CN215933459U

CN215933459U - Three-position switch

Info

Publication number: CN215933459U
Application number: CN202121606382.4U
Authority: CN
Inventors: 叶浩亮; 王安心; 钱江奇; 刘金光; 董海明
Original assignee: Murge Electric Co ltd
Current assignee: Murge Electric Co ltd
Priority date: 2021-05-27
Filing date: 2021-07-15
Publication date: 2022-03-01
Anticipated expiration: 2031-07-15
Also published as: CN215933426U; CN215644270U; CN113572074A; CN215934278U; CN215933471U; CN113571371A; CN215933460U

Abstract

The utility model discloses a three-station switch, which comprises a three-station support, an insulating main shaft and a separating and combining mechanism, wherein the insulating main shaft and the separating and combining mechanism are arranged on the three-station support, the insulating main shaft is linked with the separating and combining mechanism, the separating and combining mechanism comprises a shielding ring and a shielding cover, and the shielding ring and the shielding cover are used for controlling temperature rise and equalizing pressure of an electric field; an isolation knife structure suitable for environment-friendly gas is designed, and the temperature rise is guaranteed to be qualified; aiming at the conductive standard part on the isolation knife, the electric field voltage-sharing accessory is designed, so that the standard part meets the insulation requirement level specified by the state; the standard part is wrapped inside the shielding ring and the shielding cover, the electric field around the standard part is uniform, the purpose of reducing the interphase insulation clear distance is achieved, and meanwhile, the shielding ring is arranged at the cutter tail of the isolation cutter, so that the heat dissipation area of the isolation cutter is increased.

Description

Three-position switch

Technical Field

The utility model belongs to the field of environment-friendly gas insulation ring main units, and relates to a three-position switch.

Background

With the continuous progress and improvement of breaking and insulating technologies, environment-friendly gas-insulated metal-enclosed switchgear is developed, the switchgear is mature theoretically and technically, products produced by existing domestic equipment manufacturing enterprises pass type tests and are subjected to net hanging operation, but most of core parts in the current market are environment-friendly, and epoxy resin is used for wrapping charged parts or insulating plates are used for isolating charged bodies, so that the insulating effect is achieved.

Most of three-position switches which are environmentally friendly in the current market adopt epoxy resin to wrap charged parts or use insulating plates to isolate charged bodies so as to achieve the insulating effect; the utility model has complex structure and higher cost, and solves the technical problem.

Disclosure of Invention

The utility model provides a three-position switch for overcoming the defects of the prior art.

In order to achieve the purpose, the utility model adopts the following technical scheme: a three-position switch is characterized in that: the device comprises a three-station support, an insulating main shaft and a separating and combining mechanism, wherein the insulating main shaft and the separating and combining mechanism are arranged on the three-station support, the insulating main shaft is linked with the separating and combining mechanism, the separating and combining mechanism comprises a shielding ring and a shielding cover, and the shielding ring and the shielding cover are used for controlling temperature rise and equalizing pressure of an electric field.

Further, the method comprises the following steps of; the three-station support is composed of a support front plate, a support rear plate, a first cross beam, a second cross beam and a fourth cross beam, the first cross beam, the second cross beam and the fourth cross beam are horizontally arranged in parallel and fixedly arranged between the support front plate and the support rear plate, the support front plate and the support rear plate are fixedly connected with an air box, an insulating main shaft is horizontally arranged, the output end of the insulating main shaft is rotatably connected with the support rear plate, and the input end of the insulating main shaft penetrates through the support front plate and is connected with the support front plate in a dynamic sealing mode.

Further, the method comprises the following steps of; the opening and closing mechanism comprises a three-phase upper insulator, a three-phase lower insulator and a transmission assembly, wherein the three-phase upper insulator is fixedly arranged on a first cross beam, a bus bar is fixedly arranged on the three-phase upper insulator and fixedly connected with a three-phase insulating sleeve, a closing grounding contact base is fixedly arranged on the bus bar, the three-phase lower insulator is fixedly arranged on a second cross beam, a transition row is fixedly arranged on the three-phase lower insulator, and an arc extinguish chamber contact base is fixedly arranged on the transition row.

Further, the method comprises the following steps of; the transmission assembly comprises a connecting rod structure, the connecting rod structure comprises a transmission connecting lever, a movable knife pull rod and a movable knife pull plate, the transmission connecting lever is fixedly arranged on an insulating main shaft, the movable knife pull rod is provided with two groups which are symmetrically arranged, two ends of the movable knife pull rod are respectively rotatably connected with the transmission connecting lever and the movable knife pull plate, and nylon pins positioned on two sides of the transmission connecting lever are fixedly arranged on the insulating main shaft and used for limiting the movement of the transmission connecting lever.

Further, the method comprises the following steps of; the transmission assembly further comprises two groups of isolation knives which are arranged in parallel and fixedly connected through a first knife supporting piece and a second knife supporting piece, connecting rods located between the first knife supporting piece and the second knife supporting piece are further fixedly arranged on the two groups of isolation knives and rotatably connected with the moving knife pull plate, a first contact point located on the knife head and a second contact point located on the knife tail are fixedly arranged on the isolation knives, and the second contact points are in contact with or separated from the arc extinguish chamber contact seat.

Further, the method comprises the following steps of; the shielding cover is fixedly arranged on a cutter head of the isolation cutter, the shielding cover is provided with a stepped shielding cover mounting hole, the first cutter supporting piece penetrates through the shielding cover mounting hole, the standard pieces are arranged at two ends of the shielding cover and fixedly connected with the shielding cover and the first cutter supporting piece, and the standard pieces are wrapped inside the shielding cover through the shielding cover mounting hole.

Further, the method comprises the following steps of; the shielding ring is installed at the tool bit tail of the isolation tool through the second standard part, the second standard part is rotationally connected with the arc extinguish chamber contact seat, a shielding ring installation hole is fixedly formed in the shielding ring, the second standard part is located in the shielding ring installation hole, and the second standard part is wrapped inside the shielding ring through the shielding ring installation hole.

Further, the method comprises the following steps of; the transmission assembly further comprises a contact seat assembly, the contact seat assembly comprises a grounding bar and a grounding contact seat, the grounding bar is fixedly arranged on the three-station support, three groups of grounding bars are arranged, the grounding contact seat is inserted between the two groups of isolation knives, and two sides of the grounding contact seat are in point contact with or separated from the first contact points.

Further, the method comprises the following steps of; the surfaces of the shielding cover, the shielding ring and the isolation knife are processed in a fillet, edge-free and corner-free mode.

In conclusion, the three-station isolation knife disclosed by the utility model optimizes the traditional three-station structure, increases the switch depth and ensures the distance between the isolation knives and the ground; an isolation knife structure suitable for environment-friendly gas is designed, and the temperature rise is guaranteed to be qualified; aiming at the conductive standard part on the isolation knife, the electric field voltage-sharing accessory is designed, so that the standard part meets the insulation requirement level specified by the state; the standard part is wrapped inside the shielding ring and the shielding cover, the electric field around the standard part is uniform, the purpose of reducing the interphase insulation clear distance is achieved, meanwhile, the shielding ring is arranged at the cutter tail of the isolation cutter, the heat dissipation area of the isolation cutter is increased, the temperature rise margin of the contact seat of the arc extinguish chamber and the isolation cutter is improved, the shielding ring is arranged at the cutter head of the isolation cutter, the heat dissipation area of the isolation cutter is increased, and the temperature rise margin of the closing grounding contact seat and the isolation cutter is improved; the surface of the part is processed by round corners, no edges and corners.

Drawings

Fig. 1 is a schematic view of the installation of the internal device of the environment-friendly gas-insulated ring main unit according to the present invention.

Fig. 2 is a schematic diagram of a three-position switch of the present invention.

Fig. 3 is a schematic diagram of the shielding of the present invention.

Fig. 4 is a schematic view of the shield ring of the present invention.

FIG. 5 is a first schematic view of the isolation knife of the present invention.

FIG. 6 is a second schematic view of the isolation knife of the present invention.

FIG. 7 is a schematic view of the transmission assembly of the present invention.

Fig. 8 is a first schematic diagram of a three-station mechanism of the present invention.

FIG. 9 is a second schematic view of a three-position mechanism of the present invention.

Figure 10 is a schematic view of a cam plate of the present invention.

FIG. 11 is a schematic view of a second mechanism plate of the present invention.

FIG. 12 is a schematic view of an isolating drive crank arm of the present invention.

Fig. 13 is a schematic view of a ground engaging transmission crank arm of the present invention.

FIG. 14 is a schematic view of an indicating device of the present invention.

Fig. 15 is a first schematic diagram of a main circuit of the circuit breaker of the present invention.

Fig. 16 is a second schematic diagram of the main circuit of the circuit breaker of the present invention.

Fig. 17 is a schematic view of an arc extinguishing contact base of the present invention.

FIG. 18 is a schematic view of a double-ended screw of the present invention.

Fig. 19 is a schematic view of an interlock device of the present invention.

Fig. 20 is a schematic view of the interlock installation of the present invention.

Fig. 21 is an enlarged view of a in fig. 20.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The utility model is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.

It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

All directional indicators (such as up, down, left, right, front, rear, lateral, longitudinal … …) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the movement, etc. in a particular posture, and if the particular posture is changed, the directional indicator is changed accordingly.

The first embodiment is as follows:

as shown in fig. 1-21, a three-position switch is installed in an environment-friendly gas-insulated ring main unit, the environment-friendly gas-insulated ring main unit comprises a cabinet body 1, a three-position mechanism 3, a circuit breaker main circuit 4 and a circuit breaker mechanism 5, the three-position switch 2, the three-position mechanism 3, the circuit breaker main circuit 4 and the circuit breaker mechanism 5 are installed in the cabinet body 1, an interlocking device 6 is connected between the three-position mechanism 3 and the circuit breaker mechanism 5 and used for preventing the three-position mechanism 3 from being operated in a live-line mode, and the three-position switch 2 is connected with an indicating device 9 used for displaying the state of the three positions.

The cabinet body 1 comprises a gas tank 11, an instrument room 12 and a cabinet frame 13, a mechanism room 131 and a cable room 132 are arranged in the cabinet frame 13, an inflation compartment 111 is arranged in the gas tank 11, a circuit breaker mechanism 5 and a three-station mechanism 3 are arranged in the mechanism room 11, a three-station switch 2 and a circuit breaker main loop 4 are arranged in the inflation compartment 111, the circuit breaker mechanism 5 is connected with the circuit breaker main loop 4, the three-station switch 2 is connected with the three-station mechanism 3, and the opening and closing functions of the switches are realized.

Aerify compartment 111 top and install three-phase insulation support 7, aerify compartment 111 from top to bottom be three-phase insulation support 7, three-station switch 2 and circuit breaker main loop 4 in proper order, three-phase insulation support 7 is connected through main bus bar subassembly 71 with three-station switch 2, three-station switch 2 and circuit breaker main loop 4 linkage, circuit breaker main loop 4 lower part is connected to cable chamber 132 through a bus bar subassembly 44, gas tank 11 bottom plate has set firmly explosion-proof plate 112.

The instrument room is used for installing secondary wires and secondary elements, such as a switching-on and switching-off button, an indicator lamp, a microcomputer protection device, a current voltmeter and the like, is a gathering place of the two wire terminals of the environment-friendly gas insulation ring main unit, and is convenient for secondary wire inspection and after-sale maintenance; the microcomputer protection device can enable a user to remotely inquire the on-off state of the switch according to the on-off signal of the travel switch on the mechanism and remotely control the on-off state of the switch; meanwhile, according to the matching of detection elements such as the mutual inductor and the like, the fault on the line can be intelligently judged, and the switch is controlled to carry out fault removal or background feedback.

As shown in fig. 2 to 7, the three-position switch 2 includes a three-position support 21, an insulating main shaft 22, and a switching mechanism 23, the insulating main shaft 22 and the switching mechanism 23 are mounted on the three-position support 21, the insulating main shaft 22 is linked with the switching mechanism 23, the switching mechanism 23 includes a shielding ring 232 and a shielding cover 233, and the shielding ring 232 and the shielding cover 233 are used for controlling temperature rise and equalizing electric field pressure.

The three-station support 21 is composed of a support front plate 211, a support rear plate 212, a first cross beam 213, a second cross beam 214 and a fourth cross beam 215, the first cross beam 213, the second cross beam 214 and the fourth cross beam 215 are horizontally arranged in parallel and fixedly arranged between the support front plate 211 and the support rear plate 212, the support front plate 211 and the support rear plate 212 are fixedly connected with the air box 11, the insulating main shaft 22 is horizontally arranged, the output end of the insulating main shaft 22 is rotatably connected with the support rear plate 212, and the input end of the insulating main shaft 22 penetrates through the support front plate 211 and is connected with the support front plate 211 in a dynamic seal 25 mode.

The opening and closing mechanism 23 includes a three-phase upper insulator 230, a three-phase lower insulator 231 and a transmission assembly, the three-phase upper insulator 230 is fixedly disposed on the first beam 213, a bus bar 2301 is fixedly disposed on the three-phase upper insulator 230, the bus bar 2301 is fixedly connected to the three-phase insulating sleeve 7, a closing grounding contact 2302 is fixedly disposed on the bus bar 2301, the three-phase lower insulator 231 is fixedly disposed on the second beam 214, a transition bar 2311 is fixedly disposed on the three-phase lower insulator 231, and an arc extinguishing chamber contact 2312 is fixedly disposed on the transition bar 2311.

The transmission assembly further comprises a connecting rod structure, the connecting rod structure comprises a transmission connecting lever 2341, a movable knife pull rod 2342 and a movable knife pull plate 2343, the transmission connecting lever 2341 is fixedly arranged on an insulating main shaft 22, the movable knife pull rod 2342 is provided with two groups, the movable knife pull rod 2342 is symmetrically arranged, two ends of the movable knife pull rod 2342 are rotatably connected with the transmission connecting lever 2341 and the movable knife pull plate 2343 respectively, nylon pins 2340 located on two sides of the transmission connecting lever 2341 are fixedly arranged on the insulating main shaft 22, and the movement of the transmission connecting lever 2341 is further limited.

The transmission assembly further comprises two groups of isolation knives 235, the isolation knives 235 are provided with two groups, the two groups of isolation knives 235 are arranged in parallel and are fixedly connected through first knife supporting pieces 2351 and second knife supporting pieces 2356, connecting rods 2357 positioned between the first knife supporting pieces 2351 and the second knife supporting pieces 2356 are further fixedly arranged on the two groups of isolation knives 235, the connecting rods 2357 are rotatably connected with the movable knife pulling plate 2343, each isolation knife 235 comprises a first side surface 2358 and a second side surface 2359, the first side surfaces 2358 of the two groups of isolation knives 235 are opposite, the second side surfaces 2359 are opposite, and first contact points 2355 positioned on a knife head and second contact points 2354 positioned on a knife tail are fixedly arranged on the first side surface 2358 of each isolation knife 235 and are in contact with or separated from an arc extinguish chamber contact seat 2312.

The shielding case 233 is fixedly arranged on a cutter head of the isolation knife 235, specifically, the shielding case 233 is provided with a stepped shielding case mounting hole 2331, the first knife supporting member 2351 penetrates through the shielding case mounting hole 2331, and standard pieces are arranged at two ends of the shielding case 233 to fixedly connect the shielding case 233 and the first knife supporting member 2351, and the standard pieces are wrapped inside the shielding case 233 through the shielding case mounting hole 2331, so that the purposes of equalizing the electric field around the isolation knife 235 and reducing the interphase insulation clear distance are achieved.

The shielding ring 232 is installed at the tool tail of the isolating tool 235 through the second standard member 2322, the second standard member 2322 is rotatably connected with the arc extinguish chamber contact seat 2312, a shielding ring installation hole 2321 is fixedly arranged on the shielding ring 232, the second standard member 2322 is located in the shielding ring installation hole 2321, the second standard member 2322 is wrapped inside the shielding ring 232 through the shielding ring installation hole 2321, the purposes of uniformly isolating the electric field around the tool 235 and reducing the interphase insulation clear distance are achieved, in the embodiment, the shielding ring 232 is installed at the tool tail of the isolating tool 235, the heat dissipation area of the isolating tool 235 can be increased, and therefore the temperature rise margin of the arc extinguish chamber contact seat 2312 and the isolating tool 235 is improved.

The transmission assembly further comprises a contact seat assembly 236, the contact seat assembly 236 comprises a grounding bar 2361 and grounding contact seats 2362, the grounding bar 236 is fixedly arranged on the fourth cross beam 215, three groups of grounding bars 2361 are arranged, the grounding contact seats 2362 are inserted between the two groups of isolation knives 235, and two sides of the grounding contact seats 2362 are in contact with or separated from the first contact points 2355.

The surfaces of the shielding cover 233, the shielding ring 232 and the isolation knife 235 are processed to be round-cornered, non-edge and non-corner, so that the parts can ensure a uniform electric field when being electrified, and the purpose of improving the insulation performance of the main loop is achieved.

In the implementation process of the three-position switch 2, when the three-position mechanism 3 is subjected to opening operation, the insulating main shaft 22 is driven to rotate, the insulating main shaft 22 drives the transmission assembly to rotate, the isolating knife 235 is separated from the grounding bar 2361 and is kept at an isolating position, and at the moment, the insulation of the side shell of the air box is increased.

The three-position switch 2 can be independently moved into the existing ring main unit.

As shown in fig. 8-13, the three-position mechanism 3 includes a three-position frame 31 and a cam disc 32, the cam disc 32 is fixedly disposed on the insulating main shaft 22, the three-position frame 31 is mounted with an isolating output device, an isolating transmission device, a grounding output device, a grounding transmission device and an energy storage device, the isolating output device and the grounding output device are respectively linked with the energy storage device and control the energy storage device to store energy, the isolating transmission device and the grounding transmission device are linked with the cam disc 32, and respectively output a switching-on/off torque and a grounding torque to the insulating main shaft 22 through the cam disc 32.

The three-station frame 31 comprises a first mechanism plate 311 and a second mechanism plate 312, the first mechanism plate 311 is located at an operation input end of the three-station mechanism 3, the second mechanism plate 312 is located at an operation output end of the three-station mechanism 3, the first mechanism plate 311 and the second mechanism plate 312 are fixedly connected through a three-station support 313, and generally, the first mechanism plate 311 and the second mechanism plate 312 are arranged in parallel; the second mechanism plate 312 is fixedly connected to the partition plate of the mechanism chamber 131 through the fixing support 324, so that the three-position mechanism 3 is installed in the mechanism chamber 131.

The isolating output device comprises an isolating output shaft 33, the input end of the isolating output shaft 33 rotatably penetrates through the first mechanism plate 311, and an isolating cam sleeve 331 is fixedly sleeved on the input end of the isolating output shaft 33 positioned on the outer side of the first mechanism plate 311.

The grounding output device comprises a grounding output shaft 34, the input end of the grounding output shaft 34 rotatably penetrates through the first mechanism plate 311, and a grounding cam sleeve 341 is fixedly sleeved on the input end of the grounding output shaft 34 positioned outside the first mechanism plate 311.

The energy storage device comprises an isolation energy storage crank arm 351, an earth energy storage crank arm 352 and an energy storage pressure spring 353, the isolation energy storage crank arm 351 is fixedly arranged on an isolation output shaft 33 and can rotate along with the isolation output shaft 33, an isolation transmission pin 3511 is arranged at the free end of the isolation energy storage crank arm 35, the earth energy storage crank arm 352 is fixedly arranged on an earth output shaft 34 and can rotate along with the earth output shaft 34, an earth transmission pin 3521 is arranged at the free end of the earth energy storage crank arm 352, pressure spring heads 3531 are arranged at the two ends of the energy storage pressure spring 353, the pressure spring heads 3531 are respectively in rotating connection with the isolation transmission pin 3511 and the earth transmission pin 3521, an energy storage telescopic rod 3532 is arranged between the two groups of pressure spring heads 3531, and when the energy storage pressure spring 353 stretches or stretches, the energy storage telescopic rod 3532 can stretch or stretch along with the energy storage pressure spring.

The isolation transmission device comprises an isolation transmission crank arm 36, the isolation transmission crank arm 36 is rotatably connected with an isolation output shaft 33, an isolation sliding groove 361 is fixedly arranged on the side edge of the isolation transmission crank arm 36, an isolation transmission pin 3511 slides along the sliding groove 361, isolation limiting ends used for limiting the isolation transmission pin 3511 are fixedly arranged at two ends of the sliding groove 361, and as shown in fig. 12, the isolation limiting ends are respectively arranged as a first isolation limiting end 3611 and a second isolation limiting end 3612; the isolation transmission crank arm 36 is further fixedly provided with an isolation transmission rod 362, the second mechanism plate 312 is fixedly provided with an isolation arc groove 3121, two ends of the isolation arc groove 3121 are provided with a first isolation arc groove end 31211 and a second isolation arc groove end 31212, the isolation transmission rod 362 is inserted into the isolation arc groove 3121 and slides along the isolation arc groove 3121, the isolation transmission rod 362 is linked with the cam disc 32, and when the three-station switch 2 performs a closing operation, the isolation transmission rod 362 slides from the second isolation arc groove end 31212 to the first isolation arc groove end 31211; when the three-position switch 2 is opened, the isolation transmission rod 362 slides from the first isolation arc groove end 31211 to the second isolation arc groove end 31212.

The grounding transmission device comprises a grounding transmission crank arm 37, the grounding transmission crank arm 37 is rotatably connected with the grounding output shaft 34, a grounding chute 371 is fixedly arranged on the grounding transmission crank arm 37, a grounding transmission pin 3521 slides along the grounding chute 371, grounding limiting ends used for limiting the grounding transmission pin 3521 are fixedly arranged at two ends of the grounding chute 371, and as shown in fig. 13, the grounding limiting ends are respectively arranged as a first grounding limiting end 3711 and a second grounding limiting end 3712; the grounding transmission crank arm 37 is further fixedly provided with a grounding transmission rod 372, the second mechanism plate 312 is fixedly provided with a grounding arc groove 3122, two ends of the grounding arc groove 3122 are provided with a first grounding arc groove end 31221 and a second grounding arc groove end 31222, the grounding transmission rod 372 is inserted into the grounding arc groove 3122 and slides along the grounding arc groove 3122, the grounding transmission rod 372 is linked with the cam disc 32, and when the three-position switch 2 performs grounding operation, the grounding transmission rod 372 slides from the first grounding arc groove end 31221 to the second grounding arc groove end 31222.

The cam disc 32 is provided with a plate-shaped structure comprising a cam disc mounting hole 321, the central axis of the cam disc mounting hole 321 is collinear with the central axis of the insulating main shaft 22, the insulating main shaft 22 is connected with the cam disc 32 through a connecting shaft 26, specifically, one end of the connecting shaft 26 is positioned in the inflating compartment 111, which is fixedly provided with a first connection hole 261, the first connection hole 261 having a cross-section configured as a polygon, preferably a hexagon, matching with the section of the insulated spindle 22, the insulated spindle 22 is inserted into the first connection hole 261 and fixedly connected, the insulating main shaft 22 is prevented from rotating with respect to the connecting shaft 26, the other end of the connecting shaft 26 is located in the mechanism chamber 131, the outer section of the connecting shaft 26 is polygonal, preferably square, and is matched with the section of the cam disc mounting hole 321, the other end of the connecting shaft is inserted into the cam disc mounting hole 321 and fixedly connected, the cam disc 32 can be prevented from rotating relative to the connecting shaft 26, and the other end of the connecting shaft 26 is fixedly provided with a second connecting hole 262; the dynamic seal 25 is sleeved on the outer side of the connecting shaft 26 and is in sealing connection with the three-station support 21 and the mechanism chamber 131 through the dynamic seal 25.

The cam plate 32 is further provided with a moving arc groove, the moving arc groove comprises an isolation limiting arc groove 322 and a grounding limiting arc groove 323, the isolation limiting arc groove 322 is communicated with the grounding limiting arc groove 323, the isolation transmission rod 362 is inserted into the isolation limiting arc groove 322 and slides along the isolation limiting arc groove 322, and the grounding transmission rod 372 is inserted into the grounding limiting arc groove 323 and slides along the grounding limiting arc groove 323.

The two ends of the isolation limiting arc groove 322 are set as a first isolation limiting end 3221 and a second isolation limiting end 3222, the two ends of the grounding limiting arc groove 323 are set as a first grounding limiting end 3231 and a second grounding limiting end 3232, the second isolation limiting end 3222 and the first grounding limiting end 3231 are located at a junction position of the isolation limiting arc groove 322 and the grounding limiting arc groove 323, an upward protruding portion is arranged at the junction position, and the protruding portion is used for preventing the isolation transmission rod 362 from sliding to the grounding limiting arc groove 323 and preventing the grounding transmission rod 372 from sliding to the isolation limiting arc groove 322.

When the three-position switch 2 is in an isolated state, the isolating transmission rod 362 is positioned at the second isolating arc groove end 31212 and the second isolating limiting end 3222, the grounding transmission rod 372 is positioned at the first grounding limiting end 3231, and when the three-position switch 2 performs a closing operation, the isolating transmission connecting lever 36 drives the isolating transmission rod 362 to slide from the second isolating arc groove end 31212 to the first isolating arc groove end 31211, in the process, the isolating transmission rod 362 moves upwards in the vertical direction, so that the isolating transmission rod 362 slides from the second isolating limiting end 3222 to the first isolating limiting end 3221, thereby driving the cam disc 32 to rotate along the insulating main shaft 22 to output a closing torque for the insulating main shaft, in the process, the grounding transmission rod 372 slides along the grounding limiting arc groove 323, the arc shape of the grounding limiting arc groove 323 is matched with the path of the isolating transmission rod 362 to drive the cam disc 32 to rotate, so that when the cam disc 32 performs the closing operation, the ground transmission rod 372 is not affected, the end of the ground limiting arc groove 323 is provided as a limiting end 3232, and when the cam disc 32 is in a closed state, the ground transmission rod 372 moves into the limiting end 3232.

When the three-position switch 2 is in grounding operation, the grounding transmission crank arm 37 drives the grounding transmission rod 372 to slide from the first grounding arc groove end 31221 to the second grounding arc groove end 31222, the arc shape of the isolation limiting arc groove 322 is matched with the path of the grounding transmission rod 372 driving the cam disc 32 to rotate, so that the cam disc 32 does not affect the isolation transmission rod 362 when in grounding operation, and the grounding transmission rod 372 drives the cam disc 32 to rotate along the insulating main shaft 22 to output grounding torque for the insulating main shaft 22.

In order to ensure the safety, the operation of closing or grounding can be carried out only when the three-position switch 2 is in an isolated state, as shown in fig. 9, the three-position switch 2 is in the isolated state, in which the isolation driving pin 3511 is located at the second limiting end 3612, and when the three-position switch 2 performs a closing operation, when the isolating output shaft 33 is driven by the external force to rotate, the isolating output shaft 33 drives the isolating energy storage crank arm 351 to rotate, the isolating energy storage crank arm 351 drives the isolating transmission pin 3511 to slide along the isolating sliding groove 361, thereby driving the energy storage compression spring 353 to store energy, when the energy storage compression spring 353 rotates to the maximum energy storage position, when the external force is removed, the isolation output device continues to rotate under the action of inertia, the energy storage pressure spring 353 rotates to the maximum energy storage position, the energy storage is released, the isolation transmission connecting lever 36 is driven to rotate through the isolation transmission pin 3511, the isolation transmission rod 362 drives the cam disc 32 to rotate, and the closing torque is output to the insulation main shaft 22 through the cam disc 32.

In the process that the energy storage pressure spring 353 reaches the maximum energy storage position, the isolation transmission pin 3511 slides from the second limiting end 3612 to the first limiting end 3611 along the sliding groove 361, in the process, the isolation transmission crank arm 36 does not rotate, when the energy storage pressure spring 353 releases energy storage, the isolation transmission pin 3511 drives the isolation transmission crank arm 36 to rotate through the first limiting end 3611, then the isolation transmission rod 362 drives the cam disc 32 to rotate, and closing torque is output to the insulation main shaft 22 through the cam disc 32; when the three-position switch 2 needs to be opened, the three-position switch operates in the reverse direction, and opening torque is output to the insulating main shaft 22 through the cam disc 32.

When the three-position switch 2 is in an isolated state, the grounding transmission pin 3521 is located at the first grounding limiting end 3711, when the three-position switch 2 performs grounding operation, external force drives the grounding output shaft 34 to rotate, the grounding output shaft 34 drives the grounding energy storage crank arm 352 to rotate, the grounding energy storage crank arm 352 drives the grounding transmission pin 3521 to slide along the grounding chute 371, and further drives the energy storage pressure spring 353 to store energy, when the grounding output device rotates to enable the energy storage pressure spring 353 to reach the maximum energy storage position, the external force is removed, the grounding output device can continue to rotate under the action of inertia and enable the energy storage pressure spring 353 to rotate to the maximum energy storage position, energy storage is released, the grounding transmission crank arm 37 is driven to rotate by the grounding transmission pin 3521, the grounding transmission rod 372 drives the cam disc 32 to rotate, and grounding torque is output to the insulating main shaft 22 through the cam disc 32.

In the process that the energy storage pressure spring 353 reaches the maximum energy storage position, the grounding transmission pin 3521 slides from the first grounding limiting end 3711 to the second grounding limiting end 3712 along the grounding sliding groove 371, in the process, the grounding transmission crank arm 37 does not rotate, when the energy storage pressure spring 353 releases energy storage, the grounding transmission pin 3521 drives the grounding transmission crank arm 37 to rotate through the second grounding limiting end 3712, the grounding transmission rod 372 drives the cam disc 32 to rotate, and grounding torque is output to the insulation main shaft 22 through the cam disc 32.

In the embodiment, the cam disc 32 is driven to rotate by the isolation transmission device and the grounding transmission device to output the opening and closing torque and the grounding torque to the insulating main shaft 22, so that the structure is simple, the operation is convenient, and the transmission efficiency is high.

The three-station mechanism 3 further comprises a three-station mechanism interlocking plate 38, a lower cover plate 381, an upper cover plate 382 and a poking plate 383 are fixedly arranged on the three-station mechanism interlocking plate 38, the poking plate 383 is poked through external force to control the three-station mechanism interlocking plate 38 to move upwards or downwards, when the three-station mechanism interlocking plate 38 moves upwards, the upper cover plate 382 covers the isolation cam sleeve 331, and when the three-station mechanism interlocking plate 38 moves downwards, the lower cover plate 381 covers the grounding cam sleeve 341 to ensure that the isolation output shaft 33 and the grounding output shaft 34 cannot be operated simultaneously.

The three-position mechanism 3 also comprises an interlocking device for isolating the output device and the grounding output device,

the interlocking device comprises a hanging plate 391, an adjusting waist-shaped hole 392 is fixedly arranged on the hanging plate 391, an interlocking column 3111 is fixedly arranged on a first mechanism plate 311, the interlocking column 3111 is inserted into the adjusting waist-shaped hole 392, so that the hanging plate 391 is hung on the first mechanism plate 311, two ends of the hanging plate 391 are respectively provided with an isolating interlocking hole 394 for locking an isolating output shaft 33 and a grounding interlocking hole 395 for locking a grounding output shaft 34, gaps are arranged on the isolating interlocking hole 394 and the grounding interlocking hole 395, notches matched with the gaps of the isolating interlocking hole 394 and the grounding interlocking hole 395 are respectively arranged on the isolating output shaft 33 and the grounding output shaft 34, in the interlocking process of the embodiment, when the three-position switch 2 is in an isolating state, the notches of the isolating output shaft 33 and the grounding output shaft 34 are opposite to the gaps of the isolating interlocking hole 394 and the grounding interlocking hole 395, at the moment, the hanging plate 391, the isolating output device and the grounding output device are in an unlocking state, the hanging plate 391 can move up and down in the limited range of the adjusting waist-shaped hole 392 to realize the switching-on or grounding operation of the three-position switch, when the three-position switch is in the switching-on state, the arc surface of the isolating output shaft 33 is abutted against the notch of the isolating mutual locking hole 394, the notch of the grounding output shaft 34 is opposite to the notch of the grounding mutual locking hole 395 and limited, at the moment, the grounding output shaft 34 cannot operate, when the grounding output device is in the grounding state, the arc surface of the grounding output shaft 34 is abutted against the notch of the grounding mutual locking hole 395, the notch of the isolating output shaft 33 is opposite to the notch of the isolating mutual locking hole 394 and limited, and therefore the three-position switch can be grounded or switched-on only when the isolating output device and the grounding output device are in the isolating state.

The three-station mechanism 3 can be independently applied to the existing ring main unit.

As shown in fig. 14, the indicating device 9 is used for displaying the state of the three-position switch 2, the indicating device 9 includes an indicating main shaft 91 and an indicator plate 92, the indicating main shaft 91 is connected with the insulating main shaft 22 of the three-position switch 2, and the indicator plate 92 is connected with the indicating main shaft 91 and is used for displaying the state of the three-position switch 2.

The connecting device comprises a connecting shaft 26, one end of the connecting shaft 26 is fixedly provided with a second connecting hole 262, the indicating main shaft 91 is inserted into the second connecting hole 262 and fixedly connected, the other end of the connecting shaft 26 is fixedly provided with a first connecting hole 261, and the insulating main shaft 22 is inserted into the first connecting hole 261 and fixedly connected.

The connecting shaft 26 is sleeved with a dynamic seal 25, and the connecting shaft 26 is hermetically connected with the three-position bracket 21 and the mechanism chamber 131 partition plate through the dynamic seal 25.

The indicating device 9 of this embodiment is connected with insulating main shaft 22, and the state of three-position switch 2 directly passes through insulating main shaft 22 and exports indicating device 9 to show by sign 92, abandon middle transmission part, improved the indicating efficiency of three-position switch 2 state.

The indicating device 9 can be applied to the existing ring main unit separately.

As shown in fig. 15 to 18, the main circuit breaker circuit 4 includes a main circuit breaker circuit frame 41, the main circuit breaker circuit frame 41 is provided with an arc extinguish chamber assembly 42 and a main circuit power assembly 43, the arc extinguish chamber assembly 42 includes an arc extinguish contact base 8, the arc extinguish contact base 8 includes an arc extinguish contact base column part 81 and an arc extinguish contact base surface part 82 which are integrally formed, the main circuit power assembly 43 includes a bracket shielding ring 434, and the arc extinguish contact base 8 and the bracket shielding ring 434 are used for uniform peripheral electric fields.

The circuit breaker main circuit frame 41 comprises two groups of circuit breaker main circuit supporting plates 411, in general, the two groups of circuit breaker main circuit supporting plates 411 are arranged in parallel, an arc extinguish chamber supporting plate 412 and an epoxy supporting plate 413 are fixedly arranged between the two groups of circuit breaker main circuit supporting plates 411, the arc extinguish chamber supporting plate 412 and the epoxy supporting plate 413 are respectively fixedly provided with three groups, the three groups of arc extinguish chamber supporting plates 412 and the epoxy supporting plate 413 are horizontally distributed, the arc extinguish chamber supporting plate 412 is positioned above the epoxy supporting plate 413, and a shaft mounting plate 414 is fixedly arranged on the two groups of circuit breaker main circuit supporting plates 411; the arc extinguishing chamber assembly 42 comprises a vacuum bulb 421 and an arc extinguishing contact base 8, the arc extinguishing contact base 8 is fixedly connected with the vacuum bulb 421, the arc extinguishing contact base 8 is fixedly connected with an arc extinguishing chamber supporting plate 412 through a first fixing piece 415, and an epoxy supporting plate 413 is connected with the vacuum bulb 421 and used for supporting the vacuum bulb 421.

The arc extinguishing touches seat 8 and touches seat post spare 81 and arc extinguishing and touch seat face spare 82 including the arc extinguishing, the arc extinguishing touches one side that seat post spare 81 installed perpendicularly at arc extinguishing and touches seat face spare 82, the arc extinguishing touches seat post spare 81 and the arc extinguishing and touches seat face spare 82 integrated design, eliminate the partial discharge hidden danger that the assembly brought, the arc extinguishing of this embodiment touches seat 8 structure and replaces current copper bar and bends, through symmetrical design, guarantee that the installation of isolation sword 235 is in on same horizontal plane with vacuum bulb 421, thereby guarantee the rationality of the interval (vertical) insulating clear distance distribution of circuit breaker main loop 4, the opposite side that arc extinguishing touches seat face spare 82 has set firmly arc extinguishing contact hole 83, arc extinguishing contact hole 83 is relative with the backup pad mounting hole on the explosion chamber backup pad 412, first mounting 415 inserts arc extinguishing contact hole 83 and backup pad mounting hole and realizes the setting firmly of arc extinguishing contact 8 and explosion chamber backup pad 412 and is connected.

In this embodiment, arc extinguishing contact base post 81 is the columnar structure, arc extinguishing plate 84 of flat structure sets firmly in the upper end of arc extinguishing contact base post 81, arc extinguishing plate 84's thickness is less than the diameter of arc extinguishing contact base post 81, arc extinguishing contact base post 81 is equipped with inclined plane 845 with arc extinguishing plate 84's juncture, realize smooth connection through inclined plane 845, arc extinguishing contact base post 81 and arc extinguishing plate 84 design as an organic whole, eliminate the partial discharge hidden danger that the assembly brought, the recess 841 of indent has set firmly on arc extinguishing plate 84, arc extinguishing plate 84 is connected with isolation sword 235, recess 841 matches with isolation sword 235's second contact point 2354, second contact point 2354 blocks in the recess 841, make things convenient for the location of both installations, and isolation sword 235 and the relative rotation of arc extinguishing seat 8.

The main loop power assembly 43 comprises an insulating main shaft 431, three groups of pressure maintaining supports 433 are rotatably arranged on the insulating main shaft 431, a support shielding ring 434 is arranged on the outer side of one group of breaker main loop supporting plates 411, the support shielding ring 434 is fixedly connected with the pressure maintaining supports 433, a supporting bar 437 is arranged on the outer side of the other group of breaker main loop supporting plates 411, the supporting bar 437 is fixedly connected with the pressure maintaining supports 433, the supporting bar 437 is fixedly connected with a supporting bar assembly 44, a stepped shielding ring mounting hole 4341 is fixedly arranged on the support shielding ring 434, a first mounting hole corresponding to the shielding ring mounting hole 4341 is fixedly arranged on the breaker main loop supporting plates 411 and the pressure maintaining supports 433, a second fixing member is sequentially inserted into the shielding ring mounting hole 4341 and the first mounting hole, the support shielding ring 434, the breaker main loop supporting plates 411 and the pressure maintaining supports 433 are fixedly connected, the second fixing member is arranged inside the support shielding ring 434 through the shielding ring mounting hole 4341, the electric field around the second fixture is uniform, thereby ensuring the insulation requirements of the second fixture to the side casing of the gas box 11.

The insulating main shaft 431 is rotatably provided with a plurality of pressure maintaining cams 432, the two groups of pressure maintaining cams 432 correspond to the group of pressure maintaining supports 433, in the embodiment, the two groups of pressure maintaining cams 432 are respectively positioned at two sides of the pressure maintaining supports 433, and the arc-shaped grooves 4321 are fixedly arranged on the pressure maintaining cams 432.

The linkage of vacuum bubble 421 is provided with double threaded screw 439, double threaded screw 439 is provided with opposite screw thread, one end sets up to right-handed screw promptly, the other end sets up to left-handed screw, thereby realize adjusting the opening of vacuum bubble 421, the function of overrun, when solving both ends and being conventional screw thread, can't adjust the opening, can only adjust the problem of overrun, double threaded screw 439 adopts fine thread in this embodiment, the problem of the unable accurate adjustment opening of coarse thread has been solved, simultaneously because fine thread has better auto-lock performance, can improve circuit breaker major loop 4's mechanical stability, double threaded screw 439 has set firmly flexible coupling 438, flexible coupling 438 sets firmly with branch mother row 437 and is connected.

The double-end screw 439 is spirally connected with a vacuum switch pull rod 435, the lower end of the vacuum switch pull rod 435 is provided with a pressure maintaining cap sleeve, the pressure maintaining cap sleeve is provided with a pulley which is in sliding connection with the arc-shaped groove 4321, and a pressure maintaining spring 436 is arranged between the vacuum switch pull rod 435 and the pressure maintaining cap sleeve.

In the implementation process of the main circuit 4 of the circuit breaker, the circuit breaker mechanism 5 performs switching-on or switching-off operation to drive the insulating main shaft 431 to rotate, and the insulating main shaft 431 rotates to drive the double-threaded screw 439 to move up and down, so that the main circuit 4 of the circuit breaker is controlled to be in a switching-on or switching-off state.

The bracket shielding ring 434, the supporting busbar 437 and the arc extinguishing contact base 8 are designed to be round corners, have no edges and corners, so that the parts can ensure an even electric field when being electrified, and the purpose of improving the insulating property of the main circuit 4 of the circuit breaker is achieved.

The circuit breaker main circuit 4 can be moved into the existing ring main unit separately.

As shown in fig. 19 to 21, the interlock device 6 includes a circuit breaker interlock plate 61 and a three-position interlock plate 62, the three-position interlock plate 62 is connected to the three-position mechanism 3, and the circuit breaker mechanism 5 controls the circuit breaker interlock plate 61 through a snap-in device to restrict movement of the three-position interlock plate 62.

The interlocking device 6 is fixedly connected with the circuit breaker mechanism 5 or/and the three-station mechanism 3 through the interlocking fixing plate 63, a first interlocking hole 611 and a second interlocking hole 612 are fixedly arranged on the circuit breaker interlocking plate 61, a sliding rod 613 is fixedly arranged on a circuit breaker frame of the circuit breaker mechanism 5, the sliding rod 613 is positioned in the second interlocking hole 612 and slides along the second interlocking hole 612, the circuit breaker mechanism 5 comprises an energy storage operating handle 52, and the energy storage operating handle 52 penetrates through the first interlocking hole 611.

The three-station interlocking plate 62 is rotatably connected with the interlocking fixing plate 63, interlocking kidney-shaped holes 621 are fixedly formed in two ends of the three-station interlocking plate 62, and the circuit breaker interlocking plate 61 is rotatably connected with the three-station interlocking plate 62 and the three-station interlocking plate 62 is rotatably connected with the three-station mechanism interlocking plate 38 through fastening rotating pieces.

The interlocking device 6 further comprises an interlocking return mechanism 64, the interlocking return mechanism 64 comprises a first interlocking rod 641, a second interlocking rod 642, a third interlocking rod 643 and a return spring 644, the first interlocking rod 641 and the second interlocking rod 642 are fixedly arranged on the interlocking fixing plate 63, the third interlocking rod 643 is fixedly arranged on the circuit breaker interlocking plate 61, the return spring 644 is sleeved on the first interlocking rod 641, two sets of spring output ends 645 of the return spring 644 are arranged on two sides of the second interlocking rod 642 and the third interlocking rod 643, when the three-position mechanism interlocking plate 38 moves downwards, the third interlocking rod 643 drives the spring output end 645 arranged on the upper side to move upwards, the second interlocking rod 642 is used for limiting the spring output end 645 arranged on the lower side, when the three-position mechanism interlocking plate 38 moves upwards, the third interlocking rod 643 drives the spring output end 645 arranged on the lower side to move downwards, the second interlocking rod 642 is used for limiting the spring output end 645 arranged on the upper side, after corresponding operations are completed, the circuit breaker interlock plate 61 is controlled to return to the initial state by the return spring 644.

The buckle device comprises a first buckle plate 651 and a second buckle plate 652, the first buckle plate 651 and the second buckle plate 652 are fixedly arranged on the circuit breaker interlocking plate 61, the first buckle plate 651 is located above the second buckle plate 652, the circuit breaker mechanism 5 comprises a circuit breaker indicating assembly, the circuit breaker indicating assembly is linked with a circuit breaker operating assembly, the state of the circuit breaker main circuit 4 is displayed, the circuit breaker indicating assembly comprises a circuit breaker indicating main shaft 51 and a circuit breaker indicating plate 53, the indicating main shaft 51 is linked with the circuit breaker operating assembly, the state of the circuit breaker operating assembly controls the circuit breaker to indicate the rotating direction of the main shaft 51, and then the states of different circuit breaker main circuits 4 are displayed through different rotating directions of the circuit breaker indicating plate 53.

The circuit breaker indicating main shaft 51 is provided with a clamping notch 511, when the circuit breaker main circuit 4 is in a closing state, the circuit breaker indicating main shaft 51 rotates to enable the circuit breaker indicating main shaft 51 to be clamped between a first buckling plate 651 and a second buckling plate 652 to lock a circuit breaker interlocking plate 61, at this time, the three-station mechanism interlocking plate 38 cannot be moved through a three-station interlocking plate 62, and the isolation output shaft 33 and the grounding output shaft 34 are both in a state of being covered by the station mechanism interlocking plate 38; after the breaker main circuit 4 is opened, the breaker indicating main shaft 51 rotates to enable the buckle notch 511 to be separated from the interference state with the first buckle plate 651 and the second buckle plate 652, the breaker interlocking plate 61 is unlocked, the three-station mechanism interlocking plate 38 is operated to move up or down at the moment, the three-station mechanism 3 is operated, the purpose that the three-station mechanism 3 cannot be operated in the closing state of the breaker main circuit 3 is achieved, and the operation safety is guaranteed.

The interlocking device 6 can be independently applied to the existing ring main unit.

It is to be understood that the described embodiments are merely a few embodiments of the utility model, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. A three-position switch is characterized in that: the device comprises a three-station support, an insulating main shaft and a separating and combining mechanism, wherein the insulating main shaft and the separating and combining mechanism are arranged on the three-station support, the insulating main shaft is linked with the separating and combining mechanism, the separating and combining mechanism comprises a shielding ring and a shielding cover, and the shielding ring and the shielding cover are used for controlling temperature rise and equalizing pressure of an electric field.

2. A three position switch according to claim 1, wherein: the three-station support is composed of a support front plate, a support rear plate, a first cross beam, a second cross beam and a fourth cross beam, the first cross beam, the second cross beam and the fourth cross beam are horizontally arranged in parallel and fixedly arranged between the support front plate and the support rear plate, the support front plate and the support rear plate are fixedly connected with an air box, an insulating main shaft is horizontally arranged, the output end of the insulating main shaft is rotatably connected with the support rear plate, and the input end of the insulating main shaft penetrates through the support front plate and is connected with the support front plate in a dynamic sealing mode.

3. A three position switch according to claim 2, wherein: the opening and closing mechanism comprises a three-phase upper insulator, a three-phase lower insulator and a transmission assembly, wherein the three-phase upper insulator is fixedly arranged on a first cross beam, a bus bar is fixedly arranged on the three-phase upper insulator and fixedly connected with a three-phase insulating sleeve, a closing grounding contact base is fixedly arranged on the bus bar, the three-phase lower insulator is fixedly arranged on a second cross beam, a transition row is fixedly arranged on the three-phase lower insulator, and an arc extinguish chamber contact base is fixedly arranged on the transition row.

4. A three position switch according to claim 3 wherein: the transmission assembly comprises a connecting rod structure, the connecting rod structure comprises a transmission connecting lever, a movable knife pull rod and a movable knife pull plate, the transmission connecting lever is fixedly arranged on an insulating main shaft, the movable knife pull rod is provided with two groups which are symmetrically arranged, two ends of the movable knife pull rod are respectively rotatably connected with the transmission connecting lever and the movable knife pull plate, and nylon pins positioned on two sides of the transmission connecting lever are fixedly arranged on the insulating main shaft and used for limiting the movement of the transmission connecting lever.

5. A three position switch according to claim 3 wherein: the transmission assembly further comprises two groups of isolation knives which are arranged in parallel and fixedly connected through a first knife supporting piece and a second knife supporting piece, connecting rods located between the first knife supporting piece and the second knife supporting piece are further fixedly arranged on the two groups of isolation knives and rotatably connected with the moving knife pull plate, a first contact point located on the knife head and a second contact point located on the knife tail are fixedly arranged on the isolation knives, and the second contact points are in contact with or separated from the arc extinguish chamber contact seat.

6. A three position switch according to claim 5 wherein: the shielding cover is fixedly arranged on a cutter head of the isolation cutter, the shielding cover is provided with a stepped shielding cover mounting hole, the first cutter supporting piece penetrates through the shielding cover mounting hole, the standard pieces are arranged at two ends of the shielding cover and fixedly connected with the shielding cover and the first cutter supporting piece, and the standard pieces are wrapped inside the shielding cover through the shielding cover mounting hole.

7. A three position switch according to claim 5 wherein: the shielding ring is installed at the tool bit tail of the isolation tool through the second standard part, the second standard part is rotationally connected with the arc extinguish chamber contact seat, a shielding ring installation hole is fixedly formed in the shielding ring, the second standard part is located in the shielding ring installation hole, and the second standard part is wrapped inside the shielding ring through the shielding ring installation hole.

8. A three position switch according to claim 5 wherein: the transmission assembly further comprises a contact seat assembly, the contact seat assembly comprises a grounding bar and a grounding contact seat, the grounding bar is fixedly arranged on the three-station support, three groups of grounding bars are arranged, the grounding contact seat is inserted between the two groups of isolation knives, and two sides of the grounding contact seat are in point contact with or separated from the first contact points.

9. A three position switch according to claim 5 wherein: the surfaces of the shielding cover, the shielding ring and the isolation knife are processed in a fillet, edge-free and corner-free mode.