A cushioning device and method for a bulk circuit breaker

Abstract

The application relates to the field of circuit breakers, in particular to a buffering device and method of a large-capacity circuit breaker; the buffering device comprises a first buffering unit, a second buffering unit and a limiting unit; the buffering device comprises the first buffering unit, the second buffering unit and the limiting unit; the first buffering unit is used for contacting a moving part in a tripping spring device of the circuit breaker during tripping of the circuit breaker, so that first-stage buffering is provided; the second buffering unit is used for being oppositely arranged with a moving guide rod of an arc extinguishing chamber of the circuit breaker during tripping of the circuit breaker, so that second-stage buffering is provided; and the limiting unit is used for being in transmission cooperation with a main shaft of the circuit breaker, so that tripping movement of the circuit breaker is terminated. The buffering device can reduce impact on internal mechanical structures of the circuit breaker at the end of tripping while maintaining breaking performance, and effectively prolongs the overall service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of circuit breakers, and more specifically to a buffer device and method for a large-capacity circuit breaker. Background Technology

[0002] High-capacity circuit breakers are key protection devices in power systems. They have high requirements for tripping characteristics, especially the initial tripping speed, which is directly related to the rapid extinguishing of the arc and the reliable breaking capacity of short-circuit faults. Therefore, the industry generally pursues a high initial tripping speed.

[0003] However, while ensuring breaking capacity, a high opening speed can also cause severe impact on the internal mechanical structure of the circuit breaker. This impact can not only damage transmission components and shorten equipment life, but also easily cause overshoot and rebound at the end of the opening movement, which can interfere with the stable separation of contacts and reduce actual breaking performance and operational reliability.

[0004] To alleviate the above problems, existing technologies typically incorporate buffer devices in circuit breakers, such as hydraulic buffers, pneumatic dampers, or elastic elements installed at the end of the transmission chain or on moving parts, in order to consume some kinetic energy and reduce the impact and rebound at the end of the tripping phase.

[0005] However, existing buffering schemes often only decelerate the entire circuit at the end of the tripping phase, which is difficult to meet the two problems of high initial velocity and low end impact. If buffering is introduced too early, the velocity will be weakened and the breaking capacity will be affected; if the buffering is insufficient, the end overshoot cannot be effectively suppressed. Summary of the Invention

[0006] To address the problems mentioned in the prior art, this invention proposes a buffer device and method for a large-capacity circuit breaker. By employing multiple buffer units in coordination, the initial rapid opening and smooth stopping of the circuit breaker's opening movement are achieved, thus solving the problems in the background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The present invention provides a buffer device for a high-capacity circuit breaker, comprising a first buffer unit, a second buffer unit, and a limiting unit;

[0009] The first buffer unit is used to contact the moving parts in the circuit breaker's tripping spring device during the circuit breaker tripping process to provide buffering in the first stage.

[0010] The second buffer unit is used to be positioned opposite to the moving guide rod of the arc-extinguishing chamber of the circuit breaker during the circuit breaker tripping process, so as to provide buffering in the second stage;

[0011] The limiting unit is used to cooperate with the main shaft drive of the circuit breaker to terminate the circuit breaker's opening movement.

[0012] As a further improvement of the present invention, the first buffer unit includes a buffer spring, which is disposed on the opening spring device.

[0013] As a further improvement of the present invention, the first buffer unit further includes a washer, which is disposed between the buffer spring and the moving part in the gate spring device.

[0014] As a further improvement of the present invention, the second buffer unit includes a buffer, which is fixedly mounted on the lower support of the circuit breaker by a mounting plate; the buffer contacts the moving guide rod of the arc extinguishing chamber to achieve buffering.

[0015] As a further improvement of the present invention, the second buffer unit further includes a fixing nut, which is used to adjust the buffer stroke of the buffer.

[0016] As a further improvement of the present invention, the number of buffers is multiple, and each buffer corresponds to one phase of the circuit breaker.

[0017] As a further improvement of the present invention, the limiting unit includes a limiting screw, which contacts a roller connected to the main shaft drive.

[0018] As a further improvement of the present invention, the number of limiting screws is 2 to 5.

[0019] As a further improvement of the present invention, during the circuit breaker tripping process, the first buffer unit, the second buffer unit, and the limit unit work in sequence.

[0020] This invention proposes a buffering method for large-capacity circuit breakers, based on the aforementioned buffering device for large-capacity circuit breakers, comprising the following steps:

[0021] The circuit breaker is driven to open, causing the moving guide rod of the arc-extinguishing chamber to start moving. At this time, neither the first buffer unit nor the second buffer unit participates in buffering.

[0022] When the circuit breaker trips to the first preset distance, it triggers the first buffer unit to contact the moving part in the tripping spring device and provides the first stage of buffering.

[0023] When the circuit breaker trips to the second preset distance, it triggers the second buffer unit to contact the moving guide rod of the arc extinguishing chamber and provides the second stage of buffering.

[0024] When the main shaft drive of the circuit breaker rotates to the preset end position, the limit unit is triggered to contact the main shaft drive to terminate the circuit breaker's opening movement.

[0025] Compared with the prior art, the present invention achieves the following technical effects:

[0026] The buffer device of this invention, through a segmented buffer design, fundamentally solves the requirements of high initial opening speed and low final impact for large-capacity circuit breakers. Specifically, by setting a first buffer unit, a second buffer unit, and a limit unit, the decoupling and coordinated control of the opening process are successfully achieved. In the initial stage of opening, the first buffer unit, the second buffer unit, and the limit unit do not work, thus achieving a high initial opening speed and ensuring the arc breaking capacity of the circuit breaker. Subsequently, the first buffer unit intervenes at a first preset position to reduce the opening kinetic energy. Then, the second buffer unit intervenes to further dissipate the remaining opening kinetic energy, reducing the opening speed to a safe range. Finally, the limit unit is used to achieve mechanical stopping, completing the opening operation. The entire process allows the circuit breaker to maintain its breaking performance while reducing the impact on the internal mechanical structure of the circuit breaker at the end of the opening, effectively extending the overall life of the equipment.

[0027] The first buffer unit of this invention includes a buffer spring and a washer, which is simple and reliable in structure and realizes the control of the buffer starting point. The washer ensures that the buffer spring contacts the moving part in the opening spring device after the circuit breaker reaches the first preset distance, thereby ensuring that the opening speed is not affected. The second buffer unit adopts a buffer fixed to the lower bracket, and the stroke of the buffer can be adjusted by the fixing nut, which further improves the flexibility. The damping force of the buffer can be adjusted according to the actual working conditions and buffering requirements of different circuit breaker models to achieve the best buffering effect. At the same time, configuring multiple buffers corresponding to the number of phases of the circuit breaker not only enhances the buffering reliability, but also ensures the synchronicity and smoothness of the movement of the moving contacts of each phase, improving the stability and consistency of the circuit breaker opening. In addition, the limiting unit of this invention uses a limiting screw that contacts the roller associated with the main shaft drive to terminate the circuit breaker opening movement. Multiple limiting screws can also be used to increase the buffering effect and further improve the reliability of use. Attached Figure Description

[0028] Figure 1 This is a front view of the structure of the buffer device of the present invention;

[0029] Figure 2 This is a right view of the structure of the buffer device of the present invention;

[0030] Figure 3 This is a top view of the structure of the buffer device of the present invention;

[0031] Figure 4 This is a schematic diagram of the working timing of the buffer device of the present invention.

[0032] Reference numerals in the attached diagram: 1. Operating mechanism; 2. Limiting crank arm; 3. Roller; 4. Main shaft drive; 5. Limiting screw; 6. Insulating tie rod; 7. Crank arm; 8. Connector; 9. Lower bracket; 10. Mounting plate; 11. Fixing nut; 12. Buffer; 13. Vacuum interrupter; 13.1. Interrupter moving guide rod; 14. Opening spring device; 15. Buffer spring; 16. Washer. Detailed Implementation

[0033] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, an electrical connection, or a communication 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 according to the specific circumstances.

[0037] 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 being 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 being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0039] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0040] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0041] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0042] See Figure 1 , Figure 2 and Figure 3 This embodiment proposes a buffer device for a large-capacity circuit breaker, including a first buffer unit, a second buffer unit, and a limiting unit;

[0043] The first buffer unit is used to contact the moving parts in the circuit breaker's tripping spring device 14 during the circuit breaker tripping process to provide buffering in the first stage.

[0044] The second buffer unit is configured to be positioned opposite to the moving guide rod 13.1 of the arc-extinguishing chamber of the circuit breaker during the circuit breaker tripping process, so as to provide buffering for the second stage.

[0045] The limiting unit is used to cooperate with the main shaft drive 4 of the circuit breaker to terminate the circuit breaker's opening movement.

[0046] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0047] See Figure 1 The circuit breaker in this embodiment consists of an operating mechanism 1, a main shaft drive 4, an insulating pull rod 6, a crank arm 7, a lower support 9, an arc-extinguishing chamber moving guide rod 13.1, a tripping spring device 14, etc., to complete the tripping movement of the circuit breaker.

[0048] In this embodiment, the operating mechanism 1 is the power source for the opening movement. The operating mechanism 1 is usually a mechanism composed of a spring, a connecting rod, and a tripping device. It outputs mechanical motion to the main shaft drive 4. The main shaft drive 4 is connected to a limit crank arm 2, which rotates synchronously with the main shaft drive 4. To improve contact performance and reduce wear, a roller 3 is installed at the end of the limit crank arm 2. The mechanism also includes a linkage mechanism connected to the main shaft drive 4 to convert rotational motion into linear motion. The linkage mechanism includes an insulating pull rod 6 and a crank arm 7. One end of the insulating pull rod 6 is hinged to the output arm of the main shaft drive 4, and the other end is connected to the arc-extinguishing chamber moving guide rod 13.1 through a connector 8. When the main shaft drive 4 rotates, the power is transmitted through the crank arm 7 and the insulating pull rod 6, ultimately realizing the vertical upward linear motion of the arc-extinguishing chamber moving guide rod 13.1, thereby causing the moving contact and stationary contact inside the vacuum arc-extinguishing chamber 13 to separate.

[0049] In this embodiment, the moving part inside the opening spring device 14 is the main opening spring. After the operating mechanism 1 is unlocked, the elastic potential energy stored in the opening spring device 14 is released, and the main opening spring inside it is activated. This activation ultimately acts on the main shaft drive 4 to provide continuous rotational torque.

[0050] The aforementioned components constitute the transmission chain for circuit breaker tripping, and this embodiment adds a first buffer unit, a second buffer unit, and a limit unit to this transmission chain.

[0051] The first buffer unit in this embodiment includes a buffer spring 15, which is specifically mounted on the trip spring device 14, and the axial direction of the buffer spring 15 is consistent with the movement direction of the moving part inside the trip spring device 14. In addition, a washer 16 is provided between the buffer spring 15 and the moving part in the trip spring device 14, and the thickness of the washer 16 is adjustable. Specifically, in the initial stage of tripping, the moving part of the trip spring device 14 is activated. Within the initial distance, the washer 16 ensures that there is a gap between the moving part in the trip spring device 14 and the buffer spring 15, so they are not in contact. At this time, the buffer spring 15 does not participate in the work, and only the trip spring device 14 is working. When the moving part in the trip spring device 14 is fully attached and begins to compress the washer 16 and the buffer spring 15, the first buffer unit starts to work. At this time, the reverse elastic force generated by the buffer spring 15 will offset part of the driving force of the trip spring device 14, thereby realizing the first stage of buffering.

[0052] The second buffer unit in this embodiment is a buffer 12. The buffer 12 is preferably any one of a hydraulic buffer, an oil-air hybrid buffer, or a high-performance elastomer, and can be selected according to the application scenario; for example... Figure 2 and Figure 3 As shown, the buffer 12 is mounted on the mounting plate 10, which is fixedly mounted on the lower bracket 9 of the circuit breaker using bolts and other components. In this embodiment, the lower bracket 9 is a steel structure used to support components such as the vacuum interrupter 13. In this embodiment, the buffer 12 is positioned aligned with the lower end of the moving guide rod 13.1 of the interrupter. Specifically, during the opening movement, when the moving guide rod 13.1 of the interrupter has not yet reached this position, the buffer 12 does not work. When the opening movement is in progress, and the moving guide rod 13.1 of the interrupter contacts the buffer 12 and begins to compress it, the second buffer unit starts to work. The buffer 12 generates a strong damping force through its internal medium (oil or gas), which acts directly on the moving guide rod 13.1 of the interrupter, thereby consuming the remaining opening kinetic energy and realizing the second stage of buffering.

[0053] To optimize the buffering effect, the buffer stroke of the buffer 12 is adjustable in this embodiment. By tightening the fixing nut 11, the axial position of the buffer 12 relative to the mounting plate 10 can be changed, thereby adjusting the contact timing and compression stroke of the buffer 12 with the arc-extinguishing chamber moving guide rod 13.1 to adapt to different buffering strength requirements. Furthermore, for a three-phase circuit breaker, this embodiment preferably installs a buffer 12 on the lower support 9 of each phase. Figure 3 As shown, it can provide an independent and balanced buffer for each phase.

[0054] In this embodiment, the limiting unit includes at least one limiting screw 5, such as Figure 1As shown, the end face position of the limit screw 5 is set to the maximum opening angle allowed by the design when the main shaft drive 4 rotates. Specifically, when the opening movement is about to end, the main shaft drive 4 will drive the connected limit crank arm 2 and roller 3 to rotate together to the end position. The roller 3 will come into contact with the limit screw 5. Since the limit screw 5 is fixed, it will restrict the roller 3 from moving forward, thereby forcibly preventing the limit crank arm 2 and the main shaft drive 4 from rotating further. At this point, the entire opening movement is stopped. In addition, in order to improve the reliability of long-term use, this embodiment can set two or even more limit screws 5, and set multiple limit screws 5 on the movement trajectory of the limit crank arm 2 to form a stable structure with multiple points of contact.

[0055] See Figure 4 The usage process in this embodiment includes: first, the tripping command is triggered, the operating mechanism 1 is unlocked, and the corresponding... Figure 4 At time t1, the circuit breaker is in the initial opening stage. The energy stored in the opening spring device 14 is released instantaneously, causing the moving parts of the opening spring device 14 to move. At this time, due to the gap created by the washer 16, the opening spring device 14 and the buffer spring 15 are not in contact. The driving force generated by the moving parts of the opening spring device 14 will drive the main shaft drive 4 to rotate, thereby driving the arc-extinguishing chamber moving guide rod 13.1 to move. As the main shaft drive 4 rotates, it will drive the arc-extinguishing chamber moving guide rod 13.1 to move. At this time, after the moving parts in the opening spring device 14 have completed their stroke, they will begin to compress the washer 16 and the buffer spring 15. The buffer spring 15 will counteract part of the thrust from the opening spring, thus achieving the first stage of buffering. Figure 4 At time t2.

[0056] When the arc-extinguishing chamber moving guide rod 13.1 reaches the predetermined position, it begins to contact and compress the buffer 12. Utilizing the damping force provided by the buffer 12, the remaining tripping kinetic energy is dissipated, achieving the second stage of buffering. This reduces the tripping speed to a very low level. Figure 4 At time t3; when the main shaft drive 4 rotates to its limit angle, the roller 3 on the limit crank arm 2 contacts the limit screw 5, and the limit screw 5 limits the movement, causing the main shaft drive 4 to stop. This completes the entire circuit breaker opening and closing motion. Figure 4 At time t4.

[0057] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0058] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A buffer device for a high-capacity circuit breaker, characterized in that, It includes a first buffer unit, a second buffer unit, and a limiting unit; The first buffer unit is used to contact the moving parts in the circuit breaker's opening spring device (14) during the circuit breaker's opening process to provide buffering in the first stage; The second buffer unit is used to be positioned opposite to the moving guide rod (13.1) of the arc-extinguishing chamber of the circuit breaker during the circuit breaker tripping process, so as to provide a second-stage buffer; The limiting unit is used to cooperate with the main shaft drive (4) of the circuit breaker to terminate the circuit breaker's opening movement; The first buffer unit includes a buffer spring (15), which is disposed on the gate spring device (14); The first buffer unit further includes a washer (16), which is disposed between the buffer spring (15) and the moving part in the gate spring device (14); The second buffer unit includes a buffer (12), which is fixedly mounted on the lower bracket (9) of the circuit breaker by a mounting plate (10); the buffer (12) contacts the moving guide rod (13.1) of the arc-extinguishing chamber to achieve buffering; The limiting unit includes a limiting screw (5), which contacts a roller (3) connected to the main shaft drive (4).

2. The buffer device for a large-capacity circuit breaker according to claim 1, characterized in that, The second buffer unit also includes a fixing nut (11) for adjusting the buffer stroke of the buffer (12).

3. The buffer device for a large-capacity circuit breaker according to claim 1, characterized in that, The number of buffers (12) is multiple, and each buffer (12) corresponds to one phase of the circuit breaker.

4. The buffer device for a large-capacity circuit breaker according to claim 1, characterized in that, The number of the limiting screws (5) is 2 to 5.

5. The buffer device for a large-capacity circuit breaker according to claim 1, characterized in that, During the circuit breaker tripping process, the first buffer unit, the second buffer unit, and the limit unit operate in sequence.

6. A buffering method for a large-capacity circuit breaker, based on the buffering device for a large-capacity circuit breaker as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The circuit breaker is driven to open, causing the moving guide rod (13.1) of the arc-extinguishing chamber to start moving. At this time, neither the first buffer unit nor the second buffer unit participates in buffering. When the circuit breaker trips to the first preset distance, it triggers the first buffer unit to contact the moving part in the trip spring device (14) and provides the first stage of buffering. When the circuit breaker trips to the second preset distance, it triggers the second buffer unit to contact the moving guide rod (13.1) of the arc-extinguishing chamber and provides the second stage of buffering; When the main shaft drive (4) of the circuit breaker rotates to the preset end position, the trigger limit unit contacts the main shaft drive (4) to terminate the circuit breaker opening movement.

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