An isolated shaft assembly

Abstract

The application discloses an isolating shaft assembly, which comprises an isolating shaft, a contact blade assembly and a balancing assembly. The contact blade assembly is installed on the isolating shaft, and the balancing assembly is installed on the isolating shaft and is staggered with the contact blade assembly in the circumferential direction. When the isolating shaft rotates, the windward area of the balancing assembly is larger than that of the contact blade assembly, and the balancing assembly is suitable for balancing the gravity of the contact blade assembly through air resistance. The application has the beneficial effects that: the balancing assembly is installed on the isolating shaft, and the balancing assembly balances the gravity of the contact blade assembly when rotating through air resistance generated when rotating, so that the stability of the isolating shaft in the rotating process is achieved, and the influence of overshoot is reduced. The application only needs to ensure that there is sufficient contact area between the isolating shaft and air when rotating, and does not need to balance the gravity through the way of adding counterweights, so that the overall mass of the isolating shaft and the cost are reduced, and the reliability and stability of the isolating switch are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical equipment, in particular to an isolating shaft assembly. BACKGROUND

[0002] The isolating switch is mainly used to reliably isolate the part needing power-off from the live part in the high-voltage distribution device to ensure the safety of the maintenance work. The isolating switch mainly comprises an isolating shaft and a contact blade assembly, and the rotation of the contact blade assembly driven by the isolating shaft is used to realize the isolating opening and closing process. We know that the installation of the contact blade assembly on the isolating shaft will make the gravity distribution of the whole isolating shaft uneven, and the opening speed of the isolating shaft is very fast, so the gravity moment of the contact blade assembly will drive the isolating shaft to accelerate when closing, and then an overshoot phenomenon will be generated, which affects the stability of the operation of the isolating shaft. Therefore, how to improve the existing isolating shaft structure to overcome the above problems is a problem to be solved by the person skilled in the art. SUMMARY

[0003] One of the purposes of the present application is to provide an isolating shaft assembly capable of maintaining stable operation of the isolating shaft.

[0004] In order to achieve the above purposes, the technical scheme adopted by the present application is as follows: an isolating shaft assembly, comprising an isolating shaft, a contact blade assembly and a balancing assembly, the contact blade assembly is installed on the isolating shaft, the balancing assembly is installed on the isolating shaft, and the balancing assembly is dislocated with the contact blade assembly in the circumferential direction; when the isolating shaft rotates, the windward area of the balancing assembly is greater than the windward area of the contact blade assembly, and the balancing assembly is adapted to balance the gravity of the contact blade assembly through air resistance.

[0005] Preferably, the balancing assembly comprises a plurality of fan blades arranged in the radial direction of the isolating shaft.

[0006] Preferably, the isolating shaft comprises a shaft body and a mounting seat, the mounting seat is an insulating structure and is arranged outside the shaft body, an installation cavity is arranged in the mounting seat, and a slot opening communicating with the installation cavity is also formed in the mounting seat, the contact blade assembly is installed in the installation cavity and extends outward from the slot opening; the balancing assembly is an insulating structure, and the balancing assembly can be detachably installed on the mounting seat and covers the installation cavity.

[0007] Preferably, the balancing assembly comprises a cover body and a fan blade, the fan blade is arranged outside the cover body and arranged in the radial extension direction of the isolating shaft, and the fan blade is in a straight plate structure or the side of the fan blade is recessed to form a chamber structure.

[0008] Preferably, the cover body is in a fan-shaped shell structure, the cover body is buckled and installed on the mounting seat, and the center of the cover body is coincided with the center of the isolating shaft.

[0009] Preferably, the contact blade assembly comprises a lap plate and a pair of contact blades, the lap plate is installed in the installation cavity, the contact blades are adapted to be inserted from the slot and connected with the end of the lap plate; the center lines of the pair of contact blades and the balance assembly are uniformly distributed along the axis of the isolation shaft.

[0010] Preferably, the installation cavity is provided with an installation part, the installation part is protruded outside the installation base, the installation part is adapted to install the lap plate; the outside of the installation part and the slot are provided with reinforcing ribs connected with the installation base.

[0011] Preferably, the isolation shaft is integrally injection molded by plastic, the shaft body is in a hollow structure; the outer circumferential surface of the shaft body is inwardly recessed to form a plurality of annular grooves, and the reinforcing rings are formed between adjacent annular grooves.

[0012] Preferably, the cover body is outwardly extended at both ends to form clamping parts in the same plane, the clamping parts are respectively provided with clamping blocks and clamping plates, and the installation base is provided with a clamping groove; when the clamping installation of the cover body is performed, the clamping blocks are matched with the clamping groove, and the clamping plates are abutted to the inside of the installation cavity.

[0013] Preferably, the end of the clamping block has a hook part, the width of the clamping groove is greater than the thickness of the clamping block; when the cover body is installed, the hook part is adapted to be inwardly bent and deformed under the extrusion of the clamping groove; after the cover body is installed, the hook part is adapted to pass over the clamping groove, and then the hook part is adapted to reset and be buckled to the installation base under the action of the elastic force.

[0014] Compared with the prior art, the application has the beneficial effects that:

[0015] The application balances the gravity of the contact blade assembly during rotation by using the air resistance generated during rotation of the balance assembly, so as to achieve the stability of the isolation shaft during rotation, thereby reducing the influence of overshoot; only sufficient resistance between the isolation shaft and air during rotation is required, without the need of using the way of increasing counterweight to balance the gravity, so that the overall mass of the isolation shaft and the cost can be reduced, and the reliability and stability of the isolation switch are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The force analysis diagram of the isolation shaft before opening is shown.

[0017] Figure 2 The force analysis diagram of the isolation shaft during opening is shown.

[0018] Figure 3 The overall structure diagram of the isolation shaft of the application is shown.

[0019] Figure 4 The schematic diagram of the touch blade assembly and the balance assembly disassembled from the isolation shaft.

[0020] Figure 5 The schematic diagram of the enlarged structure at A of the application.

[0021] Figure 6 The schematic diagram of the specific structure of the touch blade assembly of the application.

[0022] Figure 7 The schematic diagram of the specific structure of the balance assembly of the application.

[0023] Figure 8 The schematic diagram of the structure of the isolation shaft along the axial direction.

[0024] Figure 9 The schematic diagram of the side structure of the isolation shaft.

[0025] Figure 10 The schematic diagram of the enlarged structure at B of the application.

[0026] Figure 11 The schematic diagram of the isolation disconnection of the application.

[0027] Figure 12 The schematic diagram of the isolation connection of the application.

[0028] Figure 13 The schematic diagram of the grounding connection of the application.

[0029] In the figure: 1, isolation shaft; 101, shaft body; 102, mounting seat; 2, touch blade assembly; 201, touch blade; 202, lap plate; 3, balance assembly; 301, cover body; 302, fan blade; 4, annular groove; 5, reinforcing ring; 6, fixed bent plate; 7, slot; 8, mounting part; 9, reinforcing rib; 10, shielding sleeve; 11, clamping block; 12, clamping plate; 13, mounting cavity; 14, bolt insert; 15, clamping groove; 16, rack; 17, vacuum arc-extinguishing chamber; 1701, static contact; 18, isolation contact; 19, grounding contact. DETAILED DESCRIPTION

[0030] In the following, the application will be further described in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments described below or the technical features between them can be combined to form new embodiments.

[0031] In the description of the present application, it should be noted that for orientation words, such as the terms "center", "transverse", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation and positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and cannot be understood as limiting the specific protection scope of the present application.

[0032] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence.

[0033] Further analysis of the causes of the overshoot of the existing isolation shaft 1 contact blade assembly 2 (mainly considering the influence of gravity):

[0034] As Figure 1 shown, the application is installed on the isolation shaft 1 and in the closing state, and the angle between the two contact blades 201 is 120° and in the upper and lower symmetrical position. From the figure, it can be seen that the gravity of the isolation shaft 1 is not evenly distributed at this time (that is, the center of gravity is on the left). We take the counterclockwise rotation of the isolation shaft 1 to open as an example: when the isolation shaft 1 rotates Figure 1 from the Figure 2 position to the position (rotates sixty degrees), its center of gravity is not at the plumb position, and the gravity will generate a torque that is biased to the isolation shaft 1. The direction of this torque always tries to pull the center of gravity to the lowest point, resulting in: for the upper contact blade 201, its full rotation from high to low, the gravity torque is the same as the rotation direction, pushing the rotating shaft to accelerate. For the lower contact blade 201, it initially rotates from high to low, the gravity torque is the same as the rotation direction, pushing the isolation shaft 1 to accelerate; when it passes the lowest point, it rotates from low to high, the gravity torque is opposite to the rotation direction, acting as a brake.

[0035] Specifically, only the circumferential component of gravity provides acceleration or inhibition effect (i.e. produces tangential acceleration), for the upper contact blade 201: F1=G·cosθ, the value of θ is from 60° to 0°, so F1 value is gradually increasing. For the lower contact blade 201: F2=G·cosθ, the value of θ is from 60° to 120°, so between 60° to 90° is positive, between 90° to 120° is negative, the positive and negative values represent the direction of force is different, and F 合 =F1+F2, since the contact blade 201 has not passed the position of the plumb line of its center of gravity, F 合Always positive, that is, the resultant force is always driving the isolation shaft 1 to accelerate.

[0036] It should be noted that, here, the counterclockwise rotation of the isolation shaft 1 is taken as the positive direction, and F is the tangential component of the gravity G of the contact blade 201, which is one of the reasons for the impact (overshoot) caused by the entire isolation shaft 1 breaking.

[0037] Therefore, the inventors of the present application have developed an isolation shaft assembly, one embodiment of which is as shown in the accompanying drawings. Figures 1 to 13 As shown, the isolation shaft assembly includes an isolation shaft 1, a contact blade assembly 2, and a balancing assembly 3, wherein the contact blade assembly 2 is installed on the isolation shaft 1, and the balancing assembly 3 is also installed on the isolation shaft 1; of course, the balancing assembly 3 is arranged in a circumferential direction offset from the contact blade assembly 2, so that the installation of the balancing assembly 3 and the contact blade assembly 2 does not interfere with each other, and the balancing assembly 3 can better function.

[0038] As can be understood, as shown in the accompanying drawings, when the isolation shaft 1 rotates, the balancing assembly 3 will be in contact with the airflow, and the windward area of the balancing assembly 3 is greater than the windward area of the contact blade assembly 2, so that the air resistance f generated by the airflow will hinder the rotation of the isolation shaft 1, that is, the air resistance will balance the gravity of the contact blade assembly 2 when it rotates, so as to achieve the stability of the isolation shaft 1 during rotation, thereby reducing the impact of overshoot. Figure 2 As can be understood, as shown in the accompanying drawings, when the isolation shaft 1 rotates, the balancing assembly 3 will be in contact with the airflow, and the windward area of the balancing assembly 3 is greater than the windward area of the contact blade assembly 2, so that the air resistance f generated by the airflow will hinder the rotation of the isolation shaft 1, that is, the air resistance will balance the gravity of the contact blade assembly 2 when it rotates, so as to achieve the stability of the isolation shaft 1 during rotation, thereby reducing the impact of overshoot.

[0039] It should be noted that, in the prior art, the skilled person in the art generally designs the isolation shaft 1 to be statically balanced, that is, a counterweight or a symmetrical arm structure is installed at the symmetrical position of the center of gravity of the isolation shaft 1, so as to eliminate the eccentricity and reduce the moment of inertia. However, this design has the following disadvantages: it increases the weight or volume of the entire isolation shaft 1, which requires further improvement in the strength or space of the isolation switch device, and increases the manufacturing cost. The balancing assembly 3 of the present application balances the gravity of the contact blade assembly 2 through air resistance during rotation, that is, only a sufficient contact area with the gas during rotation is required, so that the mass or volume of the isolation shaft 1 does not need to be increased, thereby ensuring the reliability and stability of the isolation switch.

[0040] The structure of the balancing assembly 3 is not limited in the present application, and two specific embodiments are provided below for reference:

[0041] Structure one (not shown): the balance assembly 3 includes a plurality of fan blades 302 arranged along the radial direction of the isolation shaft 1, which can effectively contact the air when the isolation shaft 1 rotates, generating sufficient air resistance to achieve the effect of balancing the gravity of the contact blade assembly 2. The number, shape and size of the fan blades 302 can be adjusted by those skilled in the art according to actual needs to achieve the best balancing effect.

[0042] Structure two: as shown in Figure 4 The isolation shaft 1 includes a shaft body 101 and a mounting seat 102, wherein the mounting seat 102 is an insulating structure and is arranged outside the shaft body 101, the mounting seat 102 is provided with a mounting cavity 13, and the mounting seat 102 is further provided with a slot 7 communicating with the mounting cavity 13, the contact blade assembly 2 is mounted in the mounting cavity 13 and extends outward from the slot 7, that is, both ends of the contact blade assembly 2 are exposed; and the balance assembly 3 is also an insulating structure, and the balance assembly 3 is detachably mounted on the mounting seat 102 and covers the mounting cavity 13.

[0043] It can be understood that the mounting seat 102 and the balance assembly 3 are designed in a structure, which can coat the installed contact blade assembly 2, and the insulating effect of the contact blade assembly 2 can be better with the design of the insulating structure. It should be known that the isolation switch is generally used in a three-phase switch, as shown in Figure 3 Therefore, the corresponding mounting seat 102 has three groups and is arranged at equal intervals on the shaft body 101, and the contact blade assemblies 2 of each phase need to be strictly insulated from each other. At the same time, this structure design is also convenient for the installation and disassembly of the contact blade assembly 2 and the balance assembly 3, that is, the mounting cavity 13 is opened after the balance assembly 3 is disassembled, and then the contact blade assembly 2 can be disassembled, which improves the maintainability and convenience of the entire isolation switch.

[0044] It should be noted that structure one is simple in structure, and structure two has better insulating effect and is convenient for disassembly and maintenance of the contact blade assembly 2 and the balance assembly 3, and those skilled in the art can select according to actual needs. Of course, based on the present application, structure two is preferred, and therefore the structure of the balance assembly 3 in the following embodiments is further described.

[0045] The specific structure of the balance assembly 3 is further optimized in the present application, the balance assembly 3 includes a cover body 301 and a fan blade 302, of course the cover body 301 is mounted at the opening position of the mounting cavity 13 to open and close the mounting cavity 13. The fan blade 302 is arranged outside the cover body 301 and extends along the radial direction of the isolation shaft 1, which is to better contact the airflow when rotating to generate better air resistance, thereby more effectively balancing the gravity of the contact blade assembly 2.

[0046] Of course, the shape and size of the fan blade 302 can be designed according to actual needs to ensure that sufficient air resistance is generated when the isolation shaft 1 rotates. For example: ① as shown in Figure 7 , the fan blade 302 is in the form of a straight plate, which is relatively simple in structure and is easy to process and install. ② The side of the fan blade 302 is recessed to form a chamber structure, or in other words, an open shell structure; for example, the fan blade 302 is in the form of a bowl. First, the recessed surface of the bowl structure forces the airflow to separate, forming a low-pressure vortex area at the back and a high-pressure area at the front, resulting in a significant pressure difference and generating stronger reverse resistance (pressure difference resistance). Second, the airflow needs to bypass the curved surface of the bowl, and the increased flow path causes more kinetic energy to be converted into heat energy, resulting in increased energy loss (increased resistance).

[0047] Further, in order to better arrange and install the fan blade 302, as shown in Figure 4 and Figure 7 , the cover 301 is in the form of a fan-shaped shell, and the cover 301 is snap-fitted to the mounting seat 102, and the center of the cover 301 coincides with the center of the isolation shaft 1.

[0048] It can be understood that, first, the snap-fitting of the cover 301 facilitates its later quick disassembly; and after the cover 301 is installed, its outer circumference is preferably tangent to the outer circumference of the entire isolation shaft 1, as shown in Figure 9 , along the axial projection direction of the isolation shaft 1, the projection of the cover 301 coincides with the projection of the isolation shaft 1, which ensures the aesthetic appearance; and the cover 301 and the fan blade 302 are preferably integrally injection molded with plastic, which not only ensures a certain strength, but also reduces the production cost while reducing the weight.

[0049] Specifically, through concentric design, the centers of rotation of the cover 301 and the isolation shaft 1 are consistent when rotating, which can ensure the stability of the relative position between the two, reduce the shaking or misalignment, and further improve the stability and reliability of the entire structure of the isolation shaft 1. At the same time, the arc-shaped shell structure and the design of the fan blade 302 can also lengthen the creepage safety distance. It should be noted that the creepage distance refers to the shortest distance between two conductive parts measured along the surface of the insulating material, and the lengthening of the creepage distance has the following advantages: ① reduces the risk of electric leakage: a longer creepage distance can effectively reduce the risk of electric leakage due to dirt, moisture or other environmental factors. ② Reduce the risk of electrical breakdown: in a high-voltage environment, increasing the creepage distance can reduce the risk of electrical breakdown. Electrical breakdown refers to the loss of insulation properties of insulating materials, causing current to flow through unintended paths. As the creepage distance increases, the likelihood of reaching the breakdown voltage decreases, thereby reducing the likelihood of electrical breakdown. ③ Enhance insulation strength and improve device reliability.

[0050] In actual implementation, in order to improve the air resistance effect of the balancing assembly 3, the number of the fan blades 302 can be set according to actual requirements. In the present application, a plurality of fan blades 302 can be uniformly arranged on the outer portion of the cover body 301 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 2. If only one fan blade 302 is used, the fan blade 302 needs to have a large enough area and be installed at the central position of the cover body 301 to ensure that the fan blade 302 can generate sufficient air resistance to balance the gravity of the contact blade assembly 2 when the isolation shaft 1 rotates. However, a fan blade 302 that is too large will not only increase the manufacturing cost, but also may interfere with the surrounding equipment during rotation. Therefore, the preferred solution is to uniformly arrange a plurality of fan blades 302 on the outer portion of the cover body 301 in the circumferential direction, which not only ensures the air resistance effect, but also avoids the problems of interference and excessive manufacturing cost.

[0051] As shown in Figure 7 and Figure 10 , the cover body 301 extends outward at both ends to form clamping portions, and the side portions of the clamping portions are respectively provided with clamping blocks 11 and clamping plates 12. The clamping blocks 11 are preferably four groups and are located at the four corner positions of the cover body 301. The clamping plates 12 are preferably a pair and are located in the length extension direction of the clamping portions. The mounting seat 102 is provided with a clamping groove 15. It should be noted that the clamping portions at both ends of the cover body 301 are preferably located in the same plane. Since the clamping portions are clamped in the same plane, the clamping can be more stable and smooth.

[0052] It can be understood that when the clamping blocks 11 and the clamping groove 15 are correspondingly inserted and matched during the clamping installation of the cover body 301, the clamping plate 12 will also abut against the inner side of the mounting cavity 13. The clamping blocks 11 and the clamping groove 15 are clamped to achieve the installation of the cover body 301, and the clamping plate 12 is used to further support and limit the installed cover body 301, increase the contact area between the cover body 301 and the mounting seat 102, and thereby improve the stability of the installation of the cover body 301 and prevent the cover body 301 from deforming.

[0053] Further, as shown in Figure 10 , the end portion of the clamping block 11 has a hook portion, and the width of the clamping groove 15 is greater than the thickness of the clamping block 11. It can be understood that during installation, the hook portion is deformed inward under the extrusion of the clamping groove 15. When the hook portion completely passes the clamping groove 15, the hook portion is restored to deform outward under the action of the elastic force and is clamped on the mounting seat 102, thereby achieving the stable clamping installation of the cover body 301 on the mounting seat 102. When disassembling the cover body 301, the hook portion is deformed inward under the action of external force, so that the hook portion corresponds to the clamping groove 15, and then the clamping block 11 and the clamping groove 15 can be separated to complete the disassembly.

[0054] It should be known that the two ends of the double-port contact blade assembly 2 are designed with a certain included angle. If the contact blade assembly 2 is directly installed as a whole into the installation cavity 13 and the two ends thereof are extended from the slot 7, the contact blade assembly 2 may be deformed due to external force during installation, thereby affecting the use effect of the contact blade assembly 2.

[0055] In order to solve the above technical problems, as shown in the embodiment, the contact blade assembly 2 includes a lap plate 202 and a pair of contact blades 201. Specifically, during installation, ① the lap plate 202 is first fixedly installed in the installation cavity 13 by bolts. ② The contact blade 201 is inserted into the slot 7, and then the first end (i.e., the end close to the lap plate 202) of the contact blade 201 is connected (by bolts) with the end position of the lap plate 202, and the second end (i.e., the end away from the lap plate 202) of the contact blade 201 is exposed outside the isolation shaft 1 to form the two end positions of the contact blade assembly 2. ③ Finally, the cover 301 is installed to close and cover the installation cavity 13. Figure 6

[0056] It can be seen that, through the cooperation of the structure design of the contact blade assembly 2 and the isolation shaft 1, the contact blade assembly 2 installed on the isolation shaft 1 is “covered”, that is, the conductive contact blade assembly 2 is located in the isolation shaft 1 except for the two end positions that need to be contacted, which plays a protective role and mainly plays an insulating role for the contact blade assembly 2. Moreover, the slot 7 has a limiting and fixing effect on the contact blade 201, so that only the stable installation of the lap plate 202 and the lap plate 202 and the contact blade 201 is required during installation, thereby simplifying the installation steps.

[0057] In the embodiment, in order to further improve the insulation performance of the isolation shaft 1, the isolation shaft 1 (i.e., the shaft body 101 and the mounting seat 102) can also be integrally injection molded with plastic, and the outer part of the shaft body 101 is in a hollow structure. It should be known that the isolation shaft 1 in the prior art is generally made of metal material. Although the metal material has high strength and rigidity, it also has conductivity, which affects the insulation performance of the isolation switch to some extent. The plastic material isolation shaft 1 is relatively thick, and the hollow structure design not only reduces the overall weight of the isolation shaft 1 and reduces the production cost, but also increases the heat dissipation area inside the isolation shaft 1 and improves the heat dissipation effect. In addition, the hollow structure design can also increase the mechanical strength of the isolation shaft 1 and improve its deformation resistance, thereby further ensuring the stability and reliability of the isolation shaft 1.

[0058] ​It should be noted that the hollow structure design of the isolation shaft 1 is also based on the overall strength of the person skilled in the art under the condition that it is sufficient. That is, although the shaft body 101 adopts a hollow structure, its overall strength can still meet the use requirements and will not cause damage or deformation due to insufficient strength.

[0059] Further, a plurality of annular grooves 4 are formed by recessing the outer circumferential surface of the shaft body 101 inward on both sides of the mounting seat 102, and a reinforcing ring 5 is formed between adjacent annular grooves 4. The cooperation of the reinforcing ring 5 and the annular groove 4 has the following advantages: ① The setting of the reinforcing ring 5 can further ensure the mechanical strength and stability of the isolation shaft 1. Specifically, the reinforcing ring 5 can increase the surface area of the outer circumferential surface of the isolation shaft 1, thereby improving its ability to withstand external pressure. At the same time, the reinforcing ring 5 can also play a role in dispersing stress. When the isolation shaft 1 is subjected to external pressure, the stress will be dispersed to each reinforcing ring 5, thereby avoiding damage or deformation caused by stress concentration. ② Increase the creepage distance; for example, the electric arc between each phase needs to pass through the reinforcing ring 5 along the surface of the isolation shaft 1, which can effectively increase the creepage distance of the electric arc and improve its anti-pollution flashover capability.

[0060] Based on the above embodiment, that is, the isolation shaft 1 is made of plastic injection molding, and the lap plate 202 generally needs to be connected by bolts, but the structural strength of the plastic is not enough; Therefore, the installation part 8 is provided in the installation cavity 13, for example, the bolt insert 14 is embedded in the installation part 8, and the cooperation of the bolt insert 14 and the bolt can realize the stable installation of the lap plate 202. Because the mounting seat 102 is provided with the slot 7 and the installation cavity 13, the whole mounting seat 102 is in a shell structure, so in order to stably install the bolt insert 14, the mounting seat 102 needs to have enough thickness, but this will increase the overall mass of the mounting seat 102. Further, without increasing the mounting seat 102, the installation part 8 can be protrudingly arranged on the outer side of the mounting seat 102, but the stability of the installation part 8 is still not good enough, and the strength of the installation part 8 is the premise of stably installing the whole contact knife assembly 2; In addition, the strength of the slot 7 on the outer side of the mounting seat 102 is also the premise of stably limiting and supporting the contact knife assembly 2. It should be known that, as shown in Figure 12 and Figure 13 When the contact knife assembly 2 is closed at both ends, the force of the contact knife assembly 2 on the slot 7 is very large, and the connection position of the slot 7 and the mounting seat 102 is very easy to cause stress concentration and damage.

[0061] Therefore, in order to further ensure the strength of the mounting portion 8 and the notch 7, a reinforcing rib 9 connected to the outside of the mounting seat 102 can be arranged outside the two. The arrangement of the reinforcing rib 9 can significantly improve the structural strength of the mounting portion 8 and the notch 7. Specifically, the reinforcing rib 9 can increase the material thickness of the mounting seat 102 in the key area, thereby improving its ability to withstand external forces. At the same time, the reinforcing rib 9 can also play a role in dispersing stress and avoiding structural damage caused by stress concentration. When designing the reinforcing rib 9, those skilled in the art can reasonably arrange the number, position and shape of the reinforcing rib 9 according to the actual situation to achieve the best reinforcing effect.

[0062] In this embodiment, as shown in Figure 9 , the included angle between the two contact knives 201 can be 120°, and the center line of the balance assembly 3 (i.e., the cover 301) is located on the extension line of the angle bisector between the two contact knives 201.

[0063] Specifically, the center lines of the two contact knives 201 and the balance assembly 3 are circumferentially equidistantly distributed with the axis of the isolation shaft 1. In combination with the above analysis of the overshoot of the contact knife assembly 2, as shown in Figure 1 and Figure 2 , under the action of gravity of the contact knife assembly 2, the isolation shaft 1 will be accelerated to generate overshoot. At this time, the fan blade 302 is arranged at the symmetrical position of the center of gravity of the contact knife assembly 2, and the fan blade 302 will generate resistance f, which will offset the gravitational torque generated by the contact knife assembly 2 to some extent, thereby effectively slowing down the overshoot. It should be noted that the cover 301 is in the mounting position at this time, and its gravity can also play a role in balancing the contact knife assembly 2. However, we know that the cover 301 is a shell structure, so its gravity is very small and can be ignored. The role of balancing the gravity of the contact knife assembly 2 is mainly the air resistance generated by the rotation of the fan blade 302.

[0064] In order to facilitate further understanding of the structure of the above isolation shaft 1 and contact knife assembly 2, the following will be applied to a three-position vacuum circuit breaker for illustration:

[0065] As shown in Figures 11 to 13 , it includes a rack 16, a vacuum interrupter 17, an isolation contact 18, and a grounding contact 19. The vacuum interrupter 17 is vertically installed in the rack 16, and the bottom end of the vacuum interrupter 17 has a static contact 1701. The isolation contact 18 and the grounding contact 19 are arranged in the rack 16. The isolation shaft 1 is rotatably installed in the rack 16 and located below the static contact 1701. The static contact 1701, the isolation contact 18, and the grounding contact 19 are circumferentially and uniformly distributed with the axis of the isolation shaft 1, that is, the angle between adjacent ones is 120°. Of course, the design of the contact knife assembly 2 at this angle is also based on the above-mentioned equidistant distribution design of the three positions.

[0066] Specifically, as shown in Figure 11 , at this time the contact blade assembly 2 is in the open position, the first end (left end) of the contact blade assembly 2 is located at the center between the static contact 1701 and the isolation contact 18, and the second end (right end) of the contact blade assembly 2 is located at the center between the grounding contact 19 and the isolation contact 18; that is, the distance between the first end of the contact blade assembly 2 and the static contact 1701 and the isolation contact 18 is equal, and the distance between the second end of the contact blade assembly 2 and the grounding contact 19 and the isolation contact 18 is equal. At the same time, the static contact 1701, the isolation contact 18 and the grounding contact 19 are uniformly distributed, and the uniform distribution structure and position reduce the local concentration (distortion) of the electric field, improve the insulation strength between the break, and enable the higher voltage to be withstood under the same opening distance, or be safer and more reliable when withstanding the same voltage.

[0067] As shown in Figure 12 , when the contact blade assembly 2 is closed, the contact blade assembly 2 can be rotated in the first direction (clockwise) and until its two ends are respectively matched with the static contact 1701 and the isolation contact 18, at which time the main circuit is turned on, and the grounding circuit is turned off. As shown in Figure 13 , when the grounding circuit is turned on, the contact blade assembly 2 can be rotated in the second direction (counterclockwise) and until its two ends are respectively matched with the grounding contact 19 and the isolation contact 18, at which time the main circuit is in an open state.

[0068] As can be seen, through the design of a knife (i.e. the contact blade assembly 2), the working position of the knife is unique at a certain moment, which is either in the closed position, or in the isolation position or the grounding position, that is, the main circuit and the grounding circuit cannot be turned on at the same time, thereby avoiding the misoperation and greatly improving the safety of use. In addition, through the bidirectional output break design of the contact blade assembly 2, as shown in Figure 11 , Figure 12 and Figure 13 , three work positions of isolation opening, isolation closing and grounding closing are provided, which are uniformly distributed, more ideal in equipotential, and through the forward and reverse rotation of the contact blade assembly 2, the switching between the three work positions can be realized, the operation is more simple, and the manufacturing cost is also reduced; the uniform distribution design of the three work positions can make the overall layout more reasonable and compact, and the space utilization rate is high; the angles between the work positions are consistent, and the mechanical limiting or position detection device is simple in design, high in precision and not easy to misoperate.

[0069] Finally, it needs to be pointed out that, in order to facilitate the understanding of the specific installation process of the isolation shaft 1, the following is described through specific embodiments: based on a plastic insulating isolation shaft 1, as shown in Figure 8 , a metal insert can be used as a fixed point (i.e. a bolt insert 14) at the bottom end of the installation cavity 13. ① Use an inner hexagonal flat round head screw M8x20, a standard spring washer Peaceful gasket The fixed bending plate 6 is fastened in the mounting cavity 13. ② The fixed bending plate 6 serves as a fastening support point, and the lap plate 202 is fastened in the mounting cavity 13 by means of the M8x25 internal hexagonal flat round head screw and the non-metallic embedded hexagonal locking nut M8. ③ The contact knife 201 is inserted into the slot 7, and then the two ends of the lap plate 202 are fixed and assembled by means of the contact knife compression spring, the M6x35 internal hexagonal flower-shaped cylindrical head screw and the hexagonal nut M6. ④ The outside of the contact knife 201 (i.e. the second end) is tightened with appropriate pre-tightening force by means of the contact knife compression spring, the shielding sleeve 10, the M6x45 internal hexagonal flower-shaped cylindrical head screw and the non-metallic embedded hexagonal locking nut M6. ⑤ After the contact knife 201 is assembled, the cover body 301 can be buckled and assembled.

[0070] The above describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.

Claims

1. An isolated shaft assembly characterized by, The utility model relates to an isolating shaft, a contact blade assembly mounted on the isolating shaft, and a balancing assembly mounted on the isolating shaft and circumferentially offset from the contact blade assembly, wherein the windward area of the balancing assembly is greater than that of the contact blade assembly when the isolating shaft rotates, and the balancing assembly is adapted to balance the gravity of the contact blade assembly by air resistance. The balancing assembly comprises a plurality of fan blades extending radially along the isolating shaft. The isolating shaft comprises a shaft body and a mounting seat which is an insulating structure and is arranged outside the shaft body, and the mounting seat is provided with a mounting cavity, and the mounting seat is further provided with a slot opening into the mounting cavity, and the contact blade assembly is mounted in the mounting cavity and extends outward from the slot. The balancing assembly comprises a cover body and fan blades which are arranged outside the cover body and extend along the radial direction of the isolating shaft, and the fan blades are in a straight plate structure or the side of the fan blades is concave to form a chamber structure. The cover body is in a fan-shaped shell structure, and the cover body is snap-fitted to the mounting seat, and the center of the cover body coincides with the center of the isolating shaft.

2. The isolated shaft assembly of claim 1, wherein: The contact blade assembly comprises a lap plate and a pair of contact blades, the lap plate is mounted in the mounting cavity, and the contact blades are adapted to be inserted from the slot and connected to the end of the lap plate, and the center lines of the pair of contact blades and the balancing assembly are uniformly distributed along the axis of the isolating shaft.

3. The isolated shaft assembly of claim 1, wherein: The mounting cavity is provided with a mounting portion which is protrudingly arranged outside the mounting seat and is adapted to mount the lap plate, and the outside of the mounting portion and the slot is provided with a reinforcing rib connected to the mounting seat.

4. The isolated shaft assembly of claim 3, wherein: The isolating shaft is integrally injection molded by plastic, and the shaft body is in a hollow structure, the outer circumferential surface of the shaft body is concave inward to form a plurality of annular grooves, and a reinforcing ring is formed between adjacent annular grooves.

5. The isolated shaft assembly of claim 4, wherein: The cover body extends outward at both ends to form clamping portions in the same plane, the side of the clamping portions is respectively provided with a clamping block and a clamping plate, and the mounting seat is provided with a clamping groove, when the cover body is snap-fitted, the clamping block is matched with the clamping groove, and the clamping plate abuts against the inside of the mounting cavity.

6. The isolated shaft assembly of claim 3, wherein: The end of the clamping block has a hook portion, the width of the clamping groove is greater than the thickness of the clamping block, when the cover body is mounted, the hook portion is adapted to be deformed inward under the extrusion of the clamping groove, and when the cover body is mounted, the hook portion is adapted to pass over the clamping groove, and then the hook portion is adapted to reset and be buckled to the mounting seat under the action of elastic force.

7. The isolated shaft assembly of claim 6, wherein: ​ 8. The isolated shaft assembly of claim 3, wherein: ​ 9. The isolated shaft assembly of claim 5, wherein: ​ 10. The isolated shaft assembly of claim 9, wherein: ​

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