Three-position transmission structure of switch cabinet and gas insulated switch cabinet

Abstract

The application discloses a three-position transmission structure of a switch cabinet and a gas insulated switch cabinet, and relates to the technical field of switch cabinets, in particular to a three-position transmission structure of a switch cabinet, which comprises a driving mechanism, at least one disconnecting switch and at least one grounding switch, the disconnecting switch and the grounding switch are arranged in a gas tank assembly of the switch cabinet, the driving mechanism comprises a first rotating output shaft and a second rotating output shaft which are independent of each other, the first rotating output shaft drives the isolation knife of each disconnecting switch to do linear reciprocating motion along the axial direction through an isolation transmission chain, so that the disconnecting switch is closed or opened, thereby realizing the connection or disconnection of the main circuit of the switch cabinet, the second rotating output shaft drives the grounding knife of each grounding switch to do rotary swing around a rotating shaft through a grounding transmission chain, so that the grounding switch is closed or opened, thereby realizing the grounding or ungrounding of the main circuit of the switch cabinet. The application solves the problem that the traditional three-position switch cannot convert the motion track because it shares the same transmission chain.

Description

Technical Field

[0001] This invention relates to the field of switchgear, and in particular to a three-position transmission structure for switchgear and a gas-insulated switchgear. Background Technology

[0002] In switchgear, the three-position switch (closing-opening-grounding) is a core functional component for realizing the switching of the main circuit, maintenance grounding, and safety isolation. Existing switchgear uses either direct-acting three-position or knife-switch type three-position switches. From the output shaft of the three-position drive mechanism to the moving knife, a single transmission chain is typically used. This chain can only drive the moving contact in a straight line or drive the knife switch to reciprocate, achieving the three functions. It is only suitable for driving a single movement of the moving knife with a single transmission chain and cannot be converted into two different motion trajectories that satisfy both linear propulsion and rotation around the axis. Direct-acting three-position switches, completing the connection, isolation, and grounding functions, typically require a large stroke. Vertical arrangement increases the height of the gas chamber, and the vertical arrangement of the working contact, moving contact, and grounding contact creates a complex electric field in the longitudinal direction. Due to the asymmetrical structure, electric field concentration is prone to occur, requiring increased spacing to ensure insulation margin. Knife-switch type three-position switches, completing the three-position switching, typically require a larger rotation radius, increasing the radial dimension of the cabinet, making them more suitable for wider cabinets. With the trend towards miniaturization and compactness in switchgear, the three-position knife switch mechanism presents significant challenges in terms of spatial layout. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a three-position transmission structure for switchgear and a gas-insulated switchgear. It breaks through the limitation of traditional three-position mechanisms that share a single transmission chain and can only achieve a single motion mode. At the same time, it avoids the risks of mechanical interference and jamming caused by sharing a transmission chain, thereby improving the reliability and safety of operation.

[0004] The technical solution adopted by this invention to solve its technical problem is: a three-position transmission structure for a switchgear, including a drive mechanism, at least one disconnecting switch and at least one grounding switch. The disconnecting switch and the grounding switch are disposed in the gas box assembly of the switchgear. The drive mechanism includes a first rotary output shaft and a second rotary output shaft that are independent of each other. The first rotary output shaft drives the isolating blade of each disconnecting switch to perform linear reciprocating motion along its axial direction through an isolating transmission chain, so that the disconnecting switch is closed or opened, thereby realizing the connection or disconnection of the main circuit of the switchgear. The second rotary output shaft drives the grounding blade of each grounding switch to rotate and swing around a rotating shaft through a grounding transmission chain, so that the grounding switch is closed or opened, thereby realizing the grounding or de-grounding of the main circuit of the switchgear.

[0005] Furthermore, it also includes at least one through-wall bushing. The gas box assembly includes a busbar gas box and a circuit breaker gas box. The through-wall bushing passes through a partition between the busbar gas box and the circuit breaker gas box and is fixed to the partition by bolts. The disconnecting switch and the grounding switch are arranged inside the busbar gas box. The through-wall bushing includes a hollow tubular central conductor and an insulating sleeve sleeved outside the central conductor. One axial end of the central conductor extends into the busbar gas box and is electrically connected to the disconnecting switch and the grounding switch, and the other end extends into the circuit breaker gas box and is electrically connected to the main circuit conductor in the circuit breaker gas box.

[0006] Furthermore, the disconnecting switch includes a working contact and an isolating blade. The isolating blade and the working contact are conductive components. The working contact is electrically connected to the main busbar in the busbar gas box. The isolating blade is slidably disposed in the central conductor along the axial direction of the central conductor and is electrically connected to the central conductor. One end of the isolating blade is a contact end.

[0007] The isolation transmission chain drives the isolation blade to reciprocate linearly along its axial direction, causing the contact end of the isolation blade to extend from one end of the central conductor along the axial direction and engage with the working contact seat, so that the disconnecting switch is in the closed state, or the isolation blade is completely retracted into the central conductor, so that the disconnecting switch is in the open state.

[0008] Furthermore, the isolated transmission chain includes a first transmission shaft, at least one insulated transmission rod, and at least one lead screw;

[0009] The first drive shaft passes through the side wall of the circuit breaker gas box and is provided with at least one first bevel gear coaxial with it. One end of the first drive shaft is connected to the first rotary output shaft through an adjustable universal joint. The first bevel gear is located inside the circuit breaker gas box.

[0010] The insulating transmission rod is located inside the circuit breaker gas box, and its two ends are respectively provided with a second bevel gear and a third bevel gear coaxial with it, with the first bevel gear meshing with the second bevel gear;

[0011] The lead screw is coaxially disposed inside the central conductor and rotatably connected to the central conductor. One end of the lead screw is threadedly connected to the isolation blade, and the other end of the lead screw is provided with a fourth bevel gear coaxial with it. The third bevel gear and the fourth bevel gear mesh. The isolation blade is circumferentially fixed relative to the central conductor to convert the rotational motion of the lead screw into the linear reciprocating motion of the isolation blade.

[0012] Furthermore, the first drive shaft is parallel to the first rotary output shaft, the insulating drive rod is perpendicular to the first drive shaft, and the lead screw is perpendicular to both the first drive shaft and the insulating drive rod. The first drive shaft includes multiple first shaft segments, adjacent first shaft segments are hinged together, and a length adjustment structure is provided at the connection point of adjacent first shaft segments.

[0013] Furthermore, the grounding switch includes a grounding stationary contact and a grounding blade, the grounding stationary contact and the grounding blade being conductive components, the grounding stationary contact being fixed to the outer wall of one end of the central conductor along its axial direction and electrically connected to the central conductor;

[0014] The grounding transmission chain drives the grounding switch to swing around one end, so that the other end of the grounding switch contacts the grounding stationary contact, so that the grounding switch is in the closed state, or so that the other end of the grounding switch is away from the grounding stationary contact, so that the grounding switch is in the open state.

[0015] The grounding switch includes two blades arranged opposite each other, and a stop is connected between the two blades on the side away from the grounding stationary contact. When the grounding switch is rotated to the closed position, the grounding stationary contact is located between the two blades and in contact with the stop, so as to restrict the grounding switch from continuing to rotate by the stop.

[0016] Furthermore, it also includes two insulating shielding rods, which are symmetrically arranged on both sides of the grounding stationary contact along the circumference of the central conductor; an insulating shielding cover is also fitted onto one end of the central conductor along its axial direction.

[0017] Furthermore, the grounding transmission chain includes a second transmission shaft and a grounding transmission shaft. One end of the second rotary output shaft is provided with a fifth bevel gear coaxial with it. The two ends of the second transmission shaft are respectively provided with a sixth bevel gear and a seventh bevel gear coaxial with it, and the fifth bevel gear meshes with the sixth bevel gear. The grounding transmission shaft is arranged through the side wall of the busbar gas box, and one end of it is provided with an eighth bevel gear coaxial with it, and the seventh bevel gear meshes with the eighth bevel gear. One end of the grounding knife is connected to the grounding transmission shaft.

[0018] Furthermore, the second rotary output shaft is parallel to the grounding drive shaft, and the second drive shaft is perpendicular to both the second rotary output shaft and the grounding drive shaft; the grounding drive shaft includes multiple second shaft segments, adjacent second shaft segments are connected, and a length adjustment structure is provided at the connection point of adjacent second shaft segments.

[0019] The present invention also provides a gas-insulated switchgear, including the three-position transmission structure of the switchgear as described above.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention achieves independent control of two different motion trajectories by setting up independent first and second rotary output shafts, each driven by an isolated transmission chain to move the isolation blade linearly, and a grounding transmission chain to drive the grounding blade to rotate and oscillate. This design overcomes the limitation of traditional three-station mechanisms that share a single transmission chain and can only achieve a single motion trajectory. It optimizes the spatial layout within the switchgear, reduces the size of the switchgear, and avoids the mechanical interference and jamming risks caused by sharing a transmission chain, thus improving operational reliability and safety.

[0022] 2. The present invention is equipped with a through-wall bushing, which is bolted to the partition between the busbar gas box and the circuit breaker gas box. The isolating blade is slidably set in the center conductor of the through-wall bushing. The integrated design of the through-wall bushing and the isolating contact provides reliable support for the movement of the isolating blade, making the whole more stable. It eliminates the connecting parts and support structure of the existing isolating contact, reduces the number of parts, and makes the layout more compact.

[0023] 3. In this invention, the grounding stationary contact is fixed on the central conductor of the wall bushing. Taking advantage of the symmetrical structure of the wall bushing, the insulating layer of the wall bushing, the insulating shield at one end of the central conductor, and the insulating shield rods on both sides of the grounding stationary contact work together to bear and disperse the high electric field intensity, thereby achieving a uniform distribution of electric field stress.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments; however, the three-position transmission structure of the switchgear and the gas-insulated switchgear of the present invention are not limited to the embodiments. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of the three-position transmission structure of the present invention. Figure 1 (First workstation);

[0026] Figure 2 This is the front view of the three-station transmission structure of the present invention. Figure 1 (First workstation);

[0027] Figure 3 This is an enlarged schematic diagram of the transmission connection between the second transmission shaft and the ground transmission shaft of the present invention;

[0028] Figure 4 This is a rear view of the three-station transmission structure of the present invention (first station).

[0029] Figure 5 yes Figure 4 A cross-sectional view along line AA;

[0030] Figure 6 yes Figure 5 Enlarged view of point B;

[0031] Figure 7 This is a three-dimensional structural diagram of the three-position transmission structure of the present invention. Figure 2 (Second workstation);

[0032] Figure 8 This is the front view of the three-station transmission structure of the present invention. Figure 2 (Second workstation);

[0033] Figure 9 yes Figure 8 A cross-sectional view along line CC;

[0034] Figure 10 This is a three-dimensional structural diagram of the three-position transmission structure of the present invention. Figure 3 (Third workstation);

[0035] Figure 11 This is the front view of the three-station transmission structure of the present invention. Figure 3 (Third workstation);

[0036] Figure 12 yes Figure 11 Enlarged diagram of point D;

[0037] Figure 13 yes Figure 11 Enlarged view of point E;

[0038] Figure 14 yes Figure 11 A cross-sectional view along line FF;

[0039] Figure 15 This is a top view of the three-station transmission structure of the present invention (third station).

[0040] Figure 16 yes Figure 15 Enlarged schematic diagram at point G;

[0041] Figure 17 This is a partial structural schematic diagram of the gas-insulated switchgear of the present invention;

[0042] Figure 18 This is a cross-sectional schematic diagram of the gas-insulated switchgear of the present invention;

[0043] In the diagram: 11. First rotary output shaft; 12. Second rotary output shaft; 121. Fifth bevel gear; 21. Isolation knife; 211. Guide groove; 22. Working contact seat; 31. Grounding knife; 311. Blade; 312. Stop block; 32. Grounding stationary contact; 41. First drive shaft; 411. First bevel gear; 412. First shaft segment; 413. First connecting piece; 4131. First elongated hole; 414. First bolt; 42. Insulating drive rod; 421. Second bevel gear; 422. Third bevel gear; 423. Insulating layer; 424. Insert; 43. Lead screw; 431. Fourth bevel gear ; 44. Universal joint; 51. Second drive shaft; 511. Sixth bevel gear; 512. Seventh bevel gear; 52. Grounding drive shaft; 521. Eighth bevel gear; 522. Second shaft section; 5221. Second elongated hole; 523. Second bolt; 6. Through-wall sleeve; 61. Center conductor; 611. Limiting component; 62. Insulating sleeve; 621. Fixing part; 622. First insulating part; 623. Second insulating part; 7. Bearing; 8. Insulating shield; 9. Insulating shield rod; 10. Busbar gas box; 101. Main busbar; 102. Partition plate; 20. Circuit breaker gas box; 201. Main circuit conductor. Detailed Implementation

[0044] In this invention, the terms "first," "second," and "third," etc., are used only to distinguish similar objects, not to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. The use of terms such as "upper," "lower," "left," "right," "front," "rear," "inner," "outer," and "top / bottom" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, and is only for the convenience of describing the invention, not to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation on the scope of protection of this invention. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Please see Figures 1-18As shown, a three-position transmission structure for a switchgear according to the present invention includes a drive mechanism, at least one disconnecting switch, and at least one grounding switch. The disconnecting switch and the grounding switch are disposed within the gas box assembly of the switchgear. The drive mechanism has a first rotary output shaft 11 and a second rotary output shaft 12 that are independent of each other. The first rotary output shaft 11 drives the isolating blades 21 of each disconnecting switch to reciprocate linearly along their axial direction via an isolating transmission chain, thereby closing or opening the disconnecting switch and thus connecting or disconnecting the main circuit of the switchgear. The second rotary output shaft 12 drives the grounding blades 31 of each grounding switch to rotate and swing around a pivot via a grounding transmission chain, thereby closing or opening the grounding switch and thus grounding or de-grounding the main circuit of the switchgear. This structure achieves independent control of two different motion trajectories, breaking through the limitation of traditional three-position mechanisms that share a single transmission chain and can only achieve a single motion trajectory. It optimizes the spatial layout within the switchgear, reduces the size of the switchgear, and avoids the mechanical interference and jamming risks caused by sharing a transmission chain, thereby improving the reliability and safety of operation.

[0047] The present invention also includes at least one through-wall bushing 6. The gas box assembly includes a busbar gas box 10 and a circuit breaker gas box 20. The through-wall bushing 6 passes through a partition 102 between the busbar gas box 10 and the circuit breaker gas box 20 and is fixed to the partition 102 by bolts. The disconnecting switch and the grounding switch are disposed inside the busbar gas box 10. The through-wall bushing 6 includes a hollow tubular central conductor 61 and an insulating sleeve 62 sleeved outside the central conductor 61. One axial end of the central conductor 61 extends into the busbar gas box 10 and is electrically connected to the disconnecting switch and the grounding switch. The other end extends into the circuit breaker gas box 20 and is electrically connected to the main circuit conductor 201 in the circuit breaker gas box 20. Specifically, the insulating sleeve 62 includes a first insulating portion 622 and a second insulating portion 623 sequentially along the axial direction of the central conductor 61. The first insulating portion 622 and the second insulating portion 623 are rotationally symmetrical about the axis of the central conductor 61. The radius of the first insulating portion 622 gradually decreases from the middle to both ends along the axial direction, and the radius of the second insulating portion 623 gradually decreases from the middle to both ends along the axial direction. The insulating sleeve 62 also includes a fixing portion 621 located in the middle, which is bolted to the partition plate 102. The first insulating portion 622 and the second insulating portion 623 are located on both sides of the fixing portion 621.

[0048] Preferably, the through-wall bushing 6 is an epoxy resin cast insulation component, that is, the insulation sleeve 62 is made of epoxy resin and is integrally cast with the center conductor 61. The through-wall bushing 6 is completely installed inside the gas box assembly and is not directly fixed to the gas box assembly by bolts, but is fixed to the partition plate 102, which effectively reduces the risk of insulation failure due to bushing aging and improves the reliability of power equipment operation.

[0049] Specifically, the number of wall bushings 6, disconnecting switches and grounding switches is the same as the number of gas box assemblies. Each gas box assembly contains one disconnecting switch, one grounding switch and one wall bushing 6.

[0050] The disconnecting switch includes a working contact 22 and an isolating blade 21. Both the isolating blade 21 and the working contact 22 are conductive components. The working contact 22 is electrically connected to the main busbar 101 in the busbar gas box 10. The isolating blade 21 is slidably disposed within the central conductor 61 along its axial direction and is electrically connected to the central conductor 61. One end of the isolating blade 21 is a contact end. Preferably, an insulating shield 8 is fitted onto the end of the working contact 22 facing the through-wall bushing 6. The isolation transmission chain drives the isolating blade 21 to reciprocate linearly along its axial direction, causing the contact end of the isolating blade 21 to extend from one axial end of the central conductor 61 and engage with the working contact 22, thus placing the disconnecting switch in the closed state (i.e., the contact end of the isolating blade 21 is electrically connected to the working contact 22, thereby connecting the main circuit of the switchgear), or causing the isolating blade 21 to retract completely into the central conductor 61, thus placing the disconnecting switch in the open state (i.e., disconnecting the main circuit of the switchgear) and achieving isolation.

[0051] Specifically, the isolation transmission chain includes a first transmission shaft 41, at least one insulating transmission rod 42, and at least one lead screw 43. The first transmission shaft 41 is disposed through the side wall of the circuit breaker gas box 20 and is provided with at least one first bevel gear 411 coaxial with it. One end of the first transmission shaft 41 is connected to the first rotary output shaft 11 via an adjustable universal joint 44. The first bevel gear 411 is located inside the circuit breaker gas box 20. The number of insulating transmission rods 42, lead screws 43, and first bevel gears 411 is consistent with the number of disconnect switches and corresponds one-to-one. The insulating transmission rod 42 is disposed inside the circuit breaker gas box 20, and its two ends are respectively provided with a second bevel gear 421 and a third bevel gear 422 coaxial with it. The first bevel gear 411 meshes with the second bevel gear 421. The lead screw 43 is coaxially disposed within the central conductor 61 and rotatably connected to the central conductor 61 via a bearing 7. One end of the lead screw 43 is threadedly connected to the isolation blade 21, and the other end is provided with a fourth bevel gear 431 coaxial with it. The third bevel gear 422 and the fourth bevel gear 431 mesh. The isolation blade 21 is circumferentially fixed relative to the central conductor 61.

[0052] This converts the rotational motion of the lead screw 43 into the linear reciprocating motion of the isolation blade 21.

[0053] like Figure 12As shown, a universal joint 44 connects the first rotary output shaft 11 and the first transmission shaft 41. The rotational nature of the universal joint 44 allows for torque transmission to adapt to different angles and directions. Preferably, the universal joint 44 includes multiple third shaft segments, with a length adjustment structure between adjacent segments. The length adjustment structure includes an elongated hole in one third shaft segment, a connecting hole in another third shaft segment, and a bolt and nut. The bolt passes through the connecting hole and the elongated hole and is threadedly connected to the nut. Length adjustment is achieved by loosening the nut and allowing the bolt to slide relative to the elongated hole.

[0054] The insulating transmission rod 42 includes an insulating layer 423 and inserts 424 respectively embedded at both ends of the insulating layer 423. The two inserts 424 are of different sizes. The smaller insert 424 is provided with the second bevel gear 421 at its end, and the larger insert 424 is provided with the third bevel gear 422 at its end.

[0055] like Figure 6 As shown, the outer side of the isolation blade 21 is provided with a guide groove 211 extending along its axial direction, and the center conductor 61 is provided with a limiting member 611. The end of the limiting member 611 is located in the guide groove 211 and slides in cooperation with the guide groove 211, so that the isolation blade 21 is restricted from rotating relative to the center conductor 61 by the cooperation of the limiting member 611 and the guide groove 211, and only the isolation blade 21 is allowed to move along its axial direction.

[0056] The first drive shaft 41 is parallel to the first rotary output shaft 11, the insulating drive rod 42 is perpendicular to the first drive shaft 41, and the lead screw 43 is perpendicular to both the first drive shaft 41 and the insulating drive rod 42. Figure 13 As shown, the first drive shaft 41 includes multiple first shaft segments 412, adjacent first shaft segments 412 are hinged together, and a length adjustment structure is provided at the connection point of adjacent first shaft segments 412. The length adjustment structure includes a first connector 413, a second connector, a first bolt 414, and a nut. The first connector 413 is hinged to one of the first shaft segments 412, and the second connector is integrally formed with the other first shaft segment 412. The first connector 413 has a first elongated hole 4131, and the second connector has a connecting hole. The first bolt 414 passes through the connecting hole and the first elongated hole 4131 and is threadedly connected to the nut. The length adjustment is achieved by loosening the nut to allow the first bolt 414 to slide relative to the first elongated hole 4131.

[0057] The grounding switch includes a grounding stationary contact 32 and a grounding blade 31. The grounding stationary contact 32 and the grounding blade 31 are conductive components. The grounding stationary contact 32 is fixed to the outer wall of one end of the central conductor 61 in the axial direction and is electrically connected to the central conductor 61. Specifically, the grounding stationary contact 32 is welded to the outer wall of one end of the central conductor 61 in the axial direction.

[0058] The grounding transmission chain drives the grounding knife 31 to swing around one end, causing the other end of the grounding knife 31 to contact the grounding stationary contact 32, thus putting the grounding switch in the closed state and achieving grounding of the main circuit of the switchgear. Alternatively, it can move the other end of the grounding knife 31 away from the grounding stationary contact 32, putting the grounding switch in the open state and de-grounding the main circuit of the switchgear. Specifically, the grounding knife 31 is connected to a metal gas box assembly via a metal braided strap. A grounding copper busbar is installed on the gas box assembly, connecting it to the grounding grid to form a reliable grounding path.

[0059] The grounding switch 31 includes two blades 311 arranged opposite to each other. A stop block 312 is connected between the two blades 311 on the side away from the grounding stationary contact 32. When the grounding switch 31 rotates to the closed position, the grounding stationary contact 32 is located between the two blades 311 and contacts the stop block 312, so as to restrict the grounding switch 31 from continuing to rotate through the stop block 312.

[0060] The invention also includes two insulating shielding rods 9, which are symmetrically arranged on both sides of the grounding stationary contact 32 along the circumference of the central conductor 61. An insulating shielding cover 8 is also fitted onto one axial end of the central conductor 61. Utilizing the symmetrical structure of the through-wall sleeve 6, the insulating sleeve 62 of the through-wall sleeve 6, the insulating shielding cover 8 at one axial end of the central conductor 61, and the insulating shielding rods 9 on both sides of the grounding stationary contact 32 work together to bear and disperse the high electric field intensity, achieving a uniform distribution of electric field stress.

[0061] The grounding transmission chain includes a second transmission shaft 51 and a grounding transmission shaft 52. One end of the second rotary output shaft 12 is provided with a fifth bevel gear 121 coaxial with it. The two ends of the second transmission shaft 51 are respectively provided with a sixth bevel gear 511 and a seventh bevel gear 512 coaxial with it. The fifth bevel gear 121 meshes with the sixth bevel gear 511. The grounding transmission shaft 52 is provided through the side wall of the busbar gas box 10, and one end of it is provided with an eighth bevel gear 521 coaxial with it. The seventh bevel gear 512 meshes with the eighth bevel gear 521. One end of the grounding knife 31 is connected to the grounding transmission shaft 52.

[0062] The second rotary output shaft 12 is parallel to the grounded transmission shaft 52, and the second transmission shaft 51 is perpendicular to both the second rotary output shaft 12 and the grounded transmission shaft 52; Figure 16As shown, the grounding drive shaft 52 includes multiple second shaft segments 522, adjacent second shaft segments 522 are connected, and a length adjustment structure is provided at the connection of adjacent second shaft segments 522. The length adjustment structure includes a second elongated hole 5221 provided in one of the second shaft segments 522, a connecting hole provided in another second shaft segment 522, a second bolt 523 and a nut. The second bolt 523 passes through the connecting hole and the second elongated hole 5221 and is threadedly connected to the nut. By loosening the nut, the second bolt 523 slides relative to the second elongated hole 5221 to achieve length adjustment.

[0063] In this embodiment, there are three gas box assemblies, three disconnect switches and three grounding switches, that is, there are three first bevel gears 411, three insulating transmission rods 42 and three lead screws 43. The three first bevel gears 411 are spaced apart on the first transmission shaft 41, and the three grounding blades 31 are spaced apart on the second transmission shaft 51.

[0064] The invention also includes an operating mechanism for controlling the rotation of the first rotary output shaft 11 and the second rotary output shaft 12. The operating mechanism has two gear transmission systems: one connected to the first rotary output shaft 11 and the other to the second rotary output shaft 12. Each system is equipped with a motor and a clutch for electric operation, and can also be equipped with a manual operating handle for manual operation. The switchgear also includes mechanical and electrical interlocks to ensure safe operating sequence, preventing the grounding switch from closing when the disconnecting switch is closed, and vice versa.

[0065] Three-position switch operation:

[0066] like Figure 1 , Figure 5 As shown, in the first working position, the first rotary output shaft 11 rotates, driving the universal joint 44 to rotate, which in turn drives the first transmission shaft 41 to rotate. The first bevel gear 411 of the first transmission shaft 41 meshes with the second bevel gear 421 on the insulating transmission rod 42, driving the insulating transmission rod 42 to rotate synchronously. The third bevel gear 422 of the insulating transmission rod 42 meshes with the fourth bevel gear 431 on the lead screw 43, thereby driving the lead screw 43 to rotate. At this time, the rotational motion of the lead screw 43 is converted into the linear movement of the isolating blade 21, so that the contact end of the isolating blade 21 extends out of the central conductor 61 and engages with the working contact seat 22, so that the isolating switch is in the closed state, realizing the connection of the main circuit of the switch cabinet.

[0067] like Figure 7 , Figure 9As shown, in the second station, the first rotary output shaft 11 rotates in the reverse direction, driving the universal joint 44 to rotate in the reverse direction, which in turn drives the first transmission shaft 41 to rotate in the reverse direction. The first bevel gear 411 of the first transmission shaft 41 meshes with the second bevel gear 421 on the insulating transmission rod 42, driving the insulating transmission rod 42 to rotate synchronously in the reverse direction. The third bevel gear 422 of the insulating transmission rod 42 meshes with the fourth bevel gear 431 on the lead screw 43, thereby driving the lead screw 43 to rotate in the reverse direction. At this time, the lead screw 43 drives the isolating blade 21 to retract axially and completely retract the isolating blade 21 into the central conductor 61, thereby putting the isolating switch in the open state, realizing the disconnection of the main circuit of the switch cabinet, and achieving isolation.

[0068] like Figure 10 , Figure 14 As shown, in the third station, the second rotary output shaft 12 rotates, and the fifth bevel gear 121 of the second rotary output shaft 12 meshes with the sixth bevel gear 511 of the second transmission shaft 51, driving the second transmission shaft 51 to rotate. The seventh bevel gear 512 of the second transmission shaft 51 meshes with the eighth bevel gear 521 on the grounding transmission shaft 52, driving the grounding transmission shaft 52 to rotate. At this time, the grounding transmission shaft 52 drives the grounding knife 31 to swing around one end, so that the other end of the grounding knife 31 contacts the grounding stationary contact 32, and the stop block 312 abuts against the grounding stationary contact 32, restricting the grounding knife 31 from continuing to rotate, so that the grounding switch is in the closed state, realizing the grounding of the main circuit of the switch cabinet.

[0069] When the grounding needs to be removed, the second rotary output shaft 12 rotates in the opposite direction, driving the grounding transmission shaft 52 to rotate in the opposite direction through the second transmission shaft 51, so that the other end of the grounding knife 31 is away from the grounding stationary contact 32, returning to the open position and removing the grounding.

[0070] The present invention provides a gas-insulated switchgear, comprising a three-position transmission structure as described above.

[0071] The present invention relates to a gas-insulated switchgear. For the structure and working principle of the three-position transmission structure of the switchgear, please refer to the preceding description, which will not be repeated here.

[0072] The present invention discloses a three-position transmission structure for a switchgear and a gas-insulated switchgear. The parts not described herein are the same as or can be implemented using existing technologies.

[0073] The above embodiments are only used to further illustrate a three-position transmission structure of a switchgear and a gas-insulated switchgear of the present invention. However, the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A three-position transmission structure for a switchgear, comprising a drive mechanism, at least one disconnecting switch, and at least one grounding switch, wherein the disconnecting switch and the grounding switch are disposed within the gas box assembly of the switchgear, characterized in that: The drive mechanism includes a first rotary output shaft and a second rotary output shaft that are independent of each other. The first rotary output shaft drives the isolating blades of each isolating switch to reciprocate linearly along their axial direction through an isolating transmission chain, so as to close or open the isolating switch, thereby realizing the connection or disconnection of the main circuit of the switch cabinet. The second rotary output shaft drives the grounding blades of each grounding switch to rotate and swing around a rotating shaft through a grounding transmission chain, so as to close or open the grounding switch, thereby realizing the grounding or de-grounding of the main circuit of the switch cabinet.

2. The three-position transmission structure of the switchgear according to claim 1, characterized in that: It also includes at least one through-wall bushing. The gas box assembly includes a busbar gas box and a circuit breaker gas box. The through-wall bushing passes through a partition between the busbar gas box and the circuit breaker gas box and is fixed to the partition by bolts. The disconnecting switch and the grounding switch are located inside the busbar gas box. The through-wall bushing includes a hollow tubular central conductor and an insulating sleeve sleeved outside the central conductor. One axial end of the central conductor extends into the busbar gas box and is electrically connected to the disconnecting switch and the grounding switch. The other end extends into the circuit breaker gas box and is electrically connected to the main circuit conductor in the circuit breaker gas box.

3. The three-position transmission structure of the switchgear according to claim 2, characterized in that: The disconnecting switch includes a working contact and an isolating blade. The isolating blade and the working contact are conductive components. The working contact is electrically connected to the main bus in the busbar gas box. The isolating blade is slidably disposed inside the central conductor along the axial direction of the central conductor and is electrically connected to the central conductor. One end of the isolating blade is a contact end. The isolation transmission chain drives the isolation blade to reciprocate linearly along its axial direction, causing the contact end of the isolation blade to extend from one end of the central conductor along the axial direction and engage with the working contact seat, so that the disconnecting switch is in the closed state, or the isolation blade is completely retracted into the central conductor, so that the disconnecting switch is in the open state.

4. The three-position transmission structure of the switchgear according to claim 2 or 3, characterized in that: The isolated transmission chain includes a first transmission shaft, at least one insulating transmission rod, and at least one lead screw; The first drive shaft passes through the side wall of the circuit breaker gas box and is provided with at least one first bevel gear coaxial with it. One end of the first drive shaft is connected to the first rotary output shaft through an adjustable universal joint. The first bevel gear is located inside the circuit breaker gas box. The insulating transmission rod is located inside the circuit breaker gas box, and its two ends are respectively provided with a second bevel gear and a third bevel gear coaxial with it, with the first bevel gear meshing with the second bevel gear; The lead screw is coaxially disposed inside the central conductor and rotatably connected to the central conductor. One end of the lead screw is threadedly connected to the isolation blade, and the other end of the lead screw is provided with a fourth bevel gear coaxial with it. The third bevel gear and the fourth bevel gear mesh. The isolation blade is circumferentially fixed relative to the central conductor to convert the rotational motion of the lead screw into the linear reciprocating motion of the isolation blade.

5. The three-position transmission structure of the switchgear according to claim 4, characterized in that: The first drive shaft is parallel to the first rotary output shaft, the insulating drive rod is perpendicular to the first drive shaft, and the lead screw is perpendicular to both the first drive shaft and the insulating drive rod. The first drive shaft includes multiple first shaft segments, adjacent first shaft segments are hinged together, and a length adjustment structure is provided at the connection point of adjacent first shaft segments.

6. The three-position transmission structure of the switchgear according to claim 2, characterized in that: The grounding switch includes a grounding stationary contact and a grounding blade. The grounding stationary contact and the grounding blade are conductive components. The grounding stationary contact is fixed to the outer wall of one end of the central conductor along its axial direction and is electrically connected to the central conductor. The grounding transmission chain drives the grounding switch to swing around one end, so that the other end of the grounding switch contacts the grounding stationary contact, so that the grounding switch is in the closed state, or so that the other end of the grounding switch is away from the grounding stationary contact, so that the grounding switch is in the open state. The grounding switch includes two blades arranged opposite each other, and a stop is connected between the two blades on the side away from the grounding stationary contact. When the grounding switch is rotated to the closed position, the grounding stationary contact is located between the two blades and in contact with the stop, so as to restrict the grounding switch from continuing to rotate by the stop.

7. The three-position transmission structure of the switchgear according to claim 6, characterized in that: It also includes two insulating shielding rods, which are symmetrically arranged on both sides of the grounding stationary contact along the circumference of the central conductor; an insulating shielding cover is also fitted at one end of the central conductor along its axial direction.

8. The three-position transmission structure of the switchgear according to claim 2 or 6, characterized in that: The grounding transmission chain includes a second transmission shaft and a grounding transmission shaft. One end of the second rotary output shaft is provided with a fifth bevel gear coaxial with it. The two ends of the second transmission shaft are respectively provided with a sixth bevel gear and a seventh bevel gear coaxial with it, and the fifth bevel gear meshes with the sixth bevel gear. The grounding transmission shaft is arranged through the side wall of the busbar gas box, and one end of it is provided with an eighth bevel gear coaxial with it, and the seventh bevel gear meshes with the eighth bevel gear. One end of the grounding knife is connected to the grounding transmission shaft.

9. The three-position transmission structure of the switchgear according to claim 8, characterized in that: The second rotary output shaft is parallel to the grounding drive shaft, and the second drive shaft is perpendicular to both the second rotary output shaft and the grounding drive shaft. The grounding drive shaft includes multiple second shaft segments, adjacent second shaft segments are connected, and a length adjustment structure is provided at the connection point of adjacent second shaft segments.

10. A gas-insulated switchgear, characterized in that: Includes the three-position drive structure of the switch cabinet as described in any one of claims 1-9.

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