Corrugated pipe assembly, vacuum arc-extinguishing chamber and vacuum circuit breaker

Abstract

The invention relates to the technical field of high-voltage or large-current switches with arc extinguishing or arc preventing devices, in particular to a corrugated pipe assembly, a vacuum arc extinguishing chamber and a vacuum circuit breaker. The corrugated pipe assembly comprises a corrugated pipe main body, the corrugated pipe main body is sleeved on the peripheral surface of the moving contact rod, two ends of the corrugated pipe main body are respectively welded with the moving contact rod and the upper cover plate when the corrugated pipe main body is used, the corrugated pipe assembly also comprises a spring, the spring is arranged in the corrugated pipe main body and sleeved outside the moving contact rod when the corrugated pipe main body is used, and the spring is arranged along the axial direction of the corrugated pipe main body. The length of the spring is not smaller than that of the corrugated pipe body, and the two ends of the spring are fixed relative to the two ends of the corrugated pipe body when the spring is used. The corrugated pipe assembly can provide axial support for the expansion and contraction process of the corrugated pipe body, so that the stress borne by the corrugated pipe body is reduced, the service life of the corrugated pipe body is prolonged, and air leakage caused by local cracks or damage of the corrugated pipe body is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage or high-current switches with arc extinguishing or arc protection devices, and in particular to a bellows assembly, a vacuum interrupter and a vacuum circuit breaker. Background Art

[0002] As an electrical switching device widely used in power systems, vacuum circuit breakers have good arc extinguishing and insulation properties. The vacuum arc extinguishing chamber inside them can quickly extinguish the arc and suppress the current when the power is cut off, thereby realizing the closing or disconnection of the circuit. When the opening and closing actions are performed in the vacuum arc extinguishing chamber, the operating mechanism will drive the moving conductive rod to move axially along the arc extinguishing chamber. By sealing the bellows and the moving conductive rod, the bellows will expand and contract with the movement of the moving conductive rod to form a movable component, thereby realizing the opening and closing actions of the moving contact. At the same time, the bellows has good sealing performance and can ensure the vacuum environment and sealing state in the vacuum arc extinguishing chamber. The bellows and the moving conductive rod are usually connected by welding. However, due to the limitations of the welding process, there will inevitably be welding defects such as welds and pores between the bellows and the moving conductive rod, or the welding connection will fail with multiple opening and closing operations, resulting in bellows sealing failure and air leakage.

[0003] In response to the above problems, a Chinese utility model patent with authorization announcement number CN214505372U and authorization announcement date 2021.10.26 discloses a bellows structure of a vacuum arc extinguishing chamber, which includes a bellows main body, and both ends of the bellows main body are respectively provided with threaded connection parts for screwing with a moving conductive rod and a moving cover plate, and compression sealing edges are installed on the threaded connection parts at both ends. When the bellows main body is sleeved on the moving conductive rod, a positioning boss is provided at one end of the moving conductive rod, and a center hole is opened on the moving cover plate for positioning. Both the outer surface of the boss and the inner surface of the center hole are provided with threads, and the threaded connection parts at both ends of the bellows body are respectively screwed and fixed with the positioning boss and the center hole threads. When the threads are screwed, the compression sealing edge on the corresponding side will press against the positioning boss and the moving cover plate of the moving conductive rod and be squeezed and deformed, thereby realizing extrusion sealing of the inside of the bellows body. At the same time, the positioning boss and the moving cover plate are connected to the threaded connection parts at both ends of the bellows body by welding, thereby realizing double sealing of extrusion sealing and welding sealing, improving the sealing effect, and preventing air leakage of the bellows body.

[0004] In the above scheme, compression sealing is achieved between the bellows body and the moving conductive rod and the moving cover plate by installing compression sealing edges at both ends of the bellows body. However, during the multiple and long-term opening and closing processes of the moving conductive rod, the moving conductive rod moves back and forth and generates tensile and compressive forces on the bellows body, causing the bellows body to expand and contract with the movement of the moving conductive rod. Although the bellows body has good flexibility, it has poor rigidity. During the expansion and contraction of the moving conductive rod, the bellows body will be subjected to greater stress, and the stress on various parts is not uniform. Over time, the bellows body is prone to local cracks or breakage, resulting in sealing failure and air leakage. The service life of the bellows body also determines the service life of the vacuum arc chamber and the vacuum circuit breaker. When the bellows body is damaged, the vacuum arc chamber and the vacuum circuit breaker cannot be used any more, which reduces the service life of the bellows, the vacuum arc chamber and the vacuum circuit breaker. Summary of the invention

[0005] The purpose of the present invention is to provide a bellows assembly, which aims to solve the problem that the bellows body is prone to local cracks or damage, resulting in sealing failure and air leakage. At the same time, the purpose of the present invention is also to provide a vacuum interrupter, which solves the problem of reduced service life of the vacuum interrupter by using the above-mentioned bellows assembly. At the same time, the purpose of the present invention is also to provide a vacuum circuit breaker, which solves the problem of reduced service life of the vacuum circuit breaker by applying the above-mentioned bellows assembly in the vacuum interrupter.

[0006] To achieve the above purpose, the bellows assembly of the present invention adopts the following technical solutions: A bellows assembly comprises a bellows main body, which is used to be sleeved on the outside of a moving contact rod. When in use, its two ends are respectively welded to the moving contact rod and an upper cover plate. The bellows assembly also comprises a spring, which is installed in the bellows main body and sleeved on the outside of the moving contact rod when in use. The spring is arranged along the axial direction of the bellows main body, and its center line coincides with the center line of the bellows main body. The length of the spring is not less than the length of the bellows main body, and its two ends are fixed relative to the two ends of the bellows main body when in use.

[0007] Furthermore, both ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

[0008] Beneficial effects: The bellows assembly of the present invention is an improved invention. By installing the spring in the bellows body to form a composite structure, the sealing of the bellows body and the high rigidity of the spring can be taken into account at the same time. When in use, the spring is located between the bellows body and the moving contact rod, and the two ends of the spring are fixed relative to the two ends of the bellows body, so that when the moving contact rod is opening and closing, the spring will expand and contract with the movement of the moving contact rod, and the bellows body welded to the moving contact rod and the upper cover plate will also expand and contract with the movement of the moving contact rod. In this process, due to the good rigidity of the spring, the deformation of each part during the axial expansion and contraction of the spring is consistent, and the restoring force generated is also consistent, thereby driving the axial expansion and contraction of the bellows body. The deformation and stress of various parts in the process are relatively consistent and uniform, and the spring can share the stress of the bellows body, so that the stress of the bellows body is evenly distributed along its axial direction. Especially in the opening process, the spring and the bellows body are compressed at the same time, and the restoring force of the spring itself can share the pressure of the bellows body, avoiding the local part of the bellows body from being subjected to large stress and large deformation, thereby avoiding local cracks or damage of the bellows body causing air leakage, improving the relative stability of various parts of the bellows body during the expansion and contraction process, and thus improving the service life of the bellows body.

[0009] The vacuum interrupter of the present invention adopts the following technical solutions: A vacuum interrupter comprises a moving contact rod, an upper cover plate and a bellows assembly. The bellows assembly comprises a bellows main body, which is used to be sleeved on the outside of the moving contact rod. When in use, its two ends are respectively welded to the moving contact rod and the upper cover plate. The vacuum interrupter also comprises a spring, which is installed in the bellows main body and sleeved on the outside of the moving contact rod when in use. The spring is arranged along the axial direction of the bellows main body, and its center line coincides with the center line of the bellows main body. The length of the spring is not less than the length of the bellows main body, and its two ends are fixed relative to the two ends of the bellows main body when in use.

[0010] Furthermore, both ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

[0011] Furthermore, a concave stop is provided on the upper cover plate, and one end of the spring is positioned by the concave stop.

[0012] Furthermore, a limiting step is provided on the moving contact rod, and one end of the spring is positioned by the limiting step.

[0013] Beneficial effects: The vacuum interrupter of the present invention is an improved invention. By installing the spring in the bellows body to form a composite structure, the sealing performance of the bellows body and the high rigidity of the spring can be taken into account at the same time. Then, when the two ends of the bellows body are respectively welded to the moving contact rod and the upper cover plate, the spring is located between the bellows body and the moving contact rod, and the two ends of the spring are fixed relative to the two ends of the bellows body, so that the spring can be synchronously extended and retracted with the movement of the moving contact rod, avoiding radial displacement of the spring, and avoiding the spring from being separated from the moving contact rod and the upper cover plate in the axial direction, resulting in the spring being unable to extend and retract with the moving contact rod. At the same time, the restoring force generated when the spring is extended and retracted can share part of the stress on the bellows body, reducing the stress on the bellows body, and improving the service life of the bellows body, avoiding local cracks or damage to the bellows body, thereby causing air leakage, and improving the service life of the vacuum interrupter.

[0014] The vacuum circuit breaker of the present invention adopts the following technical solutions: A vacuum circuit breaker includes a vacuum interrupter, which includes a moving contact rod, an upper cover plate and a bellows assembly. The bellows assembly includes a bellows body, which is used to be sleeved on the outside of the moving contact rod. When in use, its two ends are respectively welded to the moving contact rod and the upper cover plate. The vacuum circuit breaker also includes a spring, which is installed in the bellows body and sleeved outside the moving contact rod when in use. The spring is arranged along the axial direction of the bellows body, and its center line coincides with the center line of the bellows body. The length of the spring is not less than the length of the bellows body, and the two ends are fixed relative to the two ends of the bellows body when in use.

[0015] Furthermore, both ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

[0016] Furthermore, a concave stop is provided on the upper cover plate, and one end of the spring is positioned by the concave stop.

[0017] Furthermore, a limiting step is provided on the moving contact rod, and one end of the spring is positioned by the limiting step.

[0018] Beneficial effect: The vacuum circuit breaker of the present invention is an improved invention. By installing the spring in the bellows body to form a composite structure, the sealing of the bellows body and the high rigidity of the spring can be taken into account at the same time. Then, when the two ends of the bellows body are respectively welded to the moving contact rod and the upper cover plate, the spring is located between the bellows body and the moving contact rod, and the two ends of the spring are fixed relative to the two ends of the bellows body, so that the spring can be synchronously extended and retracted with the movement of the moving contact rod, avoiding radial displacement of the spring, and avoiding the spring from being separated from the moving contact rod and the upper cover plate in the axial direction, resulting in the spring being unable to extend and retract with the moving contact rod. At the same time, the restoring force generated when the spring is extended and retracted can share part of the stress on the bellows body, reducing the stress on the bellows body, and improving the service life of the bellows body, avoiding local cracks or damage to the bellows body, thereby causing air leakage, and improving the service life of the vacuum interrupter and the vacuum circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic cross-sectional view of an embodiment of a bellows assembly of the present invention; Figure 2 It is a structural schematic diagram of an embodiment of a bellows assembly of the present invention; Figure 3 It is a schematic cross-sectional structure diagram of a vacuum interrupter of an embodiment of the present invention.

[0020] In the figure: 1. bellows body; 2. moving contact rod; 3. upper cover plate; 4. spring; 5. vacuum arc extinguishing chamber; 6. concave stopper; 7. limit step. DETAILED DESCRIPTION

[0021] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0022] Bellows are used in vacuum interrupter chambers of vacuum circuit breakers because of their good flexibility and sealing properties. However, with multiple opening and closing operations of the vacuum interrupter chamber, the bellows will be subjected to greater stress during the expansion and contraction process caused by the movement of the moving contact rod, resulting in cracks and air leakage. To avoid the above problems, an elastic body with a certain rigidity that can move and contract synchronously with the bellows can be arranged in the bellows. The elastic body can disperse the stress on the bellows and can also expand and contract synchronously during the expansion and contraction of the bellows to achieve axial support for the bellows, thereby avoiding cracks in the bellows during multiple opening and closing operations and causing air leakage. Based on the above inventive concept, the present invention proposes a bellows assembly, a vacuum interrupter chamber and a vacuum circuit breaker. By installing a spring in the bellows, axial support for the bellows is achieved, while the stress on the bellows is dispersed, the service life of the bellows is increased, and cracks in the bellows are avoided to cause air leakage.

[0023] Embodiments of the bellows assembly of the present invention: See also Figure 1 to Figure 2 As a basic embodiment of the present invention, the bellows assembly includes a bellows body 1, which is used to be sleeved on the outer circumference of the moving contact rod 2. When in use, its two ends are respectively welded to the moving contact rod 2 and the upper cover plate 3, and also includes a spring 4, which is installed in the bellows body 1 and sleeved outside the moving contact rod 2 when in use. The spring 4 is arranged along the axial direction of the bellows body 1, and its center line coincides with the center line of the bellows body 1. The length of the spring 4 is not less than the length of the bellows body 1, and the two ends are connected when in use. The two ends of the bellows body 1 are fixed, so that the spring 4 and the bellows body 1 form a composite structure, which can take into account the sealing performance of the bellows body 1 and the high rigidity of the spring 4. When in use, the two ends of the bellows body 1 are welded to the moving contact rod 2 and the upper cover plate 3 respectively, and the spring 4 is located between the bellows body 1 and the moving contact rod 2, and the two ends are fixed relative to the two ends of the bellows body 1, so that when the moving contact rod 2 is opened and closed, the spring 4 can be extended and retracted with the movement of the moving contact rod 2, avoiding The spring 4 is prevented from radial displacement, and the spring 4 is prevented from being separated from the moving contact rod 2 and the upper cover plate 3 in the axial direction, which causes the spring 4 to fail and be unable to expand and contract with the movement of the moving contact rod. At the same time, during the opening and closing process, due to the good rigidity of the spring 4, the deformation of each part of the spring 4 during the axial expansion and contraction process is consistent, and the restoring force generated is also consistent, thereby driving the deformation and stress of each part of the bellows body 1 during the axial expansion and contraction process to be relatively consistent and uniform, and the spring 4 can share the stress on the bellows body 1. In particular, during the opening process, the spring 4 and the bellows body 1 are compressed at the same time, and the restoring force of the spring 4 itself can share the pressure on the bellows body 1, avoiding the local part of the bellows body 1 from being subjected to large stress and large deformation, thereby avoiding the local cracks or damage of the bellows body 1 causing leakage, improving the relative stability between the various parts of the bellows body 1 during the expansion and contraction process, and thereby improving the service life of the bellows body 1.

[0024] As a preferred embodiment of the present invention, both ends of the spring 4 are respectively provided with welding mating surfaces for welding with the upper cover plate 3 and the moving contact rod 2. The spring 4 can form a firm connection with the upper cover plate 3 and the moving contact rod 2 through the welding mating surfaces, effectively avoiding the separation of any end of the spring 4 from the upper cover plate 3 and the moving contact rod 2, resulting in the spring being unable to expand and contract with the movement of the moving contact rod 2, and thus unable to provide axial support for the bellows body 1.

[0025] The use process of the bellows assembly of the present invention is as follows: when in use, the spring 4 is sleeved on the outer peripheral surface of the moving contact rod 2, and the welding mating surface of the end of the spring 4 that contacts the moving contact rod is welded to the moving contact rod 2, then the bellows body 1 is sleeved on the outside of the spring 4, and the end of the bellows body 1 that contacts the moving contact rod 2 is welded to the moving contact rod 2, then the moving contact rod 2 is inserted into the upper cover plate 3, the welding mating surface of the end of the spring 4 that contacts the upper cover plate 3 is welded to the upper cover plate 3, and the bellows body 1 is sleeved on the outside of the spring 4, and the end of the bellows body 1 that contacts the moving contact rod 2 is welded to the moving contact rod 2, and ... bellows body 1 is sleeved on the outside of the spring 4, and the end of the bellows body 1 that contacts the moving contact rod 2 is welded to the moving contact rod 2, and then the moving contact rod 2 is inserted into the upper cover plate 3, the welding mating surface of the end of the spring 4 that contacts the upper cover plate 3 The end of the bellows body 1 that contacts the upper cover plate 3 is welded to the upper cover plate 3. At this time, when the moving contact rod 2 is opened or closed, the spring 4 will expand and contract with the movement of the moving contact rod 2, and provide axial support for the bellows body 1, so that the deformation and stress of various parts of the bellows body 1 tend to be consistent and uniform, avoiding large deformation or large stress in the local part of the bellows body 1, thereby avoiding cracks or damage in the local part of the bellows body 1, and improving the service life of the bellows body 1.

[0026] Embodiments of the vacuum interrupter of the present invention: See also Figure 3 As a basic embodiment of the present invention, the vacuum interrupter 5 includes a moving contact rod 2, an upper cover plate 3 and the above-mentioned bellows assembly. The specific structure of the bellows assembly is as described above and will not be repeated here. The spring 4 is installed in the bellows body 1. When in use, the two ends of the spring 4 are fixed relative to the two ends of the bellows body 1, and the spring 4 is sleeved on the outer circumferential surface of the moving contact rod 2. The bellows body 1 is sleeved on the outside of the spring 4, and its two ends are welded to the moving contact rod 2 and the upper cover plate 3 respectively, so that when the moving contact rod 2 is in the process of opening and closing, the spring 4 provides axial support to the bellows body 1 and shares part of the stress on the bellows body 1, so that the stress on the bellows body 1 is evenly distributed along its axial direction, thereby improving the service life of the bellows assembly, and then improving the service life of the vacuum interrupter 5.

[0027] As a preferred embodiment of the present invention, a recessed stop 6 is provided on the upper cover plate 3, and one end of the spring 4 is positioned by the recessed stop 6. Such a configuration enables the recessed stop 6 to constrain and limit the outer side of one end of the spring 4, thereby preventing the spring 4 from separating from the upper cover plate 3 and becoming ineffective during the process of the bellows body 1 moving and extending with the moving contact rod 2, thereby preventing the bellows body 1 from being unable to provide axial support to the bellows body 1.

[0028] As a preferred embodiment of the present invention, a limiting step 7 is provided on the moving contact rod 2, and one end of the spring 4 is positioned by the limiting step 7. Such a setting enables the limiting step 7 to constrain and limit the inner side of one end of the spring 4, thereby preventing the spring 4 from separating from the moving contact rod 2 and failing during the process of the bellows body 1 moving and extending with the moving contact rod 2, thereby causing the axial support of the spring 4 to the bellows body 1 to disappear.

[0029] The assembly process of the vacuum interrupter 5 of the present invention is as follows: a limiting step 7 and a concave stop 6 are respectively processed on the moving contact rod 2 and the upper cover plate 3, the spring 4 is sleeved on the outer peripheral surface of the moving contact rod 2, and the end of the spring 4 close to the moving contact rod 2 is positioned by the limiting step 7, and at the same time, the end of the spring 4 close to the moving contact rod 2 is welded to the moving contact rod 2 through a welding mating surface, and then the bellows body 1 is sleeved on the outer peripheral surface of the spring 4 and the contact part of the bellows body 1 and the moving contact rod 2 is welded, and then the moving contact rod 2 is inserted into the upper cover plate 3, and the end of the spring 4 close to the upper cover plate 3 is positioned by the concave stop 6, and at the same time, the end of the spring 4 close to the upper cover plate 3 is welded to the moving contact rod 2 through a welding mating surface. The spring 4 is welded to the upper cover plate 3. With this arrangement, the spring 4 can be expanded and contracted synchronously with the movement of the moving contact rod 2 during the opening and closing operations of the moving contact rod 2, thereby avoiding radial deviation of the spring 4 and axial separation of the spring 4 from the moving contact rod 2 and the upper cover plate 3, which causes the spring 4 to fail and be unable to expand and contract with the movement of the moving contact rod 2. At the same time, the spring 4 can provide axial support for the expansion and contraction process of the bellows body 1, and can share part of the stress on the bellows body 1, so that the stress on the bellows body 1 is evenly distributed along its axial direction, thereby avoiding local cracks in the bellows body 1 that cause air leakage, and improving the service life of the vacuum interrupter 5.

[0030] Embodiments of the vacuum circuit breaker of the present invention: The vacuum circuit breaker includes the above-mentioned vacuum interrupter 5 and the above-mentioned bellows assembly, and the specific structure is as described above and will not be repeated here. The bellows assembly is installed in the vacuum interrupter 5 of the vacuum circuit breaker, which can disperse a part of the stress on the bellows body 1, reduce the stress on the bellows body 1, and provide axial support for the bellows body 1, so that the stress on the bellows body 1 is evenly distributed along its axial direction, thereby improving the service life of the bellows body 1, avoiding local cracks or damage to the bellows body 1, thereby causing air leakage, and thus improving the service life of the vacuum interrupter 5 and the vacuum circuit breaker.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A bellows assembly, comprising a bellows body, the bellows body is used to be sleeved on the outside of a moving contact rod, and when in use, its two ends are respectively welded to the moving contact rod and the upper cover plate, characterized in that: It also includes a spring, which is installed in the bellows body and is sleeved outside the moving contact rod when in use. The spring is arranged along the axial direction of the bellows body, and its center line coincides with the center line of the bellows body. The length of the spring is not less than the length of the bellows body, and the two ends of the spring are fixed relative to the two ends of the bellows body when in use.

2. The bellows assembly according to claim 1, characterized in that: The two ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

3. A vacuum interrupter, comprising a moving contact rod, an upper cover plate and a bellows assembly, wherein the bellows assembly comprises a bellows body, which is used to be sleeved on the outer side of the moving contact rod. When in use, the two ends of the bellows body are respectively welded to the moving contact rod and the upper cover plate, and the characteristics are: The bellows assembly also includes a spring, which is installed in the bellows body and is sleeved outside the moving contact rod when in use. The spring is arranged along the axial direction of the bellows body, and its center line coincides with the center line of the bellows body. The length of the spring is not less than the length of the bellows body, and the two ends are fixed relative to the two ends of the bellows body when in use.

4. The vacuum interrupter according to claim 3, characterized in that: The two ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

5. The vacuum interrupter according to claim 4, characterized in that: The upper cover plate is provided with a concave stop, and one end of the spring is positioned by the concave stop.

6. The vacuum interrupter according to claim 4, characterized in that: The moving contact rod is provided with a limiting step, and one end of the spring is positioned by the limiting step.

7. A vacuum circuit breaker, comprising a vacuum interrupter, the vacuum interrupter comprising a moving contact rod, an upper cover plate and a bellows assembly, the bellows assembly comprising a bellows body, the bellows body being used to be sleeved on the outer side of the moving contact rod, and when in use, the two ends of the bellows body are respectively welded to the moving contact rod and the upper cover plate, characterized in that: The bellows assembly also includes a spring, which is installed in the bellows body and is sleeved outside the moving contact rod when in use. The spring is arranged along the axial direction of the bellows body, and its center line coincides with the center line of the bellows body. The length of the spring is not less than the length of the bellows body, and the two ends are fixed relative to the two ends of the bellows body when in use.

8. The vacuum circuit breaker according to claim 7, characterized in that: The two ends of the spring are respectively provided with welding matching surfaces for welding with the upper cover plate and the moving contact rod.

9. The vacuum circuit breaker according to claim 8, characterized in that: The upper cover plate is provided with a concave stop, and one end of the spring is positioned by the concave stop.

10. The vacuum circuit breaker according to claim 8, characterized in that: The moving contact rod is provided with a limiting step, and one end of the spring is positioned by the limiting step.

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