CN120809515A

CN120809515A - Combined switch equipment

Info

Publication number: CN120809515A
Application number: CN202511301613.3A
Authority: CN
Inventors: 蒋志龙; 黄余良; 欧阳道生; 韩国海
Original assignee: Ningbo Tianan Smart Grid Technology Co ltd
Current assignee: Ningbo Tianan Smart Grid Technology Co ltd
Priority date: 2025-09-12
Filing date: 2025-09-12
Publication date: 2025-10-17

Abstract

The application discloses combined switch equipment which comprises a frame, a vacuum arc-extinguishing chamber, an isolation contact, a grounding contact and a contact knife assembly, wherein the frame is formed by splicing a plurality of insulating partition boards and internally forms a plurality of isolation cavities, the vacuum arc-extinguishing chamber is vertically arranged in the corresponding isolation cavity, the bottom end of the vacuum arc-extinguishing chamber is provided with a fixed contact, the isolation contact is arranged at the bottom end of the frame through an insulating isolation beam, the isolation beam is provided with an isolation area corresponding to the isolation cavity, the isolation contact is positioned in the corresponding isolation area, the grounding contact is arranged at the bottom end of the frame and corresponds to the isolation cavity, and the contact knife assembly is rotatably arranged at the bottom end of the frame through an isolation shaft. The application has the beneficial effects that the vacuum arc-extinguishing chambers among each phase are physically isolated through the isolation cavity, and meanwhile, the isolation contact among each phase is also physically isolated through the isolation area, so that the double isolation design greatly blocks the inter-phase conductive path in space, namely, the inter-phase insulation electric field is greatly improved, and the insulation performance of the combined switch equipment is improved.

Description

Combined switch equipment

Technical Field

The application relates to the technical field of electrical equipment, in particular to combined switch equipment.

Background

In the existing switch cabinet, three-station combined switch equipment is mostly adopted, and a vacuum circuit breaker, a disconnecting switch and a grounding switch are integrated into a whole, wherein three stations refer to three working positions, namely a closing position where a main break of the disconnecting switch is connected, an isolating position where the main break is separated, and a grounding position of a grounding side.

In the switch cabinet, in order to ensure the insulativity of the switch cabinet, SF6 (namely sulfur hexafluoride gas) is filled in a box body of the combined switch, and the SF6 has good insulativity and arc extinguishing performance. Therefore, when each switch is installed, the physical insulation and isolation are not ideal, and especially in compact switching equipment, the local electric field intensity can exceed the tolerance limit of SF6 gas, discharge and even breakdown accidents are caused, and the safe operation of the equipment is threatened. Therefore, how to increase the insulation performance of the existing switchgear to overcome the above problems is a problem to be solved by those skilled in the art.

Disclosure of Invention

One of the objects of the present application is to provide a combination switch device capable of improving insulation performance.

The combined switch equipment comprises a frame, a vacuum arc-extinguishing chamber, an isolation contact, a grounding contact and a contact knife assembly, wherein the frame is formed by splicing a plurality of insulating partition boards, a plurality of isolation cavities are formed in the frame, the vacuum arc-extinguishing chamber is vertically arranged corresponding to the isolation cavities, a fixed contact is arranged at the bottom end of the vacuum arc-extinguishing chamber, the isolation contact is arranged at the bottom end of the frame through an insulating isolation cross beam, an isolation area corresponding to the isolation cavities is arranged on the isolation cross beam, the isolation contact is positioned in the isolation area, the grounding contact is arranged at the bottom end of the frame and corresponds to the isolation cavities, the contact knife assembly is rotatably arranged at the bottom end of the frame through an isolation shaft, and when switching on, the first end of the contact knife assembly is matched with the fixed contact and is positioned in the isolation cavity, and the second end of the contact knife assembly is matched with the isolation contact and is positioned in the isolation area.

Preferably, the frame includes keeps apart front bezel, keeps apart the back plate, a pair of curb plate and a plurality of three-phase baffle, two the both ends position department of curb plate is passed through respectively keep apart the front bezel with keep apart the back plate and carry out butt joint cooperation, the three-phase baffle interval is installed two between the curb plate, and then adjacent form between the three-phase baffle keep apart the chamber.

Preferably, a plurality of separation plate groups are arranged at intervals outside the separation cross beam, each separation plate group comprises a plurality of separation plate bodies, the adjacent separation plate bodies are arranged at intervals at equal intervals, and the separation plate groups are positioned at two sides of the separation contact to form the separation area.

Preferably, the bottom of the isolation beam is provided with a plurality of first insulating cylinders, the first insulating cylinders are coated at the bottom positions corresponding to the isolation contacts, the outer parts of the first insulating cylinders are provided with avoidance ports for the isolation contacts to be connected in a line, and the positions of the avoidance ports correspond to the side parts of the isolation beam.

Preferably, the static contact comprises a contact plate and a head body, the head body is arranged at the bottom end of the contact plate, an insulating plate for coating the contact plate is arranged at the bottom end of the contact plate through a connecting piece, and an insulating cylinder II for coating the connecting piece is arranged at the bottom end of the insulating plate.

Preferably, the three-phase partition plate is provided with a slot at the outer side thereof, and the three-phase partition plate is provided with a socket at the outer side thereof.

Preferably, the isolating shaft comprises a shaft body and an installation seat, the contact knife assembly is installed on the shaft body, the installation seat is of an insulating structure, the installation seat is arranged outside the shaft body and is coated on the contact knife assembly, and the end part of the contact knife assembly extends out of the installation seat.

Preferably, the isolating shaft is integrally injection molded by plastic, the shaft body is in a hollowed-out structure, the outer circumferential surface of the shaft body is inwards recessed to form a plurality of annular grooves, and reinforcing rings are formed between adjacent annular grooves.

The contact knife assembly is of a double-fracture structure, the included angle between two ends of the contact knife assembly is theta, wherein the included angle is 90 degrees < theta <150 degrees, the contact knife assembly comprises a lapping plate and a pair of contact knives, an installation cavity is formed in the installation seat, a notch communicated with the installation cavity is further formed in the installation seat, the lapping plate is installed in the installation cavity, the contact knives are suitable for being inserted from the notch and connected with the end parts of the lapping plate, a cover body of an insulation structure is detachably installed outside the installation seat, and the cover body is suitable for covering the installation cavity.

Preferably, the combined switch device further comprises a balance component, wherein the balance component is installed on the isolating shaft and is staggered with the touch knife component in the circumferential direction, when the isolating shaft rotates, the windward area of the balance component is larger than that of the touch knife component, and the balance component is suitable for balancing the gravity of the touch knife component through air resistance.

Compared with the prior art, the application has the beneficial effects that:

According to the invention, the insulating frame is provided with the plurality of isolation cavities, the insulating isolation cross beam is provided with the plurality of isolation areas, namely, the vacuum arc extinguishing chambers among each phase are physically isolated through the isolation cavities, and meanwhile, the isolation contact among each phase is also physically isolated through the isolation areas, so that the double isolation design greatly blocks the inter-phase conductive paths in space, namely, the inter-phase insulating electric field is greatly improved, and the insulating performance of the combined switch equipment is improved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of one side of the combination switch of the present invention.

Fig. 2 is a schematic diagram of the overall structure of the other side of the combination switch of the present invention.

Fig. 3 is a schematic side view of the present invention.

FIG. 4 is a schematic cross-sectional view of the structure of FIG. 3 at A-A in accordance with the present invention.

FIG. 5 is a schematic cross-sectional view of the structure of FIG. 3 at B-B in accordance with the present invention.

Fig. 6 is an enlarged schematic view of the structure of the present invention at a.

Fig. 7 is a schematic diagram of the spindle and the fixing plate after being detached.

Fig. 8 is an enlarged schematic view of the structure of the present invention at B.

Fig. 9 is a schematic diagram of a three-dimensional structure of the bottom end of the vacuum interrupter according to the present invention.

Fig. 10 is an enlarged schematic view of the structure at C of the present invention.

Fig. 11 is a schematic view of a specific structure of a grounding contact according to the present invention.

FIG. 12 is a schematic diagram of an isolation partition according to the present invention.

Fig. 13 is a schematic diagram of the isolation of the present invention.

Fig. 14 is a schematic view of the grounding connection of the present invention.

Fig. 15 is a schematic view of an exploded construction of a frame according to the present invention.

Fig. 16 is a schematic view of a specific structure of an isolating beam according to the present invention.

Fig. 17 is a schematic view of the whole structure of the isolation shaft of the present invention.

Fig. 18 is a schematic view of the contact blade assembly and balance assembly of the present invention removed from the isolation shaft.

Fig. 19 is an enlarged view of the structure of the present invention at D.

Fig. 20 is a schematic view of a specific structure of a contact blade assembly according to the present invention.

Fig. 21 is a schematic structural diagram of a balance assembly according to the present invention.

FIG. 22 is a schematic view of the axial cross-sectional structure of the isolating shaft of the present invention.

FIG. 23 is a schematic side cross-sectional view of a barrier shaft of the present invention.

Fig. 24 is an enlarged schematic view of the structure at E of the present invention.

In the figure, 1, a rack; 101, isolation front plate, 102, isolation rear plate, 103, side plate, 104, front plate of circuit breaker, 105, three-phase partition plate, 2, vacuum arc extinguishing chamber, 201, static contact, 202, moving contact, 3, isolation cavity, 4, isolation shaft, 401, shaft body, 402, installation seat, 5, grounding cross beam, 6, isolation contact, 7, isolation cross beam, 8, main shaft, 9, fixing plate, 10, guide structure, 1001, guide block, 1002, guide slot, 11, insulation pull rod, 12, contact knife assembly, 1201, contact knife, 1202, lapping plate, 13, grounding contact, 14, bolt protection cover, 15, support frame, 16, elastic pad, 17, insulation plate, 18, insulation cylinder two, 19, frame body, 20, bolt protection opening, 21, grounding copper bar, 22, isolation area, 23, partition plate group, partition plate 1, partition plate body, 24, insulation cylinder one, 25, avoidance opening, 26, balance assembly, 2601, cover body, 2602, fan blade, 27, 23028, reinforcing ring, 29, fixing plate, bending plate, 31, clamping plate, 33, clamping plate, 35, clamping plate and clamping plate.

Detailed Description

The present application will be further described with reference to the following specific embodiments, and it should be noted that, on the premise of no conflict, new embodiments may be formed by any combination of the embodiments or technical features described below.

In the description of the present application, it should be noted that, for the azimuth words such as terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the azimuth and positional relationships are based on the azimuth or positional relationships shown in the drawings, it is merely for convenience of describing the present application and simplifying the description, and it is not to be construed as limiting the specific scope of protection of the present application that the device or element referred to must have a specific azimuth configuration and operation.

It should be noted that the terms "first," "second," and the like in the description and in the claims are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

In one preferred embodiment of the present application, as shown in fig. 1 to 24, a combined switch device comprises a frame 1, a vacuum interrupter 2, an isolation contact 6, a ground contact 13 and a contact blade assembly 12, wherein the frame 1 is formed by splicing a plurality of insulating partition boards and internally forms a plurality of isolation cavities 3, the vacuum interrupter 2 is vertically installed at the corresponding isolation cavities 3, the bottom end is provided with a fixed contact 201, the isolation contact 6 is installed at the bottom end of the frame 1 through an isolation beam 7, the isolation beam 7 is provided with an isolation area 22 corresponding to the isolation cavities 3, the isolation contact 6 is positioned in the corresponding isolation area 22, the ground contact 13 is installed at the bottom end of the frame 1 and corresponds to the isolation cavities 3, and the contact blade assembly 12 is rotatably installed at the bottom end of the frame 1 through the isolation shaft 4.

It can be understood that the vacuum arc-extinguishing chamber 2 between each phase is physically isolated through the isolating cavity 3, and meanwhile, the isolating contact 6 between each phase is also physically isolated through the isolating area 22, while when the switch is closed, the first end of the contact knife assembly 12 is matched with the static contact 201 and is positioned in the isolating cavity 3, and the second end of the contact knife assembly 12 is matched with the isolating contact 6 and is positioned in the isolating area 22, so that the insulating and isolating performance between each phase is ensured, and the inter-phase conducting path is greatly blocked in space by the double-isolating design, namely, the inter-phase insulating electric field is greatly improved, and the insulating performance of the combined switch equipment is improved.

In this embodiment, as shown in fig. 15, the rack 1 includes an isolation front plate 101, an isolation rear plate 102, a pair of side plates 103 and a plurality of three-phase partition plates 105, two end positions of the two side plates 103 are respectively in butt joint through the isolation front plate 101 and the isolation rear plate 102, the three-phase partition plates 105 are installed between the two side plates 103 at intervals, and then an isolation cavity 3 is formed between the adjacent three-phase partition plates 105.

Specifically, as shown in fig. 1 and 2, that is, the front isolation plate 101, the rear isolation plate 102 and the pair of side plates 103 are assembled together in a rectangular shape, and the three-phase partition plates 105 are equidistantly arranged in the front isolation plate, and since the switches are three-phase, the number of the three-phase partition plates 105 is preferably three, and the isolation chambers 3 for installing three vacuum interrupters 2 are just formed between the adjacent three-phase partition plates 105, as shown in fig. 15.

As shown in fig. 1 and 2, both ends of the isolation shaft 4 are rotatably installed between the isolation front plate 101 and the isolation rear plate 102, respectively, and the isolation shaft 4 is located at a position below the side plates 103. The purpose of this design is that it is known that the width (or thickness) of the vacuum interrupter 2 is not very large, and therefore the distance between the two side plates 103 is not very large, which only needs to be adapted to the vacuum interrupter 2 for installation. The fixed contact 201, the isolation contact 6 and the ground contact 13 are circumferentially distributed around the axis of the isolation shaft 4, so that a sufficient space is required for installation at the lower end position of the interior of the frame 1, and the installation space is definitely larger than the space with a width (or thickness) required by the vacuum interrupter 2, so that if the fixed contact 201 and the ground contact 13 are designed to be located in the two side plates 103, a larger space is required between the two side plates 103, and the space of the whole equipment is increased, which is inconvenient for miniaturization design.

Therefore, the design of the isolating shaft 4 is arranged at the lower position of the side plates 103, so that the design of the distance between the two side plates 103 is not influenced, specifically, the installation space between the isolating front plate 101 and the isolating rear plate 102 is adaptively increased, and the installation space between the two side plates 103 is used for installing the vacuum arc extinguishing chamber 2. As shown in fig. 1 and 2, the lower space of the whole frame 1 is larger, while the upper space of the frame 1 is smaller, so that the design is more reasonable and compact.

In addition, the front isolation plate 101 and the rear isolation plate 102 are convenient for installing specific components in the isolating switch, and bear the framework bearing function of the whole frame 1, and the whole frame 1 can be assembled through four plates, so that the isolating switch is simple in structure, convenient to install and detach and beneficial to later maintenance and overhaul work.

The structure of the three-phase separator 105 is not particularly limited in the present application, and the following provides a specific example to be referred to:

As shown in fig. 5 and 15, the three-phase separator 105 has an overall "earth" shape, and thus includes an integrally formed vertical section, an upper horizontal section, and a lower horizontal section, wherein the lower horizontal section is located at the bottom of the vertical section, and the upper horizontal section is located at the middle of the vertical section. When the frame 1 is assembled, the upper horizontal section and the lower horizontal section are inserted and installed in slots of the two side plates 103, and the vertical sections are propped against the space between the two side plates 103, that is, after the frame 1 is assembled, the width of the vertical sections is the width space in the frame 1, and the vacuum arc-extinguishing chamber 2 is positioned between the two vertical sections, so that insulation isolation between each phase is realized.

Of course, the specific structure of the three-phase separator 105 is not limited to the above-mentioned "soil" structure, and the rapid disassembly and assembly of the plug-in portion and the side plate 103 can be realized by the plug-in cooperation of the plug-in portion and the side plate 103 when the three-phase separator is installed as long as the plug-in portion extends outwards near the outer side of the side plate 103.

Further, as shown in fig. 5, the upper horizontal section corresponds to the moving contact 202 at the top end of the vacuum interrupter 2, and the lower horizontal section corresponds to the fixed contact 201. The two contacts of the vacuum arc-extinguishing chamber 2 are known as areas for circuit connection, so that the insulation strength between the adjacent contacts can be greatly improved by isolating the adjacent contacts through a longer horizontal section, and the short circuit phenomenon between the adjacent phases is avoided.

It is worth mentioning that the plug-in installation of the three-phase partition plate 105 not only has the insulation and isolation effects, but also has the effect that ① strengthens the strength of the whole frame 1, and specifically, the two side plates 103 are propped against and supported at the two side positions of the three-phase partition plate 105 after being installed, so that the two side plates 103 can be prevented from inwards extruding and deforming. ② The assembly and disassembly are convenient, and particularly, the participation of fixing pieces (such as bolts) is not needed in the early assembly and the later disassembly, so that the working efficiency is greatly improved. ③ The two side plates 103 can be sleeved and propped against the two side positions of the three-phase partition plate 105 when the frame 1 is assembled, namely, the upper horizontal section and the lower horizontal section of the three-phase partition plate 105 play a role in pre-positioning, so that the two side plates 103 are ensured to correspond to each other in parallel and have uniform spacing, and the installation efficiency is further improved.

In one embodiment of the present application, as shown in fig. 2 and (a) of fig. 16, a plurality of separation plate groups 23 are installed at intervals outside the isolation beam 7, and the separation plate groups 23 are located at both sides of the isolation contact 6 to form isolation regions 22.

It will be appreciated that by designing the insulating partition plate group 23, insulating isolation can be performed between each of the isolation contacts 6, so that a short circuit phenomenon between adjacent isolation contacts 6 can be avoided. Specifically, the partition plate group 23 includes a plurality of partition plate bodies 2301, and the plurality of partition plate bodies 2301 are disposed at equal intervals, further improving insulation performance. Of course, the design of the partition plate body 2301 has the effect that ① the partition plate body 2301 and the isolation beam 7 can be connected through the reinforcing ribs 31, so that on one hand, the stability of the installation of the partition plate body 2301 can be improved, on the other hand, the partition plate body 2301 can further enhance the strength of the whole isolation beam 7, and the isolation beam 7 can also enhance the stability of the whole frame 1. ② The design of a plurality of division plate bodies 2301 can improve the contact range with gas, and then improve the heat dispersion to isolating contact 6 department, guarantee the safe and stable operation of equipment. ③ The equidistant spacing of the divider plates 2301 also helps to maintain uniformity of heat dissipation and prevent occurrence of local overheating. ④ The design of the multi-plate arrangement is also convenient for later maintenance and overhaul work, and the parts of the isolating contact 6 can be rapidly positioned, so that the working efficiency is improved. ⑤ As shown in the figure, the separation plate group 23 and the three-phase separation plate 105 are correspondingly matched, so that the corresponding contact knife assembly 12 can be isolated, and the insulation and isolation effects are further improved. In addition, the corresponding matching design between the partition plate group 23 and the three-phase partition plates 105 also makes the structure of the whole frame 1 more compact and reasonable, effectively utilizes the space in the frame 1 and avoids unnecessary space waste. In summary, the specific design of the isolating beam 7 fully considers the requirements of practical application, and achieves the goals of miniaturization, high insulation strength, high stability and easy maintenance through reasonable layout and structural design.

Further, in order to achieve a better insulation effect on the isolation beam 7, as shown in (b) of fig. 16, a plurality of first insulation cylinders 24 are arranged at the bottom end of the isolation beam 7, namely, the first insulation cylinders 24 correspond to the isolation contacts 6, the first insulation cylinders 24 are wrapped at the bottom end positions of the isolation contacts 6, and in order to facilitate connection of a line with the isolation contacts 6, avoidance openings 25 can be formed in the side portions of the first insulation cylinders 24, so that workers can conveniently connect the line through avoidance of the avoidance openings 25, insulation performance of the isolation contacts 6 is guaranteed, connection of the line is facilitated, and practicality and convenience of equipment are improved.

It should be noted that, the position of the avoiding opening 25 corresponds to the side of the isolating beam 7, that is, the adjacent avoiding openings 25 are not designed relatively, so that the interference phenomenon between adjacent lines can be avoided, and the safety and stability of the device are further improved. In order to facilitate the integral production of the isolation beam 7, the partition plate group 23 and the first insulating cylinder 24 may be integrally injection molded of insulating plastic, so as to greatly improve the insulating effect. In addition, the design of the first insulating cylinder 24 has the advantages that the first insulating cylinder 24 can also protect the isolation contact 6, so that workers are prevented from being damaged due to false touch or external impact in the later maintenance operation process, and the reliability and safety of equipment are improved.

Based on the above embodiment, a similar insulating structure may be adopted at the bottom end of the stationary contact 201, as shown in fig. 8 and 9, the stationary contact 201 includes a contact plate and a head body, the head body is disposed at the bottom end of the contact plate, it should be understood that the contact plate is for mounting the stationary contact 201, and the head body is a component that is subsequently powered on and off, so insulation isolation of the contact plate is very important. Further, an insulating plate 17 for covering the contact plate may be mounted on the bottom end of the contact plate through a connecting member (typically, a bolt), and an insulating cylinder two 18 for covering the connecting member may be provided on the bottom end of the insulating plate 17.

Specifically, the second insulating cylinder 18 and the insulating plate 17 may be integrally injection molded with plastic, and the installed bolt is located in the second insulating cylinder 18, that is, the second insulating cylinder 18 is coated at the bottom end position of the fixed contact 201. The design of the insulating plate 17 and the insulating cylinder two 18 not only improves the insulating performance of the static contact 201, but also effectively prevents the short circuit risk caused by the direct exposure of the bolt mounting piece, and of course, the insulating cylinder two 18 and the insulating cylinder one 24 can also play a role in protection.

Further, in order to prevent the contact blade assembly 12 from contacting the second insulating cylinder 18 during closing, as shown in fig. 9, an elastic pad 16 may be mounted on the bottom end of the insulating plate 17 at a position corresponding to the head body through a frame 19, and when the contact blade assembly 12 is mated with the stationary contact 201, the contact blade assembly 12 will abut against the elastic pad 16 at this time. Of course, the elastic pad 16 has the advantages that the ① elastic pad 16 can be made of insulating flexible materials such as rubber and resin, so that a buffer effect can be provided when the contact knife assembly 12 is switched on, impact and abrasion between the contact knife assembly 12 and the fixed contact 201 are reduced, and the service life of the device is prolonged. ② Because the installation position of the elastic pad 16 is fixed, when the contact knife assembly 12 is matched with the fixed contact 201, the maximum rotation angle of the contact knife assembly 12 is just reached at this time, namely, the elastic pad 16 can limit the contact knife assembly 12, so that the stability and the safety of equipment are improved.

In this embodiment, as shown in fig. 11, the ground contact 13 includes a ground beam 5, a ground copper bar 21, and a ground contact 13, wherein both ends of the ground beam 5 may be fixedly mounted between the front isolation plate 101 and the rear isolation plate 102 by bolts, and the ground contact 13 is mounted in the ground beam 5 by the ground copper bar 21, and it should be understood that the contact blade assembly 12 is mated with the ground contact 13 when grounding is performed. Naturally, the mounting manner of the grounding beams 5 can also limit and support the front isolation plate 101 and the rear isolation plate 102, and further improve the mounting strength of the frame 1.

In one embodiment of the present application, as shown in fig. 6, a main shaft 8 is horizontally rotatably mounted at the upper end of the inside of the frame 1, a plurality of fixing plates 9 are mounted at the outside of the main shaft 8, and the fixing plates 9 are matched with the moving contacts 202 of the corresponding vacuum arc extinguishing chambers 2 through a guide structure 10. It can be understood that the main shaft 8 can drive the fixed plate 9 to rotate, and the fixed plate 9 drives the moving contact 202 to be matched with the fixed contact 201 through the guide structure 10, so that the on-off of the vacuum arc extinguishing chamber 2 is realized.

Specifically, as shown in fig. 7 and 15, the spindle 8 may be installed in such a manner that the support frame 15 is installed at a position above the opposite side of the two side plates 103 by bolts, the fixing plate 9 is rotatably installed in the support frame 15, and the spindle 8 may be inserted into the fixing plate 9 to be fixed, and of course, the front circuit breaker plate 104 is installed at a position above the isolation front plate 101 corresponding to the upper end of the two side plates 103 by bolts, so that one end of the spindle 8 is rotatably installed in the front circuit breaker plate 104, thereby ensuring stable installation of the spindle 8 and improving the strength of the frame 1. In order to improve the insulation protection performance, the bolt protection cover 14 may be mounted at the bolt, but is not limited to the mounting at the position, and the bolt protection cover 14 may be used to protect other parts in the circuit breaker where the bolt is required to be mounted, for example, in fig. 11, the bolt where the ground copper bar 21 and the ground contact 13 are mounted may be protected by the bolt protection cover 20.

The structure of the guide structure 10 is not particularly limited in the present application, and the following provides a specific example to be referred to:

The guide structure 10 includes a guide groove 1002 and a guide block 1001, wherein the guide groove 1002 is provided outside the fixed plate 9, the guide block 1001 and the moving contact 202 are connected through an insulating pull rod 11, and the guide groove 1002 is matched with the guide block 1001. It can be understood that when the main shaft 8 drives the fixing plate 9 to rotate, the guide groove 1002 will rotate along with it, and the guide groove 1002 will pull the guide block 1001 to move up and down, so that the moving contact 202 moves to realize on-off of the vacuum arc extinguishing chamber 2. It should be noted that, in the prior art, the moving contact 202 needs to be driven by multiple crank arms for opening and closing, and the application adopts the cooperation of the guide groove 1002 and the guide block 1001 to effectively perform the opening and closing operation of the circuit breaker, so that the transmission efficiency is improved, and meanwhile, the complexity of the structure is reduced.

The inventors of the present application found that there is a problem when the isolating shaft 4 rotates, as shown in fig. 13 and 23, in that the double-break contact blade assembly 12 is mounted on the isolating shaft 4 and is in a closed state, and the angle between the two contact blades 1201 is 120 °, as is apparent from the figure, when the isolating shaft 4 is unevenly distributed by gravity (i.e., the center of gravity is left), we will consider that when the isolating shaft 4 rotates counterclockwise to the position of fig. 12 (rotation is sixty degrees), the center of gravity is not in the vertical position, and the gravity will generate a torque biased toward the isolating shaft 4, and the torque always tries to pull the center of gravity to the lowest point, so that when the upper contact blade 1201 rotates from the high position to the low position, the gravity moment is ‌ the same as the rotation direction ‌, and the rotating shaft is pushed to accelerate. For the lower blade 1201, it initially rotates from the high position to the low position, the gravity moment is ‌ the same as the rotation direction ‌, pushing the isolating shaft 4 to accelerate, and when it passes the lowest point, the gravity moment is ‌ opposite to the rotation direction ‌, playing a braking role.

Specifically, only the component force of gravity along the circumferential direction provides acceleration or suppression effect (i.e. tangential acceleration is generated), and the resultant force of gravity of the two contact blades 1201 in the contact blade assembly 12 always drives the isolating shaft 4 to accelerate during the opening process, so that the isolating shaft 4 generates overshoot phenomenon and affects the stability during the opening process.

In order to solve the above technical problem, as shown in fig. 17, a balance assembly 26 may be further installed on the isolation shaft 4, and of course, the balance assembly 26 is offset from the contact blade assembly 12 in the circumferential direction, so that the installation between the balance assembly 26 and the contact blade assembly 12 does not interfere, and the balance assembly 26 is better enabled to function.

It will be appreciated that, as shown in fig. 2, when the isolation shaft 4 rotates, the balance assembly 26 contacts with airflow, the windward area of the balance assembly 26 is larger than that of the contact blade assembly 12, and the air resistance generated by the airflow can prevent the rotation of the isolation shaft 4, that is, balance the gravity action of the rotation of the contact blade assembly 12 through the air resistance, so as to achieve the stability of the isolation shaft 4 during the rotation process, thereby reducing the influence of the overshoot.

It should be noted that in the prior art, a person skilled in the art generally performs a static balance design on the isolation shaft 4, that is, a balancing weight or a symmetrical arm structure is installed at a symmetrical position where the center of gravity of the isolation shaft 4 is offset, so as to eliminate the eccentricity and reduce the moment of inertia. However, this design has the disadvantage of increasing the weight or volume of the entire isolating shaft 4, which requires a further increase in the strength or space of the isolating switch device for flexibility and increases the manufacturing costs. The balancing component 26 of the present application balances the gravity of the contact blade component 12 through the air resistance during rotation, that is, only needs to ensure that there is enough contact area between the contact blade component and the gas during rotation, so that excessive mass or volume is not required to be added to balance the isolating shaft 4, and the reliability and stability of the isolating switch are ensured.

The application is not limited in particular to the structure of balance assembly 26, and two particular embodiments are provided below with reference to:

The balance assembly 26 comprises a plurality of fan blades 2602 extending along the radial direction of the isolation shaft 4, wherein the fan blades 2602 can effectively contact air when the isolation shaft 4 rotates, and generate enough air resistance so as to balance the gravity of the contact blade assembly 12. The number, shape and size of the fan blades 2602 can be adjusted according to actual needs by those skilled in the art to achieve the best balancing effect.

As shown in fig. 18 and 19, the isolation shaft 4 comprises a shaft body 401 and a mounting seat 402, wherein the mounting seat 402 is of an insulating structure and is arranged outside the shaft body 401, a mounting cavity 37 is arranged in the mounting seat 402, a notch 30 communicated with the mounting cavity 37 is further formed in the mounting seat 402, the contact blade assembly 12 is arranged in the mounting cavity 37 and extends outwards from the notch 30, namely, two ends of the contact blade assembly 12 are exposed, the balance assembly 26 is of an insulating structure, and the balance assembly 26 is detachably arranged on the mounting seat 402 and covers the mounting cavity 37.

It will be appreciated that the structural design of the mounting base 402 and the balance assembly 26 may cover the mounted contact assembly 12, and the insulation effect of the contact assembly 12 may be better due to the design of the insulation structure. It should be noted that the isolating switch is generally applied to a three-phase switch, as shown in fig. 18, so that the corresponding mounting seats 402 have three groups and are equidistantly disposed on the shaft body 401, and the contact assemblies 12 between each phase need to be strictly insulated from each other. Meanwhile, the structural design is also convenient for installing and detaching the contact knife assembly 12 and the balance assembly 26, namely the installation cavity 37 can be opened after the balance assembly 26 is detached, and then the contact knife assembly 12 is detached, so that the maintainability and convenience of the whole isolating switch are improved.

It should be noted that, the first structure is simple, and the second structure has better insulation effect, and is convenient for disassembling and maintaining the contact knife assembly 12 and the balance assembly 26, and those skilled in the art can select according to actual needs. Of course, in view of the present application, it is preferable to use the second structure, and therefore the second structure of the balancing assembly 26 is further described in the following embodiments.

The application further optimizes the specific structure of the balance assembly 26, and the balance assembly 26 comprises a cover 2601 and fan blades 2602, wherein the cover 2601 is arranged at the opening position of the installation cavity 37, so that the installation cavity 37 is opened and closed. The fan blades 2602 are disposed outside the cover 2601 and along the radial extending direction of the isolating shaft 4, so that the fan blades 2602 are better contacted with the air flow during rotation, so as to generate better air resistance, and thus, the gravity of the contact blade assembly 12 is more effectively balanced.

Of course, the shape and size of the fan blades 2602 may be designed according to practical requirements to ensure that sufficient air resistance can be generated when the isolating shaft 4 rotates. Exemplary ① As shown in FIG. 21, the fan blades 2602 are in a straight plate type structure, which is simple and convenient to process and install. ② The side recess of the fan 2602 is in a shell structure, and in general, the fan 2602 may be in a bowl structure. First, the concave surface of the bowl-like structure forces the air flow to separate, creating a low pressure swirling zone in the rear, creating a significant pressure differential with the high pressure zone in the front, creating a stronger reverse resistance (differential pressure resistance). Secondly, the airflow needs to bypass the bowl-shaped curved surface, the flow path is increased, so that more kinetic energy is converted into heat energy, and the energy loss is increased (resistance is improved).

Further, in order to make the fan blades 2602 better arrange and install, as shown in fig. 21 and 23, the cover 2601 is in a fan-shaped shell structure, the cover 2601 is mounted on the mounting seat 402 in a fastening manner, and the center of the cover 2601 coincides with the center of the isolating shaft 4.

It can be understood that the snap-in mounting of the cover 2601 is firstly convenient for the quick assembly and disassembly in the later stage, and the outer circumference of the cover 2601 is preferably cut with the outer circumference of the whole isolating shaft 4 after the cover 2601 is mounted, as shown in fig. 23, along the axial projection direction of the isolating shaft 4, the projection of the cover 2601 is completely overlapped with the projection of the isolating shaft 4, thus the design ensures the aesthetic property of the appearance, and the cover 2601 and the fan blades 2602 are preferably injection molded integrally by plastic, thus ensuring certain strength, light weight and reducing the production cost.

Specifically, when the cover 2601 and the isolation shaft 4 are rotated through concentric design, the rotation centers of the cover 2601 and the isolation shaft 4 are consistent, so that the relative position between the cover 2601 and the isolation shaft is stable, shaking or dislocation is reduced, and the stability and reliability of the whole structure of the isolation shaft 4 are further improved. Meanwhile, the circular arc-shaped shell structure and the design of the fan blades 2602 can also lengthen the creepage safety distance. It should be appreciated that creepage distance refers to the shortest distance between two conductive parts measured along the surface of an insulating material, and that lengthening the creepage distance has the advantage that ① reduces the risk of leakage, a longer creepage distance being effective in reducing leakage phenomena due to dirt, moisture or other environmental factors. ② The risk of electrical breakdown is reduced, and in a high-voltage environment, the risk of electrical breakdown can be reduced by increasing the creepage distance. Electrical breakdown refers to the loss of insulating properties of an insulating material, resulting in the flow of current through an unintended path. As the creepage distance increases, the likelihood of reaching a breakdown voltage decreases, thereby reducing the likelihood of electrical breakdown. ③ The insulation strength is enhanced, and the reliability of the device is improved.

In particular embodiments, the number of blades 2602 may be set according to actual requirements in order to increase the air resistance effect of the balancing assembly 26. In the present application, a plurality of blades 2602 may be uniformly disposed on the outer portion of the cover 2601 in the circumferential direction to increase the contact area with the air flow, thereby improving the air resistance and more effectively balancing the gravity of the contact blade assembly 12. If a single blade 2602 is used, a large enough area of the blade 2602 is required and the mounting position is also located at the center of the cover 2601 to ensure that the blade 2602 creates enough air resistance to balance the weight of the contact blade assembly 12 when the isolation shaft 4 rotates. However, an excessively large fan blade 2602 may not only increase manufacturing costs, but may also interfere with surrounding equipment when rotated. Therefore, the plurality of fan blades 2602 are uniformly arranged on the outer portion of the cover 2601 along the circumferential direction, so that the air resistance effect is ensured, and the problems of interference and high manufacturing cost are avoided.

Specifically, as shown in fig. 7 and 10, two ends of the cover 2601 extend outwards to form clamping parts located on the same straight line, clamping blocks 34 and clamping plates 35 are respectively arranged at the side parts of the clamping parts, the clamping blocks 34 are preferably four groups and located at four corners of the cover 2601, the clamping plates 35 are preferably a pair located in the length extending direction of the clamping parts, and clamping grooves 38 are formed in the mounting base 402.

It can be understood that when the cover 2601 is mounted by fastening, the clamping block 34 and the clamping groove 38 are correspondingly inserted and matched, and meanwhile, the clamping plate 35 is also propped against the inner side of the mounting cavity 37, wherein the cover 2601 is mounted by the clamping and matching between the clamping block 34 and the clamping groove 38, and the clamping plate 35 is used for further supporting and limiting the mounted cover 2601, so that the contact area between the cover 2601 and the mounting seat 402 is increased, the mounting stability of the cover 2601 is further improved, and the cover 2601 is prevented from deforming.

Further, as shown in fig. 24, the end of the latch 34 has a hook portion, and the width of the latch groove 38 is also greater than the thickness of the latch 34. It can be understood that when the cover 2601 is mounted, the hook portion deforms inward under the extrusion action of the clamping groove 38, and when the hook portion is completely inserted into the clamping groove 38, the hook portion recovers to deform outward under the action of elastic force, so that the cover 2601 is stably fastened to the mounting seat 402. When the cover 2601 is detached, the hook portion is pressed inward to deform under the action of external force, so that the hook portion corresponds to the clamping groove 38, and then the clamping block 34 and the clamping groove 38 can be separated to complete detachment.

It should be noted that, the two ends of the double-break contact blade assembly 12 are designed to have a certain angle, generally the angle θ is between 90 ° and 150 °, and the application adopts a 120 ° design, if the contact blade assembly 12 is directly integrally mounted to the mounting cavity 37 and the two ends of the contact blade assembly extend from the notch 30, the contact blade assembly 12 may be deformed due to the external force during the mounting process, so as to affect the use effect of the contact blade assembly 12.

To solve the above technical problem, as shown in fig. 20, in the present embodiment, the contact blade assembly 12 includes a lapping plate 1202 and a pair of contact blades 1201. Specifically, at the time of installation, ① first the strap 1202 may be fixedly installed in the installation cavity 37 by the fixing bent plate 29 and bolts. ② The contact blade 1201 is inserted into the notch 30, and the first end of the contact blade 1201 (i.e., the end near the strap 1202) is (bolted) connected to the end of the strap 1202, while the second end of the contact blade 1201 (i.e., the end far from the strap 1202) is exposed outside the isolation shaft 4 to form two end positions of the contact blade assembly 12, and of course, the shielding sleeve 33 may be mounted on the exposed portion of the contact blade 1201. ③ Finally, the cover 2601 is mounted and the mounting chamber 37 is closed.

In this embodiment, as shown in fig. 17, in order to further improve the insulation performance of the isolation shaft 4, the isolation shaft 4 (i.e., the shaft body 401 and the mounting seat 402) may be integrally injection molded by plastic, and the outer portion of the shaft body 401 has a hollow structure. It should be noted that, in the prior art, the isolating shaft 4 is generally made of a metal material, and although the metal material has high strength and rigidity, conductivity exists at the same time, which affects the insulation performance of the isolating switch to a certain extent. The isolating shaft 4 made of plastic materials is relatively thick, and due to the design of the hollow structure, the overall weight of the isolating shaft 4 is reduced, the production cost is reduced, the heat dissipation area inside the isolating shaft 4 is increased, and the heat dissipation effect is improved. In addition, the design of the hollowed-out structure can further increase the mechanical strength of the isolation shaft 4, improve the deformation resistance of the isolation shaft, and further ensure the stability and reliability of the isolation shaft 4.

Further, as shown in fig. 18, a plurality of annular grooves 27 are formed at both sides of the mounting seat 402 to be recessed inward corresponding to the outer circumferential surface of the shaft body 401, and a reinforcing ring 28 is formed between the adjacent annular grooves 27, and the cooperation of the reinforcing ring 28 and the annular grooves 27 has an advantage that the mechanical strength and stability of the barrier shaft 4 can be further ensured by the arrangement of the reinforcing ring 28. In particular, the stiffener ring 28 may increase the surface area of the outer circumference of the barrier shaft 4, thereby increasing its ability to withstand external pressure. Meanwhile, the reinforcing rings 28 can also play a role in dispersing stress, and when the isolating shaft 4 is subjected to external pressure, the stress can be dispersed to each reinforcing ring 28, so that the problems of damage or deformation caused by stress concentration and the like are avoided.

Based on the above embodiment, namely, the isolation shaft 4 is formed by injection molding plastic, and the lap plate 1202 is generally connected by bolts, but the structural strength of the plastic is insufficient, so that the installation cavity 37 needs to be provided with the installation part 32, for example, the installation part 32 is embedded with the bolt insert 36, and the stable installation of the lap plate 1202 can be realized by matching the bolt insert 36 with the bolts. Because the mounting base 402 has the notch 30 and the mounting cavity 37, the mounting base 402 is integrally formed as a housing, and thus the mounting base 402 needs to have a sufficient thickness for the bolt insert 36 to be stably mounted, but this increases the mass of the entire mounting base 402. Furthermore, the mounting portion 32 can be arranged at the outer side of the mounting base 402 in a protruding manner without adding the mounting base 402, but the stability of the mounting portion 32 is still not good enough, the strength of the mounting portion 32 is the premise of determining the stable mounting of the whole contact blade assembly 12, and in addition, the strength of the notch 30 at the outer side of the mounting base 402 is the premise of determining the stable limit support of the contact blade assembly 12, it should be understood that when the two ends of the contact blade assembly 12 are closed, as shown in fig. 18 and 19, the acting force of the contact blade assembly 12 on the notch 30 is very large, and the stress concentration is easily generated at the connecting position of the notch 30 and the mounting base 402, so that the damage is caused.

Therefore, in order to further secure the strength of the mounting portion 32 and the notch 30, as shown in fig. 19, the reinforcing ribs 31 may be provided outside the mounting base 402 to be connected, and the provision of the reinforcing ribs 31 may significantly improve the structural strength of the mounting portion 32 and the notch 30. In particular, the stiffener 31 may increase the material thickness of the mount 402 in critical areas, thereby increasing its ability to withstand external forces. Meanwhile, the reinforcing ribs 31 can also play a role in dispersing stress, and structural damage caused by stress concentration is avoided. When designing the reinforcing ribs 31, a person skilled in the art can reasonably set the number, the positions and the shapes of the reinforcing ribs 31 according to actual situations so as to achieve the optimal reinforcing effect.

In this embodiment, as shown in fig. 23, the included angle between the two contact blades 1201 may be 120 °, and the center line of the balance assembly 26 (i.e., the cover 2601) is located on the extension line of the angular bisector between the two contact blades 1201. Specifically, the center lines of the two contact blades 1201 and the balance component 26 are distributed at equal intervals in a circumference, and in combination with the analysis of the overshoot generated by the contact blade component 12, as shown in fig. 23, during rotation, the gravity action of the contact blade component 12 drives the isolating shaft 4 to accelerate to generate the overshoot, and at this time, the fan blades 2602 are arranged at the symmetrical positions of the center of gravity of the contact blade component 12, and the fan blades 2602 generate resistance, which counteracts the gravity moment generated by the contact blade component 12 to a certain extent, so as to effectively slow down the overshoot.

The working principle of the invention is as follows:

As shown in fig. 12 to 14, the fixed contact 201, the isolation contact 6 and the ground contact 13 are uniformly distributed circumferentially at the axis of the isolation shaft 4, that is, the angle between adjacent contacts is 120 °, and of course, the 120 ° design of the two ends of the contact blade assembly 12 is also based on the equidistant distribution design of the three stations.

① As shown in FIG. 12, in this case, the first end (left end) of the contact blade assembly 12 is located at the center between the fixed contact 201 and the isolation contact 6, and the second end (right end) of the contact blade assembly 12 is located at the center between the ground contact 13 and the isolation contact 6, and the vacuum interrupter 2 is also in the open-close state, so as to realize the double-break design of the combination switch. ② As shown in fig. 13, the isolating shaft 4 rotates clockwise under the action of the operating mechanism, and the contact blade assembly 12 rotates along with the isolating shaft until two ends of the contact blade assembly are respectively matched with the fixed contact 201 and the isolating contact 6. ③ As shown in fig. 14, the grounding operation is performed by rotating the isolating shaft 4 counterclockwise under the action of the operating mechanism, and the contact blade assembly 12 rotates along with it until both ends of the contact blade assembly are respectively engaged with the grounding contact 13 and the isolating contact 6, at this time, the grounding circuit is connected, and the main circuit is disconnected.

It should be noted that the rotation of the isolation shaft 4 and the spindle 8 is driven by an external operating mechanism, and the operating mechanism is known to those skilled in the art, so that the description is omitted. The application can separate and close the isolation fracture and the grounding fracture by rotating the isolation shaft 4 clockwise or anticlockwise, and the double fracture also effectively solves the problem of electric field creepage distance between the isolation time-sharing inlet end and the outlet end, so that the switch is safer.

Finally, the invention is mainly applied to the 24KV low-carbon environment-friendly body switch, and the 24KV low-carbon environment-friendly breaker and double-fracture three-station isolation integrated switch which is developed in the development direction of a miniaturized compact switch cabinet is provided, and the combined switch also adopts a multi-place insulation design, so that the insulation performance and the safety of the whole equipment can be effectively improved. For example, the vacuum arc extinguishing chamber 2, the contact knife assembly 12, the isolating shaft 4, the isolating contact 6, the installed bolts and the like are all wrapped or isolated by adopting insulating materials or insulating structures, so that equipment faults or safety accidents caused by interphase short-circuits or inter-contact discharge are avoided, and the insulating design can effectively improve the voltage resistance level and the breakdown resistance of the equipment, so that the equipment can stably run under more severe working conditions. Meanwhile, due to the design of the rack 1, the structure of the electrical equipment is more compact and miniaturized, the occupied working space is reduced, and the operation is convenient.

It should be noted that in the prior art, the switchgear is installed in a sealed box, and then sulfur hexafluoride (SF 6) gas is filled in the box, so that SF6 has good insulation performance and arc extinguishing performance, and safe production operation can be ensured. However, SF6 gas has stable chemical properties and is not easy to decompose in the atmosphere, SF6 gas can cause harm to the environment and cause greenhouse effect, and in addition, the conventional SF6 gas is usually mixed with toxic sulfur trifluoride, hydrogen fluoride and sulfur decafluoride gas, so that the injury to human bodies is easy to cause.

According to the application, under the design of the insulation and pressure resistance of the plurality of positions, sulfur hexafluoride (SF 6) gas is not required to be filled, and dry air or environment-friendly nitrogen can be adopted for insulation work, so that on one hand, safe production operation can be ensured, on the other hand, no harm is caused to the environment or human body, and the environment-friendly sulfur hexafluoride gas-containing insulating material has good environment-friendly performance. In addition, the conductive part of the switch metal material part is copper, and the rest parts are processed by stainless steel materials, so that the electromagnetic effect of a material magnetic field on the switch can be effectively controlled.

The foregoing has outlined the basic principles, features, and advantages of the present application. It will be understood by those skilled in the art that the present application is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present application, and various changes and modifications may be made therein without departing from the spirit and scope of the application, which is defined by the appended claims. The scope of the application is defined by the appended claims and equivalents thereof.

Claims

1. A combination switching device, comprising:

the rack is formed by splicing a plurality of insulating partition boards, and a plurality of isolation cavities are formed in the rack;

the vacuum arc-extinguishing chamber is vertically arranged in the isolating cavity and provided with a fixed contact at the bottom end;

The isolation contact is arranged at the bottom end of the rack through an insulated isolation cross beam, an isolation area corresponding to the isolation cavity is arranged on the isolation cross beam, and the isolation contact is positioned in the corresponding isolation area;

a ground contact mounted at the bottom end of the frame and corresponding to the isolation cavity, and

And when the switch-on is carried out, the first end of the contact knife assembly is matched with the fixed contact and positioned in the isolation cavity, and the second end of the contact knife assembly is matched with the isolation contact and positioned in the isolation area.

2. The combination switch device of claim 1, wherein the housing comprises an isolation front plate, an isolation rear plate, a pair of side plates and a plurality of three-phase partition plates, wherein the two end positions of the two side plates are respectively in butt joint fit through the isolation front plate and the isolation rear plate, the three-phase partition plates are installed between the two side plates at intervals, and then an isolation cavity is formed between the adjacent three-phase partition plates.

3. The combination switch device of claim 1, wherein a plurality of splitter plate groups are arranged at intervals outside the isolation beam, each splitter plate group comprises a plurality of splitter plate bodies, the splitter plate bodies are arranged at intervals between the adjacent splitter plate bodies, and the splitter plate groups are positioned at two sides of the isolation contact to form the isolation area.

4. The combination switch device of claim 3, wherein a plurality of first insulating cylinders are arranged at the bottom end of the isolation beam, the first insulating cylinders are coated at the positions corresponding to the bottom ends of the isolation contacts, an avoidance opening for the line connection of the isolation contacts is arranged outside the first insulating cylinders, and the positions of the avoidance opening correspond to the side parts of the isolation beam.

5. The combination switch device of claim 1, wherein the stationary contact comprises a contact plate and a head body, the head body is arranged at the bottom end of the contact plate, an insulating plate for coating the contact plate is arranged at the bottom end of the contact plate through a connecting piece, and an insulating cylinder II for coating the connecting piece is arranged at the bottom end of the insulating plate.

6. The combination switch device of claim 2, wherein the three-phase separator extends outward to form a plug-in portion at a position near the side of the side plate, a slot is arranged on the outer side of the side plate, the plug-in portion is matched with the slot when the three-phase separator is installed, and the side plate is matched with the three-phase separator in a propping manner.

7. The combination switch device of claim 1, wherein the isolation shaft comprises a shaft body and a mounting seat, the contact blade assembly is mounted on the shaft body, the mounting seat is of an insulating structure, the mounting seat is arranged outside the shaft body and is coated on the contact blade assembly, and the end portion of the contact blade assembly extends out of the mounting seat.

8. The combination switch device of claim 7, wherein the isolating shaft is integrally injection molded from plastic, the shaft body is in a hollowed-out structure, a plurality of annular grooves are formed by inwards recessing the outer circumferential surface of the shaft body, and reinforcing rings are formed between adjacent annular grooves.

9. The combination switch device of claim 7 or 8, wherein the contact blade assembly is of a double-break structure, the included angle between two ends is theta, wherein the included angle is 90 DEG < theta <150 DEG, the contact blade assembly comprises a lapping plate and a pair of contact blades, a mounting cavity is arranged in the mounting seat, a notch communicated with the mounting cavity is further formed in the mounting seat, the lapping plate is arranged in the mounting cavity, the contact blades are suitable for being inserted from the notch and connected with the end parts of the lapping plate, a cover body of an insulating structure is detachably arranged outside the mounting seat, and the cover body is suitable for covering the mounting cavity.

10. The combination switch apparatus of claim 9, further comprising a balancing assembly mounted to the isolation shaft and offset circumferentially from the contact blade assembly, wherein when the isolation shaft is rotated, a frontal area of the balancing assembly is greater than a frontal area of the contact blade assembly, and wherein the balancing assembly is adapted to balance a gravitational force of the contact blade assembly by air resistance.