Circuit breaker

Abstract

The invention relates to a circuit breaker, and belongs to the technical field of power transmission and distribution circuit electric appliances. The invention provides a circuit breaker. The circuit breaker comprises a base; the arc extinguish chamber is mounted at the upper part of the base, and a plurality of layers of partition plates are movably matched in the arc extinguish chamber; and the moving contact comprises a moving contact support fixed on one side of the lower part of the base, a contact assembly arranged in the moving contact support, and a static contact. According to the invention, air-blowing arc extinguishing is enhanced through follow-up of multiple layers of partition plates of the arc extinguish chamber, creepage distance is increased and arc energy is reduced through rear arrangement of a long contact blade, a plurality of sawtooth structures are matched to block prone arcs, a special housing is matched to protect the contact, the minimum electrical safety distance is ensured, and meanwhile, each component is accurately matched with the base, and is stable in movement; the arc extinguishing efficiency and the breaking reliability of the circuit breaker under the working conditions of high voltage and large current can be remarkably improved, the problems of breakdown, arc bending and difficult breaking are effectively avoided, and the service life of the circuit breaker is prolonged.

Description

Technical Field

[0001] This invention relates to a circuit breaker, belonging to the field of electrical technology for power transmission and distribution circuits. Background Technology

[0002] Circuit breakers are crucial electrical components in power transmission and distribution lines. They interrupt the current carried by the circuit to protect the lines and electrical equipment. Circuit breakers typically include core structures such as an arc-extinguishing system and a contact system. The arc-extinguishing system has an arc-extinguishing chamber, which mainly relies on arc-extinguishing grids to cut and cool the electric arc. The contact system consists of moving and stationary contacts. After the moving contact actuates, it contacts or separates from the stationary contact, thus realizing the switching on and off. Under high voltage and high current conditions, when the switch breaks, a breakdown occurs between the moving and stationary contacts, generating an electric arc. The high energy of the arc can make it difficult for the switch to break, thus damaging the circuit breaker and the circuit.

[0003] As the market demand for power capacity continues to expand, how to achieve reliable interruption of high voltage and high current while avoiding phenomena such as breakdown and arcing has become a key concern and an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a circuit breaker, comprising: a base; an arc-extinguishing chamber mounted on the upper part of the base, wherein multiple layers of partitions are movably fitted within the arc-extinguishing chamber; and a moving contact, including a moving contact support fixed to one side of the lower part of the base and a contact assembly disposed within the moving contact support. The contact assembly includes a group of short contact pieces formed by multiple linearly arranged short contact pieces and long contact pieces inserted within the group of short contact pieces. The lower parts of the long contact pieces and the group of short contact pieces are connected to a moving busbar via a flexible connection, and the moving busbar also fits into the base. The base has a base; simultaneously, the upper part of the long contact piece extends out through the short contact piece group, passes through the multi-layer partition, and extends into the interior of the arc-extinguishing chamber. The long contact piece can carry the multi-layer partition to move horizontally. The multi-layer partition is driven by the long contact piece to move back and forth along the guide rail, forming a relatively sealed space, which enhances the air blowing effect and allows the electric arc to be introduced into the arc-extinguishing chamber for cutting, cooling, and extinguishing. The stationary contact is located on the other side of the lower part of the base and is opposite to the moving contact. It includes a stationary busbar that cooperates with the base and a stationary contact cover that connects to the stationary busbar, reducing the damage of the electric arc to the stationary contact.

[0005] In some embodiments, the long contact piece can be positioned with its top end towards the rear. For example, the upper and lower sections of the long contact piece are connected by a bend to form a Z-shaped structure. The upper section of the long contact piece is positioned towards the rear to increase the creepage distance, reduce arc energy, and extinguish the arc more quickly. Furthermore, since the arc extinguishing chamber is designed with multiple layers of partitions driven by the long contact piece, positioning the top end of the long contact piece towards the rear reduces the movement distance of the partitions and prevents them from colliding with the inner walls of the base in the front-rear direction.

[0006] In some embodiments of the present invention, side plates are provided on both sides of the contact assembly, and a moving contact cover is mounted on the two side plates.

[0007] In some embodiments of the present invention, the moving contact cover has a protrusion on one side relative to the stationary contact, and the surface of the protrusion has a serrated structure for isolating electric arc.

[0008] In some embodiments of the present invention, the upper part of the stationary contact cover and the side near the moving contact are provided with serrated end faces to reduce arcing.

[0009] In some embodiments of the present invention, the position of the moving contact when breaking is set such that the protrusion of the moving contact housing is 20-25mm away from the silver dot of the stationary contact to ensure minimum electrical distance.

[0010] In some embodiments of the present invention, a long contact piece cover is riveted to the lower section of the long contact piece. Since the long contact piece is the last to separate from the stationary contact when breaking, the electric arc will concentrate on the long contact piece. The long contact piece cover can reduce the damage of the electric arc to the contact. The long contact piece cover can cover at least three sides of the long contact piece and the long contact piece cover extends to the maximum height of the moving contact cover, preventing the electric arc from affecting the remaining short contact pieces along the long contact piece.

[0011] In some embodiments of the present invention, a shaft is provided at the bottom of the side plate of the moving contact, and the shaft is movably engaged with the groove of the moving contact on the base through a bushing.

[0012] In some embodiments of the present invention, the moving busbar and the stationary busbar are respectively engaged in the moving busbar slot and the stationary busbar slot on the base.

[0013] In some embodiments of the present invention, the lower part of the arc-extinguishing chamber is provided with a partition guide rail, and multiple partitions are movably fitted to the partition guide rail. The maximum travel of the multiple partitions on the partition guide rail is limited by the two side walls of the base.

[0014] In some embodiments of the present invention, the top of the arc-extinguishing chamber is fixed to the upper part of the base by screws, the bottom of the arc-extinguishing chamber is provided with an arc-extinguishing chamber cover, the upper part of the long contact piece extends out of the short contact piece group, passes through the arc-extinguishing chamber cover and then through the multi-layer partition to extend into the interior of the arc-extinguishing chamber, and the long contact piece cooperates with the opening on the multi-layer partition.

[0015] The bottom of the arc-extinguishing chamber housing has a serrated bottom surface. When an electric arc is generated, it may spread along the smooth bottom surface of the arc-extinguishing chamber, causing damage to the arc-extinguishing chamber. The serrated bottom surface can prevent the electric arc from spreading.

[0016] Advantages and effects of the present invention: This invention enhances arc extinguishing efficiency and breaking reliability of circuit breakers under high voltage and high current conditions by using multi-layer partitions in the arc-extinguishing chamber to enhance air blowing arc extinguishing, placing long contact plates at the rear to increase creepage distance and reduce arc energy, and using multiple sawtooth structures to block arcing. It also features a dedicated housing to protect the contacts and ensure minimum electrical safety distance. At the same time, the precise coordination and stable movement of each component with the base significantly improve the arc extinguishing efficiency and breaking reliability of circuit breakers under high voltage and high current conditions, effectively avoids breakdown, arcing, and difficulty in breaking, and extends the service life of circuit breakers.

[0017] Specifically, it includes: 1. Significantly improved arc extinguishing efficiency: The multi-layered partitions in the arc extinguishing chamber are driven by long contact plates to form a relatively sealed space, which enhances the air blowing effect and can quickly guide the electric arc into the arc extinguishing chamber. The arc is then extinguished by the arc extinguishing grid plates through cutting and cooling, effectively solving the problem of the difficulty in breaking the electric arc under high voltage and high current.

[0018] 2. Reduce arc energy and optimize arc extinguishing speed: The long contact plate adopts a top rearward design, which increases the creepage distance, reduces arc energy, and speeds up arc extinguishing. It also reduces the travel of the multi-layer partition, avoids collision between the partition and the inner wall of the base, and ensures the stable operation of the structure.

[0019] 3. Effectively blocks arcing and reduces component damage: Through the serrated structure of the protruding part of the moving contact cover, the serrated end face of the stationary contact cover, and the serrated bottom face of the arc-extinguishing chamber cover, arcing is blocked at multiple points, reducing the damage of the arc to the arc-extinguishing chamber and contacts.

[0020] 4. Enhanced contact protection and extended service life: The long contact sheet cover covers at least three sides of the long contact sheet and extends to the maximum height of the moving contact sheet cover, preventing the arc from spreading along the long contact sheet and damaging the short contact sheet, thus providing targeted protection for the core contact assembly.

[0021] 5. Ensure electrical safety distance: When the moving contact breaks, the protruding part of the moving contact cover should maintain a distance of 20-25mm from the silver point of the stationary contact to meet the minimum electrical distance requirement and improve the operating safety of the circuit breaker.

[0022] 6. Reliable structural assembly and optimized overall performance: The moving / stationary busbars, contact assemblies, arc-extinguishing chambers and other components adopt a precise matching structure with the base using slots, bushings, guide rails, etc., ensuring stable assembly and smooth movement, which greatly improves the breaking reliability and overall performance of the circuit breaker in high-voltage and high-current scenarios. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the circuit breaker of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the long contact piece of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the moving contact of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the stationary contact of the present invention.

[0027] Figure 5 This is a schematic diagram of the arc-extinguishing chamber of the present invention.

[0028] Figure 6 This is a schematic diagram of the assembly of the long contact piece and the multi-layer partition plate of the present invention.

[0029] Figure 7 This is a schematic diagram of the structure of the base of the present invention.

[0030] In the diagram, 1 is the arc-extinguishing chamber; 2 is the moving contact; 3 is the stationary contact; 4 is the base; 11 is the partition rail; 12 is the serrated bottom surface; 21 is the moving contact support; 22 is the side plate; 23 is the moving contact cover; 24 is the long contact piece; 25 is the short contact piece; 26 is the flexible connection; 27 is the moving busbar; 28 is the shaft; 241 is the long contact piece cover; 31 is the stationary contact cover; 32 is the stationary busbar; 41 is the multi-layer partition; 42 is the moving busbar slot; and 43 is the stationary busbar slot. Detailed Implementation

[0031] 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, not all, of the embodiments of the present invention. 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.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this invention, the terms "first" and "second" are used only to distinguish similar components / parts in different positions or with different characteristics, and have no other limiting meaning; "upper" refers to the direction in which each component is away from the ground, and "lower" refers to the direction in which each component is away from the ground.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] This invention provides a circuit breaker, comprising: a base 4; an arc-extinguishing chamber 1, installed on the upper part of the base 4, wherein multiple partitions 41 are movably fitted inside the arc-extinguishing chamber 1; and a moving contact 2, comprising a moving contact support 21 fixed to one side of the lower part of the base 4 and a contact assembly disposed within the moving contact support 21, wherein the contact assembly comprises a group of short contact pieces 25 arranged in a straight line to form a short contact piece group and a long contact piece 24 inserted into the short contact piece group, wherein the lower parts of the long contact piece 24 and the short contact piece group are connected to a moving busbar 27 via a flexible connection 26, and the moving busbar 27 is also fitted to the base 4; simultaneously The upper part of the long contact piece 24 extends out of the short contact piece group, passes through the multi-layer partition 41, and extends into the interior of the arc-extinguishing chamber 1. The long contact piece 24 can carry the multi-layer partition 41 to move horizontally. The multi-layer partition 41 is driven by the long contact piece 24 to move back and forth along the guide rail, forming a relatively sealed space, which enhances the air blowing effect and allows the electric arc to be introduced into the arc-extinguishing chamber 1 for cutting, cooling, and extinguishing. The stationary contact 3 is located on the other side of the lower part of the base 4 and is opposite to the moving contact 2. It includes a stationary busbar 32 that cooperates with the base 4 and a stationary contact cover 31 that connects to the stationary busbar 32, reducing the damage of the electric arc to the stationary contact 3.

[0036] This circuit breaker is designed with "efficient arc extinguishing, improved electrical safety and structural stability" as its core objectives. Through the coordinated optimization of the arc extinguishing chamber 1, moving contact 2, stationary contact 3, and base 4, it specifically addresses industry pain points such as incomplete arc extinguishing, easy damage to components by electric arc, and insufficient electrical clearance in traditional circuit breakers. The linkage design of the multi-layer partition 41 and the long contact piece 24 can dynamically form a sealed air-blowing space, significantly improving the efficiency of arc cooling and extinguishing. The moving contact assembly adopts a combination structure of long contact piece 24 and short contact piece group, taking into account both conductivity and arc extinguishing specificity. The setting of the soft connection 26 ensures continuity of conductivity and can adapt to contact movement deformation. The protective design of the stationary contact cover 31 and the moving contact cover 23 forms a multi-layer arc isolation barrier, reducing the erosion of core components by electric arc and extending the service life of the circuit breaker. The overall structure is compact and easy to install, adapting to the breaking requirements of various power systems.

[0037] In some embodiments, such as Figure 2As shown, the upper and lower sections of the long contact piece 24 are connected by a bend to form a Z-shaped structure. The upper section of the long contact piece 24 is positioned rearward (i.e., close to the rear side of the multi-layer partition 41) to increase the creepage distance, reduce arc energy, and extinguish the arc more quickly. This rearward design of the top of the long contact piece 24 extends the arc's creepage path, increasing the creepage distance compared to a traditional flush design, effectively reducing the risk of arc breakdown. It also disperses the energy density in the concentrated arc area, reducing arc erosion on the contact surface. Furthermore, since the arc extinguishing chamber 1 contains a multi-layer partition 41 driven by the long contact piece 24, positioning the top of the long contact piece 24 rearward shortens the maximum travel of the multi-layer partition 41, preventing rigid collisions between the multi-layer partition 41 and the inner wall of the base 4 in the front-rear direction. This reduces component vibration and noise, decreases wear on the partition edges, and ensures smooth partition movement and stable air-blowing effect.

[0038] In some embodiments, side plates 22 are respectively provided on both sides of the contact assembly, and moving contact covers 23 are mounted on the two side plates 22. The side plates 22 adopt a symmetrical clamping design, which forms a bidirectional limit for the short contact piece group and the long contact piece 24, effectively improving the overall rigidity of the contact assembly, avoiding contact displacement caused by electromagnetic force during opening and closing, and ensuring precise docking of the moving contact 2 and the stationary contact 3; the moving contact covers 23 on the top of the two side plates 22 form an integrated protective structure with the side plates 22, which can prevent external dust and impurities from entering the interior of the contact assembly, avoiding poor contact, and at the same time providing stable support for the subsequent installation of the protrusions, enhancing the arc isolation effect.

[0039] In some embodiments, the moving contact housing 23 has a protrusion on one side relative to the stationary contact 3. The surface of the protrusion has a serrated structure to isolate the electric arc. The extended design of the protrusion can further increase the distance between the electric arc and the root of the contact during breaking, forming multiple arc barriers in conjunction with the serrated surface: the serrated structure increases the contact area between the electric arc and the housing surface, accelerates the dissipation of arc heat, and disrupts the continuous conduction path of the arc, thus dispersing and consuming arc energy and preventing the arc from concentrating and burning the contact or housing; this structure works synergistically with the air blowing effect of the arc-extinguishing chamber 1 to quickly guide the arc into the arc-extinguishing chamber 1, shorten the arc extinguishing time, and improve the breaking capacity of the circuit breaker.

[0040] In some embodiments, the upper part of the stationary contact housing 31 and the side near the moving contact 2 are provided with serrated end faces to reduce arcing. The serrated end faces of the stationary contact housing 31 can adopt an equally spaced tooth design, which can effectively disrupt the continuous path of the arc crawling along the end face, increase the surface creep resistance of the arc, and reduce the probability of arcing. At the same time, the serrated end faces can guide the arc to deflect towards the arc-extinguishing chamber 1, preventing the arc from bypassing the contact area and burning the base 4 or other insulating components, thus ensuring the insulation performance and operational safety of the circuit breaker.

[0041] In some embodiments, the position of the moving contact 2 during disconnection is set such that the distance between the protrusion of the moving contact housing 23 and the silver dot of the stationary contact 3 is 20-25mm to ensure a minimum electrical distance. This distance range strictly adheres to electrical safety standards. The 20-25mm spacing effectively prevents flashover caused by voltage breakdown during disconnection, ensuring reliable insulation under rated voltage and transient overvoltage conditions. Simultaneously, this spacing design takes into account the travel distance of the moving contact 2, avoiding an increase in the overall size of the circuit breaker due to excessive distance, thus achieving structural miniaturization while ensuring safety.

[0042] In some embodiments, the lower section of the long contact piece 24 is riveted with a long contact piece cover 241. Since the long contact piece 24 is the last to separate from the stationary contact 3 when the circuit breaks, the electric arc will concentrate on the long contact piece 24, and the long contact piece cover 241 can reduce the damage of the electric arc to the contacts. The riveting method has the advantages of strong connection and convenient disassembly and assembly, which can ensure that the long contact piece cover 241 will not fall off during long-term opening and closing vibrations. The long contact piece cover 241 adopts a U-shaped wrapping structure, which can cover at least three surfaces of the long contact piece 24: the front, back and side, forming full-circuit protection. Its design extending to the maximum height of the moving contact cover 23 can build a complete arc isolation barrier, preventing the electric arc from being conducted along the surface of the long contact piece 24 to the short contact piece group, preventing the short contact piece 25 from being burned and deformed by the electric arc, and ensuring the conductivity stability and service life of the contact assembly.

[0043] In some embodiments, a shaft 28 is provided at the bottom of the side plate 22 of the moving contact 2. The shaft 28 is movably engaged with the moving contact groove on the base 4 via a bushing. The engagement between the shaft 28 and the bushing adopts a low friction coefficient design. The bushing is preferably made of wear-resistant nylon, which reduces the movement resistance of the moving contact 2 when opening and closing, making the operation smoother and more sensitive. The arc-shaped structure of the moving contact groove is precisely matched with the shaft 28, strictly limiting the movement trajectory of the moving contact 2, ensuring the docking accuracy between the moving contact 2 and the stationary contact 3 when opening and closing, and avoiding poor contact or arcing caused by trajectory deviation. At the same time, the buffering effect of the bushing can absorb the impact of movement, reduce component vibration and noise, and improve the stability of circuit breaker operation.

[0044] In some embodiments, the moving busbar 27 and the stationary busbar 32 are respectively snapped into the moving busbar slot 42 and the stationary busbar slot 43 on the base 4. The snap-fit ​​fixing structure requires no additional fasteners, improving installation efficiency. Furthermore, the limiting protrusions of the moving busbar slot 42 and the stationary busbar slot 43 precisely match the limiting holes of the corresponding busbars, preventing the moving busbar 27 and the stationary busbar 32 from shifting due to vibration during operation, thus ensuring the stability of the conductive path. The inner wall of the slot adopts an anti-slip texture design, increasing the contact friction between the busbar and the slot, further improving the connection reliability. At the same time, the snap-fit ​​structure facilitates quick disassembly and assembly of the busbars during later maintenance, reducing maintenance costs.

[0045] In some embodiments, the lower part of the arc-extinguishing chamber 1 is provided with a partition guide rail 11, and the multi-layer partition 41 is movably fitted to the partition guide rail 11. The maximum travel of the multi-layer partition 41 on the partition guide rail 11 is limited by the two side walls of the base 4. The partition guide rail 11 adopts a parallel double-rail design, which is precisely matched with the sliding grooves on both sides of the multi-layer partition 41 to ensure the straightness of the partition during movement, avoid air leakage in the sealed space caused by offset, and ensure stable air blowing pressure. The surface of the guide rail can be smoothed to reduce the frictional resistance of the multi-layer partition 41 during movement and avoid jamming. At the same time, the protruding structure of the guide rail can limit the upper and lower positions of the partition to prevent the partition from warping and deforming under the action of air blowing pressure, ensuring that the multi-layer partition 41 always remains in a parallel state, and improving the arc cutting and cooling effect.

[0046] In some embodiments, the top of the arc-extinguishing chamber 1 is fixed to the upper part of the base 4 by screws. The bottom of the arc-extinguishing chamber 1 is provided with an arc-extinguishing chamber cover. The upper part of the long contact piece 24 extends out of the short contact piece group, passes through the arc-extinguishing chamber cover, and then through the multi-layer partition 41 to extend into the interior of the arc-extinguishing chamber 1. The upper section of the long contact piece 24 mates with the opening on the multi-layer partition 41. The screw fixing method distributes the force evenly, which can ensure that the arc-extinguishing chamber 1 is firmly connected to the base 4 and avoid loosening due to vibration during operation. The arc-extinguishing chamber cover is made of high-temperature resistant insulating material, which can not only isolate the high-temperature arc inside the arc-extinguishing chamber 1 and protect the external components from heat damage, but also guide and position the long contact piece 24 to ensure its precise fit with the opening of the multi-layer partition 41. The gap between the long contact piece 24 and the partition opening can be adjusted as needed, which can reduce the amount of air leakage during the air blowing process, improve the air blowing efficiency of the sealed space, and accelerate the extinction of the arc.

[0047] In some embodiments, the bottom of the arc-extinguishing chamber housing is provided with a serrated bottom surface 12. When an electric arc is generated, it may spread along the smooth surface at the bottom of the arc-extinguishing chamber 1, causing damage to the arc-extinguishing chamber 1. The serrated bottom surface 12 can block the arc spreading. The tooth shape of the serrated bottom surface 12 corresponds to the serrated end face of the stationary contact housing 31. A three-dimensional arc blocking network is constructed through a multi-serrated structure, further improving the anti-arc spreading effect. The tooth tips of the serrated bottom surface 12 adopt a rounded transition design to avoid local breakdown caused by concentrated electric field at the tip. At the same time, it facilitates the rapid detachment of the arc from the housing surface and entry into the arc-extinguishing chamber 1. This structure can effectively reduce arc spreading damage at the bottom of the arc-extinguishing chamber 1 and significantly extend the service life of the arc-extinguishing chamber 1.

[0048] In some embodiments, the flexible connection 26 can adopt a multi-layer copper foil stacked structure, which not only ensures conductivity but also has good flexibility. It can fully absorb the deformation of the long contact piece 24 and the short contact piece group during the movement process, and avoid conductive breakage or poor contact caused by rigid connection. The two ends of the flexible connection 26 are connected to the contact assembly and the moving busbar 27 respectively by crimping. The crimping surface is tin-plated to reduce contact resistance, improve conductivity stability, and reduce heat loss.

[0049] In some embodiments, the design of the multi-layer partition 41 allows the electric arc to form multiple cuts between the partitions, accelerating the cooling of the electric arc. The material of the multi-layer partition 41 is preferably a melamine rigid laminate. The edges of the multi-layer partition 41 are provided with a wear-resistant coating to reduce friction and wear with the partition guide rail 11 and extend its service life.

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A circuit breaker, characterized in that, include: Base; An arc-extinguishing chamber is installed on the upper part of the base, and multiple layers of partitions are movably fitted inside the arc-extinguishing chamber. A moving contact includes a moving contact support fixed to one side of the lower part of the base and a contact assembly disposed within the moving contact support. The contact assembly includes a group of short contact pieces formed by multiple linearly arranged short contact pieces and a long contact piece inserted into the short contact piece group. The lower parts of the long contact piece and the short contact piece group are connected to a moving busbar via a flexible connection, and the moving busbar also fits into the base. Simultaneously, the upper part of the long contact piece extends beyond the short contact piece group, passes through the multiple layers of partitions, and extends into the interior of the arc-extinguishing chamber. The long contact piece can carry the multiple layers of partitions for horizontal movement. A stationary contact is disposed on the other side of the lower part of the base and opposite to the moving contact, including a stationary busbar fitted into the base and a stationary contact cover connected to the stationary busbar.

2. The circuit breaker according to claim 1, characterized in that, The contact assembly has side plates on both sides, and a moving contact cover is mounted on the two side plates.

3. The circuit breaker according to claim 2, characterized in that, The moving contact cover has a protrusion on one side relative to the stationary contact, and the surface of the protrusion has a serrated structure.

4. The circuit breaker according to claim 3, characterized in that, The upper part of the stationary contact cover and the side near the moving contact are both provided with serrated end faces.

5. The circuit breaker according to claim 4, characterized in that, The position of the moving contact during disconnection is set such that the protrusion of the moving contact housing is 20-25mm away from the silver dot of the stationary contact to ensure minimum electrical distance.

6. The circuit breaker according to claim 2, characterized in that, The lower section of the long contact piece is riveted with a long contact piece cover, which extends to the maximum height of the moving contact piece cover and can cover at least three sides of the long contact piece.

7. The circuit breaker according to claim 2, characterized in that, The bottom of the side plate of the moving contact is provided with a shaft, which is movably engaged with the groove of the moving contact on the base through a bushing.

8. The circuit breaker according to claim 1, characterized in that, The moving busbar and the stationary busbar are respectively engaged in the moving busbar slot and the stationary busbar slot on the base.

9. The circuit breaker according to claim 1, characterized in that, The lower part of the arc-extinguishing chamber is provided with a partition guide rail, and multiple partitions are movably fitted to the partition guide rail. The maximum travel of the multiple partitions on the partition guide rail is limited by the two side walls of the base.

10. The circuit breaker according to claim 6 or 9, characterized in that, The upper and lower sections of the long contact piece are connected by a bend to form a Z-shaped structure, with the upper section of the long contact piece positioned towards the rear. The bottom of the arc-extinguishing chamber is provided with an arc-extinguishing chamber cover. The upper part of the long contact piece extends beyond the short contact piece group, passes through the arc-extinguishing chamber cover, and then through multiple layers of partitions to extend into the interior of the arc-extinguishing chamber. The upper section of the long contact piece mates with the openings on the multiple layers of partitions. The bottom of the arc-extinguishing chamber cover is provided with a serrated bottom surface.

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