An air tank and longitudinal knife-switch type three-position isolating switch of an air chamber

Abstract

The application belongs to the technical field of electrical equipment, and particularly relates to a gas-filled cabinet gas tank and a longitudinal knife-switch three-position isolating switch. The gas tank body comprises an upper gas-filled gas tank and a lower gas-filled gas tank. The longitudinal knife-switch three-position isolating switch is installed in the upper gas-filled gas tank, and a circuit breaker switch is installed in the lower gas-filled gas tank. The two gas-filled gas tanks are connected through upper and lower gas tank connecting insulators. The longitudinal knife-switch three-position isolating switch has three-phase units which are arranged in the same structure and longitudinally separated. Each phase unit comprises a closing contact, a moving contact and a grounding contact. The grounding contact is fixed on a grounding row and directly contacts the grounding row. The longitudinal knife-switch three-position isolating switch solves the problems of complex structure, troublesome operation and incapability of meeting miniaturization of the current three-position isolating switch for gas-filled cabinets to a certain extent, reduces the height of the isolating gas tank and realizes the miniaturization requirement of the gas-filled cabinet.

Description

Technical Field

[0001] This invention belongs to the field of electrical equipment technology, and particularly relates to a gas-filled switchgear gas box and a longitudinal knife switch type three-position disconnecting switch. Background Technology

[0002] Gas-insulated switchgear refers to gas-insulated AC metal-enclosed switchgear, characterized by its compact structure and small footprint. The circuit breaker and three-position disconnector are entirely sealed within a stainless steel gas chamber, using low-pressure gas as the insulating medium. This isolates the switchgear from the external environment, enabling stable operation even in harsh conditions such as condensation, pollution, and salt spray, unaffected by external environmental factors. However, current gas-insulated switchgear chambers have relatively weak structural strength, failing to meet the requirements of high-altitude operations. Knife-type three-position disconnectors typically utilize a transmission structure composed of bevel gears, hexagonal shafts, and crank arms. Controlling the blade's position by adjusting the bevel gear's rotation angle is challenging; even slight changes in the bevel gear's rotation angle can cause significant oscillation in the blade segment, reducing the accuracy of blade position control. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the issues of complex structure, cumbersome operation, and inability to meet miniaturization requirements of current three-position disconnect switches for gas-insulated switchgear. Therefore, the present invention provides a gas-insulated switchgear gas box and a longitudinal knife switch type three-position disconnect switch, which reduces the height of the disconnecting gas box and improves the longitudinal layout phase spacing, resulting in superior insulation performance.

[0004] To solve the above-mentioned technical problems, the present invention provides a gas-filled switchgear box and a longitudinal knife-switch type three-position disconnecting switch, comprising a box body, an operating mechanism, and a switch. The box body includes an upper gas-filled box and a lower gas-filled box. The longitudinal knife-switch type three-position disconnecting switch is installed in the upper gas-filled box, and a circuit breaker switch is installed in the lower gas-filled box. The two gas-filled boxes are connected by an upper and lower gas-filled box connecting insulator. The longitudinal knife-switch type three-position disconnecting switch has three-phase units with identical structures arranged longitudinally. Each phase unit includes a connecting contact, a moving contact, and a grounding contact. The connecting contact is fixed in the middle position of the main busbar. The main busbar has mounting holes, and the position of the connecting contact can be adjusted on the main busbar. The surface of the connecting contact is smooth and has a parallel surface as a connecting plane. The grounding contact is fixed on the grounding busbar and is in direct contact with the grounding busbar.

[0005] Furthermore, the lower panel of the lower inflation box has mounting holes, and a conical insulator is provided on the lower panel. The conical insulator is fixed to the lower panel of the lower inflation box by bolts. The upper panel of the lower inflation box has mounting holes, and upper and lower connecting insulators are fixed to the upper panel of the lower inflation box by bolts. The left and right side panels of the upper inflation box have mounting holes, and side parallel insulators are fixed to the left and right side panels of the upper inflation box by bolts. The side parallel insulators are symmetrically distributed.

[0006] Furthermore, the operating mechanism includes a circuit breaker spring operating mechanism and an isolating operating mechanism. The circuit breaker spring operating mechanism has a bellows assembly connected to the insulating pull rod of the circuit breaker switch. The isolating operating mechanism has a dynamic seal connected to a longitudinal knife-switch type three-position isolating switch to realize the opening and closing functions of the switch. The output spindle of the isolating operating mechanism is a hexagonal shaft with a cylindrical end for positioning the output spindle. A bushing is welded to the front panel of the gas box, and a bearing is installed inside the bushing. The main shaft end of the mechanism is fitted with a bearing; the output main shaft of the isolation operating mechanism is fitted with a crank arm, which is connected to a connecting rod via a pin; one end of the connecting rod is hinged to the crank arm, and the other end of the connecting rod is provided with a screw threaded to it; a second crank arm is provided on the screw, which is hinged to it, and the relative position between the two crank arms can be adjusted by rotating the thread between the screw and the connecting rod; the second crank arm is dynamically sealed to the longitudinal knife switch type three-position disconnect switch, thereby realizing the control of the longitudinal knife switch type three-position disconnect switch by the isolation operating mechanism.

[0007] Furthermore, the moving contact is composed of four identical contact blades, which are fixed on the contact support. The contact support is welded together from a pad and a connecting plate. The connecting plate has a positioning hole that corresponds to the mounting hole of the moving contact. The four contact blades are fixed to the connecting plate by pins, springs, and bolts, and the four contact blades are symmetrically distributed in pairs.

[0008] Furthermore, the longitudinal knife-switch type three-position disconnect switch also includes an insulating pull rod, a three-position main shaft, and a dynamic seal; the dynamic seal is fixedly installed on the front panel of the gas box and sealed to the front panel of the gas box; one end of the three-position main shaft is inserted into the dynamic seal; a bushing is welded to the rear panel of the upper gas box, and the other end of the three-position main shaft is rotatably fixed on the bushing, with a bearing installed inside the bushing; one side of the insulating pull rod is rotatably connected to the three-position main shaft, and the other side is rotatably connected to the three-position contact bracket, and the contact bracket and the three-position main shaft are insulated from each other.

[0009] Furthermore, the gas box body is provided with a sealing joint for adding gas. The sealing joint includes a housing connected to the gas box body, a partition plate inside the housing, and a valve core for sealing on the partition plate. The valve core can contact the partition plate, one end of the valve core is connected to a fixed bracket and can move relative to it, the fixed bracket is located on the side of the valve core near the inside of the gas box body, and the other end of the valve core contacts the partition plate. The valve core is slidably connected to a valve core rod, the valve core rod is connected to the fixed bracket, and a first elastic element is fitted on the valve core rod. The sealing joint also has a matching inflation joint, the inflation joint including an inflation sleeve, the inflation sleeve being close to... A floating locking ring is provided on one side near the valve core. A vent hole for gas to flow through is opened on the side of the inflation sleeve near the valve core. The diameter of the vent hole is smaller than the diameter of the floating locking ring. The floating locking ring can slide axially relative to the inflation sleeve. When the floating locking ring is in contact with the inflation sleeve, it can prevent gas from flowing from the inflation sleeve to the valve core. A floating bracket is fitted on the outer side of the floating locking ring. A second elastic element is provided between the floating locking ring and the inflation sleeve. A groove is opened on the side of the floating locking ring near the inflation sleeve, and the second elastic element is disposed inside the groove.

[0010] This invention employs a longitudinal knife-switch type three-position disconnecting switch, which to some extent solves the problems of complex structure, cumbersome operation, and inability to meet miniaturization requirements of current three-position disconnecting switches used in gas-filled switchgear. It reduces the height of the isolation gas box, meeting the miniaturization requirements of the gas-filled switchgear. The operating mechanism of this invention is directly connected to the three-position main shaft via connecting rods and crank arms, controlling the contact bracket to achieve the opening and closing operations of the three-position disconnecting switch. This results in a simple structure and convenient operation. It avoids the problems of previous knife-switch type three-position disconnecting switches that used bevel gears, hexagonal shafts, crank arms, and other components to form a transmission structure to control the movement of the blades, making it difficult to guarantee the accuracy of blade control. Attached Figure Description

[0011] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a front view structural diagram of the gas chamber of the gas holder in this invention; Figure 2 This is a schematic diagram of the main structure of the gas tank body of the gas-filled cabinet in this invention; Figure 3 This is a front view of the longitudinal knife-switch type three-position disconnector in this invention; Figure 4 This is a three-dimensional structural diagram of the isolation operation mechanism in this invention; Figure 5 This is a schematic diagram showing the installation relationship between the sealing joint and the inflation joint in this invention; Figure 6 This is a schematic diagram of the sealing joint in this invention; Figure 7This is a schematic diagram of the air inflator in this invention; In the diagram: 1-Gas box body, 101-Upper filling gas box, 102-Lower filling gas box, 103-Lower panel, 104-Upper panel, 105-Left and right side panels of the upper filling gas box, 2-Longitudinal knife switch type three-position disconnecting switch, 201-Connecting contact seat, 202-Moving contact, 203-Grounding contact seat, 205-Padded block, 206-Connecting plate, 207-Insulating pull rod, 208-Three-position main shaft, 209-Dynamic seal, 3-Circuit breaker switch, 4-Upper and lower gas box connecting insulator, 6-No. 3 cone insulator, 7-Side parallel insulator, 8-Circuit breaker spring operating mechanism, 9-Isolation operating mechanism, 9 01-Support frame, 902-Operating mechanism spindle end, 903-Crank arm, 904-Connecting rod, 905-Screw, 906-Crank arm two, 501-Housing, 502-Partition plate, 503-Valve core, 504-Fixed bracket, 505-Valve core rod, 506-First elastic element, 507-Inflatable sleeve, 508-Floating locking ring, 509-Ventilation hole, 510-Floating bracket, 511-Second elastic element. Detailed Implementation

[0012] See attached document Figure 1 This invention provides a gas-filled switchgear box and a longitudinal knife-switch type three-position disconnecting switch. The gas-filled switchgear box includes a box body 1, an operating mechanism, and a switch. The box body 1 includes an upper gas-filled box 101 and a lower gas-filled box 102. The upper gas-filled box 101 is equipped with a longitudinal knife-switch type three-position disconnecting switch 2, and the lower gas-filled box 102 is equipped with a circuit breaker switch 3. The two gas-filled boxes are connected by an upper and lower gas-filled box connecting insulator 4.

[0013] The gas-insulated switchgear uses low-pressure gas as the insulating medium and is sealed inside a stainless steel gas box, isolating it from the external environment.

[0014] The gas box body 1 is laser-welded from 3mm stainless steel plate. Stainless steel square tube 5 is welded inside the gas box body 1 to strengthen the strength of the box panel. The panel and the stainless steel square tube 5 are connected by laser penetration welding.

[0015] See Figure 2 The lower panel 103 of the lower inflation box 102 has mounting holes, and three cone insulators 6 are provided on the lower panel 103. The cone insulators 6 are fixed to the lower panel 103 of the lower inflation box 102 by bolts. The upper panel 104 of the lower inflation box 102 has mounting holes, and three upper and lower connecting insulators 4 are fixed to the upper panel 104 of the lower inflation box 102 by bolts. The left and right side plates of the upper inflation box 101 have mounting holes, and six side parallel insulators 7 are fixed to the left and right side plates 105 of the upper inflation box by bolts. The side parallel insulators 7 are symmetrically distributed.

[0016] The operating mechanism includes a circuit breaker spring operating mechanism 8 and an isolating operating mechanism 9. The circuit breaker spring operating mechanism 8 has a bellows assembly, which is connected to the insulating pull rod of the circuit breaker switch 3 through the bellows assembly. The isolating operating mechanism 9 has a dynamic seal 209, which is connected to the longitudinal knife switch type three-position isolating switch 2 through the dynamic seal 209 to realize the opening and closing functions of the switch.

[0017] See Figure 4 The isolation operation mechanism 9 has a support frame 901 at its end. The support frame 901 has four bolt fixing holes. Stainless steel studs are installed at the corresponding positions of the air box body 1. The isolation operation mechanism 9 ensures the fixed position of the mechanism through the corresponding fixing holes of the support frame. The output spindle of the isolation operating mechanism 9 is a hexagonal shaft with a cylindrical end for positioning the output spindle. A bushing 106 is welded to the front panel of the air box 1, containing a bearing. The end 902 of the operating mechanism spindle mates with the bearing. A crank arm 903 is fitted onto the output spindle of the isolation operating mechanism 9, and the crank arm 903 is connected to a connecting rod 904 via a pin. One end of the connecting rod 904 is hinged to the crank arm 903, and the other end of the connecting rod 904 is threadedly connected to a screw 905. A second crank arm 906 is hinged to the screw 905. By rotating the thread between the screw 905 and the connecting rod 904, the relative position between the two crank arms can be adjusted. The second crank arm 906 is connected to the longitudinal knife-switch type three-position disconnect switch 2 via a dynamic seal 209, enabling the isolation operating mechanism 9 to control the longitudinal knife-switch type three-position disconnect switch 2.

[0018] See Figure 3 The longitudinal knife-type three-position disconnect switch 2 has three phase units A, B, and C arranged longitudinally with the same structure. Each phase unit includes a connecting contact 201, a moving contact 202, and a grounding contact 203. The connecting contact 201 is fixed in the middle position of the main busbar. The main busbar has mounting holes, and the position of the connecting contact 201 can be adjusted on the main busbar. The surface of the connecting contact 201 is smooth and has a 19.8mm parallel surface as the connecting plane. The grounding contact 203 is fixed on the grounding busbar and is in direct contact with the grounding busbar.

[0019] When the main busbar of the assembly contactor 201 is installed on the side insulator 7, and the moving contact 202 rotates to the contact plane of the assembly contactor 201, a connected electrical circuit is formed inside the gas-filled cabinet.

[0020] See Figure 3 The moving contact 202 is composed of four identical contact blades, which are fixed on the contact bracket. The contact bracket is welded together from a pad 205 and a connecting plate 206. The connecting plate 206 is provided with positioning holes, which correspond one-to-one with the mounting holes of the moving contact 202. The four contact blades are fixed on the connecting plate 206 by pins, springs and bolts, and the four contact blades are symmetrically distributed in pairs.

[0021] See Figure 3 The longitudinal knife-switch type three-position disconnect switch 2 also includes an insulating pull rod 207, a three-position main shaft 208, and a dynamic seal 209. The dynamic seal 209 is fixedly installed on the front panel of the gas box and is sealed to the front panel of the gas box. The function is realized by the oil seal inside the dynamic seal 209. One end of the three-position main shaft 208 is inserted into the dynamic seal 209, and the dynamic seal 209 and the three-position main shaft 208 are installed at a specific angle. A bushing is welded to the rear panel of the upper gas box, and the other end of the three-position main shaft 208 is rotatably fixed on the bushing. The bushing contains a bearing. One side of the insulating pull rod 207 is rotatably connected to the three-position main shaft 208, and the other side is rotatably connected to the three-position contact bracket. An insulating connection is formed between the contact bracket and the three-position main shaft 208.

[0022] This invention, through the above structure, allows for the following operation: When the longitudinal knife-switch type three-position disconnector is in the disconnected position, the handle is inserted into the operating mechanism's disconnection operating hole. Rotating the handle clockwise causes the operating mechanism's main shaft to rotate. Through the crank arm, connecting rod, screw, and crank arm two, the three-position main shaft rotates counterclockwise by 60°, moving the moving contact to the closing contact seat, thus completing the change of the moving contact from the disconnected position to the closed position. When the longitudinal knife-switch type three-position disconnector is in the closed position, the handle is inserted into the operating mechanism's disconnection operating hole. Rotating the handle counterclockwise causes the operating mechanism's main shaft to rotate. Through the crank arm, connecting rod, screw, and crank arm two, the three-position main shaft rotates clockwise by 60°, moving the moving contact to the middle position, thus completing the change of the moving contact from the closed position to the disconnected position. When the longitudinal knife-switch type three-position disconnecting switch is in the isolating position, the handle is inserted into the grounding operation hole of the operating mechanism, and the handle is rotated clockwise. The handle drives the main shaft of the operating mechanism to rotate, which, through the crank arm, connecting rod, screw, and crank arm two, drives the three-position main shaft to rotate 60° clockwise. The moving contact moves to the grounding contact seat, completing the change of the moving contact from the isolating position to the grounding position. When the longitudinal knife-switch type three-position disconnecting switch is in the grounding position, the handle is inserted into the grounding operation hole of the operating mechanism, and the handle is rotated counterclockwise. The handle drives the main shaft of the operating mechanism to rotate, which, through the crank arm, connecting rod, screw, and crank arm two, drives the three-position main shaft to rotate 60° counterclockwise. The moving contact moves to the grounding contact seat, completing the change of the moving contact from the isolating position to the grounding position. This invention uses a longitudinal knife-switch type three-position disconnecting switch, which to some extent solves the problems of complex structure, cumbersome operation, and inability to meet miniaturization requirements of current three-position disconnecting switches used in gas-filled switchgear. It also reduces the height of the isolation gas box and meets the requirements for miniaturization of gas-filled switchgear. The operating mechanism of this invention is directly connected to the three-position main shaft via connecting rods and crank arms, controlling the contact bracket to realize the opening and closing operation of the three-position disconnecting switch. It features a simple structure and convenient operation. This avoids the problems of previous knife-switch type three-position disconnecting switches that used bevel gears, hexagonal shafts, crank arms, and other components to form a transmission structure to control the movement of the blades, resulting in difficulty in guaranteeing blade control accuracy.

[0023] See Figures 5 to 7 The gas tank body 1 is provided with a sealing joint for adding gas. The sealing joint includes a housing 501 connected to the gas tank body 1. The housing 501 passes through the tank body, and a partition plate 502 is provided inside the housing 501. The partition plate 502 is provided with a valve core 503 for sealing. The valve core 503 can contact the partition plate 502. One end of the valve core 503 is connected to a fixed bracket 504 and can move relative to it. The fixed bracket 504 is located on the side of the valve core 503 near the inside of the gas tank body 1. The other end of the valve core 503 contacts the partition plate 502, and the fixed bracket 504 is provided with a channel for gas to pass through; the valve core 503 is slidably connected to the valve core rod 505, the valve core rod 505 is connected to the fixed bracket 504, and a first elastic element 506 is fitted on the valve core rod 505; the sealing joint is also provided with a matching air inlet joint, the air inlet joint including an air inlet sleeve 507, the air inlet sleeve 507 is connected to a gas source, and a floating locking ring 50 is provided on the side of the air inlet sleeve 507 near the valve core 503. 8. A vent hole 509 for gas flow is provided on the side of the inflation sleeve 507 near the valve core 503. The diameter of the vent hole 509 is smaller than the diameter of the floating locking ring 508. The floating locking ring 508 can slide axially relative to the inflation sleeve 507. When the floating locking ring 508 is in contact with the inflation sleeve 507, it can prevent gas from flowing from the inflation sleeve 507 to the valve core 503. A floating bracket 510 is fitted on the outside of the floating locking ring 508. The floating bracket 510 has openings around its perimeter for gas flow. The opening allows gas to flow from the outside of the floating support 510 to the inside of the floating support 510. The floating support 510 restricts the position of the floating locking ring 508 and achieves the function of sliding the floating locking ring 508 relative to the inflation sleeve 507 by sliding relative to the two. A second elastic element 511 is provided between the floating locking ring 508 and the inflation sleeve 507. A groove is provided on the side of the floating locking ring 508 near the inflation sleeve 507, and the second elastic element 511 is provided inside the groove.

[0024] Through the above structure, the first elastic element 506 applies a certain pre-pressure to the valve core 503, causing the valve core 503 to contact the partition plate 502. Simultaneously, because the inside of the gas box 1 is filled with gas at a certain pressure, the pressure inside the box exerts a certain force on the valve core 503, further tightening the fit between the valve core 503 and the partition plate 502. Therefore, under the combined action of the gas pressure and the first elastic element 506, the valve core 503 and the partition plate 502 are tightly fitted, preventing gas leakage from the inside of the gas box 1 to the outside. The second elastic element 511 applies a pre-pressure to the floating locking ring 508, moving the floating locking ring 508 away from the inflation sleeve 507, thus reserving a flow channel for the gas. When the gas pressure inside the gas box 1 is insufficient, the supporting force on the valve core 503 decreases. When gas needs to be replenished inside the gas tank 1, the inflation sleeve 507 is brought close to the valve core 503, and the inflation gas source is opened. The gas from the gas source enters the inside of the floating support 510 through the opening, and then enters the vent 509 through the gap between the floating locking ring 508 and the inflation sleeve 507, contacting the valve core 503. Since the gas source pressure is greater than the pressure inside the gas tank 1, the gas in the gas source can push the valve core 503 away from the partition plate 502, allowing the gas source gas to enter the inside of the gas tank 1, thus replenishing the gas inside the tank. By setting the floating locking ring 508 and the second elastic element 511, in the normal state, the inflation sleeve 507 is set inside the shell 501, and the second elastic element 511 keeps the floating locking ring 508 away from the inflation sleeve 507, reserving a flow channel for the gas source gas. The gas source gas pushes the valve core 503 and enters the gas tank 1, and the gas flows at a slow flow rate. When the inflation sleeve 507 detaches from the housing 501, the gas source directly enters the external environment, and the external environment pressure is lower than the gas source pressure. The gas source loses the resistance of the valve core 503, the gas flow rate increases, and the gas pushes the floating locking ring 508 close to the inflation sleeve 507 and compresses the second elastic element 511. When the floating locking ring 508 contacts the inflation sleeve 507, it can close the gas flow channel to prevent gas from leaking to the outside and play a protective role.

[0025] This invention, through the above structure, comprises an upper and a lower gas-filling gas box. The upper gas box houses a longitudinally operated three-position disconnector, while the lower gas box houses a circuit breaker. The two gas boxes are connected via an upper and lower gas box connecting insulator. The longitudinally operated three-position disconnector has three-phase units with identical structures arranged longitudinally. Each phase unit includes a connecting contact, a moving contact, and a grounding contact. The connecting contact is fixed in the middle of the main busbar, which has mounting holes. The connecting contact's position can be adjusted on the main busbar. The connecting contact has a smooth surface and a parallel surface as a connection plane. The grounding contact is fixed on the grounding busbar and is in direct contact with it. This invention employs a longitudinally operated three-position disconnector, which to some extent solves the problems of complex structure, cumbersome operation, and inability to meet miniaturization requirements of current three-position disconnectors used in gas-filling cabinets. It reduces the height of the gas-filling gas box, achieving the miniaturization requirement of the gas-filling cabinet. The operating mechanism of this invention is directly connected to the three-position main shaft via connecting rods and crank arms, controlling the contact bracket to realize the opening and closing operation of the three-position disconnecting switch. It features a simple structure and convenient operation. This avoids the problems of previous knife-switch type three-position disconnecting switches that used bevel gears, hexagonal shafts, crank arms, and other components to form a transmission structure to control the movement of the blades, resulting in difficulty in guaranteeing blade control accuracy.

[0026] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A gas-filled switchgear gas box and a longitudinal knife switch type three-position disconnecting switch, comprising a gas box body, an operating mechanism and a switch, characterized in that, The gas box body includes an upper gas box and a lower gas box. A longitudinal knife switch type three-position isolating switch is installed in the upper gas box, and a circuit breaker switch is installed in the lower gas box. The two gas boxes are connected by an upper and lower gas box connecting insulator. The longitudinal knife-type three-position disconnect switch has three phase units with identical structures arranged longitudinally. Each phase unit includes a connecting contact, a moving contact, and a grounding contact. The connecting contact is fixed in the middle position of the main busbar, which has mounting holes. The connecting contact can be adjusted on the main busbar. The connecting contact has a smooth surface and a parallel surface as a connecting plane. The grounding contact is fixed on the grounding busbar and is in direct contact with the grounding busbar. The gas box body is provided with a sealing joint for adding gas. The sealing joint includes a housing connected to the gas box body. A partition plate is provided inside the housing. A valve core for sealing is provided on the partition plate. The valve core can contact the partition plate. One end of the valve core is connected to a fixed bracket and can move relative to it. The fixed bracket is located on the side of the valve core close to the inside of the gas box body. The other end of the valve core contacts the partition plate. The valve core is slidably connected to a valve core rod. The valve core rod is connected to the fixed bracket. A first elastic element is fitted on the valve core rod. The sealing joint is also equipped with a matching inflation joint, which includes an inflation sleeve. A floating locking ring is provided on the side of the inflation sleeve near the valve core. A vent hole for gas to flow through is opened on the side of the inflation sleeve near the valve core. The diameter of the vent hole is smaller than the diameter of the floating locking ring. The floating locking ring can slide axially relative to the inflation sleeve. When the floating locking ring is in contact with the inflation sleeve, it can prevent gas from flowing from the inflation sleeve to the valve core. A floating bracket is fitted on the outer side of the floating locking ring. A second elastic element is provided between the floating locking ring and the inflation sleeve. A groove is opened on the side of the floating locking ring near the inflation sleeve, and the second elastic element is disposed inside the groove.

2. The gas-filled switchgear and longitudinal knife-switch type three-position disconnector as described in claim 1, characterized in that, The lower panel of the lower inflation box has mounting holes, and a cone insulator is provided on the lower panel. The cone insulator is fixed to the lower panel of the lower inflation box by bolts. The upper panel of the lower inflation box has mounting holes, and an upper and lower connecting insulator is fixed to the upper panel of the lower inflation box by bolts. The left and right side panels of the upper inflation box have mounting holes, and side parallel insulators are fixed to the left and right side panels of the upper inflation box by bolts. The side parallel insulators are symmetrically distributed.

3. The gas-filled switchgear and longitudinal knife-switch type three-position disconnector as described in claim 1, characterized in that, The operating mechanism includes a circuit breaker spring operating mechanism and an isolating operating mechanism. The circuit breaker spring operating mechanism has a bellows assembly, which is connected to the insulating pull rod of the circuit breaker switch. The isolating operating mechanism has a dynamic seal, which is connected to a longitudinal knife switch type three-position isolating switch to realize the opening and closing functions of the switch. The output spindle of the isolation operating mechanism is a hexagonal shaft with a cylindrical end for positioning the output spindle. A bushing is welded to the front panel of the air box, and a bearing is installed inside the bushing; the end of the operating mechanism spindle mates with the bearing. A crank arm is fitted onto the output spindle of the isolation operating mechanism, and the crank arm is connected to a connecting rod via a pin. One end of the connecting rod is hinged to the crank arm, and the other end of the connecting rod is threaded to a screw. A second crank arm is hinged to the screw, and by rotating the thread between the screw and the connecting rod, the relative position between the two crank arms can be adjusted. The second crank arm is dynamically sealed to the longitudinal knife-switch type three-position disconnect switch, enabling the isolation operating mechanism to control the longitudinal knife-switch type three-position disconnect switch.

4. The gas-filled switchgear and longitudinal knife-switch type three-position disconnecting switch as described in claim 1, characterized in that, The moving contact is composed of four identical contact blades, which are fixed on the contact support. The contact support is welded together from a pad and a connecting plate. The connecting plate has a positioning hole that corresponds to the mounting hole of the moving contact. The four contact blades are fixed to the connecting plate by pins, springs and bolts, and the four contact blades are symmetrically distributed in pairs.

5. The gas-filled switchgear and longitudinal knife-switch type three-position disconnecting switch as described in claim 4, characterized in that, The longitudinal knife-type three-position disconnect switch also includes an insulating pull rod, a three-position main shaft, and a dynamic seal; the dynamic seal is fixedly installed on the front panel of the gas box and is sealed to the front panel of the gas box; one end of the three-position main shaft is inserted into the dynamic seal; a bushing is welded to the rear panel of the upper gas box, and the other end of the three-position main shaft is rotatably fixed on the bushing, with a bearing installed inside the bushing; one side of the insulating pull rod is rotatably connected to the three-position main shaft, and the other side is rotatably connected to the three-position contact bracket, and the contact bracket and the three-position main shaft are insulated from each other.

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