A pole-mounted vacuum circuit breaker with improved arc extinguishing device

Abstract

The application provides a pole vacuum circuit breaker with an improved arc extinguishing device, which comprises a box body, an executing mechanism, a switch mechanism and an isolating mechanism. The box body is internally provided with a rotatable first main shaft. The executing mechanism is provided with vertically installed first, second and third vacuum arc extinguishing chambers, a connecting mechanism and a transmission mechanism. The first and third vacuum arc extinguishing chambers are in transmission connection with the first main shaft. The second vacuum arc extinguishing chamber is connected with the first main shaft through the transmission mechanism. The installation direction of the first and third vacuum arc extinguishing chambers is opposite to that of the second vacuum arc extinguishing chamber. The moving contact of the first and third vacuum arc extinguishing chambers is driven to move in a first direction. The moving contact of the second vacuum arc extinguishing chamber is driven to move in a second direction opposite to the first direction. The switch mechanism is arranged on the first side of the box body. The isolating mechanism is arranged on the second side of the box body and is connected with the outgoing terminals of the arc extinguishing chambers. The application increases the creepage distance and improves the insulation performance and operation reliability without increasing the size of the box body through opposite installation directions and reverse driving.

Description

Technical Field

[0001] This invention relates to the field of vacuum circuit breaker technology, and in particular to a pole-mounted vacuum circuit breaker with an improved arc-extinguishing device. Background Technology

[0002] Pole-mounted vacuum circuit breakers are commonly used switching devices in power distribution networks. Their main function is to interrupt load current and short-circuit current, ensuring the safe operation of the power system. Currently, common pole-mounted vacuum circuit breakers typically have all three vacuum interrupters vertically installed inside the enclosure, with the moving contacts of the three interrupters moving in the same direction. To meet the requirements of overall compactness, the spacing between the interrupters and the distance between the interrupters and the inner wall of the enclosure are often designed to be relatively limited. However, this traditional unidirectional vertical installation method has significant insulation defects. Because the three-phase interrupters and connecting components are tightly arranged inside the enclosure, the creepage distance between phases and between phases and ground is short. Under harsh environmental conditions such as humidity and pollution, the short creepage distance can easily cause surface flashover, reducing the insulation reliability of the vacuum circuit breaker, and even causing phase-to-phase short circuits or ground breakdown accidents. To meet insulation requirements, designers are sometimes forced to increase the size of the enclosure, but this leads to increased equipment weight and installation inconvenience. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a pole-mounted vacuum circuit breaker with an improved arc-extinguishing device. By installing the first and third vacuum arc-extinguishing chambers in opposite directions to the second vacuum arc-extinguishing chamber, and coordinating a connecting mechanism and a transmission mechanism to achieve reverse driving, the creepage distance between each arc-extinguishing chamber is effectively increased without increasing the size of the enclosure, thereby improving insulation performance and operational reliability.

[0004] This invention provides a pole-mounted vacuum circuit breaker with an improved arc-extinguishing device, comprising: A housing having a first side and a second side opposite to each other, and a rotatable first main shaft provided inside the housing, the first main shaft extending along the length direction of the housing and located at the middle of the height direction of the housing; An actuator is disposed inside the housing. The actuator comprises three vertically mounted first vacuum interrupter chambers, second vacuum interrupter chambers, and third vacuum interrupter chambers, a connecting mechanism, and a transmission mechanism. The first and third vacuum interrupter chambers are connected to a first main shaft via a transmission mechanism. The second vacuum interrupter chamber is connected to the first main shaft via the transmission mechanism. The installation directions of the first and third vacuum interrupter chambers are opposite to those of the second vacuum interrupter chamber. The connecting mechanism converts the rotational motion of the first main shaft into linear motion to drive the moving contacts of the first and third vacuum interrupter chambers to move along a first direction. The transmission mechanism converts the rotational motion of the first main shaft into reverse linear motion to drive the moving contacts of the second vacuum interrupter chamber to move along a second direction opposite to the first direction. A switching mechanism is provided on the first side of the housing and connected to the first main shaft. The switching mechanism is used to drive the first main shaft to rotate. An isolation mechanism is provided on the second side of the housing. The isolation mechanism is connected to the outgoing terminals of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. The isolation mechanism is provided with a second main shaft, which is connected to the switching mechanism so that the isolation mechanism moves in accordance with the movement of the switching mechanism.

[0005] In some embodiments of the present invention, the connecting mechanism includes three sets of transmission components respectively corresponding to the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. Each set of transmission components is provided with a support crank arm, a first insulating pull rod, and a phase crank arm. One end of each support crank arm is connected to the corresponding vacuum interrupter, the other end of each support crank arm is connected to one end of the corresponding first insulating pull rod, the other end of each first insulating pull rod is connected to one end of the corresponding phase crank arm, and the other end of each phase crank arm is connected to the first main shaft.

[0006] In some embodiments of the present invention, the actuator is further provided with a buffer device, which includes a buffer crank arm, a first roller, a buffer bracket, a buffer oil cup, and a ejector pin. One end of the buffer crank arm is connected to the first main shaft, the first roller is disposed at the other end of the buffer crank arm, the buffer oil cup is disposed on the buffer bracket, and the ejector pin is retractably disposed outside the buffer oil cup. When the first main shaft rotates to a predetermined angle, the first roller abuts against the outer end face of the ejector pin.

[0007] In some embodiments of the present invention, the switching mechanism includes an isolation handle, an opening / closing indicator, and a mechanism cover. The middle part of the isolation handle is connected to the second main shaft and is used to drive the second main shaft to rotate. A linkage mechanism is provided between the first main shaft and the second main shaft. The linkage mechanism is used to transmit the rotational motion of the second main shaft to the first main shaft, thereby driving the first main shaft to rotate and adjust the opening / closing state of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. The opening / closing indicator is connected to the first main shaft and is used to indicate the opening / closing state of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. Both the opening / closing indicator and the isolation handle are disposed outside the mechanism cover.

[0008] In some embodiments of the present invention, the opening and closing indicator device includes a chain shaft, a transmission plate, a transmission clamp, and a pointer. One end of the chain shaft is connected to the second main shaft, the other end of the chain shaft is connected to one end of the transmission plate, the other end of the transmission plate is connected to one end of the transmission clamp, and the other end of the transmission clamp is connected to the pointer. When the first main shaft or the second main shaft rotates, the pointer swings with the first main shaft or the second main shaft under the action of the linkage mechanism to indicate the opening and closing status of the vacuum interrupter.

[0009] In some embodiments of the present invention, the linkage mechanism includes a bearing seat, a shaft plate, a second roller, and a bending plate. The shaft plate is provided with a first recess. One side of the bearing seat is connected to the pointer, and the other side of the bearing seat is connected to the shaft plate. The first recess of the shaft plate abuts against the outer surface of the second roller. The bottom of the second roller is connected to one end of the bending plate, and the other end of the bending plate is connected to the first main shaft.

[0010] In some embodiments of the present invention, the isolation mechanism includes a support frame and three sets of isolation components respectively corresponding to the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. The support frame is disposed on the second side of the housing. Each set of isolation components is provided with a first insulating support post, a second insulating support post, a first cutter holder, a second cutter holder, an isolation blade, a second insulating pull rod, a pull rod connector, and a pull rod crank arm. One end of the first insulating support post and the second insulating support post are connected to the support frame. The other end of the first insulating support post is connected to the first end of the first cutter holder. The other end of the second insulating support post is connected to the first end of the second cutter holder. The second end of the first cutter holder is connected to one end of the isolation blade. The second end of the second cutter holder is connected to the other end of the isolation blade. The third end of the first cutter holder is connected to the output terminal of the corresponding vacuum interrupter. One end of the second insulating pull rod is connected to the isolation blade through the pull rod connector. The other end of the second insulating pull rod is connected to the second main shaft through the pull rod crank arm.

[0011] In some embodiments of the present invention, the inlet and outlet terminals of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter are all straight terminals, and the straight terminals have the same shape, size, and orientation. The straight terminals are bent at ninety degrees through conductive connecting strips and then extend vertically downward to form the lower outlet terminal.

[0012] In some embodiments of the present invention, the transmission mechanism includes a main shaft drive crank arm, a first connecting rod, and an intermediate rocker arm. One end of the main shaft drive crank arm is connected to the first main shaft, and the other end of the main shaft drive crank arm is connected to one end of the first connecting rod. The other end of the first connecting rod is connected to the driving end of the intermediate rocker arm, and the driven end of the intermediate rocker arm is connected to the second vacuum interrupter. When the first main shaft rotates, the main shaft drive crank arm drives the intermediate rocker arm to swing through the first connecting rod. The direction of movement of the driven end is opposite to the direction of movement of the driving end, so as to drive the moving contact of the second vacuum interrupter to produce a displacement in the same direction as the moving contact of the first vacuum interrupter and the third vacuum interrupter relative to their respective stationary contacts.

[0013] In some embodiments of the present invention, a flange is provided between each of the vacuum interrupter chambers and the outgoing terminal.

[0014] The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to an embodiment of the present invention has at least the following beneficial effects: The high-voltage ends of the first and third vacuum interrupters are close to the top plate of the enclosure and rely on top insulation supports to achieve ground creepage distance. The high-voltage end of the second vacuum interrupter, however, is installed in the opposite direction and is close to the bottom plate of the enclosure; its creepage distance is provided by bottom insulation supports. Compared to the traditional scheme where the three interrupters are installed in the same direction, this embodiment utilizes two insulation spaces along the height of the enclosure, resulting in a total creepage distance that is approximately the sum of the upper and lower insulation distances, almost doubling the total creepage distance. Simultaneously, the staggered distribution of the high-voltage ends in height increases the three-dimensional length of the interphase surface creepage path, effectively reducing the risk of surface flashover in harsh environments such as condensation and pollution. Although the connecting mechanism and the transmission mechanism move in opposite directions, they are both driven by the same first main shaft. Through a rationally designed transmission ratio, it can be ensured that the moving contacts of the first and third interrupters and the moving contact of the second vacuum interrupter approach or move away from their respective stationary contacts in strict synchronization. This ensures that the three-phase circuit of the circuit breaker can be connected or disconnected simultaneously, avoiding electrical hazards such as arc reignition and overvoltage caused by asynchronous closing / opening during phase-by-phase operation. The first, second, and third vacuum interrupters are vertically installed with two facing forward and one facing backward. Combined with the central arrangement of the first main shaft, this ensures that the incoming and outgoing terminals of each phase are neatly oriented towards the second side of the enclosure or uniformly led downward. The design of straight terminals and 90-degree bent conductor bars ensures that all conductive connectors are regular straight columns or standard bent parts, facilitating gripping, positioning, and bolt tightening processes on automated production lines, reducing manual assembly costs, and improving product consistency and production efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a pole-mounted vacuum circuit breaker with an improved arc-extinguishing device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the pole-mounted vacuum circuit breaker provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the installation positions of the first to third vacuum interrupters provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection mechanism provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the buffer device provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the opening and closing indicator device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the linkage mechanism provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the isolation component provided in an embodiment of the present invention; Figure 9This is a schematic diagram of the transmission mechanism provided in an embodiment of the present invention. Detailed Implementation

[0016] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are 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 limiting this invention.

[0018] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0019] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0020] Reference Figures 1 to 9This invention provides a pole-mounted vacuum circuit breaker with an improved arc-extinguishing device, including a housing 100 having opposing first and second sides. A rotatable first main shaft 110 is disposed within the housing 100, extending along the length of the housing 100 and located at the center of the housing 100's height. An actuator 200 is disposed inside the housing 100, and the actuator 200 has three vertically mounted first vacuum arc-extinguishing chambers 21. 0. A second vacuum interrupter 220, a third vacuum interrupter 230, a connecting mechanism 240, and a transmission mechanism 250, wherein the first vacuum interrupter 210 and the third vacuum interrupter 230 are connected to the first main shaft 110, and the second vacuum interrupter 220 is connected to the first main shaft 110 via the transmission mechanism 250. The installation directions of the first vacuum interrupter 210 and the third vacuum interrupter 230 are opposite to the installation direction of the second vacuum interrupter 220. The connecting mechanism 240 is used for... The first main shaft 110's rotational motion is converted into linear motion to drive the moving contacts of the first vacuum interrupter 210 and the third vacuum interrupter 230 to move along a first direction. The transmission mechanism 250 is used to convert the rotational motion of the first main shaft 110 into reverse linear motion to drive the moving contact of the second vacuum interrupter 220 to move along a second direction opposite to the first direction. The switch mechanism 300 is disposed on the first side of the housing 100 and connected to the first main shaft 110. The switch mechanism 300 is used to drive the first main shaft 110 to rotate. The isolation mechanism 400 is disposed on the second side of the housing 100 and connected to the outgoing terminals of the first vacuum interrupter 210, the second vacuum interrupter 220 and the third vacuum interrupter 230. The isolation mechanism 400 is provided with a second main shaft 410, which is connected to the switch mechanism 300 so that the isolation mechanism 400 moves in accordance with the movement of the switch mechanism 300.

[0021] It should be noted that in this embodiment, the switching mechanism 300 acts as the main power source. When the switching mechanism 300 performs a tripping or closing operation, the first main shaft 110 is driven to rotate. Under the action of the connecting mechanism 240, the rotational force of the first main shaft 110 is converted into the vertical lifting and lowering motion of the moving contacts in the three vertically arranged vacuum interruptor chambers, thereby completing the on / off control of the main circuit. At the same time, since the second main shaft 410 of the isolation mechanism 400 is directly connected to the switching mechanism 300, the action of the switching mechanism 300 will synchronously drive the second main shaft 410 to rotate, thereby driving the isolation mechanism 400 to perform the corresponding tripping or closing action. This ensures the operation sequence and interlocking logic between the execution mechanism 200 and the isolation mechanism 400. That is, the isolation mechanism 400 can only operate after the execution mechanism 200 has completed the tripping operation. When the isolation mechanism 400 is in the closed position, the execution mechanism 200 cannot close the circuit, thereby effectively preventing dangerous operation of pulling or closing the execution module under load.

[0022] Furthermore, when the switching mechanism 300 drives the first main shaft 110 to rotate, the first main shaft 110 directly drives the moving contacts in the first and third arc-extinguishing chambers to move linearly in the first direction through the connecting mechanism 240. The rotation of the first main shaft 110 is simultaneously input to the transmission mechanism 250. The transmission mechanism 250 converts the rotational motion into linear motion in the opposite direction through internal reverse motion conversion, driving the moving contact of the second vacuum arc-extinguishing chamber 220 to move in the second direction. Since the first vacuum arc-extinguishing chamber 210 and the third vacuum arc-extinguishing chamber 230 are installed in opposite directions to the second vacuum arc-extinguishing chamber 220, although the movement directions of the moving contacts are opposite, their position changes relative to their respective stationary contacts are the same: that is, when the moving contacts of the first and third arc-extinguishing chambers move upward to approach the stationary contacts (closing), the moving contact of the second vacuum arc-extinguishing chamber 220 moves downward to approach its stationary contacts (because its installation direction is opposite, downward is also the closing direction), thereby realizing the simultaneous closing or simultaneous opening of the three-phase contacts. At the same time, since the second main shaft 410 is connected to the switching mechanism 300, the action of the switching mechanism 300 will synchronously drive the second main shaft 410 in the isolation mechanism 400 to rotate, and then drive the isolation blade 435 to open and close through the insulating pull rod and crank arm, forming a mechanical interlock between the circuit breaker and the disconnecting switch, ensuring the safety of the operation sequence.

[0023] Furthermore, the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 of the actuator 200 are all vertically installed. The outgoing terminals of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are led to the isolation mechanism 400 on the second side of the housing 100. Compared with the traditional horizontal or staggered arrangement, the three-dimensional layout of this embodiment significantly increases the creepage distance between high-potential components and relative to ground. At the same time, since the connection path does not need to bend or creep, the electric field distribution is more uniform, effectively reducing the risk of surface flashover and partial discharge, and improving the operational reliability of the circuit breaker in outdoor humid and polluted environments.

[0024] It should be noted that in the prior art, the drive shaft used to operate the vacuum interrupter is located at the bottom or top of the housing 100. In this case, the vacuum interrupter is usually installed horizontally or at an angle, and the moving end of the vacuum interrupter is connected to the drive shaft downwards (or upwards) via an insulating rod. Although the length of the insulating rod itself can be adjusted according to the specific application, the surface distance between the metal fittings at both ends of the insulating rod (such as the upper fitting connected to the moving end of the vacuum interrupter and the lower fitting connected to the operating shaft) is basically equal to the axial length of the insulating rod. However, since the operating shaft is located at the bottom, the distance between the stationary end (high voltage top) of the interrupter and the top plate of the housing 100 is relatively short. The top plate of the housing 100 is grounded, causing the creepage distance between the stationary end and the top plate of the housing 100 to depend on the short insulating support, which can easily lead to insufficient creepage distance of the vacuum interrupter. If the operating shaft is located at the bottom of the housing 100, the phase-to-phase distance of the vacuum interrupter is limited by the width of the housing 100, so it is necessary to increase the creepage distance of the vacuum interrupter by using air gaps and adding baffles.

[0025] In this embodiment, the first main shaft 110 is positioned at the middle of the box 100, extending along its length and at its height. In this case, the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are arranged vertically. The moving ends of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are connected to the first main shaft 110 at the middle via the first insulating tie rod 242. The stationary ends of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are located at the top. Since the first main shaft 110 is located in the middle of the enclosure 100, the first insulating rod 242, from the moving end (high potential) of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 to the first main shaft 110 (low potential), can extend downwards for a certain length, while the moving end itself has space from the bottom of the enclosure 100; and from the stationary end (high potential) of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 to the top plate (grounded) of the enclosure 100, sufficient creepage distance can also be obtained through the upper insulating support. That is, a high-voltage to ground path is divided into upper and lower insulating surfaces, and the total creepage distance is equal to the sum of the surface distance of the upper insulating component (the upper outlet end of the vacuum interrupter to the top of the enclosure) and the surface distance of the lower first insulating rod 242, and these two distances can be optimized independently without interference. In addition, the upward-mounted arc-extinguishing chambers (such as the first and third) extend to the top of the enclosure 100, and the downward-mounted arc-extinguishing chamber (the second) extends to the bottom of the enclosure 100. This significantly increases the creepage distance of the high-voltage live parts to the ground (upper and lower walls of the enclosure 100) within the limited total height of the enclosure 100, and also increases the phase-to-phase surface distance, effectively improving the insulation reliability of the equipment in harsh outdoor environments such as humidity, condensation, and pollution.

[0026] It should be noted that, in this embodiment, by placing the first main shaft 110 at the center of the height direction of the enclosure 100, the high-voltage to ground insulation path, originally concentrated on the bottom plate side, is decomposed into upwards to the top of the enclosure and downwards to both ends of the main shaft through spatial reconstruction, allowing the first insulating tie rod 242 to obtain a longer vertical extension length. Simultaneously, the vertically installed outer shells of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 also provide additional surface clearance, and phase-to-phase creepage can bend and bypass along the vertical surface. This design effectively increases the creepage distance without increasing the overall dimensions of the enclosure 100, thereby improving the insulation reliability of the circuit breaker in harsh environments such as condensation and pollution, and allowing the connecting columns to be designed as simple straight columns, facilitating automated production.

[0027] Furthermore, in this embodiment, the first vacuum interrupter 210 and the third vacuum interrupter 230 are positioned on the side near the first connecting plate 120 connected to the housing, and the second vacuum interrupter 220 is positioned on the side near the second connecting plate 130. The first connecting plate 120 and the second connecting plate 130 are arranged opposite each other, so that the first vacuum interrupter 210 and the third vacuum interrupter 230 are staggered with the second vacuum interrupter 220, thereby forming an insulation structure in which the three-phase vacuum interrupters are staggered. In the traditional planar or same-side arrangement, the three-phase interrupters are arranged in the same plane, and the interphase creepage distance is short and the path is direct. However, after the first vacuum interrupter 210, the third vacuum interrupter 230 and the second vacuum interrupter 220 are respectively placed on both sides of the opposite first connecting plate 120 and second connecting plate 130, the creepage path changes from a simple planar straight line to a three-dimensional meandering path that crosses three-dimensional space. For leakage current or flashover to travel from one phase to another along the insulating surface, it must first travel along the surface of the first vacuum interrupter 210 near the first connecting plate 120, then along the surface of the first connecting plate 120, the inner wall of the housing 100, the staggered gaps, and the surface of the second connecting plate 130 to the second vacuum interrupter 220, and then along the surface of the second connecting plate 130, the inner wall of the housing 100, the staggered gaps, and the first connecting plate 120 to the third vacuum interrupter 230. This complex path effectively extends the creepage distance. Simultaneously, this staggered arrangement improves the electric field distribution; the electric field originally concentrated on one side is dispersed to both sides. The multiple connecting plates of the housing 100 act as physical barriers, shielding electric field interference between adjacent phases to a certain extent, reducing local electric field concentration and interphase coupling strength.

[0028] like Figure 2 As shown, when viewed from the front, the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are visually aligned on the same plane. For a clearer illustration of the specific arrangement and connection relationships of these three interrupters, please refer to [reference needed]. Figure 3 , Figure 3 The structures of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 are individually labeled in the text.

[0029] Reference Figure 4The connecting mechanism 240 includes three sets of transmission components respectively corresponding to the first vacuum interrupter 210, the second vacuum interrupter 220 and the third vacuum interrupter 230. Each set of transmission components is provided with a support crank arm 241, a first insulating pull rod 242 and a phase crank arm 243. One end of each support crank arm 241 is connected to the corresponding vacuum interrupter, the other end of each support crank arm 241 is connected to one end of the corresponding first insulating pull rod 242, the other end of each first insulating pull rod 242 is connected to one end of the corresponding phase crank arm 243, and the other end of each phase crank arm 243 is connected to the first main shaft 110.

[0030] It should be noted that each transmission assembly includes a support crank arm 241, a first insulating pull rod 242, and a phase crank arm 243. One end of the phase crank arm 243 is fixed to the first main shaft 110, and the other end of the phase crank arm 243 is short-circuited to the lower end of the first insulating pull rod 242. The upper end of the first insulating pull rod 242 is hinged to one end of the support crank arm 241. The other end of the support crank arm 241 is directly connected to the moving contact (or moving end) of the vacuum interrupter. When the switching mechanism 300 drives the first main shaft 110 to rotate, the three phase crank arms 243 fixed on the first main shaft 110 rotate synchronously. The swing of each phase crank arm 243 will pull the corresponding first insulating pull rod 242 to move up and down reciprocally. The first insulating pull rod 242 then pulls the bracket crank arm 241, causing it to rotate around its own fixed fulcrum, and finally transmits the vertical pulling force or pushing force to the moving contact of the vacuum interrupter, so as to achieve close contact or rapid separation between the moving contact and the stationary contact.

[0031] Specifically, this embodiment introduces a support crank arm 241, changing the direction of force and stroke ratio. This means that a small rotation of the phase crank arm 243 is sufficient to drive the support crank arm 241 to generate sufficient linear displacement via the first insulating rod 242, ensuring the required overtravel and opening distance of the vacuum interrupter, while simultaneously reducing the required angular accuracy of the first main shaft 110. Furthermore, the three phase crank arms 243 are independently mounted on the first main shaft 110, achieving mechanical synchronization through the rigid connection of the first main shaft 110. This ensures that the three-phase circuit of the vacuum circuit breaker is simultaneously connected or disconnected, avoiding asynchrony issues caused by phase-by-phase operation. Further, the first insulating rod 242, as a key insulating isolation component, effectively separates the first main shaft 110 and phase crank arms 243, located at ground potential, from the vacuum interrupter and support crank arms 241, located at high voltage potential. Its length and surface creepage distance can be flexibly designed according to the voltage level, significantly increasing the creepage distance within the limited space of the enclosure 100. In addition, each transmission component is an independent linkage mechanism, so any jamming or mechanical failure in one phase will not directly affect other phases (except for the common input of the first spindle 110), which facilitates troubleshooting and maintenance.

[0032] Reference Figure 2 and Figure 5 The actuator 200 is also provided with a buffer device 260, which includes a buffer crank arm 261, a first roller 262, a buffer bracket 263, a buffer oil cup 264, and a ejector pin 265. One end of the buffer crank arm 261 is connected to the first spindle 110, the first roller 262 is disposed at the other end of the buffer crank arm 261, the buffer oil cup 264 is disposed on the buffer bracket 263, and the ejector pin 265 is retractably disposed outside the buffer oil cup 264. When the first spindle 110 rotates to a predetermined angle, the first roller 262 abuts against the outer end face of the ejector pin 265.

[0033] It should be noted that one end of the buffer crank arm 261 is fixedly connected to the first main shaft 110 and rotates synchronously with the first main shaft 110; the first roller 262 is installed at the other end of the buffer crank arm 261 as an actuator that contacts the buffer component. The buffer oil cup 264 is fixedly installed on the buffer bracket 263, while the ejector pin 265 is retractably disposed outside the buffer oil cup 264, that is, one end of the ejector pin 265 extends into the oil cavity inside the buffer oil cup 264 and couples with the damping mechanism (such as a spring, throttle orifice, etc.), and the other end protrudes from the end face of the oil cup. When the first main shaft 110 rotates to a predetermined angle (i.e., when the opening or closing action is close to the end position), the outer circular surface of the first roller 262 on the buffer crank arm 261 abuts against the outer end face of the ejector pin 265.

[0034] The buffer device 260 effectively suppresses the mechanical impact at the end of the circuit breaker's opening or closing. Without buffering, when the first main shaft 110 drives the moving contact of the vacuum interrupter to the end point, the moving parts will experience a violent impact due to inertia, which will not only generate high-decibel noise but may also cause the moving contact to bounce, the vacuum interrupter shell to crack, or the transmission parts to fatigue and be damaged. In this embodiment, the buffer oil cup 264 provides linear or nonlinear damping at the end of the stroke, so that the angular velocity of the first main shaft 110 is gradually reduced, and the moving contact stops at the end position at a safe speed, thereby significantly extending the service life of the vacuum interrupter and the transmission mechanism 250. Furthermore, the buffer device 260 is directly linked to the first main shaft 110 through the buffer crank arm 261, requiring no additional power source or electrical control. It has a compact structure, timely response, and is unaffected by external power fluctuations, resulting in high reliability. In addition, the first roller 262 and the ejector pin 265 are in rolling contact, resulting in low friction, smooth operation, and less likelihood of jamming or wear. At the same time, the buffer starting point in the opening and closing speed characteristics can be precisely set by the angle of the buffer crank arm 261, which facilitates fine-tuning according to the mechanical characteristic curve during the debugging process.

[0035] Reference Figure 1 and Figure 2The switching mechanism 300 includes an isolating handle 310, an opening / closing indicator 320, and a mechanism cover 330. The middle part of the isolating handle 310 is connected to the second main shaft 410 and is used to drive the second main shaft 410 to rotate. A linkage mechanism 340 is provided between the first main shaft 110 and the second main shaft 410. The linkage mechanism 340 is used to transmit the rotational motion of the second main shaft 410 to the first main shaft 110, thereby driving the first main shaft 110 to rotate and adjust the opening / closing status of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230. The opening / closing indicator 320 is connected to the first main shaft 110 and is used to indicate the opening / closing status of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230. Both the opening / closing indicator 320 and the isolating handle 310 are located outside the mechanism cover 330.

[0036] It should be noted that the middle part of the isolating handle 310 is directly fixedly connected to the second main shaft 410. When the operator rotates the isolating handle 310, the second main shaft 410 rotates accordingly. A linkage mechanism 340 is provided between the first main shaft 110 and the second main shaft 410. The linkage mechanism 340 can accurately transmit the rotational motion of the second main shaft 410 to the first main shaft 110, thereby driving the first main shaft 110 to rotate. Since the first main shaft 110 is connected to the moving contacts of the first vacuum interrupter 210, the second vacuum interrupter 220, and the third vacuum interrupter 230 through the connecting mechanism 240 mentioned above, the rotation of the first main shaft 110 directly adjusts the opening and closing state of the vacuum interrupter. The opening and closing indicator device 320 is mechanically connected to the first main shaft 110 and can display the words or symbols of opening or closing in real time, following the position change of the first main shaft 110. The isolating handle 310 and the opening / closing indicator 320 are both located outside the mechanism cover 330, so that operation and observation can be completed without opening the mechanism cover 330.

[0037] Because the isolating handle 310 simultaneously drives the second main shaft 410 (controlling the isolating mechanism 400) and the first main shaft 110 (controlling the disconnection actuator) through the linkage mechanism 340, as long as the linkage mechanism 340 is designed according to the sequence of circuit breaker opening first and disconnecting switch opening later or disconnecting switch closing first and circuit breaker closing later, serious misoperation of opening and closing the disconnecting switch under load can be eliminated. Operators do not need additional steps or judgment; they only need to turn the isolating handle 310 to safely complete the entire power outage or power restoration process, greatly improving the safety of power operations. Furthermore, the opening and closing indicator 320 is directly driven by the first main shaft 110, effectively reflecting the current mechanical position of the vacuum interrupter contacts, rather than the signal from the electrical auxiliary contacts. Therefore, it has higher reliability and anti-interference capability, and there is no risk of misindication due to auxiliary switch failure or line abnormality.

[0038] Reference Figure 6The opening and closing indicator device 320 includes a chain shaft 321, a transmission plate 322, a transmission clamp 323, and a pointer 324. One end of the chain shaft 321 is connected to the second main shaft 410, and the other end of the chain shaft 321 is connected to one end of the transmission plate 322. The other end of the transmission plate 322 is connected to one end of the transmission clamp 323, and the other end of the transmission clamp 323 is connected to the pointer 324. When the first main shaft 110 or the second main shaft 410 rotates, the pointer 324 swings with the first main shaft 110 or the second main shaft 410 under the action of the linkage mechanism 340 to indicate the opening and closing status of the vacuum interrupter.

[0039] It should be noted that the opening / closing indicator 320 is composed of a locking shaft 321, a transmission plate 322, a transmission clamping plate 323, and a pointer 324 connected in sequence. One end of the locking shaft 321 is fixedly connected to the second main shaft 410, and the other end is hinged or fixedly connected to one end of the transmission plate 322. The other end of the transmission plate 322 is connected to one end of the transmission clamping plate 323. The pointer 324 is mounted on the other end of the transmission clamping plate 323. When the operator rotates the isolating handle 310 to drive the second main shaft 410 to rotate, the locking shaft 321 rotates accordingly, causing the transmission plate 322 to undergo planar motion. The transmission plate 322 then pushes the transmission clamping plate 323 to swing around its own axis, ultimately driving the pointer 324 to rotate to the corresponding position. Since the second main shaft 410 is mechanically coupled to the first main shaft 110 through the linkage mechanism 340, the state change of the first main shaft 110 will also be transmitted to the second main shaft 410 in the reverse direction. Therefore, whether the first main shaft 110 or the second main shaft 410 rotates, the transmission chain can make the pointer 324 accurately follow the angular displacement of the main shaft, thereby indicating the opening and closing status of the first vacuum interrupter 210, the second vacuum interrupter 220 and the third vacuum interrupter 230.

[0040] Specifically, since the driving source of pointer 324 comes from the second main shaft 410, and the second main shaft 410 is simultaneously controlled by the isolating handle 310 and associated with the first main shaft 110 through the linkage mechanism 340, the position displayed by pointer 324 actually reflects the combined logical state of the first main shaft 110 (vacuum interruptor opening and closing) and the second main shaft 410 (isolating switch opening and closing). Only one pointer 324 needs to be observed to determine the on / off status of the entire device, avoiding potential misreadings from multiple indicators. Furthermore, the transmission plate 322 and transmission clamp 323 can flexibly adjust the lever ratio, thereby ensuring a suitable correspondence between the swing angle of pointer 324 and the actual rotation angle of the first main shaft 110. This facilitates the installation of a clear, large-angle indicator dial outside the mechanism cover 330, improving visibility. In addition, the interlocking shaft 321 is directly connected to the second main shaft 410, which is located on the second side of the housing 100 and extends to the vicinity of the mechanism cover 330. This allows the entire indicator device to be compactly installed inside or outside the mechanism cover 330 and arranged side by side with the isolation handle 310 on the outside of the mechanism cover 330. This makes it convenient for maintenance personnel to observe directly with binoculars or the naked eye under the tower without having to climb or open the mechanism cover 330.

[0041] Reference Figure 6 and Figure 7 The linkage mechanism 340 includes a bearing seat 341, a shaft plate 342, a second roller 343, and a bending plate 344. The shaft plate 342 is provided with a first recess 3421. One side of the bearing seat 341 is connected to the pointer 324, and the other side of the bearing seat 341 is connected to the shaft plate 342. The first recess 3421 of the shaft plate 342 abuts against the outer surface of the second roller 343. The bottom of the second roller 343 is connected to one end of the bending plate 344, and the other end of the bending plate 344 is connected to the first main shaft 110.

[0042] It should be noted that when the first main shaft 110 rotates due to the operation of the switching mechanism 300 or the isolating handle 310, the bending plate 344 swings synchronously with the first main shaft 110, driving the second roller 343 to move along an arc. Since the second roller 343 always maintains contact with the first recess 3421 of the shaft plate 342, the movement of the second roller 343 forces the shaft plate 342 to rotate around its own rotation center. The rotation of the shaft plate 342 is transmitted to the pointer 324 through the bearing seat 341, causing the pointer 324 to swing and indicate the opening and closing status of the vacuum interrupter. This linkage mechanism 340 directly establishes the mechanical transmission relationship between the first main shaft 110 and the pointer 324, while the rotation of the first main shaft 110 is directly determined by the second main shaft 410 through other linkage links (or directly driven by the switching mechanism 300). Therefore, the pointer 324 can accurately reflect the actual working status of the circuit breaker.

[0043] Furthermore, since the bearing housing 341 isolates the pointer 324 from the shaft plate 342, it provides stable rotational support for the pointer 324 and allows the pointer 324 to extend to the outside of the mechanism cover 330, leaving only the motion conversion components inside the housing 100, thereby improving the dustproof and waterproof capabilities of the housing 100. In addition, the linkage mechanism 340 is independent of the other indication path from the second main shaft 410 through the interlocking shaft 321, the transmission plate 322, and the transmission clamp 323 to the pointer 324, providing mechanical redundancy for the opening and closing indication. Even if one path becomes loose or malfunctions, the other path can still guarantee the basic indication function, thereby enhancing the overall performance of the machine.

[0044] Reference Figure 8 The isolation mechanism 400 includes a mechanism support 420 and three sets of isolation components 430 respectively arranged corresponding to the first vacuum interrupter 210, the second vacuum interrupter 220 and the third vacuum interrupter 230. The mechanism support 420 is arranged on the second side of the housing 100. Each set of isolation components 430 is provided with a first insulating support 431, a second insulating support 432, a first blade holder 433, a second blade holder 434, an isolation blade 435, a second insulating pull rod 436, a pull rod joint 437 and a pull rod crank arm 438. One end of the first insulating support 431 and the second insulating support 432 are connected to the mechanism support 420. The other end of the first insulating support 431 is connected to the first end of the first tool holder 433, the other end of the second insulating support 432 is connected to the first end of the second tool holder 434, the second end of the first tool holder 433 is connected to one end of the isolation blade 435, the second end of the second tool holder 434 is connected to the other end of the isolation blade 435, the third end of the first tool holder 433 is connected to the output terminal of the corresponding vacuum interrupter, one end of the second insulating pull rod 436 is connected to the isolation blade 435 through the pull rod joint 437, and the other end of the second insulating pull rod 436 is connected to the second spindle 410 through the pull rod crank arm 438.

[0045] It should be noted that the first insulating support 431 and the second insulating support 432 lift the knife holder and the isolating blade 435 to a certain height, so that the knife holder and the isolating blade 435 form a sufficient air gap and surface creepage distance between the grounded mechanism support 420 and the housing 100. At the same time, the first insulating support 431 and the second insulating support 432 together form a stable parallel support structure, which enhances the bending stiffness and dynamic and thermal stability of the isolating blade 435 in the closed state.

[0046] Specifically, the isolating blade 435 is connected to the first blade holder 433 and the second blade holder 434 at both ends. When the circuit is closed, the current path is the outgoing terminal, the first blade holder 433, the isolating blade 435, and the second blade holder 434. The isolating blade 435 itself is a fluid conductor, eliminating the need for additional flexible connections, resulting in a simple structure and reliable contact. When the circuit is opened, the isolating blade 435 rotates away from the blade holder, forming a clear and visible break, facilitating on-site personnel to confirm that the equipment is in an isolated state. Furthermore, the second insulating pull rod 436 serves as a transmission element. One end is connected to the isolating blade 435 via a pull rod connector 437, and the other end is connected to the second main shaft 410 via a pull rod crank arm 438. This achieves both electrical insulation between the second main shaft 410 and the high-voltage side isolating blade 435 and provides sufficient mechanical strength. In addition, each isolation assembly 430 is independently mounted on the mechanism bracket 420, and the insulating supports, blade holders, pull rods, etc., in each assembly have regular shapes, facilitating positioning, assembly, and testing by automated equipment.

[0047] The inlet terminals 270 and outlet terminals 280 of the first vacuum interrupter 210, the second vacuum interrupter 220 and the third vacuum interrupter 230 are all straight terminals, and the shape, size and orientation of the straight terminals are the same as each other. The straight terminals are bent at ninety degrees through the conductive connection bar and then extend vertically downward to form the lower outlet terminal.

[0048] It should be noted that standardizing the incoming and outgoing terminals to be straight terminals of the same specification completely standardizes the conductive interfaces of the three arc-extinguishing chambers. Furthermore, by uniformly bending the connecting strip at a 90-degree angle and leading it vertically downwards, all outgoing terminals that might have faced different directions (e.g., horizontal or oblique) are aligned to face downwards without altering the vertical installation layout of the arc-extinguishing chambers. The conductive connecting strip acts as a transition component; one end is reliably connected to the straight terminal (e.g., by bolting or welding), while the other end is bent and extends downwards, serving both extension and deflection purposes while avoiding the need for complex, irregularly shaped terminals on the arc-extinguishing chamber itself.

[0049] It should be noted that the three straight terminals are identical in shape, size, and orientation, so there is no need to distinguish between phases or the left and right directions of the terminals on the assembly line. During production, the same set of fixtures and fastening parameters can be used to install all terminals, thereby reducing tooling investment and shortening changeover time. Furthermore, the connectors use a uniform 90-degree bend, and the length of the lower cable outlet is consistent, facilitating batch processing using automated bending equipment and enabling standard connection with external cables or busbars.

[0050] Both incoming and outgoing terminals adopt a straight terminal design, which helps to improve the electric field distribution of the vacuum circuit breaker and effectively increase the creepage distance. The straight terminals themselves have no sharp corners or irregular protrusions, and the surface of the bent connection bar is smooth and the direction is regular, which significantly reduces the local field concentration phenomenon around the high-voltage end. In addition, the vertical downward lead-out method keeps the live parts away from the side wall of the enclosure and other phase lines, making it easy to install insulating sleeves or phase-to-phase insulating partitions.

[0051] In this embodiment, both the incoming terminal 270 and the outgoing terminal 280 are straight terminals, which effectively simplifies on-site wiring operations. With all outgoing terminals facing the ground, operators can connect cable heads or grounding wires from below during operations, eliminating the need to search for terminals in different directions on the narrow side of the enclosure 100, thus reducing the risk of incorrect wiring. Furthermore, the standardized design facilitates modular expansion. For example, current transformers or zero-sequence transformers can be uniformly installed at the outgoing terminals, eliminating the need to customize different mounting brackets for each phase.

[0052] Each vacuum interrupter is equipped with an insulating cover. It should be noted that the insulating cover significantly extends the creepage distance between the high-voltage energized parts of the interrupter (such as the metal end caps and ceramic shell surface) and adjacent phases, as well as to the grounding box 100. In humid, condensation-prone, or heavily polluted environments, the surface of the insulating cover is designed with awnings or corrugations to effectively block the formation path of leakage current, thereby significantly reducing the risk of surface flashover. Simultaneously, the insulating cover isolates each phase of the interrupter from each other, acting as an interphase insulation partition. Even if an insulation fault occurs in one phase, it can effectively limit the fault from affecting adjacent phases. The insulating cover (especially the structure with an internal structure that fits tightly against the interrupter surface or has appropriate air gaps) can effectively improve the electric field concentration phenomenon around the metal parts at the end of the interrupter. By selecting appropriate insulating materials (such as epoxy resin or silicone rubber) and shapes (such as adding equalizing rings or stress cone structures), the insulating cover can shield and homogenize the electric field, reduce the local maximum field strength, reduce the probability of partial discharge, and thus improve the long-term service life of the vacuum circuit breaker.

[0053] Reference Figure 9The transmission mechanism 250 includes a main shaft drive crank arm 251, a first connecting rod 252, and an intermediate rocker arm 253. One end of the main shaft drive crank arm 251 is connected to the first main shaft 110, and the other end of the main shaft drive crank arm 251 is connected to one end of the first connecting rod 252. The other end of the first connecting rod 252 is connected to the driving end of the intermediate rocker arm 253, and the driven end of the intermediate rocker arm 253 is connected to the second vacuum interrupter 220. When the first main shaft 110 rotates, the main shaft drive crank arm 251 drives the intermediate rocker arm 253 to swing through the first connecting rod 252. The direction of movement of the driven end is opposite to the direction of movement of the driving end, so as to drive the moving contact of the second vacuum interrupter 220 to produce a displacement in the same direction as the moving contact of the first vacuum interrupter 210 and the third vacuum interrupter 230 relative to their respective stationary contacts.

[0054] It should be noted that the transmission mechanism 250, through the lever action of the intermediate rocker arm 253, converts the rotational motion of the first main shaft 110 into an output motion in the opposite direction, thereby driving the second vacuum interrupter 220, which is installed in the opposite direction, to synchronously complete the opening and closing of the circuit breaker with the first vacuum interrupter 210 and the third vacuum interrupter 230. When the switching mechanism 300 drives the first main shaft 110 to rotate, the main shaft drive crank arm 251 fixed on the first main shaft 110 rotates accordingly, driving the first connecting rod 252 to move; the other end of the first connecting rod 252 is connected to the active end of the intermediate rocker arm 253, pushing the active end to swing; due to the lever principle, the driven end of the intermediate rocker arm 253 generates a swing in the opposite direction to the active end, and this reverse swing directly drives the moving contact of the second vacuum interrupter 220 to move along its axial direction. Because the installation direction of the second vacuum interrupter 220 (i.e., the relative position of the moving and stationary contacts) is completely opposite to that of the first vacuum interrupter 210 and the third vacuum interrupter 230, the reverse motion output from the driven end causes the moving contact of the second vacuum interrupter 220 to produce a displacement in the same direction as the moving contact of the first vacuum interrupter 210 and the third vacuum interrupter 230 relative to their respective stationary contacts, thereby achieving simultaneous closing or opening of the three phases. Since the transmission mechanism 250 allows the high-voltage end of the second vacuum interrupter 220 to extend towards the bottom (or top) of the enclosure 100, while the high-voltage ends of the first vacuum interrupter 210 and the third vacuum interrupter 230 extend in the opposite direction, the upper and lower insulation spaces in the height direction of the enclosure 100 are fully utilized, significantly increasing the creepage distance to ground and improving the insulation tolerance of the equipment in harsh environments such as condensation and pollution.

[0055] It should be noted that the length ratio of the driving arm to the driven arm of the intermediate rocker arm 253 can be designed as needed, and the stroke and speed of the moving contact of the second vacuum interrupter 220 can be adjusted to match the mechanical characteristics of the first vacuum interrupter 210 and the third vacuum interrupter 230, so as to optimize the overall operation performance.

[0056] Each vacuum interrupter is equipped with a flange between itself and the outgoing terminal. It should be noted that the flange ensures a low-resistance, highly reliable electrical connection between the outgoing terminal and the conductive rod inside the interrupter. The flange is made of a highly conductive metal (such as copper or aluminum alloy), and its contact surface is precision-machined to ensure sufficient contact pressure and contact area, reducing contact resistance and preventing overheating during operation. Simultaneously, the uniform compression structure of the flange helps eliminate partial discharge points, preventing temperature rise or arcing caused by poor contact. Furthermore, the flange serves as a base for installing insulating covers or shielding covers, facilitating the connection of insulating sleeves, increasing creepage distance, and improving insulation levels to ground and between phases.

[0057] The above provides a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A pole-mounted vacuum circuit breaker with an improved arc-extinguishing device, characterized in that, include: A housing having a first side and a second side opposite to each other, and a rotatable first main shaft provided inside the housing, the first main shaft extending along the length direction of the housing and located at the middle of the height direction of the housing; An actuator is disposed inside the housing. The actuator comprises a vertically mounted first vacuum interrupter, a second vacuum interrupter, and a third vacuum interrupter. The actuator also includes a connecting mechanism and a transmission mechanism. The first and third vacuum interrupters are respectively connected to a first main shaft via a transmission mechanism. The second vacuum interrupter is connected to the first main shaft via the transmission mechanism. The installation directions of the first and third vacuum interrupters are opposite to those of the second vacuum interrupter. The connecting mechanism converts the rotational motion of the first main shaft into linear motion to drive the moving contacts of the first and third vacuum interrupters to move along a first direction. The transmission mechanism converts the rotational motion of the first main shaft into reverse linear motion to drive the moving contacts of the second vacuum interrupter to move along a second direction opposite to the first direction. A switching mechanism is provided on the first side of the housing and connected to the first main shaft. The switching mechanism is used to drive the first main shaft to rotate. An isolation mechanism is provided on the second side of the housing. The isolation mechanism is connected to the output terminals of the first vacuum interrupter, the second vacuum interrupter and the third vacuum interrupter respectively. The isolation mechanism is provided with a second main shaft, which is connected to the switching mechanism so that the isolation mechanism moves in accordance with the movement of the switching mechanism.

2. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, The actuator is also provided with a buffer device, which includes a buffer crank arm, a first roller, a buffer bracket, a buffer oil cup, and a ejector pin. One end of the buffer crank arm is connected to the first main shaft, the first roller is disposed at the other end of the buffer crank arm, the buffer oil cup is disposed on the buffer bracket, and the ejector pin is retractably disposed outside the buffer oil cup. When the first main shaft rotates to a predetermined angle, the first roller abuts against the outer end face of the ejector pin.

3. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, The switching mechanism includes an isolating handle, an opening / closing indicator, and a mechanism cover. The middle part of the isolating handle is connected to the second main shaft and is used to drive the second main shaft to rotate. A linkage mechanism is provided between the first main shaft and the second main shaft. The linkage mechanism is used to transmit the rotational motion of the second main shaft to the first main shaft, driving the first main shaft to rotate, so as to adjust the opening / closing status of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. The opening / closing indicator is used to indicate the opening / closing status of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter. Both the opening / closing indicator and the isolating handle are located outside the mechanism cover.

4. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 3, characterized in that, The opening and closing indicator device includes a chain shaft, a transmission plate, a transmission clamp, and a pointer. One end of the chain shaft is connected to the second main shaft, and the other end of the chain shaft is connected to one end of the transmission plate. The other end of the transmission plate is connected to one end of the transmission clamp, and the other end of the transmission clamp is connected to the pointer. When the first main shaft or the second main shaft rotates, the pointer swings with the first main shaft or the second main shaft under the action of the linkage mechanism to indicate the opening and closing status of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter.

5. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 4, characterized in that, The linkage mechanism includes a bearing housing, a shaft plate, a second roller, and a bending plate. The shaft plate is provided with a first recess. One side of the bearing housing is connected to the pointer, and the other side of the bearing housing is connected to the shaft plate. The first recess of the shaft plate abuts against the outer surface of the second roller. The bottom of the second roller is connected to one end of the bending plate, and the other end of the bending plate is connected to the first main shaft.

6. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, The isolation mechanism includes a support frame and three sets of isolation components corresponding to the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter, respectively. The support frame is located on the second side of the housing. Each set of isolation components includes a first insulating support post, a second insulating support post, a first cutter holder, a second cutter holder, an isolation blade, a second insulating pull rod, a pull rod connector, and a pull rod crank arm. One end of the first insulating support post and the second insulating support post are connected to the support frame. The other end of the first insulating support post is connected to the first end of the first cutter holder, and the other end of the second insulating support post is connected to the first end of the second cutter holder. The second end of the first cutter holder is connected to one end of the isolation blade, and the second end of the second cutter holder is connected to the other end of the isolation blade. The third end of the first cutter holder is connected to the output terminal of the corresponding vacuum interrupter. One end of the second insulating pull rod is connected to the isolation blade through the pull rod connector, and the other end of the second insulating pull rod is connected to the second main shaft through the pull rod crank arm.

7. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, The inlet and outlet terminals of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter are all straight terminals, and the shape, size, and orientation of the straight terminals are the same as each other. The straight terminals are bent at ninety degrees through conductive connecting strips and then extend vertically downward to form the lower outlet terminal.

8. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, The transmission mechanism includes a main shaft drive crank arm, a first connecting rod, and an intermediate rocker arm. One end of the main shaft drive crank arm is connected to the first main shaft, and the other end of the main shaft drive crank arm is connected to one end of the first connecting rod. The other end of the first connecting rod is connected to the driving end of the intermediate rocker arm, and the driven end of the intermediate rocker arm is connected to the second vacuum interrupter. When the first main shaft rotates, the main shaft drive crank arm drives the intermediate rocker arm to swing through the first connecting rod. The direction of movement of the driven end is opposite to the direction of movement of the driving end, so as to drive the moving contact of the second vacuum interrupter to produce a displacement in the same direction as the moving contact of the first vacuum interrupter and the third vacuum interrupter relative to their respective stationary contacts.

9. The pole-mounted vacuum circuit breaker with an improved arc-extinguishing device according to claim 1, characterized in that, Each of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter is provided with a flange between itself and the corresponding outgoing terminal.

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