod 10. Power from an external mechanism is transmitted to the pull rod 10A, causing the pull rod 10A to drive the conductive rod 10 axially to complete the opening and closing action of the vacuum interrupter.

[0024] The conductive base 20 has a cylindrical, open-end medium-pressure cavity 21 inside, a protruding air inlet 22 on the outside, and a silver-plated interface 23 for connecting to an external conductor. The silver-plated interface 23 serves as a fixed interface for the output conductor.

[0025] The connection between the conductive base 20 and the moving end cover plate 2 has a connecting flange 24. The conductive base 20 is fixed to the outer end of the moving end cover plate 2 by multiple screws. The conductive base shield 4 is fixed to the outside of the connecting flange 24 to shield the moving end of the arc extinguishing chamber, the conductive base 20, and the bolt head.

[0026] The opening of the intermediate pressure chamber 21 faces the moving end cover plate 2, and an O-ring 241 is installed at the connection between the conductive seat connecting flange 24 and the moving end cover plate 2. The conductive seat 20 has an axial guide hole 25, through which the moving conductive rod 10 passes. The guide hole 25 has two annular grooves 251 on its wall, and a conductive ring 252 is installed in each annular groove 251. The inner wall of the conductive ring 252 slides in contact with the moving conductive rod 10. The conductive ring 252 can be a spring contact finger or a watchband contact finger.

[0027] The inflation connector 22 is located on the outer wall of the conductive base 20, and has multiple evenly distributed threaded holes. In the center is an inflation port 221 that communicates with the intermediate pressure chamber 21. An inflation valve 222 is installed on the inflation connector 22 and is a one-way inflation valve. An inflation port shield 223 is fixed to the inflation connector 22, covering the inflation valve 222 to prevent discharge from the valve tip.

[0028] The dynamic sealing frame 30 is fixed to the bottom surface of the outer end of the conductive seat 20 by screws. The joint between the dynamic sealing frame 30 and the conductive seat 20 is equipped with two end face sealing rings 31. The dynamic sealing frame 30 includes an axial hole 32, which is coaxial with the guide hole 25 of the conductive seat 20. The dynamic conductive rod 10 passes through the axial hole 32 of the dynamic sealing frame 30.

[0029] The pull rod 10A passes through the axial hole 32 of the dynamic seal frame 30. The dynamic seal frame 30 includes a guide ring 33, a V-ring seal 34, and a clamping threaded sleeve 35. The pull rod 10A passes through the guide ring 33, the V-ring seal 34, and the clamping threaded sleeve 35 sequentially from front to back. The axial hole 32 of the dynamic seal frame 30 includes, from the inside to the outside, a guide ring bearing hole 36, a V-ring bearing hole 37, and a threaded hole 38. The guide ring 33 is installed in the guide ring bearing hole 36. Two O-ring seals 331 are installed between the outer diameter of the guide ring 33 and the guide ring bearing hole 36. The inner hole of the guide ring 33 slides with the pull rod 10A. The V-ring seal 34 is installed in the V-ring bearing hole 37. The clamping threaded sleeve 35 of the V-ring seal 34 is screwed into the threaded hole 38 of the dynamic seal frame 30 and presses against the rear end face of the V-ring seal 34. The inner hole of the compression threaded sleeve 35 is fitted with an O-ring 351 and a dustproof sealing ring 352 from the inside out.

[0030] The working principle of the vacuum interrupter in the above embodiments of this utility model is as follows:

[0031] The vacuum interrupter is fixed in a high-pressure sealed container. A suitable amount of gas is introduced by the one-way inflation valve 222 installed on the conductive base 20 to establish a stepped pressure difference between the external gas pressure, intermediate gas pressure, and vacuum. The external gas pressure is the rated pressure of the environmentally friendly gas circuit breaker, and the intermediate gas pressure is atmospheric pressure. The one-way inflation valve 222 (inflation self-closing valve) ensures the uniformity of the electric field under the shielding cover. The external mechanism drives the pull rod 10A to move axially, thereby driving the moving conductive rod 10 of the interrupter to move axially to realize the opening and closing of the vacuum interrupter. The moving conductive rod is always in contact with the conductive parts. Electricity is input from the other end of the interrupter. After closing, it is transmitted to the moving conductive rod 10, the conductive ring 252, and the conductive base 20. Finally, the conductor is connected to the interface 23 of the conductive base 20 for output.

[0032] The protective structure of the vacuum interrupter bellows in the above embodiments of this utility model has the following beneficial effects:

[0033] The above embodiments of this utility model reduce the pressure difference between the inside and outside of the arc extinguishing chamber by filling the gas chamber of the cylindrical medium-pressure cavity of the conductive base with intermediate-pressure gas, so that the bellows is subjected to uniform stress and the mechanical life is improved. This utility model does not require the addition of an extra static bellows, which simplifies the structure and reduces the processing difficulty and cost.

[0034] 1) By filling the gas chamber of the cylindrical intermediate pressure cavity of the conductive base with an appropriate amount of gas pressure, the pressure difference between the inside and outside of the arc extinguishing chamber changes from external gas pressure to vacuum to external gas pressure to intermediate gas pressure to vacuum, forming a stepped pressure difference structure. This directly reduces the pressure difference between the inside and outside of the arc extinguishing chamber, reduces the stress on the bellows, and thus improves the mechanical life of the bellows.

[0035] 2) Simple structure. The above embodiments can achieve the purpose of reducing the pressure difference between the inside and outside of the arc extinguishing chamber by directly using a few machined structures, solving the problem of short mechanical life of the bellows caused by large pressure difference. The structure is simple, flexible and versatile, easy to process, and has low production cost.

[0036] 3) Superior guidance. Power equipment often operates in complex environments. When the vacuum interrupter is opened and closed, the moving conductive rod moves along its axis, and the bellows will also be compressed and restored accordingly. In addition to the guiding design of the interrupter itself, the guiding mechanism in the conductive base and dynamic sealing frame of this embodiment can ensure good guidance of the axial movement of the moving conductive rod, reduce radial impact force, and ensure the mechanical life of the interrupter.

[0037] 4) Good sealing performance. The above embodiments are equipped with sealing structures in multiple places, including multiple static seals and dynamic seals. Under high pressure conditions, the moving conductive rod is subjected to mechanical impact and vibration load during axial movement, and high-pressure gas is prone to leak into the low-pressure gas space. The above embodiments are equipped with multiple static seals and dynamic seals to ensure sealing performance.

Claims

1. A protective structure for a bellows of a vacuum interrupter, the vacuum interrupter comprising an interrupter shell, a moving end cover, a moving conductive rod, a bellows, and a conductive base, characterized in that, The device includes an inflation valve, a conductive base comprising a medium-pressure chamber and an inflation connector, the conductive base being fixed to the outer end of a moving end cover, the opening of the medium-pressure chamber facing the moving end cover, and the connection between the conductive base and the moving end cover including a sealing ring; the conductive base including a guide hole, through which a moving conductive rod passes; the guide hole wall including an annular groove, in which a conductive ring is installed, the inner wall of the conductive ring slidingly contacting the moving conductive rod; the inflation connector located on the outer wall of the conductive base, including an inflation hole communicating with the medium-pressure chamber, and an inflation valve mounted on the inflation connector.

2. The protection structure of the vacuum interrupter bellows according to claim 1, characterized in that, It includes a dynamic sealing frame, which is fixed on the bottom surface of the outer end of the conductive base; the joint between the dynamic sealing frame and the conductive base includes an end face sealing device, the dynamic sealing frame includes an axial hole, the axial hole is coaxial with the guide hole of the conductive base, the dynamic conductive rod passes through the axial hole of the dynamic sealing frame, and a radial sealing device is installed in the axial hole.

3. The protection structure of the bellows of the vacuum interrupter according to claim 2, characterized in that, The movable conductive rod includes a pull rod, the rear end of which includes a threaded hole, and the front end of which includes a connecting stud. The front connecting stud of the pull rod is screwed into the threaded hole of the movable conductive rod; the pull rod passes through the axial hole of the dynamic sealing frame.

4. The protection structure of the bellows of the vacuum interrupter according to claim 2, characterized in that, The dynamic sealing frame includes a guide ring, a V-ring, and a threaded clamping sleeve. The moving conductive rod passes through the guide ring, V-ring, and threaded clamping sleeve sequentially from front to back. The axial holes of the dynamic sealing frame, from the inside to the outside, include a guide ring bearing hole, a V-ring bearing hole, and a threaded hole. The guide ring is installed in the guide ring bearing hole, and an O-ring is installed between the outer diameter of the guide ring and the guide ring bearing hole. The inner hole of the guide ring slides with the moving guide rod. The V-ring is installed in the V-ring bearing hole, and the threaded clamping sleeve is screwed into the threaded hole of the dynamic sealing frame and presses against the V-ring. An O-ring and a dustproof seal are installed in the inner hole of the threaded clamping sleeve from the inside to the outside.

5. The protection structure of a vacuum interrupter bellows according to claim 1, characterized in that, The conductive ring is a spring contact finger or a watch strap contact finger.

6. The protection structure of a vacuum interrupter bellows according to claim 1, characterized in that, The conductive base includes an inflation port shield, which is fixed to the inflation connector and covers the inflation valve. The inflation valve is a one-way inflation valve.

7. The protective structure for the bellows of the vacuum interrupter according to claim 1, characterized in that, The conductive base includes a silver-plated interface for connecting to an external conductor.

8. The protection structure of a vacuum interrupter bellows according to claim 1, characterized in that, It includes a conductive seat shield, and the connection between the conductive seat and the moving end cover includes a connecting flange, with the conductive seat shield fixed to the outside of the connecting flange.

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