Closing holding device for vacuum arc-extinguishing chamber and vacuum circuit breaker

Abstract

The invention provides a closing holding device for a vacuum arc-extinguishing chamber and a vacuum circuit breaker, and belongs to the technical field of switch equipment. The switch-on holding device comprises a spring cylinder, a guide block is installed in the spring cylinder, a switch-on holding spring is installed between the guide block and the cylinder bottom in a pressing mode, the spring cylinder comprises a guide inner circumferential face used for guiding the switch-on holding spring, a lining cylinder is fixedly arranged in the spring cylinder, and the lining cylinder is sleeved with the switch-on holding spring. The lining cylinder comprises a guiding outer peripheral surface, wherein the outer diameter of the guiding outer peripheral surface is matched with the inner diameter of the closing retaining spring so as to guide the compression deformation of the closing retaining spring. According to the invention, the guide outer circumferential surface of the lining cylinder is utilized to guide the compression deformation of the closing retaining spring, and the guide inner circumferential surface of the spring cylinder is combined to realize the inner and outer guide functions of the closing retaining spring, so that the stable output of the magnitude and direction of closing retaining force is ensured, and the good centering effect and stable contact of the moving and static contacts are ensured; and the performance stability and the service life prolonging of the vacuum arc-extinguishing chamber are facilitated.

Description

Technical Field

[0001] This invention relates to a closing and holding device for a vacuum interrupter and a vacuum circuit breaker, belonging to the field of switchgear technology. Background Technology

[0002] In a vacuum interrupter, the moving and stationary contacts are in butt contact when the circuit is closed. To ensure a certain contact pressure between the moving and stationary contacts, a closing holding device is usually connected between the pull rod connected to the operating mechanism and the moving end conductive rod. For example, Chinese invention patent application CN114429880A discloses a vacuum interrupter assembly and vacuum circuit breaker, which involves a closing holding device. The closing holding device includes a spring cylinder disposed in a moving support. One end of the spring cylinder has an opening, and the other end has a bottom. A guide block is guidedly installed inside the spring cylinder, and a spring (i.e., a closing holding spring) is press-fitted between the guide block and the bottom of the spring cylinder. An end cap is installed at the opening of the spring cylinder to prevent the guide block from dislodging. The moving end conductive rod of the vacuum interrupter includes a stud. The stud passes through the conductive base and the bottom of the spring cylinder and extends into the interior of the spring cylinder, and is connected to a nut to fix the spring cylinder, conductive base, and moving end conductive rod. One end of the guide block protruding from the end cover is connected to the pull rod. When the circuit is closed, under the action of the operating mechanism, the pull rod drives the spring cylinder through the guide block, which in turn drives the moving end conductive rod to make the moving contact contact the stationary contact. Then the pull rod continues to move, driving the guide block to compress the spring, thereby maintaining a certain contact pressure between the moving and stationary contacts.

[0003] The aforementioned closing and holding device provides the closing and holding force required by the moving and stationary contacts through the compression of the spring during the closing process. During this process, the inner guide surface of the spring cylinder guides the compression deformation of the spring. However, due to the high closing speed, the spring is prone to inward twisting deformation during the compression deformation process, which in turn causes the direction and magnitude of the output closing and holding force to change. This makes it impossible to guarantee a good alignment effect and stable contact between the moving and stationary contacts. Over time, this will affect the performance stability and service life of the vacuum interrupter. Summary of the Invention

[0004] The purpose of this invention is to provide a closing and holding device for a vacuum interrupter, so as to solve the problem that the spring in the existing closing and holding device is prone to inward torsional deformation during compression deformation, which causes the direction and magnitude of the output closing and holding force to change, and thus cannot guarantee good alignment and stable contact between the moving and stationary contacts; the purpose of this invention is also to provide a vacuum circuit breaker to solve the above problems.

[0005] To achieve the above objectives, the closing and holding device for the vacuum interrupter in this invention adopts the following technical solution: A closing and holding device for a vacuum interrupter includes a spring cylinder with an opening at one end and a bottom at the other end. A guide block is slidably installed inside the spring cylinder, and a closing and holding spring is press-fitted between the guide block and the bottom of the cylinder. The spring cylinder includes an inner guide surface for guiding the compression deformation of the closing and holding spring. An inner liner is fixedly installed inside the spring cylinder, and the closing and holding spring is sleeved on the outside of the inner liner. The inner liner includes an outer guide surface with an outer diameter that matches the inner diameter of the closing and holding spring to guide the compression deformation of the closing and holding spring.

[0006] The beneficial effects of the above technical solution are as follows: This invention proposes an improved closing and holding device for a vacuum interrupter. The improvement lies in the fact that an inner liner is fixedly installed inside the spring cylinder, and the closing and holding spring is sleeved on the outside of the inner liner. The inner liner includes a guide outer circumferential surface whose outer diameter is adapted to the inner diameter of the closing and holding spring to guide the compression deformation of the closing and holding spring. This can prevent the closing and holding spring from twisting inward during the compression deformation process. The guide outer circumferential surface and the guide inner circumferential surface of the spring cylinder together ensure that the direction and magnitude of the closing and holding force are stably output, thereby ensuring good alignment and stable contact of the moving and stationary contacts, which is beneficial to the stable performance and extended service life of the vacuum interrupter.

[0007] Furthermore, the inner liner is made of a self-lubricating material.

[0008] Furthermore, the self-lubricating material is polyetheretherketone.

[0009] Furthermore, the radial clearance between the outer peripheral surface of the guide and the closing holding spring is smaller than the radial clearance between the inner peripheral surface of the guide and the closing holding spring.

[0010] Furthermore, the inner liner is provided with an insertion section at one end near the opening of the spring cylinder, which is inserted into the inner hole of the guide block and slides in cooperation with the inner hole of the guide block. The inner liner also includes a guide section with an outer diameter larger than the outer diameter of the insertion section, and the guide section has the aforementioned guide outer peripheral surface.

[0011] Furthermore, an annular groove is provided on the outer circumferential surface of the insertion section, and a guide ring for guiding the guide block is installed in the annular groove.

[0012] Furthermore, the inner liner includes a cylinder body and an end plate disposed at one end of the cylinder body, the end plate being fixedly connected to the bottom of the spring cylinder.

[0013] Furthermore, the other end of the cylinder is open, and the closing holding device for the vacuum interrupter also includes connecting screws for passing through the end plate and the bottom of the cylinder and being fixedly connected to the moving end conductive rod.

[0014] Furthermore, the head end face of the connecting screw is provided with an anti-rotation structure for engaging with the anti-rotation mechanism of the screw-tightening tool.

[0015] To achieve the above objectives, the vacuum circuit breaker in this invention adopts the following technical solution: A vacuum circuit breaker includes a vacuum interrupter and a pull rod. The vacuum interrupter includes a moving-end conductive rod. The vacuum circuit breaker also includes a closing holding device connected between the pull rod and the moving-end conductive rod. The closing holding device includes a spring cylinder with an opening at one end and a bottom at the other end. A guide block is slidably installed inside the spring cylinder, and a closing holding spring is press-fitted between the guide block and the bottom of the cylinder. The spring cylinder includes a guide inner circumferential surface for guiding the compression deformation of the closing holding spring. An inner liner is fixedly installed inside the spring cylinder. The closing holding spring is sleeved on the outside of the inner liner. The inner liner includes a guide outer circumferential surface whose outer diameter is adapted to the inner diameter of the closing holding spring to guide the compression deformation of the closing holding spring.

[0016] The beneficial effects of the above technical solution are as follows: This invention proposes an improved vacuum circuit breaker. The improvement lies in that an inner liner is fixedly installed inside the spring cylinder of the closing holding device, and the closing holding spring is sleeved on the outside of the inner liner. The inner liner includes a guide outer circumferential surface whose outer diameter is adapted to the inner diameter of the closing holding spring to guide the compression deformation of the closing holding spring. This can prevent the closing holding spring from twisting inward during the compression deformation process. The guide outer circumferential surface and the guide inner circumferential surface of the spring cylinder together ensure that the direction and magnitude of the closing holding force are stably output, thereby ensuring good alignment and stable contact of the moving and stationary contacts, which is beneficial to the stable performance and extended service life of the vacuum interrupter.

[0017] Furthermore, the inner liner is made of a self-lubricating material.

[0018] Furthermore, the self-lubricating material is polyetheretherketone.

[0019] Furthermore, the radial clearance between the outer peripheral surface of the guide and the closing holding spring is smaller than the radial clearance between the inner peripheral surface of the guide and the closing holding spring.

[0020] Furthermore, the inner liner is provided with an insertion section at one end near the opening of the spring cylinder, which is inserted into the inner hole of the guide block and slides in cooperation with the inner hole of the guide block. The inner liner also includes a guide section with an outer diameter larger than the outer diameter of the insertion section, and the guide section has the aforementioned guide outer peripheral surface.

[0021] Furthermore, an annular groove is provided on the outer circumferential surface of the insertion section, and a guide ring for guiding the guide block is installed in the annular groove.

[0022] Furthermore, the inner liner includes a cylinder body and an end plate disposed at one end of the cylinder body, the end plate being fixedly connected to the bottom of the spring cylinder.

[0023] Furthermore, the other end of the cylinder is open, and the closing holding device also includes a connecting screw for passing through the end plate and the bottom of the cylinder and being fixedly connected to the moving end conductive rod.

[0024] Furthermore, the head end face of the connecting screw is provided with an anti-rotation structure for engaging with the anti-rotation mechanism of the screw-tightening tool. Attached Figure Description

[0025] Figure 1 This is a structural diagram (released state) of an embodiment of the closing and holding device for a vacuum interrupter of the present invention. Figure 2 This is a structural diagram (closed state) of an embodiment of the closing and holding device for the vacuum interrupter of the present invention.

[0026] In the diagram: 1. Connector; 2. Guide block; 21. First guide section; 22. Second guide section; 23. Annular boss; 3. End cover; 4. First guide ring; 5. Spring cylinder; 6. Closing holding spring; 7. Second guide ring; 8. Inner liner; 81. Insertion section; 82. Guide section; 83. End plate; 9. Connecting screw. Detailed Implementation

[0027] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0028] To address the technical problems existing in the prior art, the basic technical concept of this invention is to add an inner liner inside the spring cylinder. The outer guide surface of the inner liner guides the compression deformation of the closing holding spring. At the same time, combined with the inner guide surface of the spring cylinder, the closing holding spring can achieve a dual guiding function of inner and outer guidance, ensuring that the magnitude and direction of the closing holding force are stably output.

[0029] An embodiment of the closing and holding device for a vacuum interrupter in this invention: like Figure 1 and Figure 2 As shown, a spring cylinder 5 includes an opening at one end (the upper end shown in the figure) and a bottom at the other end (the lower end shown in the figure). A guide block 2 is slidably installed inside the spring cylinder 5, and a closing holding spring 6 is press-fitted between the guide block 2 and the bottom of the cylinder. The guide block 2 includes a first guide section 21, a second guide section 22, and an annular boss 23 located between the first guide section 21 and the second guide section 22. One end face of the annular boss 23 is used to press against the closing holding spring 6. An end cap 3 is fixed to the opening of the spring cylinder 5 by a threaded connection. The end cap 3 is engaged with the other end face of the annular boss 23 to prevent the guide block 2 from falling out of the spring cylinder 5. A first guide ring 4 is installed on the inner wall of the end cap 3. The first guide ring 4 engages with the outer circumferential surface of the first guide section 21 to guide the sliding of the guide block 2. The guide block 2 has an inner hole with an internal thread at one end. The connector 1 is connected to the internal thread to achieve a fixed connection with the guide block 2. The connector 1 is used to connect the pull rod to transmit the force of the operating mechanism.

[0030] The spring cylinder 5 includes a guide inner circumferential surface, which is the inner wall surface of the spring cylinder 5, for guiding the compression deformation of the closing holding spring 6, so as to prevent the closing holding spring 6 from twisting outward during the compression deformation. Of course, in order to facilitate the installation of the closing holding spring 6, the spring cylinder 5 and the closing holding spring 6 have a gap in the radial direction, that is, the guide inner circumferential surface and the closing holding spring 6 have a gap in the radial direction.

[0031] In this invention, an inner liner 8 is fixedly installed inside the spring cylinder 5, and the closing holding spring 6 is sleeved on the outside of the inner liner 8. The inner liner 8 includes a guide outer circumferential surface whose outer diameter is adapted to the inner diameter of the closing holding spring 6 to guide the compression deformation of the closing holding spring 6. "Adapted" means that the guide outer circumferential surface and the closing holding spring 6 have a certain gap in the radial direction, so that the closing holding spring 6 can be naturally assembled on the outside of the inner liner 8. At the same time, the guide outer circumferential surface can also guide the compression deformation of the closing holding spring 6, thereby preventing the closing holding spring 6 from twisting inward during the compression deformation process. Together with the guide inner circumferential surface of the spring cylinder 5, it ensures that the direction and magnitude of the closing holding force are stably output, thereby ensuring good alignment effect and stable contact of the moving and stationary contacts, which is beneficial to the stable performance and extended life of the vacuum interrupter.

[0032] Specifically, in this embodiment, the spring cylinder 5 is made of metal to ensure sufficient strength. To reduce the weight of the moving parts and decrease the operating effort during opening and closing, weight-reducing holes are spaced circumferentially on the cylinder wall of the spring cylinder 5, and these holes are elongated holes extending axially. Simultaneously, the inner liner 8 in this invention is made of a self-lubricating material. This reduces the generation of metal particles when the closing holding spring 6 contacts and rubs against the inner liner 8, ensuring the reliability of the vacuum interrupter's operation. Specifically, in this embodiment, the self-lubricating material is polyetheretherketone (PEEK). PEEK is a special engineering plastic with excellent properties such as high temperature resistance, self-lubrication, easy processing, and high mechanical strength. Furthermore, its low density minimizes the impact of the increased mass of the moving parts caused by adding the inner liner 8.

[0033] Furthermore, the radial gap between the outer guide surface and the closing holding spring 6 is smaller than the radial gap between the inner guide surface and the closing holding spring 6. This makes it easier for the closing holding spring 6 to contact the outer guide surface of the inner liner 8 during compression deformation, reducing the generation of metal particles. In other words, the inner liner 8 plays the main guiding role, avoiding easy contact with the spring cylinder 5 and the generation of more metal particles.

[0034] In this embodiment, the inner liner 8 includes a cylinder and an end plate 83 disposed at one end of the cylinder, the end plate 83 being fixedly connected to the bottom of the spring cylinder 5. Specifically, the other end of the cylinder is open, and the closing holding device for the vacuum interrupter also includes a connecting screw 9 for passing through the end plate 83 and the bottom of the cylinder and being fixedly connected to the moving end conductive rod, wherein the moving end conductive rod includes a conductive seat. The opening at the other end of the cylinder allows for the installation of the connecting screw 9. Thus, a fixed connection between the inner liner 8, the spring cylinder 5, and the moving end conductive rod can be achieved through a single connecting screw 9. Of course, if the conductive seat is independent of the moving end conductive rod, the connecting screw 9 also needs to pass through the conductive seat before being fixedly connected to the moving end conductive rod.

[0035] To facilitate cooperation with the closing holding spring 6, the outer diameter of the inner liner 8 can be basically determined, which limits the inner diameter of the inner liner 8, that is, the operating space inside the inner liner 8 will be limited. In order to ensure the installation operation of the connecting screw 9, the head end face of the connecting screw 9 is provided with an anti-rotation structure for cooperating with the anti-rotation of the screwing tool. In this embodiment, the anti-rotation structure is a hexagonal hole, but in other embodiments it can also be a square hole, a square head, or a hexagonal head.

[0036] The inner liner 8 comprises an insertion section 81 and a guide section 82. The insertion section 81 is located at the end of the inner liner 8 near the opening of the spring cylinder 5. The insertion section 81 is inserted into the inner hole of the guide block 2 and slides in cooperation with it. That is, the insertion section 81 is inserted into the second guide section 22 of the guide block 2 and slides in cooperation with it. In this way, when the guide block 2 moves and compresses the closing retaining spring 6, the inner liner 8 will not interfere with it. Furthermore, an annular groove is provided on the outer circumferential surface of the insertion section 81, and a guide ring, namely the second guide ring 7, is installed in the annular groove to guide the second guide section 22. This also guides the movement of the guide block 2, thereby cooperating with the first guide ring 4 to achieve the inner and outer guiding functions.

[0037] The outer diameter of the guide section 82 is larger than the outer diameter of the insertion section 81. The guide section 82 has the aforementioned guide outer peripheral surface, and the axial length of the guide section 82 is much larger than the axial length of the insertion section 81. The axial length of the insertion section 81 only needs to meet the requirement of not interfering with the guide block 2, so as to ensure that the inner side of the closing holding spring 6 has a larger area of ​​guide outer peripheral surface to guide it.

[0038] When the vacuum interrupter chamber closing and holding device of the present invention is in use, such as Figure 1 As shown, the closing holding spring 6 has a certain pre-compression amount, which can be adjusted by adjusting the position of the end cover 3. During closing, the operating mechanism control rod drives the connector 1 and guide block 2 to move and compress the closing holding spring 6, as shown... Figure 2As shown, the closing holding spring 6 will be compressed by L according to the design, and the closing holding device will change from the released state to the closed state. During the deformation process of the closing holding spring 6, it is limited by the size of the spring cylinder 5 and the inner liner cylinder 8. At the same time, under the guidance of the guide block 2, the closing holding spring 6 is stably compressed along the closing direction, ensuring that the magnitude and direction of the closing holding force are stable. This ensures that the moving and stationary contacts of the vacuum interrupter are in stable contact, and that the moving and stationary contacts are well aligned, which is beneficial to the stable performance and extended service life of the vacuum interrupter.

[0039] In other embodiments of the closing holding device for vacuum interrupters: when the internal space of the inner liner is sufficient, the connecting screw may not have an anti-rotation structure on the head end face, but may directly use a connecting screw with a hexagonal head. In this case, the connecting screw uses the outer peripheral surface of the head to engage with the tightening tool to prevent rotation.

[0040] In other embodiments of the closing holding device for vacuum interrupters: the connection between the inner liner, the spring cylinder, and the moving end conductive rod can also be such that the screw of the moving end conductive rod passes through the conductive seat, the spring cylinder, and the inner liner in sequence, and then a nut is installed inside the inner liner. In this case, the installation method is the same as that in the prior art.

[0041] In other embodiments of the closing holding device for vacuum interrupters: the end plate and the bottom of the spring cylinder can be directly welded and fixed, and the spring cylinder, conductive seat, and moving end conductive rod are also welded and fixed; in other embodiments, when the inner liner is directly welded and fixed to the bottom of the spring cylinder, the end plate can be omitted, and the end face of the inner liner can be directly welded and fixed to the bottom of the spring cylinder.

[0042] In other embodiments of the closing holding device for vacuum interrupters: the annular groove may not be provided on the outer circumferential surface of the insertion section, and the guide ring is no longer installed. The insertion section can directly slide with the guide section using its own outer circumferential surface.

[0043] In other embodiments of the closing holding device for vacuum interrupters: the inner liner may not include the insertion section, that is, the inner liner is no longer inserted into the inner hole of the guide block. In this case, the inner liner is entirely composed of the guide section, and the inner liner is slightly shorter, as long as it does not affect the movement of the guide block.

[0044] In other embodiments of the closing and holding device for vacuum interrupters: the radial gap between the outer guide surface and the closing and holding spring can also be equal to the radial gap between the inner guide surface and the closing and holding spring. In order to reduce the generation of metal particles, the machining accuracy of the inner guide surface of the spring cylinder needs to be improved.

[0045] In other embodiments of the closing holding device for vacuum interrupters: the self-lubricating material used to manufacture the inner liner can also be other engineering plastics such as nylon and polytetrafluoroethylene, or of course, graphite.

[0046] In other embodiments of the closing and holding device for vacuum interrupters: the inner liner can also be made of metal. In this case, the machining accuracy of the outer guide surface of the inner liner needs to be improved to reduce the generation of metal particles.

[0047] An embodiment of the vacuum circuit breaker in this invention is as follows: The vacuum circuit breaker includes a vacuum interrupter and a pull rod. The vacuum interrupter includes a moving end conductive rod. The vacuum circuit breaker also includes a closing holding device connected between the pull rod and the moving end conductive rod. The specific structure of the closing holding device is the same as that of the closing holding device for the vacuum interrupter in the above embodiment, and will not be repeated here.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A closing and holding device for a vacuum interrupter, comprising a spring cylinder having an opening at one end and a bottom at the other end, a guide block being slidably mounted inside the spring cylinder and a closing and holding spring being press-fitted between the guide block and the bottom of the cylinder, the spring cylinder including a guide inner circumferential surface for guiding the compression deformation of the closing and holding spring, characterized in that, An inner liner is fixedly installed inside the spring cylinder, and the closing holding spring is sleeved on the outside of the inner liner. The inner liner includes a guide outer circumferential surface whose outer diameter is adapted to the inner diameter of the closing holding spring to guide the compression deformation of the closing holding spring.

2. The closing and holding device for a vacuum interrupter according to claim 1, characterized in that, The inner liner is made of a self-lubricating material.

3. The closing and holding device for a vacuum interrupter according to claim 2, characterized in that, The self-lubricating material is polyetheretherketone.

4. The closing and holding device for a vacuum interrupter according to claim 2, characterized in that, The radial clearance between the outer circumferential surface of the guide and the closing holding spring is smaller than the radial clearance between the inner circumferential surface of the guide and the closing holding spring.

5. The closing and holding device for a vacuum interrupter according to any one of claims 1 to 4, characterized in that, The inner liner has an insertion section at one end near the opening of the spring cylinder, which is inserted into the inner hole of the guide block and slides in cooperation with the inner hole of the guide block. The inner liner also includes a guide section with an outer diameter larger than the outer diameter of the insertion section, and the guide section has the aforementioned guide outer peripheral surface.

6. The closing and holding device for a vacuum interrupter according to claim 5, characterized in that, An annular groove is provided on the outer circumferential surface of the insertion section, and a guide ring for guiding the guide block is installed in the annular groove.

7. The closing and holding device for a vacuum interrupter according to any one of claims 1 to 4, characterized in that, The inner liner includes a cylinder body and an end plate disposed at one end of the cylinder body. The end plate is fixedly connected to the bottom of the spring cylinder.

8. The closing and holding device for a vacuum interrupter according to claim 7, characterized in that, The other end of the cylinder is open, and the closing holding device for the vacuum interrupter also includes connecting screws for passing through the end plate and the bottom of the cylinder and being fixedly connected to the moving end conductive rod.

9. The closing and holding device for a vacuum interrupter according to claim 8, characterized in that, The head end face of the connecting screw is provided with an anti-rotation structure for engaging with the screw-tightening tool to prevent rotation.

10. A vacuum circuit breaker, comprising a vacuum interrupter and a pull rod, the vacuum interrupter comprising a moving-end conductive rod, the vacuum circuit breaker further comprising a closing holding device connected between the pull rod and the moving-end conductive rod, characterized in that, The closing holding device is the closing holding device for a vacuum interrupter as described in any one of claims 1 to 9.

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