CN108615645B

CN108615645B - Direct-acting type three-station isolation operating mechanism positioned by special-shaped shaft and control method thereof

Info

Publication number: CN108615645B
Application number: CN201810776573.1A
Authority: CN
Inventors: 周家龙; 胥威; 黎明强; 胥向阳
Original assignee: China Energy Engineering Haimen Changtai Electric Co ltd
Current assignee: China Energy Engineering Haimen Changtai Electric Co ltd
Priority date: 2018-07-16
Filing date: 2018-07-16
Publication date: 2023-08-01
Anticipated expiration: 2038-07-16
Also published as: CN108615645A

Abstract

A direct-acting three-station isolation operating mechanism positioned by a special-shaped shaft and a control method thereof comprise a fixed plate and a rotary table capable of rotating relative to the fixed plate, wherein the rotary table realizes an independent isolating switch operation state, an operation shielding state and a grounding switch operation state when rotating, the back of the rotary table is fixedly connected with the special-shaped shaft, a first rib and a second rib are axially and sequentially arranged on the special-shaped shaft, a guide block installation space is arranged between the first rib and the second rib, and the first rib and the second rib are radially and longitudinally arranged at an included angle of 41 degrees; the back of the fixed plate is provided with a gear transmission mechanism and a screw transmission mechanism to enable the moving contact, the isolation fixed contact and the grounding fixed contact to realize linear motion, the special-shaped shaft is provided with a guide block, the guide block is matched with the first convex edge and the second convex edge to realize the state locking of isolation or grounding operation, when the isolation operation is carried out, the moving contact is ensured to act between the isolation fixed contact and the moving contact, and when the grounding operation is carried out, the moving contact is ensured to act between the grounding fixed contact and the moving contact.

Description

Direct-acting type three-station isolation operating mechanism positioned by special-shaped shaft and control method thereof

Technical Field

The invention relates to a direct-acting type three-station isolating switch, in particular to a direct-acting type three-station isolating operating mechanism positioned by a special-shaped shaft and a control method thereof.

Background

The operating mechanism of the direct-acting three-station isolating switch mainly aims at transmitting the rotary motion of the driving motor to the rotary shaft of the three-station isolating switch through a series of transmission parts. At present, three-station direct-acting type isolation operating mechanisms widely used in the market all have the following two defects:

1. the disc spring is adopted for operation, the deformation and the rotation angle of the disc spring are used as the positions of the three stations for positioning, and the disc spring has errors due to the force of the disc spring, and meanwhile, the disc spring is high in manufacturing cost and cannot be widely adopted from the aspects of reliability and economy;

2. the pulling plate is adopted to drive the spring pin to be positioned, but the radial shearing force of the transmission rod can deform the spring pin, failure causes operation failure of the switch, and even safety accidents.

Disclosure of Invention

The invention aims to solve the technical problem of providing a direct-acting type three-station isolation operating mechanism positioned by a special-shaped shaft and a control method thereof, aiming at the defects of the prior art, and the direct-acting type three-station isolation operating mechanism can smoothly, reliably and automatically perform reasonable operation on a direct-acting type isolation closing/isolation opening/grounding three-station switch according to the operation of a panel operation command panel.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides an adopt three station isolation operating mechanism of direct-acting of dysmorphism axle location, includes the fixed plate, sets up carousel and the isolation static contact that constitutes switch main loop conductive system and set up in same straight line in proper order, moving contact, ground static contact, when isolation static contact and moving contact combine, the isolator switch-on, when ground static contact and moving contact combine, the ground switch-on, its characterized in that is equipped with first isolation operation hole, first ground operation hole and carousel connecting hole on the fixed plate, is equipped with isolation hole, dislocation hole and the ground hole that is in same arc and set up in proper order between first isolation operation hole and the first ground operation hole; the front surface of the turntable is provided with a selective positioning rod which can be selectively inserted into the isolation hole, the dislocation hole or the grounding hole to realize positioning of the turntable, the back surface of the turntable is fixedly connected with a special-shaped shaft, the special-shaped shaft penetrates through the turntable connecting hole of the fixed plate and is supported on the fixed plate, the turntable is also provided with a second isolation operation hole matched with the first isolation operation hole and a second grounding operation hole matched with the first grounding operation hole, when the selective positioning rod is inserted into the isolation hole, the second isolation operation hole and the first isolation operation hole concentrically form an isolation switch operation state, and when the selective positioning rod is inserted into the dislocation hole, the first isolation operation hole, the first grounding operation hole, the second grounding operation hole are respectively staggered with the second isolation operation hole and the second grounding operation hole to form an operation shielding state, and when the selective positioning rod is inserted into the grounding hole, the second grounding operation hole and the first grounding operation hole concentrically form a grounding switch operation state; the first rib and the second rib are sequentially arranged in the axial direction of the special-shaped shaft, a guide block installation space is arranged between the first rib and the second rib, and the first rib and the second rib are arranged at an included angle of 41 degrees in the radial direction of the special-shaped shaft; the back of the first isolation operation hole is provided with a first operation shaft, the tail of the first operation shaft is fixedly provided with a first gear, the back of the first grounding operation hole is provided with a second operation shaft, the tail of the second operation shaft is fixedly provided with a second gear, the first gear and the second gear are meshed with each other, the first gear and the second gear are meshed with a third gear, and the back of the first gear and the back of the second gear are fixedly connected with a main transmission screw rod; the front surface of the third gear is fixedly connected with a guide screw, a guide block is arranged on the guide screw through threaded connection, the guide block is arranged on the guide block installation space of the special-shaped shaft in a clearance fit manner, a guide groove matched with the radial sections of the first convex edge and the second convex edge of the special-shaped shaft is formed in the upper part of the guide block, and when the first convex edge or the second convex edge is aligned with the guide groove, the guide block moves relative to the special-shaped shaft under the driving of the guide screw; the movable contact is arranged in the middle of the main transmission screw rod through threads, the two ends of the main transmission screw rod are respectively penetrated with the isolation fixed contact and the grounding fixed contact, and the movable contact moves relative to the main transmission screw rod under the drive of the main transmission screw rod, so that the movable contact is combined with the isolation fixed contact or the grounding fixed contact.

And a curve arc groove is arranged between the first isolation operation hole and the first grounding operation hole, one end of the curve arc groove is provided with the isolation hole, the other end of the curve arc groove is provided with the grounding hole, and the middle of the curve arc groove is provided with the dislocation hole.

The selective positioning rod comprises a connecting piece fixedly connected with the turntable and a positioning pin which is fixed in the connecting piece and provided with a head, and the positioning pin is connected with the connecting piece through a spring.

The sum of the length of the first convex rib and the thickness of the guide block is equal to the moving contact isolating closing stroke length, and the sum of the length of the second convex rib and the thickness of the guide block is equal to the moving contact grounding closing stroke length.

The movable contact, the isolation fixed contact and the grounding fixed contact are all sealed in the pole column of the epoxy resin.

The pitch of the main transmission screw rod is 10mm, the fracture opening distance of the isolating switch is 155mm, the fracture opening distance of the grounding switch is 135mm, and when the isolating switch and the grounding switch are switched on, the over-stroke of the moving contact during insertion is 10mm.

In order to solve the technical problems, the invention also provides a control method of the direct-acting type three-station isolation operating mechanism adopting the special-shaped shaft positioning, which comprises the following steps:

when the selective positioning rod is inserted into the dislocation hole of the fixed plate, the rotary table and the special-shaped shaft fixedly connected with the rotary table are automatically positioned and automatically locked in the operation shielding state, and the rotary table blocks the first isolation operation hole and the first grounding operation hole on the fixed plate, so that the operation handle cannot be inserted;

when the turntable rotates anticlockwise and the locating rod is inserted into the isolation hole of the fixed plate, the turntable and the special-shaped shaft fixedly connected with the turntable are automatically located and automatically locked in the operation state of the isolating switch, the second isolation operation hole on the turntable is concentric with the first isolation operation hole on the fixed plate, namely the first isolation operation hole is opened, the first grounding operation hole is closed, meanwhile, the first convex rib on the special-shaped shaft is aligned with the guide groove on the upper part of the guide block, and the second convex rib is staggered with the guide groove of the guide block, so that the guide block can only move forwards along the first convex rib; when the operation handle is inserted and the first operation shaft is rotated, the first gear drives the main transmission screw rod to rotate, so that the moving contact moves forwards to realize the switching-on operation of the isolating switch, and meanwhile, the third gear and the guide screw rod fixedly connected with the third gear synchronously rotate to enable the guide block to move forwards along the first convex edge, namely, the first convex edge of the irregular shaft is locked with the guide block, and the gear shifting operation of the selective positioning rod cannot be performed until the isolating switch is switched on in place; when the operating handle is operated in the opposite direction, the isolating switch is opened in place;

when the rotary table rotates clockwise and the locating rod is inserted into the grounding hole of the fixed plate, the rotary table and the special-shaped shaft fixedly connected with the rotary table are automatically located and automatically locked in the grounding switch operating state, the second grounding operation hole on the rotary table is concentric with the first grounding operation hole on the fixed plate, namely, the first grounding operation hole is opened, the first isolation operation hole is closed, meanwhile, the second convex rib on the special-shaped shaft is aligned with the guide groove on the upper part of the guide block, and the first convex rib is staggered with the guide groove of the guide block, so that the guide block can only move backwards along the second convex rib; when the operating handle is inserted and the second operating shaft is rotated, the second gear drives the main transmission screw rod to rotate, so that the moving contact moves backwards to realize the switching-on operation of the grounding switch, and meanwhile, the third gear and the guide screw rod fixedly connected with the third gear synchronously rotate to enable the guide block to move backwards along the second convex edge, namely, in the whole process of the grounding stroke, the second convex edge of the irregular shaft is locked with the guide block, and the gear shifting operation of the positioning rod cannot be performed until the grounding switch is switched on in place; when the operating handle is operated in the opposite direction, the grounding switch is opened in place.

When the rotary table of the operating mechanism rotates, the fixed plate presents an isolating switch operating state, an operating shielding state and a grounding switch operating state which are independent of each other, the gear transmission mechanism and the screw transmission mechanism are arranged on the back surface of the fixed plate to enable the moving contact, the isolating fixed contact and the grounding fixed contact to realize linear motion, the back surface of the rotary table is fixedly connected with a special-shaped shaft, the special-shaped shaft is provided with a first convex rib and a second convex rib, the first convex rib and the second convex rib are arranged at intervals, a guide block is arranged between the first convex rib and the second convex rib, the first convex rib and the second convex rib are arranged at an included angle of 41 degrees in the radial direction of the special-shaped shaft, and the first convex rib and the second convex rib are matched to realize the state locking of isolating or grounding operation.

Compared with the prior art, the invention has the following beneficial effects:

1) The position of the selective positioning rod on the turntable is selected to form a unique movement mode with the movable contact and the fixed contact on the main transmission screw rod;

2) The position selection of the selection positioning rod on the rotary table cannot be changed before or after the first operation shaft and the second operation shaft are operated in place, and the rotary table is rotated after the first operation shaft and the second operation shaft are operated in place, so that automatic limiting can be realized;

3) The locking distance of the special-shaped shaft and the contact opening distance in the pole post are within 1 mm;

4) Low manufacturing cost, simple operation, safety and reliability.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a schematic diagram of a turntable structure with a contoured shaft.

Fig. 3 is a connection structure diagram of the profiled shaft and the guide wire rod.

Fig. 4 is a block structure diagram.

Fig. 5 is a structural view of the fixing plate.

Detailed Description

As shown in fig. 1 to 5, the direct-acting three-station isolation operating mechanism adopting special-shaped shaft positioning comprises a fixed plate 1 and a rotary table 2. The fixed plate 1 is provided with a first isolation operation hole 15, a first grounding operation hole 16 and a turntable connection hole 18, a curve arc groove 17 is arranged between the first isolation operation hole 15 and the first grounding operation hole 16, one end of the curve arc groove 17 is provided with an isolation hole 171, the other end is provided with a grounding hole 173, and a dislocation hole 172 is arranged in the middle. The front of the turntable 2 is provided with a selective positioning rod 3 which can be selectively inserted into different positions of the curved arc groove 17 to realize the positioning of the turntable 2, the back of the turntable 2 is fixedly connected with the special-shaped shaft 14, and the special-shaped shaft 14 passes through a turntable connecting hole 18 of the fixed plate 1 to be supported on the fixed plate 1. In this embodiment, the selective positioning rod 3 includes a connecting member 31 fixedly connected to the turntable 2, and a positioning pin 33 with a head 32 fixed in the connecting member 31, wherein the positioning pin 33 is connected to the connecting member 31 by a spring, and when the selective positioning rod 3 is pulled out through the head 32, the spring is compressed, the positioning pin 33 retreats to enable the end of the positioning pin 33 to move along the curved arc groove 17 and be selectively inserted into the isolation hole 171, the grounding hole 173, and the dislocation hole 172 on the curved arc groove 17. The turntable 2 is also provided with a second isolation operation hole 19 matched with the first isolation operation hole 15 and a second grounding operation hole 20 matched with the first grounding operation hole 16, and when the selection positioning rod 3 is inserted into the isolation hole 171, the second isolation operation hole 19 is concentric with the first isolation operation hole 15 and is in an isolation switch operation state; when the selective positioning rod 3 is inserted into the dislocation hole 172, the first isolation operation hole 15 and the first grounding operation hole 16 are respectively staggered with the second isolation operation hole 19 and the second grounding operation hole 20, and are in an operation shielding state; when the select positioning lever 3 is inserted into the ground hole 173, the second ground operating hole 20 is concentric with the first ground operating hole 16, and is in the ground switch operating state. The special-shaped shaft 14 is provided with a first rib A and a second rib B, the first rib A and the second rib B are separated by a guide block installation space L in the axial direction of the special-shaped shaft 14, and the guide block installation space L is arranged at an included angle of 41 degrees in the radial direction of the special-shaped shaft 14. The back of the first isolation operation hole 15 of the fixed plate 1 is provided with a first operation shaft 12, and the tail part of the first operation shaft 12 is fixedly provided with a first gear 11; the second operating shaft 5 is installed on the back of the first grounding operating hole 16 of the fixed plate 1, the second gear 11' is fixedly installed on the tail of the second operating shaft 5, the first gear 11 and the second gear 11' are meshed, and the first gear 11 and the second gear 11' are meshed with the third gear 6. The front surface of the third gear 6 is fixedly provided with a guide screw 4, and the back surface is fixedly provided with a main transmission screw 10. The guide screw 4 is fixedly provided with the guide block 13 through threaded connection, and the guide block 13 is installed on the guide block installation space L of the profiled shaft 14 in a clearance fit manner, so that the guide block 13 can be driven to move through the guide screw 4. The upper part of the guide block 13 is provided with a guide groove 131 matched with the radial cross section of the first and second ribs A, B, and when the first rib A or the second rib B is aligned with the guide groove 131, the guide block 13 can move relative to the profiled shaft 14 under the drive of the guide screw 4. The sum of the length of the first convex rib A and the thickness of the guide block 13 is equal to the moving contact isolating closing stroke length, and the sum of the length of the second convex rib B and the thickness of the guide block 13 is equal to the moving contact grounding closing stroke length. The moving contact 8 is arranged in the middle of the main transmission screw rod 10 through threads, the main transmission screw rod 10 is penetrated with the isolation fixed contact 7 and the grounding fixed contact 9, the isolation fixed contact 7 is positioned at the front end of the moving contact 8, and the grounding fixed contact 9 is positioned at the rear end of the moving contact 8. The moving contact 8, the isolation fixed contact 7 and the grounding fixed contact 9 are all sealed in the pole column of the epoxy resin to form a main loop conductive system of the power supply switch, and the main loop conductive system is connected with the operating mechanism through a main transmission screw rod 10.

The isolation/grounding switch-on switch in the existing solid insulation switch cabinet adopts a three-station direct-acting structure, and has the characteristics of small volume and uniform electrical analysis. In fig. 1, a moving contact 8, an isolation fixed contact 7, a grounding fixed contact 9 and a main transmission screw 10 are single-phase structure schematic diagrams of a three-station isolation switch, wherein the moving contact 8 is inserted into the isolation fixed contact 7 to realize isolation switching-on operation, the moving contact 8 is inserted into the grounding fixed contact 9 to realize grounding switching-on operation, the pitch of the main transmission screw 10 is generally 10mm, the opening distance of a break of the isolation switch is 155mm, the overtravel (moving contact insertion amount) is 10mm, the opening distance of a break of the grounding switch is 135mm, the overtravel is 10mm, and according to the national power system standard requirement, the isolation switch and the grounding switch must be separately operated, namely two operation holes are required, and according to national standard requirement, the application adopts a first isolation operation hole 15 and a second grounding operation hole 16 to perform double-hole operation. The purpose of the offset holes 172 in fig. 5 is: when the positioning rod 3 is selected to be switched on by the isolating switch, the positioning rod is turned to a staggered hole in the middle to be locked and isolated, and the power supply switch can be operated to switch on and off; when the selective positioning rod 3 is switched on by the grounding switch, the selective positioning rod is turned to a staggered hole in the middle to lock the grounding, and the switch cabinet door can be opened for maintenance; when the power supply switch is not opened or the cabinet door of the switch cabinet is not closed perfectly, the mechanical interlocking can automatically lock the rotary table 2 and cannot be operated (namely, the rotary table 2 and the operation hole of the fixed plate 1 are in a dislocation state); only when the guide block 13 is positioned at the middle position of the special-shaped shaft 14, the selection positioning rod 3 can select the operation position from the middle dislocation hole 172, so that the isolating switch can be operated in a counterclockwise rotation mode, and the grounding switch can be operated in a clockwise rotation mode.

When the selective positioning rod 3 is pulled out and rotated to the dislocation hole 172 (as shown in fig. 5) of the curved arc groove 17 of the fixed plate 1, after the selective positioning rod 3 is released, the positioning pin 33 in the selective positioning rod 3 pops out under the action of the internal spring force and is inserted into the middle dislocation hole 172 of the curved arc groove of the fixed plate 1, and the turntable 2 and the selective positioning rod 3 are fixedly connected into a whole, so that the turntable 2 and the fixedly connected irregular shaft 14 are automatically positioned and automatically locked, and at the moment, the turntable 2 blocks the first isolation operation hole 15 and the first grounding operation hole 16 on the fixed plate 1, and the operation handle cannot be inserted, and at the moment, is in a power transmission state.

When the selection positioning rod 3 is positioned in the middle misplacement hole 172 and the guide block 13 is positioned between the first and second convex edges A, B of the profiled bar 14, the selection positioning rod 3 is pulled out, the selection positioning rod 3 is rotated anticlockwise by 41 degrees, the selection positioning rod 3 is released, the positioning pin 33 of the selection positioning rod 3 is ejected under the action of the internal spring force and is inserted into the left isolation hole 171 of the curved circular arc groove 17 of the fixed plate 1, the rotation plate 2 and the profiled bar 14 fixedly connected with the rotation plate 2 are automatically positioned and automatically locked, and at the moment, the second isolation operation hole 19 on the rotation plate 2 is concentric with the first isolation operation hole 15 on the fixed plate 1, so that the first isolation operation hole 15 is opened, and the first grounding operation hole 16 on the right side is closed. Since the turntable 2 is fixedly connected with the profiled shaft 14, the profiled shaft 14 rotates 41 degrees along with the turntable 2, at this time, the first rib a on the profiled shaft 14 is aligned with the guide groove 131 on the upper portion of the guide block 13, and the second rib B is offset from the guide groove 131 of the guide block 13, so that the guide block 13 can only move forward in the direction shown in fig. 1. The operation handle is inserted and the first operation shaft 12 is rotated, the first gear 11 connected with the operation handle drives the main transmission screw 10 and the moving contact 8 connected with the main transmission screw through threads to move forwards, so that the closing operation of the isolating switch is realized, meanwhile, the third gear 6 connected with the first gear 11 and the second gear 11' and the guide screw 4 fixedly connected with the third gear 6 synchronously act, the guide screw 4 drives the guide block 13 to move forwards, and after the guide block 13 is started, the first convex edge A enters the guide block 13 and penetrates through the whole process of the isolating stroke, the first convex edge A of the irregular shaft 14 is locked with the guide block 13, so that the gear shifting operation of the selection positioning rod 3 cannot be performed until the isolating switch is closed in place. Because the sum of the thicknesses of the first convex edge A and the guide block 13 is equal to the isolation closing stroke of the movable contact, when the isolating switch is closed in place, the selective positioning rod 3 returns to the dislocation hole 172, so that the isolation operation locking limit can be realized, and the power supply switch can be operated to open and close at the moment. When the first isolation operation hole 15 is opened, the operation handle rotates in the opposite direction to open the isolation switch in place.

When the selection positioning rod 3 is positioned at the middle opening position 172 and the guide block 13 is positioned between the first convex edge A, B and the second convex edge A, B of the profiled shaft 14, the selection positioning rod 3 is pulled out and rotated clockwise for 41 degrees to be released, and the positioning pin 33 in the selection positioning rod 3 is ejected under the action of the internal spring force and inserted into the right side of the curved circular arc groove of the fixed plate 1, the positioning pin is automatically positioned and automatically locked together with the turntable 2 and the profiled shaft 14 fixedly connected with the turntable, as shown in fig. 1-3, at the moment, the second grounding operation hole 20 on the turntable 2 is concentric with the first grounding operation hole 16 on the fixed plate 1, namely, at the moment, the first grounding operation hole 16 on the right side is opened, the first isolation operation hole 15 on the left side is closed, and because the turntable 2 is fixedly connected with the profiled shaft 14, when the turntable is rotated clockwise for 41 degrees, the profiled shaft is synchronously rotated 41 degrees, at the moment, the second convex edge B on the profiled shaft is aligned with the guide groove on the upper part of the guide block 13, and the first convex edge A is misplaced with the guide groove 131 of the guide block 13, as shown in fig. 3, namely, the first convex edge 131 moves backward direction as shown in fig. 1. The operation handle is inserted and the second operation shaft 5 is rotated, the second gear 11 'connected with the second operation shaft 5 drives the main transmission screw rod 10 and the moving contact 8 connected with the main transmission screw rod through threads to move backwards, so that the switching-on operation of the grounding switch is realized, meanwhile, the third gear 6 connected with the second gear 11' and the guide screw 4 fixedly connected with the third gear 6 synchronously act, the guide screw 4 drives the guide block 13 to move backwards, and after the guide block 13 is started, the second convex edge B enters the guide groove 131 of the guide block 13 and penetrates through the whole process of the grounding stroke, and the second convex edge B of the special-shaped shaft 14 is locked with the guide block 13, so that the gear shifting operation of the positioning rod 3 cannot be selected until the grounding switch is switched on in place. Because the sum of the thicknesses of the second convex edge B and the guide block 13 is equal to the grounding closing stroke of the movable contact, when the grounding switch is closed in place, the selective positioning rod 3 returns to the dislocation hole 172, so that the grounding operation locking limit can be realized, and the door can be opened for maintenance. When the first grounding operation hole 16 is opened, the grounding switch can be opened in place by operating the operation handle in the opposite direction.

Claims

1. The utility model provides a direct-acting type three-station isolation operating mechanism adopting special-shaped shaft positioning, which comprises a fixed plate (1), a rotary table (2) arranged on the fixed plate, and an isolation static contact (7), a moving contact (8) and a grounding static contact (9) which are sequentially arranged on the same straight line and form a power supply switch main loop conducting system, when the isolation static contact is combined with the moving contact, the isolation switch is switched on, when the grounding static contact is combined with the moving contact, the grounding switch is switched on,

the fixed plate is provided with a first isolation operation hole (15), a first grounding operation hole (16) and a turntable connection hole (18), and an isolation hole (171), a dislocation hole (172) and a grounding hole (173) which are arranged on the same arc line and are sequentially arranged between the first isolation operation hole and the first grounding operation hole;

the front surface of the turntable is provided with a selective positioning rod (3) which can be selectively inserted into the isolation hole, the dislocation hole or the grounding hole to realize positioning of the turntable, the back surface of the turntable is fixedly connected with a special-shaped shaft (14), the special-shaped shaft penetrates through the turntable connecting hole of the fixed plate and is supported on the fixed plate, the turntable is also provided with a second isolation operation hole (19) matched with the first isolation operation hole and a second grounding operation hole (20) matched with the first grounding operation hole, when the selective positioning rod is inserted into the isolation hole, the second isolation operation hole and the first isolation operation hole form an isolation switch operation state in a concentric manner, and when the selective positioning rod is inserted into the dislocation hole, the first isolation operation hole and the first grounding operation hole are respectively staggered with the second isolation operation hole and the second grounding operation hole to form an operation shielding state, and when the selective positioning rod is inserted into the grounding hole, the second grounding operation hole and the first grounding operation hole form a grounding switch operation state in a concentric manner; the first rib (A) and the second rib (B) are sequentially arranged in the axial direction of the special-shaped shaft, a guide block installation space (L) is arranged between the first rib and the second rib, and the first rib and the second rib are arranged at an included angle of 41 degrees in the radial direction of the special-shaped shaft; a first operating shaft (12) is arranged on the back of the first isolation operating hole, a first gear (11) is fixedly arranged at the tail of the first operating shaft, a second operating shaft (5) is arranged on the back of the first grounding operating hole, a second gear (11') is fixedly arranged at the tail of the second operating shaft, the first gear and the second gear are meshed with each other, the first gear and the second gear are meshed with a third gear (6), and the back of the third gear is fixedly connected with a main transmission screw rod (10);

the front surface of the third gear is fixedly connected with a guide screw (4), a guide block (13) is arranged on the guide screw in a threaded connection manner, the guide block is arranged on the guide block installation space of the special-shaped shaft in a clearance fit manner, a guide groove (131) matched with the radial sections of the first convex edge and the second convex edge of the special-shaped shaft is formed in the upper part of the guide block, and when the first convex edge or the second convex edge is aligned with the guide groove, the guide block moves relative to the special-shaped shaft under the driving of the guide screw;

the movable contact is arranged in the middle of the main transmission screw rod through threads, the two ends of the main transmission screw rod are respectively penetrated with the isolation fixed contact and the grounding fixed contact, and the movable contact moves relative to the main transmission screw rod under the drive of the main transmission screw rod, so that the movable contact is combined with the isolation fixed contact or the grounding fixed contact.

2. The direct-acting type three-station isolation operating mechanism adopting special-shaped shaft positioning according to claim 1, wherein a curve arc groove (17) is arranged between the first isolation operating hole and the first grounding operating hole, one end of the curve arc groove is provided with the isolation hole, the other end of the curve arc groove is provided with the grounding hole, and the dislocation hole is arranged in the middle of the curve arc groove.

3. The direct-acting type three-station isolation operating mechanism adopting special-shaped shaft positioning according to claim 1, wherein the selective positioning rod comprises a connecting piece (31) fixedly connected with the turntable and a positioning pin (33) which is fixed in the connecting piece and provided with a head (32), and the positioning pin is connected with the connecting piece through a spring.

4. The direct-acting three-station isolation operating mechanism adopting special-shaped shaft positioning according to claim 1, wherein the moving contact, the isolation fixed contact and the grounding fixed contact are all sealed in a pole of epoxy resin.

5. The direct-acting three-station isolation operating mechanism adopting special-shaped shaft positioning according to claim 1, wherein the pitch of the main transmission screw rod is 10mm, the fracture opening distance of the isolating switch is 155mm, the fracture opening distance of the grounding switch is 135mm, and the over-stroke of the moving contact insertion is 10mm when the isolating switch and the grounding switch are closed.

6. The direct-acting three-station isolation operating mechanism adopting special-shaped shaft positioning according to claim 1, wherein the sum of the length of the first convex rib and the thickness of the guide block is equal to the moving contact isolation closing stroke length, and the sum of the length of the second convex rib and the thickness of the guide block is equal to the moving contact grounding closing stroke length.

7. A control method of a direct-acting three-station isolation operating mechanism employing special-shaped shaft positioning as set forth in any one of claims 1 to 6, characterized by comprising: