A combined bellows assembly for a vacuum interrupter

Abstract

The present application discloses a combined bellows assembly for a vacuum interrupter, comprising: a moving contact, a porcelain shell, an internal pressure bellows, a moving end cover plate, a sliding sealing ring and an external pressure bellows. Both the internal pressure bellows and the external pressure bellows are sleeved on the moving contact; the moving end cover plate is located between the internal pressure bellows and the external pressure bellows; one end of the moving end cover plate is hermetically and fixedly connected to the porcelain shell, and the other end is hermetically and slidably connected to the moving contact through the sliding sealing ring; a first sealed cavity is formed among the internal pressure bellows, the moving contact, the moving end cover plate and the sliding sealing ring, and a second sealed cavity is formed among the external pressure bellows, the moving contact, the moving end cover plate and the sliding sealing ring. The air pressure in the second sealed cavity is higher than that in the first sealed cavity. The present invention can reduce the complexity of the mechanism, enable the vacuum interrupter to achieve early energy storage and rapid acceleration from its own initial opening point to short arcing, thereby reducing the short arcing and long arcing time of the circuit breaker and alleviating the later breaking pressure.

Description

Technical Field

[0001] This application relates to the technical field of vacuum interrupters, and particularly to a combined bellows assembly for a vacuum interrupter. Background Art

[0002] Generally, when a vacuum interrupter is opened, the bellows are required to drive the contacts of the interrupter to move. Through this elastic element of the bellows, both sealing and movement can be achieved, so as to separate the contacts and complete the current interruption process.

[0003] At the current stage, for the interruption from low voltage to high voltage, the contacts of the interrupter need to have a certain longitudinal magnetic field intensity to control the arc to maintain a diffused state, avoid current concentration (anode spot) and achieve current interruption. For all interruption processes (including outgoing line faults, near zone faults, and out-of-step), short arcing and long arcing interruptions are required. For any short arcing and long arcing interruptions, the average opening speed of the circuit breaker is increased, so as to increase the speed at the moment when the contacts of the interrupter are separated, which is beneficial to shortening the arcing time, making the short arcing and long arcing times shorter and more conducive to the subsequent interruption process.

[0004] Currently, the commonly used methods all rely on the overtravel spring and operating work of the circuit breaker to adjust the average opening speed. By directly increasing the operating work, the energy reserve before opening is increased, and the overtravel spring is adjusted to increase the compression amount (which also increases the energy reserve before opening) to reserve more opening energy. At the moment of initial opening, the average opening speed is increased by the instantaneous release of the pre-reserved energy. However, since all rely on the opening spring of the circuit breaker for energy storage, whether it is increasing the overtravel (compression amount of the opening spring) or increasing the operating work (compression amount of the opening spring or replacing the opening spring with a larger energy storage), almost all rely on the circuit breaker for adjustment. This adjustment method is single and the effect is average. Once the energy storage of the opening spring of the circuit breaker reaches the limit, it is impossible to further increase the energy reserve at the moment of initial opening and impossible to increase the average opening speed. As a result, the short arcing and long arcing times of the circuit breaker will increase rapidly, causing difficulties for subsequent interruptions. Therefore, the present invention proposes a combined bellows assembly for a vacuum interrupter. Summary of the Invention

[0005] The embodiments of the present application provide a combined bellows assembly for a vacuum interrupter, which can reduce the complexity of the mechanism, enable the vacuum interrupter to achieve early energy storage and rapid acceleration from its own initial opening point to short arcing, thereby reducing the short arcing and long arcing times of the circuit breaker and alleviating the subsequent interruption pressure.

[0006] In view of this, the present application provides a combined bellows assembly for a vacuum interrupter, including: a moving contact, a porcelain shell, an internal pressure bellows, a moving end cover plate, a sliding sealing ring, and an external pressure bellows;

[0007] Both the internal pressure corrugated pipe and the external pressure corrugated pipe are sleeved on the moving contact, and both the internal pressure corrugated pipe and the external pressure corrugated pipe are hermetically and fixedly connected to the moving contact;

[0008] The moving end cover plate is located between the internal pressure corrugated pipe and the external pressure corrugated pipe, and the moving end cover plate is hermetically and fixedly connected to the internal pressure corrugated pipe and the external pressure corrugated pipe respectively;

[0009] One end of the moving end cover plate is hermetically and fixedly connected to the porcelain shell, and the other end is hermetically and slidably connected to the moving contact through the sliding sealing ring;

[0010] A first sealed cavity is formed among the internal pressure corrugated pipe, the moving contact, the moving end cover plate and the sliding sealing ring;

[0011] A second sealed cavity is formed among the external pressure corrugated pipe, the moving contact, the moving end cover plate and the sliding sealing ring;

[0012] The second sealed cavity is filled with high-pressure gas;

[0013] The air pressure in the second sealed cavity is higher than the air pressure in the first sealed cavity.

[0014] Optionally, one side of the sliding sealing ring is hermetically and slidably connected to the moving end cover plate, and the other side is hermetically and slidably connected to the moving contact.

[0015] Optionally, between the internal pressure corrugated pipe and the moving contact, between the external pressure corrugated pipe and the moving contact, between the internal pressure corrugated pipe and the moving end cover plate, between the moving end cover plate and the external pressure corrugated pipe, and between the moving end cover plate and the porcelain shell, all are fixed by welding.

[0016] Optionally, a limiting groove is formed on the moving contact;

[0017] The sliding sealing ring is arranged in the limiting groove.

[0018] Optionally, the outer diameter of the external pressure corrugated pipe is larger than the outer diameter of the internal pressure corrugated pipe.

[0019] Optionally, the material of the sliding sealing ring is a high-temperature resistant material.

[0020] Optionally, the inside of the first sealed cavity is vacuum.

[0021] As can be seen from the above technical solutions, the embodiments of the present application have the following advantages: The combined bellows assembly for the vacuum interrupter can simplify the complexity of the mechanism design. The overall structure is simpler for the interior of the interrupter and the circuit breaker design, making it easier to implement. It can reduce the costs of the interrupter and the circuit breaker. At the same time, through this bellows assembly, the vacuum interrupter can achieve early energy storage from its own initial opening point to short arcing and rapid acceleration, thereby reducing the short arcing and long arcing times of the circuit breaker, alleviating the later breaking pressure. Moreover, due to the self - contained closing resistance, it not only increases the average initial opening speed for opening energy storage in advance but also buffers the closing process, reduces the closing bounce, further simplifies the complexity of the mechanism design, and avoids adding a heavy oil buffering process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the combined bellows assembly for the vacuum interrupter in the embodiment of the present application;

[0023] Figure 2 is a schematic structural diagram of the combined bellows assembly for the vacuum interrupter in the closing state (initial opening point position) in the embodiment of the present application;

[0024] Figure 3 is a schematic structural diagram of the combined bellows assembly for the vacuum interrupter at the start of opening in the embodiment of the present application;

[0025] Figure 4 is a schematic structural diagram of the combined bellows assembly for the vacuum interrupter during the opening process (end of short arcing) in the embodiment of the present application;

[0026] Among them, the reference numerals are:

[0027] 1 - moving contact, 2 - porcelain shell, 3 - internal pressure bellows, 4 - moving end cover plate, 5 - sliding sealing ring, 6 - external pressure bellows, 7 - first sealed cavity, 8 - second sealed cavity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0029] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] Unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected to" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0031] The present application provides an embodiment of a combined bellows assembly for a vacuum interrupter. Specifically, please refer to Figures 1 to 4 .

[0032] The combined bellows assembly for a vacuum interrupter in this embodiment includes: a moving contact 1, a porcelain shell 2, an inner pressure bellows 3, a moving end cover plate 4, a sliding sealing ring 5, and an outer pressure bellows 6. Both the inner pressure bellows 3 and the outer pressure bellows 6 are sleeved on the moving contact 1, and both the inner pressure bellows 3 and the outer pressure bellows 6 are hermetically and fixedly connected to the moving contact 1; the moving end cover plate 4 is located between the inner pressure bellows 3 and the outer pressure bellows 6, and the moving end cover plate 4 is hermetically and fixedly connected to the inner pressure bellows 3 and the outer pressure bellows 6 respectively; one end of the moving end cover plate 4 is hermetically and fixedly connected to the porcelain shell 2, and the other end is hermetically and slidably connected to the moving contact 1 through the sliding sealing ring 5; a first sealed cavity 7 is formed among the inner pressure bellows 3, the moving contact 1, the moving end cover plate 4, and the sliding sealing ring 5, and a second sealed cavity 8 is formed among the outer pressure bellows 6, the moving contact 1, the moving end cover plate 4, and the sliding sealing ring 5. The second sealed cavity 8 is filled with high-pressure gas, and the air pressure in the second sealed cavity 8 is higher than the air pressure in the first sealed cavity 7.

[0033] It should be noted that: The combined bellows assembly for the vacuum interrupter can simplify the complexity of the mechanism design. For the internal structure of the interrupter and the breaker design, the overall structure is simpler and easier to implement, which can reduce the costs of the interrupter and the breaker. At the same time, through this bellows assembly, the vacuum interrupter can achieve early energy storage and rapid acceleration from its own initial opening point to short arcing, thereby reducing the short arcing and long arcing times of the breaker, alleviating the later breaking pressure. Moreover, due to the self - contained closing resistance, it not only increases the average initial opening speed for opening energy storage in advance, but also buffers the closing process, reduces the closing bounce, further simplifies the complexity of the mechanism design, and avoids adding a heavy oil buffering process.

[0034] The above is the first embodiment of a combined bellows assembly for a vacuum interrupter provided by the embodiment of the present application. The following is the second embodiment of a combined bellows assembly for a vacuum interrupter provided by the embodiment of the present application. For details, please refer to Figures 1 to 4 。

[0035] The combined bellows assembly for the vacuum interrupter in this embodiment includes: a moving contact 1, a porcelain shell 2, an internal pressure bellows 3, a moving - end cover plate 4, a sliding sealing ring 5, and an external pressure bellows 6. The internal pressure bellows 3 and the external pressure bellows 6 are both sleeved on the moving contact 1, and the internal pressure bellows 3 and the external pressure bellows 6 are both hermetically and fixedly connected to the moving contact 1; the moving - end cover plate 4 is located between the internal pressure bellows 3 and the external pressure bellows 6, and the moving - end cover plate 4 is hermetically and fixedly connected to the internal pressure bellows 3 and the external pressure bellows 6 respectively; one end of the moving - end cover plate 4 is hermetically and fixedly connected to the porcelain shell 2, and the other end is hermetically and slidably connected to the moving contact 1 through the sliding sealing ring 5; a first sealed cavity 7 is formed among the internal pressure bellows 3, the moving contact 1, the moving - end cover plate 4, and the sliding sealing ring 5, and a second sealed cavity 8 is formed among the external pressure bellows 6, the moving contact 1, the moving - end cover plate 4, and the sliding sealing ring 5. The second sealed cavity 8 is filled with high - pressure gas (that is, the inside of the external pressure bellows 6 is filled with high - pressure gas), and the air pressure in the second sealed cavity 8 is higher than the air pressure in the first sealed cavity 7.

[0036] It can be understood that the external pressure bellows 6 can be welded to the moving contact 1, the moving - end cover plate 4, and the sliding sealing ring 5 in an environment with a pressure exceeding atmospheric pressure. In this way, after welding, the second sealed cavity 8 will be filled with the gas in the welding environment, keeping its internal pressure high. If a greater or smaller gas pressure is required, the air pressure of the welding environment can be adjusted, so that the air pressure in the second sealed cavity 8 can be adjusted correspondingly after welding.

[0037] One side of the sliding sealing ring 5 is hermetically and slidably connected to the moving - end cover plate 4, and the other side is hermetically and slidably connected to the moving contact 1.

[0038] Between the internal pressure bellows 3 and the moving contact 1, between the external pressure bellows 6 and the moving contact 1, between the internal pressure bellows 3 and the moving end cover plate 4, between the moving end cover plate 4 and the external pressure bellows 6, and between the moving end cover plate 4 and the porcelain shell 2, welding fixation is adopted.

[0039] In this embodiment, the internal pressure bellows 3 and the moving contact 1 are subjected to airtight brazing, the external pressure bellows 6 and the moving contact 1 are subjected to airtight brazing, the internal pressure bellows 3 and the moving end cover plate 4 are subjected to airtight brazing, the moving end cover plate 4 and the external pressure bellows 6 are subjected to airtight argon arc welding, and the moving end cover plate 4 and the porcelain shell 2 are subjected to airtight brazing.

[0040] A limiting groove is formed on the moving contact 1, and the sliding sealing ring 5 is arranged in the limiting groove. When the external pressure bellows 6 is compressed or stretched, the external pressure bellows 6 will drive the moving end cover plate 4 to slide on the sliding sealing ring 5 (the sliding sealing ring 5 will not move in the limiting groove) to achieve the moving seal between the moving end cover plate 4 and the moving contact 1.

[0041] The outer diameter of the external pressure bellows 6 is larger than the outer diameter of the internal pressure bellows 3.

[0042] The material of the sliding sealing ring 5 is a high-temperature resistant material, enabling it to withstand a high temperature of 800 degrees when entering the furnace.

[0043] Preferably, the inside of the first sealing cavity 7 is vacuum (i.e., the inside of the internal pressure bellows 3 is vacuum).

[0044] During specific implementation, in the closed state, the area enclosed by the moving contact 1, the porcelain shell 2, the internal pressure bellows 3, and the moving end cover plate 4 remains vacuum, and the inside of the first sealing cavity 7 is also vacuum, while the second sealing cavity 8 is filled with high-pressure gas (the gas pressure is adjusted according to the calculated required power. The greater the required opening power, the corresponding increase in the internal gas pressure of the second sealing cavity 8). In the closed holding state, the contact is ensured to be in the closed state through an external locking device. At this time, the external pressure bellows 6 is in a compressed state, and the internal gas pressure thereof becomes larger.

[0045] When starting to open (as shown in Figure 2 and Figure 3 ), the locking device is released. Due to the high-pressure gas filled in the second sealing cavity 8, the moving contact 1 is subjected to the positive pressure of the external pressure bellows 6 and moves upward, thereby accelerating the work done at the moment of initial contact separation and increasing the average initial contact separation speed. The external pressure bellows 6 can be regarded as a non-linear energy storage spring powered by gas, which is used to increase the speed of initial contact separation, thereby shortening the short arcing time of the arc extinguishing chamber and improving the breaking capacity.

[0046] When starting to close, the moving contact 1 is driven by the external closing spring of the circuit breaker to move downward and close. At the same time, the external pressure bellows 6 is compressed and stored with energy during the movement process to prepare for increasing the average initial contact separation speed for the next opening.

[0047] It should be noted that: due to the self-closure force of the vacuum interrupter and the relatively large mass of the moving parts during the closing of the circuit breaker, it is a rigid collision, which will cause a large bounce of the interrupter and affect the performance. In the prior art, generally, an oil buffer is added during the closing process to increase the closing resistance, thereby reducing the bounce. However, the combined bellows assembly for this vacuum interrupter realizes the opening assistance through the positive pressure of the gas (the gas pressure releases the compressed energy during opening). At the same time, since the external pressure bellows 6 will be gradually compressed and absorb energy during the closing process, the buffer function of the closing resistance can be realized, which can effectively reduce the closing speed (the lower the closing speed, the smaller the closing bounce), and thus there is no need to add a cumbersome oil buffer process, simplifying the complexity of the mechanism design.

[0048] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A combined bellows assembly for a vacuum interrupter, characterized in that: include: Moving contact, porcelain shell, internal pressure bellows, moving end cover, sliding seal ring and external pressure bellows; The internal pressure bellows and the external pressure bellows are both sleeved on the moving contact, and the internal pressure bellows and the external pressure bellows are both airtightly fixedly connected to the moving contact; The movable end cover plate is located between the internal pressure bellows and the external pressure bellows, and the movable end cover plate is respectively and airtightly fixedly connected to the internal pressure bellows and the external pressure bellows; One end of the movable end cover plate is fixedly connected to the ceramic shell in an airtight manner, and the other end is slidably connected to the movable contact in an airtight manner through the sliding sealing ring; A first sealing cavity is formed between the internal pressure bellows, the moving contact, the moving end cover plate and the sliding sealing ring; A second sealing cavity is formed between the external pressure bellows, the moving contact, the moving end cover plate and the sliding sealing ring; The second sealed cavity is filled with high-pressure gas; The air pressure in the second sealed cavity is higher than the air pressure in the first sealed cavity.

2. The combined bellows assembly for a vacuum interrupter according to claim 1, characterized in that: One side of the sliding sealing ring is connected to the moving end cover plate in an airtight sliding manner, and the other side is connected to the moving contact in an airtight sliding manner.

3. The combined bellows assembly for vacuum interrupter according to claim 1, characterized in that: The internal pressure bellows and the moving contact, the external pressure bellows and the moving contact, the internal pressure bellows and the moving end cover plate, the moving end cover plate and the external pressure bellows, and the moving end cover plate and the porcelain shell are all fixed by welding.

4. The combined bellows assembly for a vacuum interrupter according to claim 1, characterized in that: A limit groove is provided on the moving contact; The sliding sealing ring is arranged in the limiting groove.

5. The combined bellows assembly for vacuum interrupter according to claim 1, characterized in that: The outer diameter of the external pressure bellows is greater than the outer diameter of the internal pressure bellows.

6. The combined bellows assembly for vacuum interrupter according to claim 1, characterized in that: The sliding sealing ring is made of high temperature resistant material.

7. The combined bellows assembly for a vacuum interrupter according to claim 1, characterized in that: The first sealed cavity is vacuum.

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