A kind of opening and closing operation mechanism

Abstract

This invention relates to the field of circuit breaker operation technology and discloses a circuit breaker operation mechanism, including a housing and a hot-melt metal rod. A U-shaped mounting plate is installed inside the housing, and a drive motor is installed on one side of the mounting plate. The output shaft of the drive motor is driven by a bevel gear set. The bevel gear set includes a first bevel gear connected to the output shaft of the drive motor, a second bevel gear meshing with the first bevel gear, and a third bevel gear meshing with the second bevel gear. The second bevel gear is driven by a closing control terminal, and the third bevel gear is driven by a opening control terminal. A closing stationary terminal is also provided on the mounting plate, and the closing stationary terminal is electrically connected to the closing control terminal. The circuit breaker operation mechanism provided by this invention, through the synergistic effect of a triple protection mechanism and an automatic recovery function, effectively solves the technical problems of traditional mechanisms being prone to failure to operate under extreme faults and having high maintenance costs, significantly improving the safety and automation level of the power system.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker opening and closing technology, specifically to a circuit breaker opening and closing operating mechanism. Background Technology

[0002] The opening and closing operating mechanism is a core control component in power switchgear, and its performance directly affects the safe and stable operation of the power system. Modern power systems place higher demands on the operating mechanism, requiring not only reliable opening and closing operations but also comprehensive fault protection functions. Currently, mainstream opening and closing operating mechanisms generally adopt a thermal-magnetic protection scheme, using bimetallic strips for overload protection and electromagnets for short-circuit protection.

[0003] However, existing technical solutions still have significant shortcomings in terms of protection reliability, automatic recovery capability, and mechanism design. For example, patent document CN105006409A discloses an automatic opening and closing operation device, which achieves precise detection and control of the handle device position by setting up status detection sensors, opening detection sensors, and closing detection sensors, in conjunction with magnetic induction, thereby driving and realizing the automatic opening and closing of the circuit breaker. This solution has made progress in automatic control, but still has the following limitations: First, in terms of protection reliability, this scheme and traditional thermomagnetic protection mechanisms mostly adopt single-stage or limited dual-stage protection structures. When the system encounters an extreme short-circuit fault, the strong electrodynamic force may cause the moving contact and stationary contact to weld together, causing the protection mechanism to fail to operate and resulting in the expansion of the accident. There is a lack of effective redundant protection mechanisms to deal with such extreme situations.

[0004] Secondly, in terms of maintenance convenience, some schemes that use fuses as backup protection require manual replacement after the fuses trip, resulting in long power outage times and high maintenance costs, which cannot meet the development needs of modern power distribution network automation. The CN105006409A scheme mainly solves the control problem of automatic opening and closing, but does not involve the automatic recovery function after the protection element trips.

[0005] Furthermore, in terms of mechanism design, traditional transmission systems often suffer from problems such as complex structures and insufficient coordination of movements. In particular, the reset of the protection mechanism often requires manual intervention, affecting the continuous operation capability of the equipment. At the same time, after long-term operation, the reliability of the mechanism may decrease due to problems such as component wear and foreign object blockage.

[0006] Therefore, a switching mechanism is needed to solve the above problems. Summary of the Invention

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A circuit breaker operating mechanism, comprising a housing and a thermoplastic metal rod, wherein a U-shaped mounting plate is installed inside the housing, a drive motor is installed on one side of the mounting plate, and a bevel gear set is drivenly connected to the output shaft of the drive motor. The bevel gear set includes a first bevel gear connected to the output shaft of the drive motor, a second bevel gear meshing with the first bevel gear, and a third bevel gear meshing with the second bevel gear. The second bevel gear is drivenly connected to a closing control terminal, and the third bevel gear is drivenly connected to a closing control terminal. A closing stationary terminal is also provided on the mounting plate, and the closing stationary terminal is electrically connected to the closing control terminal. The thermoplastic metal rod slidably connects the opening control terminal, the closing control terminal, and the closing stationary terminal.

[0008] Furthermore, the trip control terminal includes a support frame, a linkage rod, a rotating rod, a spur gear, a rack, and a feed box. The support frame is fixed to the mounting plate. Both ends of the support frame are rotatably connected to the rotating rod via the linkage rod. One end of the rotating rod is connected to a third bevel gear, and the other end of the rotating rod is connected to a spur gear. The spur gear meshes with the rack, the rack is fixedly connected to the feed box, and the feed box is slidably connected to the mounting plate.

[0009] Furthermore, the feed box includes a threaded upper cover plate and a lower cover plate, and a feed elastic element is provided between the upper cover plate and the lower cover plate. One end of the feed elastic element is connected to the lower cover plate, and the other end of the feed elastic element is connected to one end of the hot melt metal rod. The lower cover plate has a sliding hole, which is slidably connected to the mounting plate.

[0010] Furthermore, the closing control terminal includes a ratchet, a pawl, a linkage structure, a lifting cam, and a lifting rod. The ratchet is connected to the second bevel gear via a rotating shaft. The pawl is rotatably connected to the mounting plate and meshes with the ratchet. The lower end of the pawl is connected to the mounting plate via a reset elastic element. The pawl is connected to one end of the linkage structure, and the other end of the linkage structure is slidably connected to the lifting cam. The lifting cam is slidably connected to the mounting plate. The middle part of the lifting cam is fixedly connected to the lifting rod. The lifting rod is slidably connected to the mounting plate. A moving contact is fixed at the top of the lifting rod. The lower end of the lifting rod is connected to the lower end of the opening elastic element, and the upper end of the opening elastic element is connected to the bottom of the mounting plate.

[0011] Furthermore, the closing stationary terminal includes a first stationary contact, a second stationary contact, a solenoid electromagnet, and an arc-extinguishing chamber. Both the first and second stationary contacts are fixed on the mounting plate. The first stationary contact is electrically connected to one end of the solenoid electromagnet, and the other end of the solenoid electromagnet is electrically connected to the second stationary contact. The second stationary contact is in sliding contact with the moving contact. The second stationary contact is electrically connected to one end of the arc-extinguishing chamber, and the other end of the arc-extinguishing chamber is in sliding contact with the moving contact.

[0012] Furthermore, the closing stationary end includes a bimetallic strip, the other end of the arc-extinguishing chamber is electrically connected to one end of the bimetallic strip, and the other end of the bimetallic strip is electrically connected to a solenoid electromagnet.

[0013] Furthermore, both the second stationary contact and the moving contact are provided with through holes for the hot-melt metal rod to pass through, and a sleeve is fixed to one side of the second stationary contact.

[0014] Furthermore, the inner wall of the sleeve, the inner wall of the perforation of the second stationary contact, and the inner wall of the perforation of the moving contact are all coated with a polytetrafluoroethylene coating.

[0015] Compared with the prior art, the technical solution of the present invention has the following advantages: (1) Triple protection: The first level is provided by a solenoid electromagnet for millisecond-level instantaneous short-circuit protection; the second level is provided by a bimetallic strip for overload delay protection that matches the heat accumulation characteristics; and the third level is provided by a thermoplastic metal rod as the final physical backup protection. These three are connected in parallel through the thermoplastic metal rod as the core transmission component to form a redundant system. When an extreme short circuit occurs, which may cause the moving and stationary contacts to overheat and cause the first two levels of protection to fail, the huge current will directly melt the thermoplastic metal rod. At this time, the energy stored in the feed elastic element is released, providing a strong mechanical impact force to force trip and open the circuit breaker. This multi-layered and independent protection path design fundamentally solves the industry problem of "refusal to operate" due to contact welding, ensuring reliable tripping under any fault conditions and greatly improving the safety level of the entire system.

[0016] (2) Automatic recovery of protection function, significantly improving equipment operation and maintenance efficiency and automation level. This invention upgrades the one-time fuse protection to an intelligent module that can be automatically recovered through ingenious mechanical design. The core lies in the combination of the feed box and the feed elastic element. When the thermoplastic metal rod partially melts and triggers protection, when the circuit is closed again, the feed elastic element will immediately push the rear thermoplastic metal rod into the perforation position. This fuse continuation mechanism enables the overload protection function of the mechanism to automatically and instantly return to the standby state after experiencing the protection action, without any manual replacement of the fuse or reset operation. This not only saves maintenance costs and time, but also achieves uninterrupted protection.

[0017] (3) Optimize power transmission and mechanism linkage to achieve precise control and long-term stable operation. The transmission and execution mechanism of this invention is well designed and exhibits high coordination and durability. First, the bevel gear set is used as the power distribution center to realize independent and decoupled control of the single motor for closing and opening the circuit breaker. The action is precise and does not interfere with each other. Second, during the closing process, the continuous lifting action of the ratchet and pawl, as well as the timing control of the hot melt metal rod being pushed into the hole by the feed elastic element only after the moving and stationary contacts are fully aligned, ensures the absolute synchronization between the closing state and the protection preparation state, avoiding false triggering and mechanical interference. Finally, the inner wall of the sleeve and the contact hole is coated with polytetrafluoroethylene. This key detail treatment can effectively prevent the blockage caused by hot melt metal residue, ensuring the smoothness of each action and connection of the hot melt metal rod, and structurally guaranteeing the long-term stability and service life of the mechanism. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the box in this invention; Figure 3 This is a schematic diagram of the trip control terminal in this invention; Figure 4 This is a schematic diagram of the connecting rod structure in this invention; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the structure of the moving contact in this invention; Figure 7 This is a schematic diagram of the solenoid electromagnet in this invention; Figure 8 This is a schematic diagram of the closing stationary terminal in this invention; Figure 9 This is a schematic diagram of the feed box structure in this invention; Figure 10 This is a schematic diagram of the mounting plate in this invention; Figure 11 This is a schematic diagram of the structure of the second stationary contact in this invention.

[0019] In the diagram: 1-box body, 2-mounting plate, 3-drive motor, 4-bevel gear set, 41-first bevel gear, 42-second bevel gear, 43-third bevel gear, 5-closing control terminal, 51-ratchet, 52-pawl, 53-reset elastic element, 55-linkage structure, 56-lifting protrusion, 57-lifting rod, 58-opening elastic element, 59-moving contact, 591-insulating cover plate, 6-closing stationary terminal, 61-first stationary contact, 62-sowary electromagnet, 63-bimetallic strip, 64-tube sleeve, 65-arc extinguishing chamber, 66-second stationary contact, 7-thermofused metal rod, 8-opening control terminal, 81-support frame, 82-linkage rod, 83-spur gear, 84-rack, 85-feed box, 851-upper cover plate, 852-lower cover plate, 853-feeding elastic element. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure 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 this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0021] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "comprising" or "including," and similar terms used in this disclosure, mean that an element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may also include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0022] like Figures 1 to 11As shown, the present invention provides a circuit breaker operating mechanism, including a housing 1 and a hot-melt metal rod 7. A U-shaped mounting plate 2 is installed inside the housing 1. A drive motor 3 is mounted on one side of the mounting plate 2. The output shaft of the drive motor 3 is driven by a bevel gear set 4. The bevel gear set 4 includes a first bevel gear 41 connected to the output shaft of the drive motor 3, a second bevel gear 42 meshing with the first bevel gear 41, and a third bevel gear 43 meshing with the second bevel gear 42. The second bevel gear 42 is driven by a closing control terminal 5, and the third bevel gear 43 is driven by a opening control terminal 8. A closing stationary terminal 6 is also provided on the mounting plate 2. The stationary terminal 6 is electrically connected to the closing control terminal 5. The thermofused metal rod 7 is slidably connected to the opening control terminal 8, the closing control terminal 5, and the closing stationary terminal 6. The thermofused metal rod 7 is made of a low-melting-point alloy. Through the design of the U-shaped mounting plate 2 and the bevel gear set 4, a compact modular layout is achieved. The drive motor 3 drives the second bevel gear 42 and the third bevel gear 43 simultaneously through the first bevel gear 41, realizing the synchronous control of the closing control terminal 5 and the opening control terminal 8 by a single power source. Furthermore, the design of the thermofused metal rod 7 running through the three functional terminals establishes a unified protection trigger channel, laying the foundation for subsequent multiple protection mechanisms.

[0023] The tripping control terminal 8 includes a support frame 81, a linkage rod 82, a rotating rod, a spur gear 83, a rack 84, and a feed box 85. The support frame 81 is fixed on the mounting plate 2. Both ends of the support frame 81 are rotatably connected to the rotating rod via the linkage rod 82. One end of the rotating rod is connected to the third bevel gear 43, and the other end is connected to the spur gear 83. The spur gear 83 meshes with the rack 84, and the rack 84 is fixedly connected to the feed box 85. The feed box 85 is slidably connected to the mounting plate 2. The tripping control terminal 8 adopts a stable support structure of the support frame 81 and the linkage rod 82. Combined with the transmission method of the spur gear 83 and the rack 84, the rotational motion is accurately converted into linear motion, ensuring the smoothness and reliability of the tripping action, while also ensuring the precise displacement of the feed box 85.

[0024] The feed box 85 includes a threaded upper cover plate 851 and a lower cover plate 852. A feed elastic element 853 is provided between the upper cover plate 851 and the lower cover plate 852. One end of the feed elastic element 853 is connected to the lower cover plate 852, and the other end of the feed elastic element 853 is connected to one end of the hot melt metal rod 7. A sliding hole is provided on the lower cover plate 852, and the sliding hole is slidably connected to the mounting plate 2. When the hot melt metal rod 7 partially melts, the energy stored in the feed elastic element 853 can continue to push the hot melt metal rod 7 into the hole when the circuit is closed again, and immediately return to the standby state without any manual replacement of the melt or reset operation. This not only saves maintenance costs and time, but also achieves uninterrupted protection.

[0025] The closing control terminal 5 includes a ratchet 51, a pawl 52, a connecting rod structure 55, a lifting protrusion 56, and a lifting rod 57. The ratchet 51 is connected to the second bevel gear 42 via a rotating shaft. The pawl 52 is rotatably connected to the mounting plate 2 and meshes with the ratchet 51. The lower end of the pawl 52 is connected to the mounting plate 2 via a reset elastic element 53. The pawl 52 is connected to one end of the connecting rod structure 55. The other end of the connecting rod structure 55 is slidably connected to the lifting protrusion 56. The lifting protrusion 56 is slidably connected to the mounting plate 2. The middle part of the lifting protrusion 56 is fixedly connected to the lifting rod 57. The lifting rod 57 is slidably connected to the mounting plate 2. A moving contact 59 is fixed at the top of the lifting rod 57. The lower end of the lifting rod 57 is connected to the lower end of the opening elastic element 58. The upper end of the opening elastic element 58 is connected to the bottom of the mounting plate 2.

[0026] The closing stationary terminal 6 includes a first stationary contact 61, a second stationary contact 66, a solenoid electromagnet 62, and an arc-extinguishing chamber 65. Both the first stationary contact 61 and the second stationary contact 66 are fixed on the mounting plate 2. The first stationary contact 61 is electrically connected to one end of the solenoid electromagnet 62, and the other end of the solenoid electromagnet 62 is electrically connected to the second stationary contact 66. The second stationary contact 66 is in sliding contact with the moving contact 59. The second stationary contact 66 is electrically connected to one end of the arc-extinguishing chamber 65, and the other end of the arc-extinguishing chamber 65 is in sliding contact with the moving contact 59. The closing stationary terminal 6 establishes a complete current path through the series connection of the first stationary contact 61, the second stationary contact 66, and the solenoid electromagnet 62. The arc-extinguishing chamber 65 effectively solves the problem of arc interruption and significantly improves the service life and safety of the equipment.

[0027] The closing stationary terminal 6 includes a bimetallic strip 63. The other end of the arc-extinguishing chamber 65 is electrically connected to one end of the bimetallic strip 63, and the other end of the bimetallic strip 63 is electrically connected to the solenoid electromagnet 62.

[0028] Both the second stationary contact 66 and the moving contact 59 have through holes for the hot-melt metal rod 7 to pass through, and a sleeve 64 is fixed on one side of the second stationary contact 66.

[0029] The inner wall of the sleeve 64, the inner wall of the perforation of the second stationary contact 66, and the inner wall of the perforation of the moving contact 59 are all coated with polytetrafluoroethylene (PTFE). Coating the sleeve 64 and its inner wall with PTFE effectively solves the technical problem of molten metal adhesion. The low coefficient of friction and non-stick properties of the coating ensure the smooth operation of the hot-melt metal rod 7 and ensure the long-term unobstructed flow of the protection channel, greatly improving the maintainability and service life of the equipment.

[0030] Working principle: In the opening preparation state, the moving contact 59 is in a low position, and its through hole is misaligned with the through hole of the second stationary contact 66. At this time, the feeding elastic element 853 continuously applies a pushing force, attempting to push the hot-melt metal rod 7 forward. However, due to the obstruction of the insulating cover plate 591 on the top of the moving contact 59, the hot-melt metal rod 7 cannot pass through and is in a pre-compression state. When the closing operation is performed, the drive motor 3 rotates forward, and the power is transmitted through the ratchet 51, pawl 52, and connecting rod structure 55, pushing the lifting rod 57 and the moving contact 59 upward. In the initial and middle stages of the rising of the moving contact 59, its through hole and the through hole of the second stationary contact 66 remain misaligned. The insulating cover 591 continues to block the advancement of the hot-melt metal rod 7 until the moving contact 59 rises to its highest point. The moving contact 59 and the second stationary contact 66 then make reliable electrical contact, completing the closing operation. At the instant the holes on the moving contact 59 and the second stationary contact 66 are precisely aligned, the hot-melt metal rod 7, which has been pushed by the feed elastic element 853 and blocked by the insulating cover 591, loses its obstacle. The elastic force of the feed elastic element 853 is released instantaneously, rapidly and accurately pushing the tip of the hot-melt metal rod 7 through the holes of the moving contact 59 and the second stationary contact 66 until it reaches the final working position limited by the sleeve 64. Thus, the closing operation and the establishment of the protection channel are completed simultaneously, physically connecting the moving contact 59 and the second stationary contact 66 in the closed state, putting the overload protection function into standby mode.

[0031] When the control system issues a tripping command, the drive motor 3 starts to reverse. The reverse rotation power of the drive motor 3 is transmitted and converted through the bevel gear set 4. The specific path is as follows: the first bevel gear 41 reverses, driving the third bevel gear 43 meshing with it to rotate forward. The forward rotation of the third bevel gear 43 is transmitted to the spur gear 83 through the rotating rod, so that it rotates forward synchronously. The rotating spur gear 83 drives the rack 84 meshing with it to move in a straight line. The linear movement of the rack 84 pulls the feed box 85 to move backward along the sliding hole on the mounting plate 2, thereby allowing the hot melt metal rod 7 to disengage from the hole and realize the tripping.

[0032] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A circuit breaker operating mechanism, comprising a housing (1) and a hot-melt metal rod (7), characterized in that: A U-shaped mounting plate (2) is installed inside the housing (1). A drive motor (3) is installed on one side of the mounting plate (2). The output shaft of the drive motor (3) is connected to a bevel gear set (4). The bevel gear set (4) includes a first bevel gear (41) connected to the output shaft of the drive motor (3), a second bevel gear (42) meshing with the first bevel gear (41), and a third bevel gear (43) meshing with the second bevel gear (42). The second bevel gear (42) is connected to a closing control terminal (5). The third bevel gear (43) is connected to a opening control terminal (8). A closing stationary terminal (6) is also provided on the mounting plate (2). The closing stationary terminal (6) is electrically connected to the closing control terminal (5). The hot-melt metal rod (7) is slidably connected to the opening control terminal (8), the closing control terminal (5), and the closing stationary terminal (6).

2. The opening and closing operating mechanism according to claim 1, characterized in that: The trip control terminal (8) includes a support frame (81), a linkage rod (82), a rotating rod, a spur gear (83), a rack (84), and a feed box (85). The support frame (81) is fixed on the mounting plate (2). Both ends of the support frame (81) are rotatably connected to the rotating rod through the linkage rod (82). One end of the rotating rod is connected to the third bevel gear (43) for transmission, and the other end of the rotating rod is connected to the spur gear (83) for transmission. The spur gear (83) meshes with the rack (84). The rack (84) is fixedly connected to the feed box (85), and the feed box (85) is slidably connected to the mounting plate (2).

3. The opening and closing operation mechanism according to claim 2, characterized in that: The feed box (85) includes a threaded upper cover plate (851) and a lower cover plate (852). A feed elastic element (853) is provided between the upper cover plate (851) and the lower cover plate (852). One end of the feed elastic element (853) is connected to the lower cover plate (852), and the other end of the feed elastic element (853) is connected to one end of the hot melt metal rod (7). The lower cover plate (852) has a sliding hole, which is slidably connected to the mounting plate (2).

4. The opening and closing operating mechanism according to claim 1, characterized in that: The closing control terminal (5) includes a ratchet (51), a pawl (52), a linkage structure (55), a lifting cam (56), and a lifting rod (57). The ratchet (51) is connected to the second bevel gear (42) via a rotating shaft. The pawl (52) is rotatably connected to the mounting plate (2) and meshes with the ratchet (51). The lower end of the pawl (52) is connected to the mounting plate (2) via a reset elastic element (53). The pawl (52) is connected to one end of the linkage structure (55). Then, the other end of the connecting rod structure (55) is slidably connected to the lifting protrusion (56), the lifting protrusion (56) is slidably connected to the mounting plate (2), the middle part of the lifting protrusion (56) is fixedly connected to the lifting rod (57), the lifting rod (57) is slidably connected to the mounting plate (2), the top of the lifting rod (57) is fixed with a moving contact (59), the lower end of the lifting rod (57) is connected to the lower end of the tripping elastic element (58), and the upper end of the tripping elastic element (58) is connected to the bottom of the mounting plate (2).

5. The opening and closing operating mechanism according to claim 4, characterized in that: The closing stationary terminal (6) includes a first stationary contact (61), a second stationary contact (66), a solenoid electromagnet (62), and an arc-extinguishing chamber (65). The first stationary contact (61) and the second stationary contact (66) are both fixed on the mounting plate (2). The first stationary contact (61) is electrically connected to one end of the solenoid electromagnet (62), and the other end of the solenoid electromagnet (62) is electrically connected to the second stationary contact (66). The second stationary contact (66) is in sliding contact with the moving contact (59). The second stationary contact (66) is electrically connected to one end of the arc-extinguishing chamber (65), and the other end of the arc-extinguishing chamber (65) is in sliding contact with the moving contact (59).

6. The opening and closing operation mechanism according to claim 5, characterized in that: The closing stationary terminal (6) includes a bimetallic strip (63), and the other end of the arc-extinguishing chamber (65) is electrically connected to one end of the bimetallic strip (63). The other end of the bimetallic strip (63) is electrically connected to a solenoid electromagnet (62).

7. The opening and closing operating mechanism according to claim 5, characterized in that: Both the second stationary contact (66) and the moving contact (59) are provided with through holes for the hot melt metal rod (7) to pass through, and a sleeve (64) is fixed on one side of the second stationary contact (66).

8. The opening and closing operation mechanism according to claim 7, characterized in that: The inner wall of the sleeve (64), the inner wall of the perforation of the second stationary contact (66), and the inner wall of the perforation of the moving contact (59) are all coated with polytetrafluoroethylene.

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