A small reclosing circuit breaker with high arc extinguishing efficiency

Abstract

The application relates to the technical field of circuit breakers, and discloses a small reclosing circuit breaker capable of efficiently extinguishing arc, which comprises a shell, a static contact is arranged in the shell, a rotating structure is arranged in the shell, a dynamic contact is arranged on the rotating structure, the rotating structure is used for realizing separation or abutment of the dynamic contact and the static contact, the dynamic contact comprises an abutment part and a connecting part, the abutment part is arranged on the connecting part, the connecting part is arranged on the rotating structure, a plastic sleeve is arranged on the connecting part, and the plastic sleeve separates the arc generated when the dynamic contact and the static contact are separated from the rotating structure.

Description

Technical Field

[0001] This application relates to the technical field of circuit breakers, and in particular to a small reclosing circuit breaker with efficient arc extinguishing capability. Background Technology

[0002] In power distribution networks, when an overhead line trips due to a transient fault, the insulation at the fault point can often recover on its own. In this case, the power supply can be restored by an automatic reclosing circuit breaker in a short time. This method is called reclosing. Miniature reclosing circuit breakers have become key equipment for realizing the self-restoration of power supply of lines due to their compact size and ease of integration into the distribution terminal.

[0003] The related circuit breaker includes a housing, a stationary contact inside the housing, a rotating structure inside the housing, a moving contact on the rotating structure, the rotating structure is used to drive the moving contact to rotate, the moving contact is used to abut against the stationary contact to realize circuit connection, and an arc-extinguishing chamber is provided inside the housing.

[0004] Due to the constraints of miniaturization design, the isolation space between the arc-extinguishing chamber and the rotating structure is extremely limited. When the moving and stationary contacts interrupt the current, although part of the arc is guided into the arc-extinguishing chamber, some of the arc may still spread towards the area of ​​the rotating structure. The high-temperature arc directly erodes the rotating parts such as the shaft and connecting rod, as well as their insulating supports, leading to insulation deterioration, jamming of the mechanism, or even deformation. This seriously affects the reliability of the circuit breaker's opening and closing, and consequently causes the reclosing function to fail or significantly shortens the equipment's lifespan. Summary of the Invention

[0005] To address the issue of arc propagation towards rotating structures, this application provides a small reclosing circuit breaker capable of efficiently extinguishing arcs.

[0006] This application provides a small reclosing circuit breaker with high-efficiency arc extinguishing capability, which adopts the following technical solution: A small reclosing circuit breaker with efficient arc extinguishing capability includes a housing, a stationary contact inside the housing, a rotating structure inside the housing, and a moving contact on the rotating structure. The rotating structure is used to separate or engage the moving contact and the stationary contact. The moving contact includes an engaging portion and a connecting portion. The engaging portion is disposed on the connecting portion, and the connecting portion is disposed on the rotating structure. A plastic sleeve is fitted on the connecting portion. When the moving contact and the stationary contact are separated, an electric arc is generated and the rotating structure is engaged.

[0007] By adopting the above technical solution, a plastic sleeve is fitted onto the connection part of the moving contact, physically separating the electric arc generated when the moving contact separates from the stationary contact from the rotating structure. When the electric arc is generated and spreads towards the rotating structure area, the plastic sleeve forms a barrier, effectively preventing the high-temperature electric arc from directly eroding the shaft, connecting rod, and other components and their insulating supports in the rotating structure. This avoids insulation degradation, mechanism jamming, or deformation caused by arc erosion, thereby ensuring the reliability of the opening and closing actions, making the reclosing function effective for a long time, and significantly extending the service life of the equipment.

[0008] Optionally, a limiting groove is provided on one side of the connecting part, and a limiting block is provided on the plastic sleeve. When the limiting block is located in the limiting groove, the plastic sleeve is fixed at the connecting part.

[0009] By adopting the above technical solution, the plastic sleeve can be reliably positioned circumferentially and axially on the connection part through the cooperation of the limiting groove and the limiting block, preventing the plastic sleeve from shifting or falling off under the vibration of the circuit breaker operation or the impact of the electric arc, and ensuring that the plastic sleeve is always stably maintained in the protective position between the electric arc and the rotating structure, thus maintaining its arc extinguishing and isolation effect.

[0010] Optionally, a groove is provided on the side of the connecting part away from the limiting groove, and the groove is for the limiting block to be inserted; when the limiting block in the plastic sleeve rotates from the limiting groove into the groove, the axial fixed position of the plastic sleeve on the connecting part is changed.

[0011] By adopting the above technical solution, a groove is added to the other side of the connecting part, allowing the plastic sleeve to rotate so that the limiting block moves from the limiting groove into the groove, thereby changing the axial fixed position of the plastic sleeve on the connecting part. This gives the plastic sleeve at least two different positioning points, allowing the coverage area of ​​the plastic sleeve to be adjusted or easily disassembled and assembled according to actual needs, improving the flexibility of protection for the rotating structure, and adapting to different assembly or maintenance conditions.

[0012] Optionally, the plastic sleeve includes a first part and a second part, the second part being slidably disposed on the first part along the axial direction, the second part being provided with a movable strip, the first part being provided with an annular groove for the movable strip to slide, the limiting block being disposed on the second part, and the second part having elastic deformation capability; when the limiting block is located in the groove, the movable strip abuts against the groove wall of the annular groove.

[0013] By adopting the above technical solution, when the axial position changes due to the switching of the limiting block from the limiting groove to the recess, the second part can adapt its position change by sliding. At the same time, the elastic deformation capability of the second part is used to make the movable strip press against the wall of the annular groove, eliminating the fit gap between the components. In this way, after adjustment and positioning, an elastic locking can be formed, effectively suppressing loosening caused by vibration and arcing force, and further ensuring the long-term reliable fixation of the plastic sleeve.

[0014] Optionally, the distance between the groove and the rotating structure is less than the distance between the limiting groove and the rotating structure, and the distance between the inner walls of the opposite sides of the annular groove gradually decreases along the direction from the abutment to the connection; when the limiting block is located in the groove, the movable strip abuts against the groove wall of the annular groove.

[0015] By adopting the above technical solution, when the limiting block enters the groove, the movable strip of the second part is gradually pressed tight by the conical groove wall of the annular groove, achieving wedge self-locking. This structure allows the plastic sleeve to automatically generate a fastening force after being adjusted to a position close to the rotating structure, becoming tighter with use, greatly enhancing its resistance to loosening and ensuring protective stability under extreme working conditions.

[0016] Optionally, a chip guide groove is formed on the outer surface of the connecting part, the chip guide groove is spirally arranged along the circumference of the connecting part, and a chip guide block is provided inside the plastic sleeve for inserting into the chip guide groove; when the plastic sleeve rotates, the chip guide block is used to push the impurities in the chip guide groove.

[0017] By adopting the above technical solution, when the rotating plastic sleeve is used for position switching or maintenance, the chip guide block moves along the spiral groove, which can actively push out impurities such as contact wear debris and arc erosion carbon deposits along the chip guide groove. This achieves automatic cleaning of the connection area, avoids the accumulation of impurities that may cause the rotating structure to jam or the insulation to deteriorate, and improves long-term operational reliability.

[0018] Optionally, the housing is provided with an arc-extinguishing chamber, which is located on the side of the moving contact away from the rotating structure. The end face of the plastic sleeve away from the rotating structure is provided with a gas guiding surface. The gas guiding surface is arc-shaped and concave in the direction away from the arc-extinguishing chamber, so that the gas generated by the electric arc can flow along the gas guiding surface in the direction of the arc-extinguishing chamber.

[0019] By adopting the above technical solution, when the moving contact separates from the stationary contact and generates an arc, the high-temperature gas generated by the arc impacts the concave arc surface and deflects along the wall, effectively guiding and accelerating its flow towards the arc-extinguishing chamber. This, on the one hand, promotes faster entry of the arc and hot gas into the arc-extinguishing chamber for cooling and deionization, significantly improving arc-extinguishing efficiency; on the other hand, the directional airflow inhibits the diffusion of high-temperature gas into the rotating structure area, further enhancing the thermal protection of the rotating components by the plastic sleeve, preventing insulation degradation and mechanism jamming, and ensuring the long-term reliable opening and closing of the circuit breaker.

[0020] Optionally, the distance between the two opposite surfaces of the connecting portion gradually increases along the direction from the abutment portion to the connecting portion, the inner diameter of the plastic sleeve is the same as the outer diameter of the abutment portion, and the plastic sleeve has a certain elastic deformation capability.

[0021] By adopting the above technical solution, during installation, the plastic sleeve can be smoothly inserted from the smaller abutment end and elastically expanded as it is pushed towards the larger connecting part, ultimately clamping tightly onto the connecting part to form an interference fit. This method is convenient to install, requires no additional fasteners, and can automatically adapt to the changing diameter of the connecting part, achieving long-term stable assembly and effectively withstanding the impact of opening and closing.

[0022] In summary, this application includes at least one of the following beneficial technical effects: By sleeved with a plastic sleeve on the connection of the moving contact, the plastic sleeve physically separates the electric arc generated when the moving contact separates from the stationary contact from the rotating structure. When the electric arc is generated and spreads to the rotating structure area, the plastic sleeve forms a barrier, effectively preventing the high-temperature electric arc from directly eroding the shaft, connecting rod, and other components and their insulating supports in the rotating structure. This avoids insulation deterioration, mechanism jamming, or deformation caused by arc erosion, thereby ensuring the reliability of the opening and closing actions, making the reclosing function effective for a long time, and significantly extending the service life of the equipment.

[0023] When the limiting block enters the groove, the movable strip of the second part is gradually pressed tight by the conical groove wall of the annular groove, achieving wedge self-locking. This structure allows the plastic sleeve to automatically generate a tightening force after being adjusted to a position close to the rotating structure, becoming tighter with use, greatly enhancing its resistance to loosening and ensuring protective stability under extreme working conditions. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application; Figure 2 yes Figure 1 An enlarged schematic diagram of part A in the middle; Figure 3 This is a schematic diagram of the structure of Embodiment 2 of this application; Figure 4 This is a schematic diagram of the structure of the plastic sleeve in Embodiment 2 of this application; Figure 5 This is an exploded schematic diagram highlighting the moving contact in Embodiment 2 of this application; Figure 6 This is a schematic diagram of the structure of the chip guide block in Embodiment 2 of this application.

[0025] Reference numerals: 1. Housing; 11. Stationary contact; 12. Rotating structure; 13. Arc extinguishing chamber; 14. Moving contact; 141. Abutting part; 142. Connecting part; 143. Limiting groove; 144. Groove; 145. Chip guide groove; 2. Plastic sleeve; 21. Limiting block; 22. First part; 23. Second part; 24. Annular groove; 241. Movable strip; 25. Chip guide block; 26. Air guide surface. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-6 This application will be described in further detail. Example

[0027] This embodiment discloses a small reclosing circuit breaker capable of efficient arc extinguishing. (Refer to...) Figure 1 A small reclosing circuit breaker with efficient arc extinguishing capability includes a housing 1. Inside the housing 1 are a stationary contact 11, a rotating structure 12, and an arc-extinguishing chamber 13. A moving contact 14 is fixedly connected to the rotating structure 12, which is used to drive the moving contact 14 to contact or separate from the stationary contact 11. The arc-extinguishing chamber 13 is located on the side of the stationary contact 11 away from the rotating structure 12. When the moving contact 14 separates from the stationary contact 11, the resulting arc can move towards the arc-extinguishing chamber 13, allowing the arc-extinguishing chamber 13 to extinguish the arc.

[0028] Reference Figure 1 and Figure 2 The moving contact 14 includes an abutting portion 141 and a connecting portion 142. The abutting portion 141 is integrally formed on the connecting portion 142, and the connecting portion 142 is integrally formed on the surface of the rotating structure 12. The abutting portion 141 is used to abut the stationary contact 11. A plastic sleeve 2 is fitted onto the moving contact 14, and the plastic sleeve 2 can be fitted onto the connecting portion 142. The plastic sleeve 2 can separate the electric arc generated when the moving contact 14 and the stationary contact 11 are separated from the rotating structure 12, making it difficult for the electric arc to affect the rotating structure 12.

[0029] Reference Figure 1 and Figure 2 A limiting groove 143 is formed on the surface of the connecting part 142 facing the stationary contact 11. The limiting groove 143 is arc-shaped. A limiting block 21 is integrally formed on the inner wall of the plastic sleeve 2. The limiting block 21 protrudes away from the stationary contact 11 and can be inserted into the limiting groove 143. When the limiting block 21 is located in the limiting groove 143, the plastic sleeve 2 is fixed in position to the connecting part 142.

[0030] The implementation principle of Example 1 is as follows: by isolating the electric arc with the plastic sleeve 2, the electric arc is less likely to affect the rotating structure 12. Example

[0031] Reference Figure 3 and Figure 4 The difference between this embodiment and embodiment 1 is that the rotating structure 12 is provided with two moving contacts 14, both of which are used to abut against the stationary contact 11.

[0032] Reference Figure 5 A plastic sleeve 2 is provided on the moving contact 14. The plastic sleeve 2 can be fitted onto the position of the connecting part 142. The plastic sleeve 2 has a certain elastic deformation capability.

[0033] Reference Figure 5The distance between the two opposite surfaces of the connecting part 142 gradually increases along the direction from the abutting part 141 to the connecting part 142. The inner diameter of the plastic sleeve 2 is the same as the outer diameter of the abutting part 141. That is, when the plastic sleeve 2 is fitted onto the connecting part 142, the plastic sleeve 2 undergoes elastic deformation, thereby fixing the plastic sleeve 2 to the moving contact 14.

[0034] Reference Figure 5 The plastic sleeve 2 includes a first part 22 and a second part 23, with the second part 23 slidably disposed on the first part 22 along the axial direction. A limiting block 21 is integrally formed on the inner wall of the second part 23. An annular groove 24 is formed on the end face of the first part 22, extending circumferentially along the first part 22, and the distance between the annular groove 24 and the inner walls on both sides gradually decreases along the direction from the second part 23 to the first part 22. A movable strip 241 is integrally formed on the end face of the second part 23, and the movable strip 241 can slide within the annular groove 24.

[0035] Reference Figure 5 A groove 144 is formed on the surface of the connecting part 142 away from the limiting groove 143, and the limiting block 21 is inserted into the groove 144. Due to the arrangement of the two moving contacts 14, the plastic sleeve 2 is square or similar to a square structure, and the plastic sleeve 2 can rotate at the connecting part 142. The distance between the groove 144 and the rotating structure 12 is less than the distance between the limiting groove 143 and the rotating structure 12.

[0036] Reference Figure 5 The operator manually rotates the second part 23, allowing the limiting block 21 to move from the limiting groove 143 into the groove 144. The limiting block 21 is positioned within the groove 144, enabling the other side of the second part 23 away from the limiting block 21 to be positioned on the side of the arc facing the rotating structure 12. This changes the axial fixed position of the plastic sleeve 2 on the connecting part 142, allowing the other side of the second part 23 to continue isolating the arc. At this time, the operator needs to press the second part 23 towards the first part 22, causing the movable strip 241 to press against the groove wall of the annular groove 24, further reinforcing the stability of the second part 23 within the first part 22.

[0037] Reference Figure 5 and Figure 6 A chip guide groove 145 is formed on the outer surface of the connecting part 142, and the chip guide groove 145 is spirally arranged circumferentially along the connecting part 142. A chip guide block 25 is integrally formed on the inner wall of the second part 23, and the chip guide block 25 is used to insert into the chip guide groove 145. When the plastic sleeve 2 is ablated by an electric arc, some impurities will be generated in the plastic sleeve 2, and the impurities will accumulate in the chip guide groove 145. When the second part 23 rotates, the chip guide block 25 can push the impurities in the chip guide groove 145 to facilitate the subsequent disassembly of the plastic sleeve 2 and the cleaning of the impurities.

[0038] Reference Figure 5The second part 23 has a gas guiding surface 26 on its end face away from the first part 22. The gas guiding surface 26 surrounds the second part 23 in a circumferential direction and is arc-shaped. The gas guiding surface 26 is concave towards the first part 22 to facilitate the flow of gas towards the arc-extinguishing chamber 13. When an electric arc is generated, some gas is generated simultaneously. The gas can flow along the gas guiding surface 26 towards the arc-extinguishing chamber 13, allowing the gas to propel the electric arc towards the arc-extinguishing chamber 13.

[0039] The implementation principle of Example 2 is as follows: When the plastic sleeve 2 is burned by the electric arc, the staff needs to manually rotate the second part 23 to move the limiting block 21 from the limiting groove 143 to the groove 144, and then press the second part 23 so that the second part 23 and the first part 22 can be fixed to each other, so that the unburned part of the second part 23 can be located between the electric arc and the rotating structure 12.

[0040] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the design concept of this application should be included within the protection scope of this application.

Claims

1. A small reclosing circuit breaker with efficient arc extinguishing capability, comprising a housing (1), wherein a stationary contact (11) is provided inside the housing (1), and a rotating structure (12) is provided inside the housing (1), wherein a moving contact (14) is provided on the rotating structure (12), and the rotating structure (12) is used to realize the separation or contact between the moving contact (14) and the stationary contact (11), characterized in that: The moving contact (14) includes an abutting part (141) and a connecting part (142). The abutting part (141) is disposed on the connecting part (142), and the connecting part (142) is disposed on the rotating structure (12). A plastic sleeve (2) is sleeved on the connecting part (142). The plastic sleeve (2) separates the moving contact (14) and the stationary contact (11) from generating an electric arc and rotating structure (12) when they are separated.

2. The miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 1, characterized in that: A limiting groove (143) is provided on one side of the connecting part (142), and a limiting block (21) is provided on the plastic sleeve (2). When the limiting block (21) is located in the limiting groove (143), the plastic sleeve (2) is fixed at the connecting part (142).

3. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 2, characterized in that: The connecting part (142) has a groove (144) on the side away from the limiting groove (143), and the groove (144) is for the limiting block (21) to be inserted; when the limiting block (21) in the plastic sleeve (2) rotates from the limiting groove (143) into the groove (144), the axial fixed position of the plastic sleeve (2) on the connecting part (142) is changed.

4. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 3, characterized in that: The plastic sleeve (2) includes a first part (22) and a second part (23). The second part (23) is slidably disposed on the first part (22) along the axial direction. The second part (23) is provided with a movable strip (241). The first part (22) is provided with an annular groove (24) for the movable strip (241) to slide. The limiting block (21) is disposed on the second part (23). The second part (23) has elastic deformation capability. When the limiting block (21) is located in the groove (144), the movable strip (241) abuts against the groove wall of the annular groove (24).

5. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 4, characterized in that: The distance between the groove (144) and the rotating structure (12) is less than the distance between the limiting groove (143) and the rotating structure (12). The distance between the inner walls of the opposite sides of the annular groove (24) gradually decreases along the direction from the abutment part (141) to the connecting part (142). When the limiting block (21) is located in the groove (144), the movable strip (241) abuts against the groove wall of the annular groove (24).

6. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 3, characterized in that: A chip guide groove (145) is provided on the outer surface of the connecting part (142). The chip guide groove (145) is spirally arranged along the circumference of the connecting part (142). A chip guide block (25) is provided inside the plastic sleeve (2) for inserting into the chip guide groove (145). When the plastic sleeve (2) rotates, the chip guide block (25) is used to push the impurities in the chip guide groove (145).

7. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 1, characterized in that: The housing (1) is provided with an arc-extinguishing chamber (13), which is located on the side of the moving contact (14) away from the rotating structure (12). The plastic sleeve (2) has a gas guiding surface (26) on the end face away from the rotating structure (12). The gas guiding surface (26) is arc-shaped and concave in the direction away from the arc-extinguishing chamber (13). The gas generated by the electric arc can flow along the gas guiding surface (26) towards the arc-extinguishing chamber (13).

8. A miniature reclosing circuit breaker with high-efficiency arc extinguishing capability according to claim 1, characterized in that: The distance between the two opposite surfaces of the connecting part (142) gradually increases along the direction from the abutment part (141) to the connecting part (142). The inner diameter of the plastic sleeve (2) is the same as the outer diameter of the abutment part (141). The plastic sleeve (2) has a certain elastic deformation capability.

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