Vacuum circuit breaker

Abstract

The invention relates to a vacuum circuit breaker (20). The vacuum circuit breaker (20) may be provided so as to pass through the interior space (12) of the housing (10) and the housing (10). The vacuum circuit breaker (20) comprises a vacuum cut-off part (210) and a linkage mechanism (230), and the linkage mechanism (230) can be provided with a piston (246) providing force capable of counteracting the self-closing force of the vacuum cut-off part (210). The piston (246) is formed so as to have a larger diameter than a drive rod (254) penetrating through the housing (10), and may have the same or similar diameter as the effective diameter of a bellows (224) located in the vacuum cut-off section (210).

Description

Technical Field

[0001] The present invention relates to a vacuum circuit breaker. Background Art

[0002] A vacuum circuit breaker is a circuit breaker that incorporates a vacuum interrupting section (VI: Vacuum Interrupter) using vacuum as the arc extinguishing medium. In addition to performing power transmission / reception, switching, and stopping as planned, it can also quickly and automatically open the circuit when a fault occurs in the power system.

[0003] In the vacuum circuit breaker as described above, a vacuum interrupting section with a vacuum inside is disposed within a housing filled with an insulating gas at high or low pressure, and an operating section outside the housing performs an operation for the action of the vacuum interrupting section.

[0004] However, the inside of the vacuum interrupting section is a vacuum, and the pressure of the insulating gas inside the housing in which the vacuum interrupting section is disposed is greater than atmospheric pressure. Therefore, due to the pressure difference between the inside of the housing and the inside of the vacuum interrupting section, the movable rod of the vacuum interrupting section is always subjected to a force that attempts to enter the inside of the vacuum interrupting section. Generally, this force is referred to as a self-closing force.

[0005] In addition, an operator for driving the movable rod of the vacuum interrupting section is disposed outside the housing, and a driving rod for transmitting the driving force of the operator to the movable rod can only penetrate the housing. Since the driving rod is directly connected to the movable rod, it is affected by the self-closing force, and there is a problem that the self-closing force hinders the movement of the movable rod and the driving rod.

[0006] In particular, the vacuum interrupting section disposed inside the housing is inevitably affected by the pressure of the insulating gas inside the housing. The pressure value of the insulating gas and the self-closing force can act in a direction to maintain the state where the movable electrode of the vacuum interrupting section is in contact with the fixed electrode. And this force can change the magnitude of the operating force for separating the movable electrode from the fixed electrode through the operator. That is, when the pressure of the insulating gas inside the housing changes, the operating force of the operator for satisfying the operating characteristics also has to change, so there is a problem that the design of the operator becomes complicated.

[0007] In addition, as an environmentally friendly gas is used as the insulating gas, the pressure inside the housing becomes higher, increasing the load on the bellows, and there is a problem that high-pressure bellows need to be applied.

[0008] Prior art documents of the vacuum circuit breaker as described above include Korean Patent Publication No. 10-2016-0048320, Korean Patent Publication No. 10-2017-0058637, and Korean Registered Patent No. 10-1060780. Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] An object of the present invention is to reduce the self-closing force by causing a linkage mechanism provided so as to penetrate a housing to simultaneously withstand atmospheric pressure and the pressure inside the housing.

[0011] An object of the present invention is to maintain a constant target speed when a vacuum circuit breaker performs a breaking operation.

[0012] Solution to the Problem

[0013] According to the features of the present invention for achieving the above object, a vacuum circuit breaker of the present invention, a part of which is located inside a housing and the other part is provided so as to penetrate the housing, may include: a vacuum interruption part provided inside the housing, a vacuum space in a vacuum state being formed inside a housing of the vacuum interruption part, the vacuum space having a fixed electrode and a movable electrode that contacts / separates from the fixed electrode; and a linkage mechanism that transmits a force for driving the movable electrode, the linkage mechanism having a drive rod and a piston, the drive rod being provided so as to penetrate the housing, the piston acting integrally with the drive rod and having an outer diameter larger than that of the drive rod.

[0014] The linkage mechanism may further include: a piston guide member provided so as to penetrate the housing, a guide member main body of the piston guide member having a rod through-hole and a cylinder, wherein the rod through-hole is penetrated by the drive rod and communicates with the outside of the housing, the cylinder having a piston space in which the piston is movably provided, and the piston space opening to the inside of the housing.

[0015] An airtight packing and a piston wear ring may be provided between an outer surface of the piston and an inner surface of the piston space.

[0016] A rod wear ring may be provided between an inner surface of the rod through-hole and an outer surface of the drive rod.

[0017] It may have a movable rod provided so as to penetrate the housing, one side of the movable rod being connected to the movable electrode and the other side of the movable rod being connected to the linkage mechanism, and the movable rod and the housing being sealed by a bellows.

[0018] The effective diameter of the bellows may have the same value as the outer diameter of the piston.

[0019] A guide tube is provided so as to penetrate the housing, the movable rod penetrates the guide tube, and the bellows may be provided between the guide tube and the movable rod.

[0020] It may also have an insulating rod, which is made of insulating material and connects the movable rod and the piston of the linkage mechanism.

[0021] A piston guide may be provided in a way that penetrates the housing. The piston guide is provided with the piston and the drive rod of the linkage mechanism. An installation flange is formed on one side of the outer surface of the guide body that forms the piston guide, and one side surface of the installation flange is in close contact with the outer surface of the housing.

[0022] A rod through-hole may be formed in a way that penetrates the center of the guide body. The drive rod penetrates the rod through-hole. A cylinder with a cylinder space protrudes toward the vacuum cut-off portion. One side of the cylinder space communicates with the rod through-hole, and the other side of the cylinder space communicates with the internal space of the housing.

[0023] Advantages of the Invention

[0024] The vacuum circuit breaker of the present invention may have at least one of the following effects.

[0025] In the present invention, a piston with a diameter larger than that of the drive rod is installed in the linkage mechanism that constitutes the vacuum circuit breaker and is provided in a way that penetrates the housing. The force provided by the piston is equivalent to the force acting from the pressure of the insulating gas inside the housing minus the force acting from the atmospheric pressure outside the housing, so that the self-closing force of the vacuum cut-off portion can be correspondingly reduced. Therefore, it has the effect of reducing the force required for the operator to drive the movable electrode.

[0026] In addition, in the present invention, the diameter of the piston (or the diameter of the airtight packing of the piston) that bears the force from the insulating gas inside the housing and the force from the atmospheric pressure is made the same as the effective diameter of the bellows that bears the self-closing force, so as to cancel out the self-closing force. Therefore, during the cut-off operation, the target speed can be constant. Thus, it has the effect of facilitating the design of an operator or the like for the operation of the vacuum circuit breaker. Description of the Drawings

[0027] Figure 1 A schematic cross-sectional view of the housing with a preferred embodiment of the vacuum circuit breaker of the present invention shown.

[0028] Figure 2 For showing Figure 1 An enlarged cross-sectional view of the piston guide and its related structure in the shown embodiment.

[0029] Figure 3 A cross-sectional perspective view of the piston guide and its surroundings that constitute the embodiment of the present invention shown.

[0030] Figure 4A cross-sectional view showing the structure of the piston guide constituting an embodiment of the present invention.

[0031] Figure 5 An operation state diagram showing the energized state in which the movable electrode contacts the drive electrode in an embodiment of the present invention.

[0032] Figure 6 An operation state diagram for explaining the operation in which the pressures inside and outside the housing act on the piston in an embodiment of the present invention.

[0033] Figure 7 (a) of which is an explanatory diagram showing the pressures acting on the drive rod and the bellows in the prior art, and (b) is an explanatory diagram showing the pressures acting on the drive rod, the piston, and the bellows in the present invention. Detailed Description of the Invention

[0034] Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. It should be noted that when reference numerals are assigned to the components of each drawing, even if they appear in different drawings, the same reference numerals are assigned to the same components as much as possible. And when describing the embodiments of the present invention, when it is determined that the specific description of the related well-known structures or functions hinders the understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

[0035] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are only used to distinguish one component from other components, and the nature or order or sequence of the corresponding components is not limited to such terms. When describing that one component is "connected", "coupled" or "joined" to another component, it can be understood not only that one component is directly connected or joined to another component, but also that other components can be "connected", "coupled" or "joined" between the components.

[0036] As shown in the drawings, the vacuum circuit breaker 20 of an embodiment of the present invention can be disposed in a housing 10 having an internal space 12 formed therein. The internal space 12 of the housing 10 can be filled with an insulating gas. The internal space 12 of the housing 10 can have various components including the vacuum circuit breaker 20, conductors, etc. of the present embodiment.

[0037] The vacuum circuit breaker 20 of the present embodiment can include a vacuum interruption portion 210 disposed in the internal space 12 of the housing 10 and a linkage mechanism 230 disposed so as to penetrate the housing 10.

[0038] The housing 212 can form the appearance of the above-mentioned vacuum cut-off portion 210. A vacuum space 214 can be formed inside the housing 212. The inside of the vacuum space 214 can be maintained in a vacuum state. The fixed electrode 216 is located on one side inside the vacuum space 214. The fixed electrode 216 can be electrically connected to the outside of the housing 212.

[0039] The movable electrode 218 can be movably arranged in the housing 212 in such a way as to contact and separate from the fixed electrode 216. When the movable electrode 218 contacts the fixed electrode 216, the circuit is connected, and when it separates from the fixed electrode 216, the circuit is cut off. The movable rod 220 is connected to the movable electrode 218. The movable rod 220 can receive a driving force through a linkage mechanism 230 to be described below and connected to the actuator 260 to actuate the movable electrode 218.

[0040] The guide tube 222 can be arranged to penetrate the housing 212. The guide tube 222 can be a hollow cylindrical shape. The movable rod 220 can be arranged to penetrate the inside of the guide tube 222.

[0041] The bellows 224 can be arranged such that its two ends are respectively connected to one side of the movable rod 220 and the other side of the guide tube 222. The bellows 224 can be a cylindrical shape with wrinkles as a whole. The length of the bellows 224 can be changed. The bellows 224 can be arranged between the movable rod 220 and the guide tube 222, so as to shield the inside of the housing 212 from the outside. That is, the bellows 224 can prevent the vacuum space 214 of the housing 212 from communicating with the outside, and at the same time, can enable the movable rod 220 to move in a state of penetrating the housing 212. The bellows 224 has continuous wrinkles, so that it can expand and contract to change the length. For example, the inner surface of one end of the bellows 224 can be joined to the outer surface of one side of the movable rod 220, and the outer surface of the other end of the bellows 224 can be joined to the inner surface of the guide tube 222.

[0042] The above-mentioned vacuum cut-off portion 210 can be fixedly arranged in the outer shell 10 through an insulating support 226. The insulating support 226 is fixed on one side of the internal space 12 of the outer shell 10, and can play a role in supporting the vacuum cut-off portion 210 and the linkage mechanism 230 to be described below.

[0043] The movable rod 220 and the piston 246 of the linkage mechanism 230 can be connected through an insulating rod 228. The insulating rod 228 is made of an insulating material, so as to insulate between the movable rod 220 and the piston 246, that is, the linkage mechanism 230.

[0044] The structure of the above-mentioned linkage mechanism 230 will be described. The above-mentioned linkage mechanism 230 has a piston guide 232. The above-mentioned piston guide 232 can be arranged in a way that penetrates the above-mentioned housing 10. The piston 246 and the drive rod 254 penetrate the above-mentioned piston guide 232, so that linear reciprocating motion can be performed. In other words, the above-mentioned piston guide 232 can play a role in guiding the movement of the above-mentioned piston 246 and the above-mentioned drive rod 254.

[0045] The frame of the above-mentioned piston guide 232 can be formed by a guide body 234. The above-mentioned guide body 234 can be cylindrical as a whole. The above-mentioned guide body 234 can have a mounting flange 236. The above-mentioned mounting flange 236 protrudes around one side edge of the above-mentioned guide body 234. One side surface of the above-mentioned mounting flange 236 is closely attached to the outer surface of the above-mentioned housing 10, so as to prevent the above-mentioned piston guide 232 from further entering the interior of the above-mentioned housing 10.

[0046] A rod through-hole 238 can be formed in a way that penetrates the center of the length direction of the above-mentioned piston guide 232. The drive rod 254 is movably arranged in the above-mentioned rod through-hole 238. An annular channel 240 can be formed around the inner surface of the above-mentioned rod through-hole 238. A rod wear ring 250 to be described below can be arranged in the above-mentioned annular channel 240.

[0047] The guide body 234 of the above-mentioned piston guide 232 can have a cylinder 242. A piston space 244 is formed inside the above-mentioned cylinder 242. The above-mentioned piston space 244 communicates with the above-mentioned rod through-hole 238. A piston 246 to be described below is arranged in the above-mentioned piston space 244 and can perform linear reciprocating motion. The cross-section of the above-mentioned piston space 244 can be circular. The cross-sectional shape of the above-mentioned piston space 244 can be formed to be the same as the cross-sectional shape of the piston 246 to be described below. Therefore, for example, if the cross-section of the above-mentioned piston space 244 is square, the cross-sectional shape of the above-mentioned piston 246 can also be square.

[0048] The piston 246 can perform linear reciprocating motion inside the above-mentioned cylinder 242. One surface of the above-mentioned piston 246 can be exposed to the internal space 12 of the above-mentioned housing 10. This is because the above-mentioned cylinder 242 is open to the above-mentioned internal space 12. The diameter of the above-mentioned piston 246 is larger than the diameter of the drive rod 254 to be described below.

[0049] One surface of the piston 246 can function to bear the pressure in the internal space 12. Another surface of the piston 246 can function to bear the atmospheric pressure outside the housing 10. Generally, since the pressure in the internal space 12 of the housing 10 is greater than the atmospheric pressure outside the housing 10, the piston 246 has a tendency to move outside the housing 10.

[0050] The outer diameter of the piston 246 can be the same as or similar to the effective diameter of the bellows 224. This is to make the pressure acting on the internal space 12 of the piston 246 the same as or similar to the pressure acting on the internal space 12 of the bellows 224. Of course, the self-closing force can also be relatively reduced or eliminated by making the outer diameter of the piston 246 larger than the effective diameter of the bellows 224.

[0051] An annular channel (not labeled in the drawings) is formed around the outer surface of the piston 246, and an airtight packing 248 can be provided in this annular channel. The airtight packing 248 functions to maintain airtightness. One of the annular channels can be provided with a piston wear ring 249. The piston wear ring 249 can prevent wear and eccentricity during operation caused by metal surface contact between the piston 246 and the inner surface of the cylinder 242. The piston wear ring 249 can also be provided on the inner surface of the cylinder 242 instead of the piston 246.

[0052] An annular channel 240 on the inner surface of the rod through-hole 238 can be provided with a rod wear ring 250. The rod wear ring 250 can prevent wear and eccentricity during operation caused by metal surface contact between the rod through-hole 238 and the drive rod 254. The rod wear ring 250 can also be provided on the outer surface of the drive rod 254.

[0053] An airtight packing 252 can be provided between the outer surface of the guide member main body 234 of the piston guide member 232 and the inner surface of the through-hole portion of the housing 10. The airtight packing 252 can be provided on the guide member main body 234 or formed on the inner surface of the through-hole portion of the housing 10. The airtight packing 252 can prevent the insulating gas from leaking through between the outer surface of the piston guide member 232 and the housing 10.

[0054] The drive rod 254 extends from the above-mentioned piston 246 and extends outside the above-mentioned housing 10. The above-mentioned drive rod 254 may also be integrally formed with the above-mentioned piston 246. The diameter of the above-mentioned drive rod 254 has a value smaller than the diameter of the above-mentioned piston 246. The above-mentioned drive rod 254 may be connected to the operator 260. The above-mentioned drive rod 254 is connected to the above-mentioned operator 260 and receives the operating force provided by the operator 260 to control the movement of the above-mentioned movable rod 220, so that the above-mentioned movable electrode 218 performs the actions of contacting and separating from the above-mentioned fixed electrode 216.

[0055] The following will describe in detail the use process of the vacuum circuit breaker according to the present invention having the above structure.

[0056] The vacuum circuit breaker 20 of the present invention can function to connect and disconnect the circuit within the above-mentioned housing 10. As Figure 5 shown, the above-mentioned fixed electrode 216 and the movable electrode 218 are in a state of contacting each other and connecting the circuit. If an emergency signal is provided, then through the action of the above-mentioned operator 260, the above-mentioned movable electrode 218 separates from the above-mentioned fixed electrode 216 and disconnects the circuit. For example, in Figure 1 the state where the above-mentioned movable electrode 218 is separated from the above-mentioned fixed electrode 216 is shown.

[0057] When the above-mentioned operator 260 pulls the above-mentioned drive rod 254 upward with reference to the drawing, the above-mentioned movable electrode 218 can separate from the above-mentioned fixed electrode 216. This is because when the above-mentioned drive rod 254 is pulled, the above-mentioned piston 246 moves from one side of the above-mentioned cylinder 242 to the other side, that is, in the direction outside the above-mentioned housing 10, and the insulating rod 228 connected to the above-mentioned piston 246 moves together. Through the movement of the above-mentioned insulating rod 228, the above-mentioned movable rod 220 performs a linear motion, and the movement of the above-mentioned movable rod 220 causes the above-mentioned movable electrode 218 to perform a linear movement, thereby separating from the above-mentioned fixed electrode 216.

[0058] When operating in this way, a force as Figure 6 shown can act on the above-mentioned piston 246. As Figure 6 shown, one side surface of the above-mentioned piston 246 is exposed to the internal space 12 of the above-mentioned housing 10. Therefore, it is subjected to the pressure PI of the insulating gas in the above-mentioned internal space 12.

[0059] And, since the rod wear ring 250 is provided in the rod through-hole 238 of the above-mentioned piston guide 232, the atmospheric pressure PO can act on the other side surface of the above-mentioned piston 246 between the inner surface of the above-mentioned rod through-hole 238 and the above-mentioned drive rod 254. Therefore, the insulating gas pressure PI inside the housing 10 and the atmospheric pressure PO act on the above-mentioned piston 246 at the same time, and actually a force in the direction opposite to the self-closing force is generated.

[0060] On the other hand, the force can act on the component that actuates the movable electrode 218 according to the relationship between the pressure PE in the vacuum space 214 of the vacuum cut-off portion 210 described above, the pressure PI in the internal space 12 of the housing 10, and the pressure PO outside the housing 10, i.e., the atmospheric pressure.

[0061] The force D acting on the bellows 224 can be obtained by multiplying the effective cross-sectional area A3 of the bellows 224 by the pressure PI of the insulating gas inside the housing 10. That is, D = PI * A3.

[0062] The force A acting on the drive rod 254 can be obtained by multiplying the effective cross-sectional area A1 of the drive rod 254 by the atmospheric pressure PO. That is, A = PO * A1.

[0063] The forces B and C acting on the piston 246 are as follows. First, the force B exerted by the atmospheric pressure PO is equal to the effective cross-sectional area A2 of the piston 246 multiplied by the atmospheric pressure PO, i.e., B = PO * A2. Second, the force C exerted by the pressure PI of the insulating gas inside the housing 10 is C = PI * A2. Generally, the force C is greater than the force B.

[0064] First, as Figure 7 (a) shown, due to the pressures inside and outside the housing 10 and the vacuum in the vacuum cut-off portion 210, the force of A + D acts on the side of the movable electrode 218. Therefore, in order to separate the movable electrode 218 from the fixed electrode 216, a corresponding force needs to be increased on the actuator 260.

[0065] However, as Figure 7 (b) shown, a force equivalent to (C - B) acting on the piston 246 acts less on the side of the movable electrode 218. That is, in Figure 7 (b), the finally acting force is (A + D) - (C - B). Therefore, compared with the conventional case, the force acting on the side of the movable electrode 218 is relatively reduced. Thus, the force required for the actuator 260 for the movement of the movable electrode 218 can be relatively reduced.

[0066] Furthermore, if the effective diameter of the bellows 224 and the effective diameter of the piston 246 (or the effective diameter of the airtight packing 248) are the same or almost the same, the self-closing force of the vacuum cut-off portion 210 during the opening and closing operation and the load magnitude caused by the pressure difference between the inside and outside of the housing will be similar, so that the movement speed of the movable electrode 218 can be made constant during the opening and closing and insertion operations.

[0067] As described above, even taking the case where all components constituting the embodiments of the present invention are combined into one or combined and operate as an example, the present invention is not limited to these embodiments. That is, as long as it is within the scope of the object of the present invention, all its components can be selectively combined in more than one to operate. And unless there is a particularly contrary record, terms such as "including", "constituting", or "having" described above mean including the corresponding components. Therefore, it should not be interpreted as excluding other components, but should be understood to also include other components. Unless otherwise defined, the meanings of all terms, including technical terms or scientific terms, are the same as those generally understood by those of ordinary skill in the technical field to which the present invention belongs. Terms commonly used as defined by a dictionary should be interpreted to have the same meaning as their meaning in the context of the related art, and should not be interpreted as ideal or overly formal meanings unless clearly defined in the present invention.

[0068] The above description only illustratively explains the technical idea of the present invention. As long as those of ordinary skill in the technical field to which the present invention belongs can make various modifications and variations without exceeding the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are used to illustrate the technical idea of the present invention, rather than to limit the technical idea of the present invention. The scope of the technical idea of the present invention is not limited to these embodiments. The protection scope of the present invention should be interpreted by the appended claims. All technical ideas within the same scope should be interpreted as being included within the scope of the claims of the present invention.

Claims

1. A vacuum circuit breaker is arranged such that a part thereof is located inside a housing and another part penetrates through the housing. It includes: A vacuum interruption part which is arranged inside the housing, and a vacuum space in a vacuum state is formed inside the housing of the vacuum interruption part. The vacuum space has a fixed electrode and a movable electrode which contacts / separates from the fixed electrode. And A linkage mechanism which transmits a force for driving the movable electrode. The linkage mechanism has a driving rod and a piston. The driving rod is arranged in a way that it penetrates through the housing. The piston moves integrally with the driving rod and has an outer diameter larger than that of the driving rod.

2. The vacuum circuit breaker according to claim 1, wherein, The linkage mechanism further includes: a piston guide which is arranged in a way that it penetrates through the housing. The guide body of the piston guide has a rod through-hole and a cylinder. The rod through-hole is penetrated by the driving rod and communicates with the outside of the housing. The cylinder has a piston space, and the piston is movably arranged in the piston space. And the piston space is open to the inside of the housing.

3. The vacuum circuit breaker according to claim 2, wherein, An airtight packing and a piston wear ring are arranged between the outer surface of the piston and the inner surface of the piston space.

4. The vacuum circuit breaker according to claim 2, wherein, A rod wear ring is arranged between the inner surface of the rod through-hole and the outer surface of the driving rod.

5. The vacuum circuit breaker according to claim 1, wherein, It has a movable rod which is arranged in a way that it penetrates through the housing. One side of the movable rod is connected to the movable electrode, and the other side of the movable rod is connected to the linkage mechanism. The movable rod and the housing are sealed by a bellows.

6. The vacuum circuit breaker according to claim 5, wherein, The effective diameter of the bellows has the same value as the outer diameter of the piston.

7. The vacuum circuit breaker according to claim 6, wherein, A guide cylinder is arranged in a way that it penetrates through the housing. The movable rod penetrates through the guide cylinder, and the bellows is arranged between the guide cylinder and the movable rod.

8. The vacuum circuit breaker according to claim 5, wherein, It also has an insulating rod which is made of insulating material and connects the movable rod and the piston of the linkage mechanism.

9. The vacuum circuit breaker according to claim 1, wherein, A piston guide is arranged in a way that it penetrates through the housing. The piston and the driving rod of the linkage mechanism are arranged on the piston guide. An installation flange is formed on the outer surface side of the guide body of the frame forming the piston guide in a surrounding manner. One side surface of the installation flange is closely attached to the outer surface of the housing.

10. The vacuum circuit breaker according to claim 9, wherein, A rod through-hole is formed in a way that it penetrates through the center of the guide body. The driving rod penetrates through the rod through-hole. A cylinder with a cylinder space protrudes towards the vacuum interruption part. One side of the cylinder space communicates with the rod through-hole, and the other side of the cylinder space communicates with the internal space of the housing.

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