A circuit breaker and a stationary end structure thereof

Abstract

The application relates to a circuit breaker and a static terminal structure thereof, the static terminal structure of the circuit breaker comprising a static main contact, a static arc contact and a static support, the static main contact being provided with a front barrel opening and a rear barrel opening at the front end and the rear end respectively, the rear barrel opening facing the static support, the rear end of the static main contact being provided with an intermediate beam crossing the rear barrel opening, the intermediate beam being provided with a through hole for the static arc contact, the intermediate beam and the inner wall of the barrel of the static main contact surrounding an airflow through hole, the intermediate beam being a straight line structure, the airflow through hole being an arc-shaped hole, the airflow through hole being two and being symmetrically arranged on the left and right sides of the intermediate beam, the airflow through hole being used for the hot airflow generated by the breaking point of the circuit breaker to flow from the inner cavity of the static main contact into the inner cavity of the static support; the intermediate beam is used as a carrier for supporting the static arc contact, the two sides of the intermediate beam can surround the inner wall at the rear barrel opening of the static main contact to form an airflow through hole with a large opening area, the through-flow area is increased, and the smoothness of the static side airflow exhaust passage is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-voltage switch, in particular to a circuit breaker and a static side structure thereof. BACKGROUND

[0002] The high-voltage SF6 circuit breaker is mainly used for closing, carrying and breaking the circuit current, and is crucial to the safe operation of the extra-high voltage and ultra-high voltage power transmission lines. In the breaking process of the short-circuit current, the thermal breakdown phenomenon occurs from time to time, in which the excessively high temperature in the arc-extinguishing chamber is the main cause of the decrease in the dielectric insulation performance. In order to avoid the excessively high temperature in the arc-extinguishing chamber, the hot gas caused by the arc between the breaking points needs to be quickly discharged, and the cooling of the gas at the breaking position after the arc is continuously strengthened. In order to discharge the hot gas flow, the static side of the circuit breaker is provided with a corresponding gas discharge passage for the high-temperature and high-pressure gas at the breaking points to flow along the gas discharge passage.

[0003] The static side structure of the circuit breaker comprises a static support, a static main contact and a static arc contact, the static support and the static main contact are both cylindrical and coaxially arranged with respect to a central axis, the static arc contact is a rod and is arranged on the central axis, the cylindrical bottom of the static main contact is connected to the static support, the cylindrical bottom of the static main contact is provided with a through hole, the static arc contact is arranged in the through hole, the cylindrical bottom of the static main contact serves as a carrier of the static arc contact, a circular hole is formed on the cylindrical bottom of the static main contact on the side of the through hole, the circular hole forms a gas flow through hole, in the process of breaking the large-capacity short-circuit current by the high-voltage circuit breaker, after the static arc contact is separated from the throat of the nozzle, the high-temperature, high-speed and high-pressure gas flow is blown from the nozzle to the static side, the hot gas flow enters the inner cavity of the static main contact, and then enters the inner cavity of the static support through the gas flow through hole, and then is discharged from the static support to the shell of the circuit breaker, wherein the inner cavity of the static main contact, the gas flow through hole and the inner cavity of the static support are used to form a static side gas flow discharge passage.

[0004] The unreasonable design of the static side gas flow discharge passage can seriously affect the performance of the product. For the existing scheme of arranging the gas flow through hole on the side of the through hole on the cylindrical bottom of the static main contact, the gas flow through hole cannot well conduct the gas flow in actual application, the gas discharge passage is not smooth enough, and the high-temperature gas is easy to accumulate between the moving and static contacts, thereby affecting the establishment of the gas medium recovery characteristic. SUMMARY

[0005] The present application aims to provide a static side structure of a circuit breaker to solve the problem that the static side gas flow discharge passage of the existing circuit breaker is not smooth enough and affects the breaking performance, and also aims to provide a circuit breaker to solve the problem that the static side gas flow discharge passage of the circuit breaker is not smooth enough and affects the breaking performance.

[0006] The technical scheme of the static side structure of the circuit breaker of the present application is as follows:

[0007] The static end structure of the circuit breaker comprises a static main contact, a static arc contact and a static support, the static main contact and the static support are both in the form of a cylinder and coaxially arranged relative to a central axis, the static arc contact is arranged in the inner cavity of the static main contact, the central axis extends in the front-rear direction, the front-rear ends of the static main contact are respectively provided with a front cylinder opening and a rear cylinder opening, the rear cylinder opening faces the static support, the rear end of the static main contact is provided with an intermediate beam which spans the rear cylinder opening, the intermediate beam extends in the radial direction of the static main contact and its two ends are connected to the inner wall of the cylinder of the static main contact, the intermediate beam is provided with a through hole for the static arc contact, the intermediate beam and the inner wall of the cylinder of the static main contact enclose an airflow through hole, the intermediate beam is in the form of a straight line, the airflow through hole is in the form of an arc-shaped hole, there are two airflow through holes which are symmetrically arranged on the left and right sides of the intermediate beam, and the airflow through hole is used for the hot airflow generated by the breaking point of the circuit breaker to flow from the inner cavity of the static main contact into the inner cavity of the static support.

[0008] Beneficial effects: the static main contact is arranged in the form of a cylinder with cylinder openings at both ends, and an intermediate beam which spans the rear cylinder opening is arranged at the rear cylinder opening which communicates with the static support, so that the through hole for the static arc contact can be arranged by using the intermediate beam, the intermediate beam replaces the cylinder bottom as the carrier for supporting the static arc contact, the area of the rear cylinder opening occupied by the intermediate beam is limited, so that the intermediate beam can enclose an airflow through hole with a larger opening area with the inner wall of the rear cylinder opening of the static main contact, and the portions of the rear cylinder opening located on both sides of the intermediate beam can form airflow through holes, the static main contact and the static support have a larger conduction area, and the smoothness of the static side airflow exhaust passage is improved, which is conducive to ensuring the breaking performance of the circuit breaker.

[0009] Further, the front end of the static support is connected to the rear end of the static main contact, the rear end of the static support is provided with a gas guide cone, the conical part of the gas guide cone extends into the inner cavity of the static support, and the tip of the conical part faces forward and corresponds to the front-rear of the intermediate beam.

[0010] Beneficial effects: the gas guide cone is arranged to guide the hot airflow entering the inner cavity of the static support, which is conducive to the smooth flow of the gas.

[0011] Further, two flow ports are arranged on the outer circumferential surface of the rear end of the static support, the two flow ports are symmetrically arranged on the left and right sides relative to the central axis, and the flow ports correspond to the conical part of the gas guide cone to allow the hot airflow to flow out of the inner cavity of the static support.

[0012] Beneficial effects: based on the two airflow through holes which are symmetrically arranged on the left and right sides, the two flow ports on the static support are also symmetrically arranged on the left and right sides, which is conducive to the flow of the gas.

[0013] Further, a metal pressing plate is arranged on the rear side of the gas guide cone, a support surface facing the rear is arranged on the static support, a fixing part is arranged at the rear end of the gas guide cone, and the metal pressing plate is fixedly connected to the static support to press the fixing part of the gas guide cone against the support surface.

[0014] Beneficial effect: By setting a metal pressure plate to press and fix the air guide cone on the static support, the stability of the installation is not affected by the softness of the air guide cone material.

[0015] Furthermore, a radially penetrating flow port is provided on the outer peripheral surface of the stationary support, and an inner guide shroud is fitted around the periphery of the stationary support. The inner guide shroud extends in the front-to-back direction and covers the flow port. The heated airflow from the flow port flows into the inner guide shroud from the inner cavity of the stationary support. The rear end of the inner guide shroud is fixed to the stationary support, and a forward-facing inner passage is formed between the front end of the inner guide shroud and the outer peripheral surface of the stationary support. The heated airflow from the inner passage flows out from the inner guide shroud.

[0016] Beneficial effect: By setting an inner flow guide, the hot airflow can be guided to flow from back to front, which helps to remove the heat from the static support.

[0017] Furthermore, an outer guide shroud is fitted around the front end of the stationary support. The front end of the outer guide shroud is fixed to the stationary support. The front end of the inner guide shroud extends into the annular gap between the outer guide shroud and the outer peripheral surface of the stationary support so that the heated airflow enters the outer guide shroud through the inner through-hole. A rearward outer through-hole is formed between the rear end of the outer guide shroud and the outer peripheral surface of the inner guide shroud. The heated airflow flows out from the outer guide shroud through the outer through-hole.

[0018] Beneficial effect: The inner and outer guide shields work together to create a turning point in the airflow, preventing contaminated gas from being blown between the moving and stationary contacts after the circuit breaker is opened, thus affecting the insulation.

[0019] Furthermore, the gap between the inner circumferential surface of the outer fairing and the outer circumferential surface of the inner fairing is greater than the gap between the inner circumferential surface of the inner fairing and the outer circumferential surface of the static support.

[0020] Beneficial effects: It can gradually increase the flow area of ​​the exhaust channel, which is conducive to smooth exhaust.

[0021] Furthermore, the rear end of the inner guide shield is fixed to the static support by a bolt connection structure, and the static support is provided with a shielding structure for shielding the bolt connection structure.

[0022] Beneficial effects: The inner guide shield is bolted to the static support, which facilitates the connection operation. At the same time, the shielding structure shields the bolted connection, optimizing the electric field distribution.

[0023] Furthermore, a stationary main contact finger is circumferentially installed on the inner wall of the front end of the stationary main contact, and a shielding cover is provided at the front opening of the stationary main contact. The shielding cover is fitted onto the front end of the stationary main contact and has an inwardly turned edge that extends into the front opening of the stationary main contact. The inwardly turned edge is opposite to the stationary main contact finger.

[0024] Beneficial effects: A shielding cover is fitted on the front end of the stationary main contact, and the inward folding edge of the shielding cover surrounds the front side of each stationary main contact finger, thereby achieving a shielding effect and optimizing the electric field distribution.

[0025] The technical scheme of the circuit breaker of the present application is:

[0026] A circuit breaker comprises a housing and a static side structure arranged in the housing, the static side structure comprising a static main contact, a static arc contact and a static support, the static main contact and the static support are both in the form of a cylinder and coaxially arranged relative to a central axis, the static arc contact is arranged in the inner cavity of the static main contact, the central axis extends in the front-rear direction, the front-rear ends of the static main contact are respectively provided with a front cylinder opening and a rear cylinder opening, the rear cylinder opening faces the static support, the rear end of the static main contact is provided with an intermediate beam which spans the rear cylinder opening, the intermediate beam extends in the radial direction of the static main contact and its two ends are connected to the inner wall of the cylinder of the static main contact, the intermediate beam is provided with a through hole for the static arc contact to pass through, the intermediate beam and the inner wall of the cylinder of the static main contact enclose an airflow passing hole, the intermediate beam is in the form of a straight line, the airflow passing hole is in the form of an arc-shaped hole, there are two airflow passing holes which are symmetrically arranged on the left and right sides of the intermediate beam, and the airflow passing hole is for the hot airflow generated by the breaking point of the circuit breaker to flow from the inner cavity of the static main contact into the inner cavity of the static support.

[0027] Beneficial effects: The static main contact is arranged in the form of a cylinder with cylinder openings at both ends, and an intermediate beam which spans the rear cylinder opening is arranged at the rear cylinder opening which communicates with the static support, so that the through hole for the static arc contact to pass through can be arranged by using the intermediate beam, and the intermediate beam replaces the bottom of the cylinder as the carrier for supporting the static arc contact, the area of the rear cylinder opening occupied by the intermediate beam is limited, so that the intermediate beam can enclose an airflow passing hole with a larger opening area with the inner wall of the rear cylinder opening of the static main contact, and the portions of the rear cylinder opening located on both sides of the intermediate beam can form airflow passing holes, the static main contact and the static support have a larger conduction area between the inner cavities thereof, the smoothness of the static side airflow exhaust passage is improved, and the breaking performance of the circuit breaker is ensured.

[0028] Further, the front end of the static support is connected to the rear end of the static main contact, the rear end of the static support is provided with a gas guide cone, the conical part of the gas guide cone extends into the inner cavity of the static support, and the tip of the conical part faces forward and corresponds to the front-rear of the intermediate beam.

[0029] Beneficial effects: The gas guide cone is arranged to guide the hot airflow entering the inner cavity of the static support, which is beneficial to the smooth flow of the gas.

[0030] Further, two flow passages are arranged on the outer circumferential surface of the rear end of the static support, the two flow passages are symmetrically arranged on the left and right sides relative to the central axis, and the flow passages correspond to the conical part of the gas guide cone to allow the hot airflow to flow out of the inner cavity of the static support.

[0031] Beneficial effects: Based on the two airflow passing holes which are symmetrically arranged on the left and right sides, the two flow passages on the static support are also symmetrically arranged on the left and right sides, which is beneficial to the flow of the gas.

[0032] Further, the rear side of the air guide cone is provided with a metal pressing plate, the static support is provided with a rear supporting surface, the rear end of the air guide cone is provided with a fixing part, and the metal pressing plate is fixedly connected with the static support to press the fixing part of the air guide cone on the supporting surface.

[0033] Beneficial effects: The air guide cone is pressed and fixed on the static support through the metal pressing plate, so that the stability of installation is not affected by the soft material of the air guide cone.

[0034] Further, the outer circumferential surface of the static support is provided with a radial through-flow port, the static support is provided with an inner flow guide cover, the inner flow guide cover extends along the front-rear direction and covers the through-flow port, the through-flow port is used for the hot gas flow to flow from the inner cavity of the static support into the inner flow guide cover, the rear end of the inner flow guide cover is fixed with the static support, and an inner through port is formed between the front end of the inner flow guide cover and the outer circumferential surface of the static support, and the inner through port is used for the hot gas flow to flow out of the inner flow guide cover.

[0035] Beneficial effects: The inner flow guide cover can guide the hot gas flow to flow from the rear to the front, and is beneficial to taking away the heat on the static support.

[0036] Further, the outer circumferential surface of the front end of the static support is provided with an outer flow guide cover, the front end of the outer flow guide cover is fixed with the static support, the front end of the inner flow guide cover extends into the annular gap between the outer circumferential surface of the static support and the outer flow guide cover, so that the hot gas flow enters the outer flow guide cover through the inner through port, and the rear end of the outer flow guide cover and the outer circumferential surface of the inner flow guide cover form an outer through port facing the rear, and the outer through port is used for the hot gas flow to flow out of the outer flow guide cover.

[0037] Beneficial effects: The inner flow guide cover and the outer flow guide cover cooperate to make the gas flow form a turn, so that after the circuit breaker is opened, the contaminated gas is prevented from being blown to the moving and static contacts again to affect the insulation.

[0038] Further, the gap between the inner circumferential surface of the outer flow guide cover and the outer circumferential surface of the inner flow guide cover is greater than the gap between the inner circumferential surface of the inner flow guide cover and the outer circumferential surface of the static support.

[0039] Beneficial effects: The flow area of the exhaust passage is gradually increased, which is beneficial to smooth exhaust.

[0040] Further, the rear end of the inner flow guide cover is fixed with the static support through a bolt connection structure, and the static support is provided with a shielding structure for shielding the bolt connection structure.

[0041] Beneficial effects: The inner flow guide cover is connected with the static support through bolts, which is convenient for connection operation, and meanwhile, the bolt connection part is shielded through the shielding structure, so that the electric field distribution is optimized.

[0042] Further, the inner wall of the front end of the static main contact is circumferentially provided with a static main contact finger, and the front tube opening of the static main contact is provided with a shielding cover, the shielding cover is sleeved on the front end of the static main contact, and the shielding cover has an inward turning edge extending into the front tube opening of the static main contact, and the inward turning edge is opposite to the static main contact finger in the front-rear direction.

[0043] Beneficial effects: the shielding cover is sleeved on the front end of the static main contact, and the inward turning edge of the shielding cover surrounds the front side of each static main contact finger, so that the shielding effect is achieved, and the electric field distribution is optimized. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a schematic view of the static end structure of the circuit breaker of the application.

[0045] Figure 2 It is a schematic view of the structure of the rear tube opening of the static main contact in Figure 1

[0046] In the figure: 1, static support; 2, pressing plate; 3, gas guide cone; 4, inner flow guide cover; 5, outer flow guide cover; 6, static main contact; 61, gas flow hole; 62, through hole; 63, middle beam; 7, static arc contact; 8, shielding cover; 9, spring; 10, static main contact finger. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and are not used to limit the application, that is, the described examples are only a part of the examples of the application, but not all the examples. The components of the application embodiments described and shown in the drawings herein can be arranged and designed in various different configurations.

[0048] Therefore, the detailed description of the embodiments of the application provided in the drawings below is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0049] ​It should be noted that the terms "first", "second" and the like, which can appear in the description of specific embodiments of the present application, are used to distinguish one entity or action from another, but do not necessarily require or imply these entities or actions to be present in any actual relationship or order. Moreover, the terms "include", "contain" or any other variants thereof appearing in the description are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the elements defined by the appearing statements "include a" and the like do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0050] In the description of the present application, unless otherwise explicitly specified and limited, the appearing terms "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the description of the present application, unless otherwise explicitly specified and limited, the appearing term "provided with" should be understood broadly, for example, the object "provided with" can be part of the body, or it can be arranged separately from the body and connected to the body, and the connection can be detachable or non-detachable. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] The present application will be further described in detail below in combination with embodiments.

[0053] Embodiment 1 of the static end structure of the circuit breaker of the present application:

[0054] As Figure 1 , Figure 2As shown, the stationary end structure of the circuit breaker includes a stationary main contact 6, a stationary arc contact 7, a stationary support 1, a vent cone 3, an inner guide shroud 4, and an outer guide shroud 5. The stationary main contact 6, stationary support 1, and vent cone 3 are coaxially arranged relative to the central axis, which extends in the front-to-back direction. The stationary arc contact 7 is located on the central axis. Both the stationary main contact 6 and the stationary support 1 are cylindrical structures and have internal cavities. The internal cavity of the stationary main contact 6 communicates with the internal cavity of the stationary support 1. The stationary arc contact 7 passes through the stationary main contact 6. Inside the cavity, the inner guide shroud 4 and the outer guide shroud 5 are fitted around the periphery of the stationary support 1, with the inner guide shroud 4 located inside the outer guide shroud 5. The front end of the stationary arc contact 7 faces the nozzle between the moving and stationary contacts of the circuit breaker. The hot airflow generated by the arc at the break enters the inner cavity of the stationary main contact 6, flows backward into the inner cavity of the stationary support 1, is guided by the air guide cone 3, flows out from the inner cavity of the stationary support 1 and into the inner guide shroud 4, then into the outer guide shroud 5, and finally is discharged into the housing of the circuit breaker.

[0055] The stationary main contact 6 is cylindrical, with a front opening and a rear opening at its front and rear ends, respectively. The rear opening faces the stationary support 1. A central beam 63 spans the rear opening at the rear end of the stationary main contact 6. The central beam 63 extends radially along the stationary main contact 6 and its two ends connect to the inner wall of the cylinder of the stationary main contact 6. The inner wall of the cylinder of the stationary main contact 6 is the circumferential sidewall where the inner circumferential surface of the stationary main contact 6 is located. The central beam 63 is a straight structure located in the middle of the rear opening. The axis of the central beam 63 extends vertically and intersects the central axis. The central beam 63 and the inner wall of the cylinder of the stationary main contact 6 form an airflow passage 61. The airflow passage 61 allows the hot airflow generated by the circuit breaker's break to flow from the inner cavity of the stationary main contact 6 into the inner cavity of the stationary support 1. Since the intermediate beam 63 spans the middle of the rear cylinder opening, the vertically extending intermediate beam 63 divides the rear cylinder opening into left and right parts, thus forming two airflow passages 61. The two airflow passages 61 are symmetrically arranged on the left and right sides of the intermediate beam 63. Furthermore, the airflow passages 61 are arc-shaped holes. The arc-shaped holes symmetrically distributed on both sides of the intermediate beam 63 can make full use of the opening area of ​​the rear cylinder opening and effectively facilitate the diffusion of airflow.

[0056] The intermediate beam 63 is provided with a through hole 62 for the static arc contact 7 to pass through. The through hole 62 is located in the middle of the intermediate beam 63 in the vertical direction. The static arc contact 7 extends in the front-back direction, and the rear end of the static arc contact 7 passes through the through hole 62. The width of the intermediate beam 63 in the left-right direction meets the requirements of the through hole 62 and is slightly larger than the diameter of the through hole 62 to ensure maximum utilization of the open rear cylinder opening.

[0057] The inner cavity of the static support 1 extends in the front-rear direction, the static support 1 has a front opening and a rear opening, the front end of the static support 1 is connected to the rear end of the static main contact 6, and the front opening of the static support 1 is communicated with the inner cavity of the static main contact 6 through the airflow through hole 61. The rear end of the static support 1 is provided with the gas guide cone 3, the gas guide cone 3 is blocked at the rear opening of the static support 1, the gas guide cone 3 includes a fixed part and a conical part, the conical part is located at the front side of the fixed part, the conical part of the gas guide cone 3 extends into the inner cavity of the static support 1, the conical part is a rotary body with the central axis as the rotary axis, the tip of the conical part faces forward and corresponds to the front-rear direction of the through hole 62 on the intermediate beam 63, which is conducive to guiding the airflow.

[0058] The material of the gas guide cone 3 is a high-temperature-resistant ablation material, and in this embodiment, polytetrafluoroethylene is used, and the processing process can be machining from a polytetrafluoroethylene rod or pressing from polytetrafluoroethylene powder.

[0059] The rear end of the fixed part of the gas guide cone 3 is provided with a flange, the flange is provided with a flange hole, the edge of the rear opening of the static support 1 is provided with a threaded hole, the rear side of the gas guide cone 3 is provided with a metal pressing plate 2, the metal pressing plate 2 is provided with a bolt hole, and the bolt is sequentially threaded through the bolt hole on the metal pressing plate 2, the flange hole on the gas guide cone 3, and is screwed into the threaded hole at the edge of the rear opening of the static support 1, so that the metal pressing plate 2 is fixedly connected with the static support 1, and the fixed part of the gas guide cone 3 is pressed tightly on the rear end face of the static support 1, and the part of the rear end face of the static support 1 around the rear opening constitutes a rear support surface on the static support 1. Because the material of the gas guide cone 3 is soft, it is not easy to meet the requirement of pre-tightening force when directly fastened with a bolt, so a metal pressing plate 2 made of metal material is used for transition, the gas guide cone 3 is pressed and fixed on the static support 1 through the metal pressing plate 2, the pre-tightening force of the bolt is ensured, and the stability of the installation is avoided.

[0060] The inner flow guide cover 4 extends in the front-rear direction, the rear end of the inner flow guide cover 4 is provided with an outward turning edge, the rear end of the static support 1 is provided with an annular boss, the outer edge of the annular boss is provided with a front annular shielding protrusion protruding forward, the annular boss has a front side, the outward turning edge of the rear end of the inner flow guide cover 4 abuts on the front side of the annular boss and is located inside the front annular shielding protrusion, and the outward turning edge of the rear end of the inner flow guide cover 4 is fixed on the front side of the annular boss through a bolt, the front annular shielding protrusion constitutes a shielding structure, the front annular shielding protrusion protrudes forward from the head of the bolt to shield the inside bolt connection part, and the electric field distribution is optimized. The outer edge of the annular boss is provided with a rear annular shielding protrusion protruding backward, the metal pressing plate 2 is located in the groove surrounded by the rear annular shielding protrusion, and the rear annular shielding protrusion is used to shield the bolt connection structure of the metal pressing plate 2, the gas guide cone 3 and the static support 1, so as to optimize the electric field distribution.

[0061] The outer circumferential surface of the static support 1 is provided with two radial through-flow openings, which are long holes formed in the rear end of the static support 1 and symmetrically arranged about the central axis. The inner flow cover 4 covers the through-flow openings, and the through-flow openings correspond to the conical part of the gas guide cone 3 in position to allow the hot gas flow to flow from the inner cavity of the static support 1 to the inner flow cover 4. The front end of the inner flow cover 4 and the outer circumferential surface of the static support 1 form a forward inner through-flow opening, which allows the hot gas flow to flow out of the inner flow cover 4.

[0062] The outer flow cover 5 is sleeved on the front end of the static support 1 and has a cylindrical structure with the barrel mouth facing backward. The barrel bottom of the outer flow cover 5 is provided with a sleeving opening, and the sleeving opening is provided with a forwardly extending annular turning edge. The annular turning edge is in contact with the outer circumferential surface of the static support 1 and is fixedly connected by bolts. The bolts used here are round head bolts to optimize the electric field distribution. One end of the annular turning edge of the outer flow cover 5 is the front end thereof.

[0063] The front end of the inner flow cover 4 extends into the annular gap between the inner circumferential surface of the outer flow cover 5 and the outer circumferential surface of the static support 1 through the backward barrel mouth of the outer flow cover 5 to allow the hot gas flow to enter the outer flow cover 5 through the inner through-flow opening. One end of the barrel mouth of the outer flow cover 5 is the rear end thereof, and the rear end of the outer flow cover 5 and the outer circumferential surface of the inner flow cover 4 form a backward outer through-flow opening, which allows the hot gas flow to flow out of the outer flow cover 5. The inner flow cover 4 cooperates with the outer flow cover 5, and the hot gas flow flows from back to front in the inner flow cover 4 and then flows from front to back in the outer flow cover 5, so that the gas flow forms a turn, preventing the contaminated gas from being blown to the moving and static contacts in front of the circuit breaker after the circuit breaker is opened, which affects the insulation. The moving and static contacts are the weak link of the insulation structure.

[0064] The cross-sectional area of the annular gap between the inner circumferential surface of the inner flow cover 4 and the outer circumferential surface of the static support 1 is greater than the area of the two through-flow openings, and the gap between the inner circumferential surface of the outer flow cover 5 and the outer circumferential surface of the inner flow cover 4 is greater than the gap between the inner circumferential surface of the inner flow cover 4 and the outer circumferential surface of the static support 1, so that the flow area of the exhaust passage gradually increases, which is beneficial to smooth exhaust.

[0065] The inner wall surface of the front end of the static main contact 6 is a stepped surface, the stepped surface has a forward annular surface, the annular surface is provided with a contact finger slot, the static main contact 6 is provided with static main contact fingers 10 at the front end, the static main contact fingers 10 are a plurality of and are uniformly distributed in the circumferential direction, and rear ends of the static main contact fingers 10 are inserted into the contact finger slot. The static main contact 6 is provided with a shielding cover 8 at the front barrel port, the shielding cover 8 is sleeved on the outer circumferential surface of the front end of the static main contact 6, the shielding cover 8 is fixedly connected with the static support 1 through bolts, the front end of the shielding cover 8 is provided with an inward turning edge extending into the front barrel port of the static main contact 6, the inward turning edge is opposite to the static main contact fingers 10 in the front-rear direction, a limiting slot is arranged on the rear side surface of the inward turning edge, and the front end of the static main contact finger 10 is inserted into the limiting slot. Through the contact finger slot on the static support and the limiting slot on the shielding cover 8, the limiting installation of the static main contact finger 10 is realized, and two springs 9 are arranged between each static main contact finger 10 and the inner wall of the static support 1 in the front-rear direction, one end of the spring 9 is pressed against the inner wall of the static support 1, and the other end of the spring 9 is pressed against the static main contact finger 10. The inward turning edge of the shielding cover 8 surrounds the front side of each static main contact finger 10 and plays a shielding role on the periphery of the static main contact finger 10, so that the electric field distribution is effectively optimized.

[0066] In the process of breaking the large-capacity short-circuit current by the circuit breaker, after the static arc contact 7 is separated from the throat of the nozzle, the high-temperature, high-speed and high-pressure gas flow is blown to the static side from the nozzle, and the gas flow path of the static side is as follows: static main contact inner cavity→gas flow hole 61→static support inner cavity→gas guide cone 3→flow port→inner gas guide cover 4→outer gas guide cover 5→housing, and the path also forms a static side gas flow exhaust channel.

[0067] Since the intermediate beam 63 across the rear barrel port of the static main contact 6 is used for the static arc contact 7 to pass through and install, the area of the rear barrel port occupied by the intermediate beam 63 is limited, so that the intermediate beam 63 can surround the static main contact inner wall to form a gas flow hole 61 with a large opening area, and the portions of the rear barrel port located on both sides of the intermediate beam 63 can also form the gas flow hole 61, the static main contact inner cavity and the static support 1 inner cavity have a large conduction area, the smoothness of the static side gas flow exhaust channel is improved, the breaking performance of the circuit breaker is ensured, and the electrical reliability of the circuit breaker is enhanced. Moreover, the long inner gas guide cover can effectively cool the high-temperature gas before the high-temperature gas enters the housing area, so that the temperature of the exhaust gas is prevented from being too high. The circuit breaker is suitable for high-voltage circuit breakers of various voltage levels, especially circuit breakers with high rated short-circuit breaking current and long time constant.

[0068] Embodiment 2 of the static end structure of the circuit breaker of the present application:

[0069] The difference between the embodiment and the embodiment 1 is that in the embodiment 1, the outer edge of the annular boss is provided with a forward annular shielding protrusion protruding forward, the forward annular shielding protrusion is used for shielding the bolt connection structure between the inner shielding cover and the static support, and the forward annular shielding protrusion constitutes the shielding structure. In the embodiment, the shielding cover is mounted on the static support and surrounds the bolt connection structure, and the shielding cover constitutes the shielding structure for shielding the bolt connection structure.

[0070] Embodiment 3 of the static end structure of the circuit breaker of the application:

[0071] The difference between the embodiment and the embodiment 1 is that in the embodiment 1, the outer edge of the annular boss is provided with a forward annular shielding protrusion protruding forward, the forward annular shielding protrusion is used for shielding the bolt connection structure between the inner shielding cover and the static support, and the forward annular shielding protrusion constitutes the shielding structure. In the embodiment, the shielding cover is mounted on the static support and surrounds the bolt connection structure, and the shielding cover constitutes the shielding structure for shielding the bolt connection structure.

[0072] Embodiment of the circuit breaker of the application:

[0073] The circuit breaker comprises a shell and a static end structure arranged in the shell, the static end structure in the embodiment is the same as the static end structure of the circuit breaker described in any one of the embodiments 1-3 of the static end structure of the circuit breaker, and details are not repeated here.

[0074] Finally, it should be noted that the above only describes the preferred embodiments of the application, and is not used to limit the application, although the application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions described in the foregoing embodiments can be modified without creative labor, or some technical features can be replaced equivalently. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A stationary end structure of a circuit breaker, comprising a stationary main contact (6), a stationary arc contact (7), and a stationary support (1), wherein the stationary main contact (6) and the stationary support (1) are both cylindrical structures and are coaxially arranged relative to the central axis, the stationary arc contact (7) is inserted into the inner cavity of the stationary main contact (6), and the central axis extends in the front-rear direction, characterized in that, The stationary main contact (6) has a front cylinder opening and a rear cylinder opening at its front and rear ends, respectively. The rear cylinder opening faces the stationary support (1). The rear end of the stationary main contact (6) has a middle beam (63) that spans the rear cylinder opening. The middle beam (63) extends radially along the stationary main contact (6) and its two ends are connected to the inner wall of the cylinder of the stationary main contact (6). The middle beam (63) has a through hole (62) for the stationary arc contact (7) to pass through. The middle beam (63) and the inner wall of the cylinder of the stationary main contact (6) form an airflow passage (61). The middle beam (63) is a straight structure. The airflow passage (61) is an arc-shaped hole. There are two airflow passages (61), which are symmetrically arranged on the left and right sides of the middle beam (63). The airflow passage (61) allows the hot airflow generated by the circuit breaker's break to flow from the inner cavity of the stationary main contact (6) into the stationary support (1). The inner cavity of the static support; a radially penetrating flow port is provided on the outer peripheral surface of the static support; an inner guide shroud (4) is fitted around the periphery of the static support, the inner guide shroud extends in the front-back direction and covers the flow port, the heat supply airflow from the inner cavity of the static support flows into the inner guide shroud; the rear end of the inner guide shroud is fixed to the static support, and a forward-facing inner passage is formed between the front end and the outer peripheral surface of the static support, the heat supply airflow from the inner passage flows out of the inner guide shroud; an outer guide shroud (5) is fitted around the front end of the static support, the front end of the outer guide shroud is fixed to the static support, the front end of the inner guide shroud extends into the annular gap between the outer guide shroud and the outer peripheral surface of the static support so that the heat supply airflow enters the outer guide shroud through the inner passage, the rear end of the outer guide shroud and the outer peripheral surface of the inner guide shroud form a rearward-facing outer passage, the heat supply airflow from the outer passage flows out of the outer guide shroud.

2. The stationary end structure of the circuit breaker according to claim 1, characterized in that, The front end of the stationary support (1) is connected to the rear end of the stationary main contact (6). The rear end of the stationary support (1) is provided with a guide cone (3). The conical part of the guide cone (3) extends into the inner cavity of the stationary support (1). The tip of the conical part faces forward and corresponds to the front and rear of the intermediate beam (63).

3. The stationary end structure of the circuit breaker according to claim 2, characterized in that, There are two flow ports, which are arranged symmetrically about the central axis. The flow ports correspond to the conical part of the air guide cone (3) so that the heated airflow can flow out from the inner cavity of the static support (1).

4. The stationary end structure of the circuit breaker according to claim 2, characterized in that, A metal pressure plate (2) is provided on the rear side of the air guide cone (3), and a rearward support surface is provided on the static support (1). A fixing part is provided at the rear end of the air guide cone (3). The metal pressure plate (2) is fixedly connected to the static support (1) to press the fixing part of the air guide cone (3) onto the support surface.

5. The stationary end structure of the circuit breaker according to claim 1, characterized in that, The gap between the inner circumferential surface of the outer shroud (5) and the outer circumferential surface of the inner shroud (4) is greater than the gap between the inner circumferential surface of the inner shroud (4) and the outer circumferential surface of the static support (1).

6. The stationary end structure of the circuit breaker according to claim 1, characterized in that, internal The rear end of the fairing (4) is fixed to the stationary support (1) by a bolt connection structure. The stationary support (1) is provided with a shielding structure for shielding the bolt connection structure.

7. The stationary end structure of the circuit breaker according to any one of claims 1-4, characterized in that, A stationary main contact finger (10) is installed circumferentially on the inner wall of the cylinder at the front end of the stationary main contact (6). A shield (8) is provided at the front opening of the stationary main contact (6). The shield (8) is fitted onto the front end of the stationary main contact (6). The shield (8) has an inwardly turned edge that extends into the front opening of the stationary main contact (6). The inwardly turned edge is opposite to the stationary main contact finger (10).

8. A circuit breaker, comprising a housing and a stationary terminal structure disposed within the housing, characterized in that, The stationary end structure is the stationary end structure of the circuit breaker as described in any one of claims 1-7.

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