Vacuum interrupter electrical connection and compression device

Abstract

The application discloses a vacuum arc-extinguishing chamber electric connection and pressing device, and relates to the technical field of electrical equipment, which comprises a vacuum arc-extinguishing chamber, a first shielding cover is fixedly installed on the upper and lower ends of the vacuum arc-extinguishing chamber, a guide piece is arranged on the inner side of the top of the vacuum arc-extinguishing chamber in an axial direction, an electric connection module is arranged on the top of the guide piece, a pressing module is arranged on the top of the electric connection module, an insulating support is fixedly installed on the top of the vacuum arc-extinguishing chamber through bolts, a second shielding cover is arranged on the top of the insulating support, an insulating pull rod is inserted into the axial position of the second shielding cover, and the bottom end of the insulating pull rod is rotationally connected with a disc spring sleeve. The application has the advantages of reasonable structure, low resistance, large current, uniform and stable electric connection, reduced contact resistance and temperature rise, and improved current passing reliability.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, and in particular to an electrical connection and clamping device for a vacuum interrupter. Background Technology

[0002] Vacuum interrupters are the core shut-off components of vacuum circuit breakers. The reliability of their electrical connections and the stability of their clamping directly determine the temperature rise level, electrical life, mechanical life, and operational safety of the circuit breaker. With the rapid development of new energy, smart grids, and environmentally friendly switchgear, vacuum interrupters are widely used in harsh operating conditions such as wind power, offshore, vehicle-mounted, and high-altitude applications, placing higher demands on electrical connections and clamping mechanisms.

[0003] With the advancement of global energy transition and the "dual carbon" goal, the power system has put forward core requirements for high-voltage switchgear: environmental protection, compactness, reliability, intelligence, and long service life. High-voltage circuit breakers are the "control and protection heart" of the power grid and new energy power plants. Conventional 126kV circuit breakers mostly adopt a double-break design, which improves the breaking capacity, but the structure is complex, there are many parts, the transmission chain is long, and the size and weight are large, making it difficult to adapt to the narrow spaces such as wind turbine towers and compact GIS.

[0004] The current traditional electrical connection and clamping structures of vacuum interrupters generally suffer from the following technical defects: 1. Traditional structures often use flat flange connections, simple bolt crimping, or single-point contact finger connections. Gaps, misalignment, and oxide films are prone to appear on the contact surface, resulting in high contact resistance and uneven current flow. Under high current conditions, local overheating and ablation are likely to occur, and even contact welding and equipment burnout may occur.

[0005] 2. Traditional bolt tightening and ordinary cylindrical helical spring tightening will cause the tightening force to decay rapidly due to thread creep, spring fatigue, and vibration loosening. They cannot maintain constant pressure for a long time and cannot meet the requirements of long service life and maintenance-free operation.

[0006] 3. The lack of a coaxial guiding mechanism in the moving end makes it prone to eccentricity, tilting, and jamming, resulting in uneven stress distribution and localized stress concentration in the arc-extinguishing chamber. In severe cases, this can lead to cracking of the ceramic shell and failure of the arc-extinguishing chamber. Summary of the Invention

[0007] The purpose of this application is to provide an electrical connection and clamping device for a vacuum interrupter, which achieves low resistance, high current, uniform and stable electrical connection, reduces contact resistance and temperature rise, improves current flow reliability, provides long-term constant, non-attenuating, creep-resistant and fatigue-resistant axial clamping force, automatically compensates for temperature rise, thermal expansion and wear gap, achieves self-centering, high-precision coaxial guidance, anti-eccentric load, anti-jamming, and anti-eccentric wear, and protects the vacuum interrupter from damage by eccentric force.

[0008] To achieve the above objectives, this application provides the following technical solution: an electrical connection and clamping device for a vacuum interrupter, comprising a vacuum interrupter, wherein a first shielding cover is fixedly installed at both the upper and lower ends of the vacuum interrupter, a guide member is provided at the axial position of the inner top of the vacuum interrupter, an electrical connection module is provided at the top of the guide member, a clamping module is provided at the top of the electrical connection module, an insulating support is fixedly installed at the top of the vacuum interrupter by bolts, a second shielding cover is provided at the top of the insulating support, an insulating pull rod is inserted into the axial position of the second shielding cover, and the bottom end of the insulating pull rod is rotatably connected to a disc spring sleeve; The electrical connection module includes a tapered inclined surface contact seat disposed at the top of the guide member. The tapered inclined surface contact seat forms a circumferential flexible conductive structure through spring contact fingers to achieve stable current flow with low resistance and large current. A pair of first guide sleeves are disposed on the outer ring of the tapered inclined surface contact seat. The clamping module consists of a butterfly spring, a disc spring sleeve, and a guide rod to form a constant force axial clamping mechanism. The disc spring sleeve is equipped with a butterfly spring inside. The tapered inclined surface contact seat forms a self-centering fit with the vacuum interrupter end electrode. The spring contact finger is embedded in the outer ring groove of the tapered inclined surface contact seat to form a 360° multi-point conductive path. The clamping module uses a guide rod for coaxial guidance, a sleeve for limiting and preventing instability, and a disc spring to provide constant preload. It can automatically compensate for thermal expansion due to temperature rise and long-term wear gaps, ensuring long-term reliable clamping of electrical connections.

[0009] Preferably, the taper-shaped contact seat of the electrical connection module is provided with a taper-shaped slope of 1 to 10°, the surface roughness Ra≤0.8μm, the effective contact area is increased by more than 100% compared with the traditional planar connection, the current density is uniform, and the local electric field and temperature rise are significantly reduced.

[0010] Preferably, the spring contact finger is a multi-turn spiral spring contact finger or a slotted annular contact finger made of copper alloy, which is embedded in the annular groove of the tapered inclined contact seat. The radial preload is evenly distributed to achieve 360° multi-point flexible conductivity and the contact resistance is ≤20μΩ under rated current conditions.

[0011] Preferably, the clamping module includes a tapered inclined contact seat, a second guide sleeve, a locking disc spring, a pressure plate, a disc spring sleeve, a butterfly spring, and a guide rod. The guide rod and the second guide sleeve are fitted with a precision clearance, and the overall coaxiality is ≤0.05mm, which effectively prevents uneven loading, jamming, and uneven wear.

[0012] Preferably, the disc springs are assembled into spring groups using a combination of opposite or overlapping springs to provide a constant axial clamping force. The clamping force fluctuation during long-term operation is ≤±5%, and the force value remains stable within a temperature range of -40℃ to +120℃.

[0013] Preferably, the disc spring sleeve is a cylindrical limiting structure with an inner diameter that is clearance-fitted with the outer diameter of the disc spring. This structure is used to limit the disc spring from radially turning outward, bending laterally, and becoming unstable, thereby ensuring uniform axial force and stable and reliable clamping.

[0014] Preferably, the locking disc spring is located on the outside of the pressure plate and is used for pre-tightening, locking, and preventing loosening.

[0015] In summary, the present invention has the following beneficial effects: 1. The electrical connection is stable and reliable with extremely low contact resistance. The tapered surface of the taper-shaped contact seat is in 360° contact with the spring finger, resulting in a large effective contact area, uniform current flow, contact resistance ≤20μΩ, and significantly reduced temperature rise.

[0016] 2. The disc spring is fatigue-resistant and creep-resistant, and the clamping force is stable over a long period of time. The locking disc spring and the guide rod cone surface friction provide double anti-loosening, adapting to high vibration conditions. The cone surface is self-centering and coaxially positioned with the guide rod, ensuring high coaxiality, no off-center load, no jamming, and no off-center wear, significantly reducing the risk of arc-extinguishing chamber damage.

[0017] 3. The axial extension and retraction of the disc spring can absorb the heat elongation of the arc-extinguishing chamber and long-term wear, and always maintain reliable compression. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall cross-sectional structure of the vacuum interrupter. Figure 2 This is a schematic diagram of the three-dimensional structure of the first shielding cover; Figure 3 This is a schematic diagram of the three-dimensional structure of the insulating tie rod; Figure 4 This is a schematic diagram of the internal structure of the tapered inclined surface contact seat; Figure 5 This is a schematic diagram of the three-dimensional cross-sectional structure of the disc spring sleeve.

[0020] In the diagram: 1. Vacuum interrupter; 101. First shielding cover; 102. Guide component; 103. Electrical connection module; 104. Clamping module; 105. Insulating support; 106. Second shielding cover; 107. Insulating pull rod; 2. Tapered inclined surface contact seat; 201. Spring contact finger; 202. First guide sleeve; 3. Disc spring; 301. Disc spring sleeve; 302. Guide rod; 303. Second guide sleeve; 304. Locking disc spring; 305. Pressure plate. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example: Reference Figures 1-5 The device shown is an electrical connection and clamping device for a vacuum interrupter, including a vacuum interrupter 1. A first shield 101 is fixedly installed at both the upper and lower ends of the vacuum interrupter 1. A guide 102 is axially positioned on the inner side of the top of the vacuum interrupter 1. An electrical connection module 103 is positioned at the top of the guide 102. A clamping module 104 is positioned at the top of the electrical connection module 103. An insulating support 105 is fixedly installed at the top of the vacuum interrupter 1 by bolts. A second shield 106 is positioned at the top of the insulating support 105. An insulating pull rod 107 is inserted axially into the second shield 106. The bottom end of the insulating pull rod 107 is rotatably connected to a disc spring sleeve 301.

[0023] The electrical connection module 103 includes a tapered inclined surface contact seat 2 located at the top of the guide member 102. The tapered inclined surface contact seat 2 forms a circumferential flexible conductive structure through the spring contact finger 201 to achieve stable current flow with low resistance. A pair of first guide sleeves 202 are provided on the outer ring of the tapered inclined surface contact seat 2.

[0024] The clamping module 104 includes a butterfly spring 3, a disc spring sleeve 301, and a guide rod 302 to form a constant force axial clamping mechanism. The disc spring sleeve 301 is equipped with a butterfly spring 3. The tapered inclined surface contact seat 2 and the end electrode of the vacuum interrupter 1 form a self-centering fit. The spring contact finger 201 is embedded in the outer ring groove of the tapered inclined surface contact seat 2 to form a 360° multi-point conductive path. After long-term operation, the clamping force of the electrical connection and the clamping module 104 do not decrease and the contact resistance does not increase. The mechanical life is ≥10,000 times, the electrical life is ≥20 times, and the maintenance-free cycle is significantly extended.

[0025] The clamping module 104 is coaxially guided by the guide rod 302, the sleeve limits and prevents instability, and the disc spring 3 provides constant preload. It can automatically compensate for thermal expansion and long-term wear gaps, ensuring long-term reliable clamping of electrical connections.

[0026] As one implementation method in this embodiment, the tapered inclined surface contact seat 2 of the electrical connection module 103 is provided with a tapered inclined surface of 1 to 10°, the surface roughness Ra≤0.8μm, the effective contact area is increased by more than 100% compared with the traditional planar connection, the current density is uniform, and the local electric field and temperature rise are significantly reduced. The spring contact finger 201 is made of copper alloy multi-turn spiral spring contact finger or slotted annular contact finger, which is embedded in the annular groove of the tapered inclined surface contact seat 2. The radial preload is evenly distributed, realizing 360° multi-point flexible conductivity around the circumference. The contact resistance is ≤20μΩ under rated current conditions.

[0027] As one embodiment of this invention, the clamping module 104 includes a tapered inclined contact seat 2, a second guide sleeve 303, a locking disc spring 304, a pressure plate 305, a disc spring sleeve 301, a butterfly spring 3, and a guide rod 302. The guide rod 302 and the second guide sleeve 303 are precision clearance fitted, with an overall coaxiality ≤0.05mm, effectively preventing uneven loading, jamming, and uneven wear. The butterfly spring 3 is assembled into a spring group using a mating or stacked combination to provide a constant axial clamping force. The clamping force fluctuation during long-term operation is ≤±5%. The force value remains stable within the temperature range of 40℃~+120℃. The disc spring sleeve 301 is a cylindrical limiting structure with a clearance fit between its inner diameter and the outer diameter of the disc spring 3. It is used to limit the radial outward bending, lateral bending and instability of the disc spring 3, and to ensure uniform axial force and stable and reliable clamping. The locking disc spring 304 is set on the outside of the pressure plate 305 for pre-tightening and locking and to prevent loosening. It does not loosen, depressurize or reduce the clamping force under high vibration conditions such as wind power, vehicle and marine applications.

[0028] Working principle of the invention: In the closed state, the transmission box drives the insulating pull rod 107 to push the moving end to move, and the moving and stationary contacts of the vacuum interrupter 1 close; the clamping module 104 maintains a constant axial clamping force, and the tapered inclined surface of the tapered inclined surface contact seat 2 and the spring contact finger 201 form a low resistance path, and the current is stably conducted.

[0029] Opening state: The transmission box drives the moving end to retract quickly, the contacts separate, the vacuum arc is quickly extinguished, and the circuit is disconnected.

[0030] Normal operation: The butterfly spring 3 continuously provides constant force to compensate for the thermal expansion and mechanical wear of the vacuum interrupter 1, the spring contact finger 201 maintains flexible fit and stable contact resistance, and the guide rod 302 ensures no uneven wear and no jamming.

[0031] Vibration condition: The locking disc spring 304 and the top conical surface of the guide 102 form a double anti-loosening mechanism through friction, and the flexible contact finger at the top of the guide 102 does not disengage, so the clamping force does not decrease.

[0032] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrical connection and clamping device for a vacuum interrupter, characterized in that, include: A vacuum interrupter (1) is provided with a first shield (101) fixedly installed at both the upper and lower ends. A guide (102) is provided on the inner side of the top of the vacuum interrupter (1) in an axial position. An electrical connection module (103) is provided on the top of the guide (102). A clamping module (104) is provided on the top of the electrical connection module (103). An insulating support (105) is fixedly installed on the top of the vacuum interrupter (1) by bolts. A second shield (106) is provided on the top of the insulating support (105). An insulating pull rod (107) is inserted in the axial position of the second shield (106). The bottom end of the insulating pull rod (107) is rotatably connected to the disc spring sleeve (301). The electrical connection module (103) includes a tapered inclined surface contact seat (2) disposed at the top of the guide (102). The tapered inclined surface contact seat (2) forms a circumferential flexible conductive structure through a spring contact finger (201) to achieve stable current flow with low resistance and large current. A pair of first guide sleeves (202) are provided on the outer ring of the tapered inclined surface contact seat (2). The clamping module (104) consists of a butterfly spring (3), a disc spring sleeve (301) and a guide rod (302) forming a constant force axial clamping mechanism. The disc spring sleeve (301) is equipped with a butterfly spring (3). The tapered inclined surface contact seat (2) forms a self-centering fit with the end electrode of the vacuum interrupter (1). The spring contact finger (201) is embedded in the outer ring groove of the tapered inclined surface contact seat (2) to form a 360° multi-point conductive path. The clamping module (104) is coaxially guided by the guide rod (302), the sleeve is limited to prevent instability, and the butterfly spring (3) provides constant preload. It can automatically compensate for thermal expansion and long-term wear gaps, and ensure long-term reliable clamping of electrical connections.

2. The vacuum interrupter electrical connection and clamping device according to claim 1, characterized in that: The tapered inclined surface contact seat (2) of the electrical connection module (103) is provided with a tapered inclined surface of 1 to 10°, with an inclined surface roughness Ra≤0.8μm. The effective contact area is increased by more than 100% compared with the traditional planar connection, and the current density is uniform, and the local electric field and temperature rise are significantly reduced.

3. The vacuum interrupter electrical connection and clamping device according to claim 2, characterized in that: The spring contact (201) is made of copper alloy multi-turn spiral spring contact or slotted annular contact, which is embedded in the annular groove of the tapered inclined surface contact seat (2). The radial preload is evenly distributed to achieve 360° multi-point flexible conductivity. The contact resistance is ≤20μΩ under rated current conditions.

4. The vacuum interrupter electrical connection and clamping device according to claim 3, characterized in that: The clamping module (104) includes a tapered inclined contact seat (2), a second guide sleeve (303), a locking disc spring (304), a pressure plate (305), a disc spring sleeve (301), a butterfly spring (3), and a guide rod (302). The guide rod (302) and the second guide sleeve (303) are fitted with a precision clearance, and the overall coaxiality is ≤0.05mm, which effectively prevents uneven loading, jamming and uneven wear.

5. A vacuum interrupter electrical connection and clamping device according to claim 4, characterized in that: The disc spring (3) is composed of a pairing or stacking combination to form a spring group, providing a constant axial clamping force. The clamping force fluctuation during long-term operation is ≤±5%, and the force value remains stable within the temperature range of -40℃ to +120℃.

6. The vacuum interrupter electrical connection and clamping device according to claim 5, characterized in that: The disc spring sleeve (301) is a cylindrical limiting structure with an inner diameter that is clearance-fitted with the outer diameter of the disc spring (3). It is used to limit the radial outward bending, lateral bending and instability of the disc spring (3) and ensure uniform axial force and stable and reliable clamping.

7. A vacuum interrupter electrical connection and clamping device according to claim 6, characterized in that: The locking disc spring (304) is located on the outside of the pressure plate (305) and is used for pre-tightening, locking and preventing loosening.

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