A medium voltage vacuum circuit breaker

Abstract

The application discloses a medium-voltage vacuum circuit breaker, which comprises an arc-extinguishing chamber, an operating mechanism, a first bellows shield and a second bellows shield which do not interfere with each other, the first bellows shield is sleeved outside a bellows and is sealingly connected with a shell, a movable conducting rod is provided with a shoulder, the second bellows shield is sleeved outside the first bellows shield and is sealingly connected with the shoulder of the movable conducting rod, the distance between the end of the second bellows shield and the shell is less than the stroke of the movable conducting rod, the distance between the end of the first bellows shield and the shoulder is less than the stroke of the movable conducting rod, and the inner wall of the bellows is provided with a fluororubber layer, one end of the fluororubber layer is sealingly connected with the shell, and the other end of the fluororubber layer is sealingly connected with the shoulder. The bellows is prevented from being eroded by metal vapor, has good sealing performance, and when the bellows is mechanically damaged, the fluororubber layer can also seal the arc-extinguishing chamber, so that the vacuum tightness is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a circuit breaker, in particular to a medium voltage vacuum circuit breaker. BACKGROUND

[0002] In the breaking process of the prior art vacuum circuit breaker, the current is gradually concentrated on the contact points of fewer and fewer contacts, and the temperature of the contact points rises sharply, resulting in melting. As the contacts continue to separate, the melted metal bridge is elongated and thinned, and eventually becomes metal vapor. The temperature of the metal vapor is very high, so that some metal atoms may be thermionized. In addition, when the contacts are just separated, the opening distance is small and the electric field strength is very strong. Under the action of high temperature and strong electric field, a large number of electrons will be emitted from the cathode surface and quickly develop into cathode spots, and then the cathode spots continue to evaporate new metal vapor and generate new electrons. Metal vapor sputtering causes erosion to the surface of the bellows, reduces the strength of the bellows, and causes vacuum damage; each time the moving and static contacts of the circuit breaker are separated, the corrugated wall of the bellows will produce mechanical deformation, and since there is a high requirement for the opening speed, the opening speed is fast, and the opening process will produce rebounding and oscillation, affecting the mechanical life of the bellows. For example, a medium voltage vacuum circuit breaker disclosed in Chinese Patent Document CN208256571U has a layer of epoxy resin wrapped outside the vacuum arc-extinguishing chamber and its supporting components on the body of the medium voltage vacuum circuit breaker. The moving and static contacts of the medium voltage vacuum circuit breaker include a ring-shaped contact, a copper base, and a ring-shaped spring sheet ring. The ring-shaped contact is composed of multiple copper metal sheets, which are arranged in a ring shape on the upper end of the copper base. The multiple copper metal sheets and the copper base are integrally formed. The upper part of the multiple copper metal sheets is recessed inward by a portion. The recessed part of the multiple copper metal sheets forms a ring. The outer side of the middle part of the multiple copper metal sheets has a recess. The recesses on the outer side of the multiple copper metal sheets form another ring. The ring-shaped spring sheet ring is sleeved on the outer side of the other ring. The moving and static contacts are transversely installed on the bracket of the vacuum circuit breaker body, and the wires are inserted into the ring-shaped contact. This scheme ensures the normal operation of the vacuum circuit breaker body. However, this scheme has the above-mentioned problems. SUMMARY

[0003] The present application is to overcome the above-mentioned problems of the prior art, and to provide a medium voltage vacuum circuit breaker. The medium voltage vacuum circuit breaker has good vacuum tightness and long service life.

[0004] A further object of the present application is to fine-tune the buffering effect by providing a fine-tuning buffering mechanism.

[0005] In order to achieve the above-mentioned objects, the present application adopts the following technical solutions:

[0006] The utility model provides a kind of medium voltage vacuum circuit breaker, including arc-extinguishing chamber and operating mechanism, the arc-extinguishing chamber is mainly composed of shell, static contact, moving contact, static conducting rod, moving conducting rod and bellows, the static contact and moving contact are respectively arranged on static contact and moving contact, the static conducting rod is fixed in shell, the moving conducting rod is connected with insulated pull rod, the insulated pull rod is connected with operating mechanism, and it further includes mutually interfering first bellow shield and second bellow shield, the first bellow shield is sleeved bellows outside and is sealingly connected with shell, the moving conducting rod is equipped with shoulder, the second bellow shield is sleeved in first bellow shield outside and is sealingly connected with the shoulder of moving conducting rod, the end of second bellow shield and the spacing of shell is less than moving conducting rod stroke, the end of first bellow shield and the spacing of shoulder is less than moving conducting rod stroke, the inner wall of bellows is equipped with fluorine rubber layer, one end of fluorine rubber layer is sealingly connected with shell, and the other end is sealingly connected with shoulder.

[0007] In the scheme, the outer side of the bellows is provided with the first bellow shield and the second bellow shield, which are nested with each other to cover the bellows, the second bellow shield moves with the moving conducting rod and always protects the bellows from the metal vapor erosion with the first bellow shield, and the inner wall of the bellows is provided with the fluorine rubber layer, which is elastic and has good sealing performance, so that the arc-extinguishing chamber can be sealed by the fluorine rubber layer when the bellows is mechanically damaged, to ensure the vacuum tightness.

[0008] As preferred, it further includes a main shield and two auxiliary shields, the main shield is sleeved on the outer periphery of the static contact and the moving contact, the two auxiliary shields are arranged at the two ends of the main shield and fixed on the shell, and the two ends of the main shield are inwardly retracted and partially inserted into the two auxiliary shields, to improve the electric field distribution and facilitate the improvement of the insulation strength of the arc-extinguishing chamber.

[0009] As preferred, the first bellow shield is connected with a graphite ring, and the outer periphery of the graphite ring abuts against the second bellow shield, to seal the gap between the first bellow shield and the second bellow shield by the graphite ring, block the high-temperature metal vapor, and facilitate the smooth operation of the second bellow shield.

[0010] As preferred, the fine-tuning buffer mechanism further comprises a frame, a suspension, a spring, an adjusting rod, a connecting block, a bottom plate and a reciprocating pushing mechanism, the frame is arranged at one end of the shell close to the movable conducting rod, the bottom plate is fixedly installed on the insulating pull rod, the suspension is abutted on the bottom plate and the frame at both sides, the middle part of the suspension is connected with the buffer, the reciprocating pushing mechanism is arranged at one side of the suspension close to the shell, one end of the spring is abutted on the suspension and the other end is abutted on the reciprocating pushing mechanism, the connecting block is hinged with the reciprocating pushing mechanism, the connecting block is provided with an installation rod and is rotationally connected with the suspension by taking the installation rod as the shaft, and the adjusting rod is connected with the connecting block. The operating mechanism will produce slight changes in the cooperation of the internal components with the increase of the running time, the pull rod vibrates during the opening process, the circuit breaker action data is collected according to the circuit breaker fault diagnosis technology, the characteristic parameters are extracted through the signal processing means, and finally the diagnosis or prediction model is established by the intelligent algorithm to evaluate the working state of the circuit breaker. According to the evaluation result, the fine-tuning buffer mechanism is adjusted to make the circuit breaker action restore to the best level. The suspension of the fine-tuning buffer mechanism is two crossed supporting arms, one side is provided with a roller which is slidingly connected with the bottom plate and the frame respectively, and the other side is hinged with the bottom plate and the frame. The bottom plate is connected with the insulating pull rod and acts simultaneously. The reciprocating pushing mechanism changes the position of the spring in the suspension, so that the moment of the suspension changes, thereby fine-tuning the buffer effect.

[0011] As preferred, the reciprocating pushing mechanism comprises a connecting plate, a first ratchet, a second ratchet and a toothed plate, the connecting plate is hinged with the connecting block, the toothed plate is arranged at the side of the connecting plate, the first ratchet and the second ratchet are rotationally connected with the connecting plate respectively and are arranged in opposite directions to push the toothed plate, the reciprocating pushing mechanism further comprises a tension spring for forcing the first ratchet and the second ratchet to approach the toothed plate, one side of the first ratchet and the second ratchet close to the bottom plate is respectively provided with a protruding first limiting part and a second limiting part, the bottom plate is provided with a corresponding first limiting groove and a second limiting groove, the first limiting part and the second limiting part are respectively arranged in the corresponding first limiting groove and the second limiting groove, the first limiting groove and the second limiting groove are shaped to limit the first ratchet and the second ratchet from engaging with the toothed plate at the same time, and the spring is abutted on the toothed plate. When the first ratchet pushes the toothed plate to move in one direction, the second ratchet is limited to approach the toothed plate due to the second limiting groove, and the first ratchet will not bring back the toothed plate when resetting due to its own structure; when the second ratchet pushes the toothed plate to move in the other direction, the first ratchet is limited to approach the toothed plate due to the action of the first limiting groove, and the same reason applies to the resetting. The first ratchet, the second ratchet and the toothed plate cooperate to achieve fine control of the buffer effect.

[0012] Preferably, both the first limiting groove and the second limiting groove include a wide portion for engagement and a narrow portion for limiting engagement, wherein the wide portion and the narrow portion are smoothly connected, and when the first ratchet pushes the tooth plate backward, the first limiting portion and the second limiting portion are respectively located in the wide portion and the narrow portion, and when the second ratchet pushes the tooth plate forward, the first limiting portion and the second limiting portion are respectively located in the narrow portion and the wide portion.

[0013] Preferably, there are two sets of suspension, springs, connecting blocks, and reciprocating propulsion mechanism, each set located on both sides of the tie rod, with the two sets of connecting blocks connected by an adjusting rod. This symmetrical arrangement ensures a smoother buffering effect for the circuit breaker.

[0014] Therefore, the present invention has the following beneficial effects: the vacuum circuit breaker has good airtightness and long service life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of one structure of the present invention.

[0016] Figure 2 This is the invention Figure 1 Side view.

[0017] Figure 3 This is a schematic diagram of the bellows structure of the present invention.

[0018] Figure 4 This is a schematic diagram of the fine-tuning buffer mechanism of the present invention.

[0019] Figure 5 This is a schematic diagram of the reciprocating propulsion mechanism of the present invention.

[0020] Figure 6 This is the invention Figure 4 Enlarged view of section B in the middle.

[0021] Figure 7 This is the invention Figure 4 Enlarged view of point C in the middle.

[0022] Figure 8 This is the invention Figure 5 Enlarged view of point A in the middle.

[0023] In the figure: 1, arc extinguishing chamber 1-1, shell 1-2, moving contact 1-3, static contact 1-4, static conducting rod 1-5, moving conducting rod 1-6, bellows 1-7, insulating pull rod 1-8, first bellow shield 1-9, second bellow shield 1-10, fluororubber layer 1-11, main shield 1-12, auxiliary shield 2, fine adjustment buffer mechanism 2-1, frame 2-2, suspension 2-3, spring 2-4, adjusting rod 2-5, connecting block 2-6, bottom plate 2-61, first limiting groove 2-62, second limiting groove 2-7, reciprocating advancing mechanism 2-71, connecting plate 2-72, first ratchet 2-721, first limiting part 2-731, second limiting part 2-73, second ratchet 2-74, toothed plate 2-75, tension spring 2-8, buffer. DETAILED DESCRIPTION

[0024] The application will be further described below in conjunction with the drawings and specific embodiments. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the above description refer to the directions in the drawings, and the words "inner" and "outer" refer to the directions towards or away from the geometric center of a particular component.

[0025] As shown in the embodiment of Figure 1 , Figure 2 A medium voltage vacuum circuit breaker, comprising an arc extinguishing chamber 1 and an operating mechanism (not shown), the arc extinguishing chamber mainly consists of a shell 1-1, a static contact 1-2, a moving contact 1-3, a static conducting rod 1-4, a moving conducting rod 1-5 and a bellows 1-6, the static contact and the moving contact are respectively arranged on the static contact and the moving contact, the static conducting rod is fixedly arranged in the shell, the shell is composed of an integral ceramic part and a microcrystalline glass part, the ceramic part is at the position of the moving contact and the static contact, and the microcrystalline glass part is at the position of the bellows, the color change of the arc in the vacuum can be monitored to monitor the oxidation of the internal parts of the vacuum degree through the microcrystalline glass part. The moving conducting rod is movably connected with the shell, the moving conducting rod is connected with an insulating pull rod, and the insulating pull rod is connected with the operating mechanism. As shown in Figure 3As shown, the circuit breaker further comprises a first bellows shield 1-8, a second bellows shield 1-9, a main shield 1-11 and two auxiliary shields 1-12, the main shield is sleeved on the outer periphery of the static contact and the moving contact, the two auxiliary shields are arranged at the two ends of the main shield and are fixed on the shell, the two ends of the main shield are inwardly contracted and partially extend into the two auxiliary shields, so as to improve the electric field distribution and facilitate the improvement of the arc-extinguishing chamber insulation strength. The first bellows shield is sleeved on the outside of the bellows and is sealingly connected with the shell, the moving conducting rod is provided with a shoulder, the second bellows shield is sleeved on the outside of the first bellows shield and is sealingly connected with the shoulder of the moving conducting rod, the distance between the end of the second bellows shield and the shell is less than the stroke of the moving conducting rod, the distance between the end of the first bellows shield and the shoulder is less than the stroke of the moving conducting rod, the first bellows shield is connected with a graphite ring, and the outer periphery of the graphite ring abuts against the second bellows shield. The gap between the first bellows shield and the second bellows shield is sealed by the graphite ring, so as to block the high-temperature metal vapor, and meanwhile, the second bellows shield operates smoothly and is prevented from being blocked. The inner wall of the bellows is provided with a fluororubber layer 1-10, one end of the fluororubber layer is sealingly connected with the shell, and the other end is sealingly connected with the shoulder.

[0026] As Figure 4 to Figure 8As shown, the circuit breaker further comprises a fine-tuning buffer mechanism 2, which includes a frame 2-1, a suspension 2-2, a spring 2-3, an adjusting rod 2-4, a connecting block 2-5, a bottom plate 2-6, and a reciprocating advancing mechanism 2-7. The frame is arranged at one end of the housing close to the moving conducting rod. The bottom plate is fixedly installed on the insulating pull rod. The suspension is abutted on the bottom plate and the frame at both sides. The middle part of the suspension is connected with the buffer 2-8. The reciprocating advancing mechanism is arranged at one side of the suspension close to the housing. One end of the spring is abutted on the suspension, and the other end is abutted on the reciprocating advancing mechanism. The connecting block is hinged with the reciprocating advancing mechanism. The connecting block is provided with an installation rod and is rotationally connected with the suspension by the installation rod as the shaft. The adjusting rod is connected with the connecting block. The cooperation of the internal components of the operating mechanism will produce slight changes as the operation time increases. The pull rod vibrates during the opening process. According to the circuit breaker fault diagnosis technology, the circuit breaker action data is collected, the characteristic parameters are extracted by the signal processing means, and finally the diagnosis or prediction model is established by the intelligent algorithm to evaluate the working state of the circuit breaker. According to the evaluation result, the fine-tuning buffer mechanism is adjusted to restore the best level of the circuit breaker action. The suspension of the fine-tuning buffer mechanism is two crossed support arms. One side is provided with a roller, which is slidingly connected with the bottom plate and the frame respectively. The other side is hinged with the bottom plate and the frame. The bottom plate is connected with the insulating pull rod and acts simultaneously. The reciprocating advancing mechanism changes the position of the spring in the suspension, so that the suspension torque changes, thereby fine-tuning the buffer effect. The suspension, spring, connecting block, and reciprocating advancing mechanism are all two sets, which are arranged on both sides of the pull rod. The two sets of connecting blocks are connected by the adjusting rod. The symmetrical arrangement makes the buffer effect of the circuit breaker more stable. The reciprocating advancing mechanism includes a connecting plate 2-71, a first ratchet 2-72, a second ratchet 2-73, and a tooth plate 2-74. The connecting plate is hinged with the connecting block. The tooth plate is arranged on the side surface of the connecting plate. The first ratchet and the second ratchet are rotationally connected with the connecting plate and arranged in opposite directions to push the tooth plate. The reciprocating advancing mechanism further includes a tension spring 2-75 for forcing the first ratchet and the second ratchet to approach the tooth plate. The side close to the bottom plate of the first ratchet and the second ratchet is respectively provided with a protruding first limiting part 2-721 and a second limiting part 2-731. The bottom plate is provided with a corresponding first limiting groove 2-61 and a second limiting groove 2-62. The first limiting part and the second limiting part are arranged in the corresponding first limiting groove and second limiting groove respectively. The first limiting groove and the second limiting groove are shaped to limit the first ratchet and the second ratchet from engaging with the tooth plate at the same time. The spring is abutted on the tooth plate. When the first ratchet pushes the tooth plate in one direction, the second ratchet is limited to approach the tooth plate due to the second limiting groove. When resetting, the first ratchet does not bring back the tooth plate due to its own structure. When the second ratchet pushes the tooth plate in the other direction, the first ratchet is limited to approach the tooth plate due to the first limiting groove. When resetting, the same applies. The cooperation of the first ratchet, the second ratchet, and the tooth plate realizes fine control of the buffer effect.The first limiting groove and the second limiting groove each include a wide part for engagement and a narrow part for limiting engagement, the wide part and the narrow part are smoothly connected, the first limiting part and the second limiting part are respectively located at the wide part and the narrow part when the first ratchet pushes the tooth plate, and the first limiting part and the second limiting part are respectively located at the narrow part and the wide part when the second ratchet pushes the tooth plate.

[0027] In the scheme, the corrugated pipe is provided with a first corrugated pipe shield and a second corrugated pipe shield, both of which are nested to cover the corrugated pipe, the second corrugated pipe shield moves with the moving conducting rod and always protects the corrugated pipe from the metal vapor erosion with the first corrugated pipe shield, meanwhile, the inner wall of the corrugated pipe is provided with a fluororubber layer, the fluororubber layer is elastic and has good sealing performance, when the corrugated pipe is mechanically damaged, the fluororubber layer can also seal the arc-extinguishing chamber to ensure the vacuum tightness. When the fine adjustment buffer mechanism is used, the adjusting rod is rotated by about 30° to one side, the adjusting rod drives the connecting block to move, the connecting block and the adjusting rod act as a lever mechanism and have a labor-saving effect, the connecting block drives the connecting plate to move along the bottom plate, the connecting block connects the first ratchet or the second ratchet to push the tooth plate to move forward or backward, so as to change the position of the spring in the suspension and achieve the effect of fine adjustment of the buffer. Therefore, the vacuum circuit breaker has the advantages of good air tightness and long service life.

[0028] Those skilled in the art will appreciate that the embodiments herein are presented to assist the reader in understanding the implementation method of the present application, and should be understood as the protection scope of the present application is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations according to the technical inspiration disclosed in the present application without departing from the essence of the present application, and these modifications and combinations are still within the protection scope of the present application.

Claims

1. A medium-voltage vacuum circuit breaker, comprising an arc-extinguishing chamber and an operating mechanism, wherein the arc-extinguishing chamber mainly comprises a shell, stationary contacts, moving contacts, a stationary conductive rod, a moving conductive rod, and a bellows; the stationary contacts and moving contacts are respectively disposed on the stationary and moving contacts; the stationary conductive rod is fixed in the shell; the moving conductive rod is movably connected to the shell and aligned with the stationary conductive rod; the moving conductive rod is connected to an insulating pull rod; the insulating pull rod is connected to the operating mechanism; characterized in that... It also includes a first bellows shield and a second bellows shield that do not interfere with each other. The first bellows shield is fitted over the outside of the bellows and is sealed to the shell. The moving conductive rod has a shoulder. The second bellows shield is fitted over the outside of the first bellows shield and is sealed to the shoulder of the moving conductive rod. The distance between the end of the second bellows shield and the shell is less than the stroke of the moving conductive rod. The distance between the end of the first bellows shield and the shoulder is less than the stroke of the moving conductive rod. The inner wall of the bellows is provided with a fluororubber layer. One end of the fluororubber layer is sealed to the shell, and the other end is sealed to the shoulder. It also includes a fine-tuning buffer mechanism, which includes a reciprocating propulsion mechanism. The frame is located at one end of the outer shell near the moving conductive rod. The base plate is fixedly installed on the insulating tie rod. The two sides of the suspension abut against the base plate and the frame. The middle part of the suspension is connected to the frame with a buffer. The reciprocating propulsion mechanism is located on the side of the suspension near the shell. One end of the spring abuts against the suspension, and the other end abuts against the reciprocating propulsion mechanism. The connecting block is hinged to the reciprocating propulsion mechanism. The connecting block is provided with a mounting rod and is rotatably connected to the suspension with the mounting rod as the axis. The adjusting rod is connected to the connecting block.

2. A medium-voltage vacuum circuit breaker according to claim 1, characterized in that, It also includes a main shield and two auxiliary shields. The main shield is fitted around the periphery of the stationary contact and the moving contact. The two auxiliary shields are set at both ends of the main shield and fixed to the housing. The two ends of the main shield are retracted inward and partially extend into the two auxiliary shields.

3. A medium-voltage vacuum circuit breaker according to claim 1, characterized in that, The first corrugated pipe shield is connected to a graphite ring, and the outer periphery of the graphite ring abuts against the second corrugated pipe shield.

4. A medium-voltage vacuum circuit breaker according to claim 1, characterized in that, The fine-tuning buffer mechanism includes a frame, suspension, spring, adjusting rod, connecting block, base plate, and reciprocating propulsion mechanism.

5. A medium-voltage vacuum circuit breaker according to claim 4, characterized in that, The reciprocating propulsion mechanism includes a connecting plate, a first ratchet, a second ratchet, and a toothed plate. The connecting plate is hinged to a connecting block. The toothed plate is disposed on the side of the connecting plate. The first and second ratchets are rotatably connected to the connecting plate and are arranged in opposite directions to push the toothed plate. The reciprocating propulsion mechanism also includes a tension spring that forces the first and second ratchets to approach the toothed plate. The first and second ratchets are respectively provided with a protruding first limiting part and a second limiting part on the side of the first and second ratchets near the bottom plate. The bottom plate is provided with a corresponding first limiting groove and a second limiting groove. The first and second limiting parts are respectively disposed in the corresponding first limiting groove and second limiting groove. The first limiting groove and the second limiting groove are both shaped to restrict the first and second ratchets from simultaneously meshing with the toothed plate. The spring abuts against the toothed plate.

6. A medium-voltage vacuum circuit breaker according to claim 5, characterized in that, Both the first limiting groove and the second limiting groove include a wide portion for engagement and a narrow portion for limiting engagement. The wide portion and the narrow portion are smoothly connected. When the first ratchet pushes the tooth plate backward, the first limiting portion and the second limiting portion are respectively located in the wide portion and the narrow portion. When the second ratchet pushes the tooth plate forward, the first limiting portion and the second limiting portion are respectively located in the narrow portion and the wide portion.

7. A medium-voltage vacuum circuit breaker according to claim 4, characterized in that, The suspension, spring, connecting block, and reciprocating propulsion mechanism are all in two sets, respectively installed on both sides of the tie rod, and the two sets of connecting blocks are connected by an adjusting rod.

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