An arc extinguishing device

Abstract

The application discloses an arc extinguishing device and relates to the technical field of switch electric appliances. The device comprises an insulating shell, a static contact, a dynamic contact and a magnetic adsorption assembly, and further comprises at least one insulating rotor which is installed on an arc movement path through a high-temperature-resistant bearing, and the rotating axis of the rotor is perpendicular to the movement direction of the dynamic contact. A spiral arc guiding groove is arranged on the outer circumferential wall of the rotor. The rotor is integrally made of a high-temperature-resistant gas generating material, and the moment of inertia of the rotor is configured to be sufficient to drive the rotation of the rotor when the arc heat flux density is greater than a preset threshold value, so that the recoil gas flow generated by the surface gasification of the rotor is sufficient to drive the rotation of the rotor, and the arc is forced to be guided into the spiral groove to be cut and cooled. Preferably, the arc guiding groove is a trapezoidal contraction channel. A micropore-equipped shielding cover is arranged outside the bearing. The magnetic adsorption assembly can adopt multiple permanent magnets to form an alternating magnetic field. Double rotors, an exhaust channel, a ceramic coating and a magnetic shielding sheet can also be arranged. The application realizes the active utilization and dynamic cutting of arc energy, and has high arc extinguishing efficiency, fast response and long service life.

Description

Technical Field

[0001] This invention relates to the field of switching electrical equipment technology, specifically to an arc extinguishing device. Background Technology

[0002] Arc extinguishing devices are key components used to quickly extinguish the electric arc generated when switching electrical appliances break circuits. Their performance directly determines the breaking capacity, electrical life, and operational reliability of electrical equipment. In the field of low-voltage electrical appliances, such as circuit breakers and contactors, high-temperature, high-energy electric arcs are generated the instant the contacts separate. If these arcs are not extinguished in time, they will cause contact burnout or even electrical fires.

[0003] Currently, commonly used arc-extinguishing technologies in the industry can be mainly divided into the following categories: The first category is electromagnetic arc-extinguishing devices, which generate a magnetic field through permanent magnets or electromagnetic coils to drive the arc into the arc-extinguishing chamber, using the Lorentz force to lengthen the arc to extinguish it. However, under high-current conditions, these devices are prone to insufficient arc-driving force due to magnetic field saturation, and for DC systems, the lack of a current zero-crossing point significantly increases the difficulty of arc extinguishing. The second category is grid-plate arc-extinguishing devices, which use ferromagnetic grid plates to divide a long arc into multiple short arc segments, using the near-cathode effect or dielectric strength recovery to extinguish the arc. However, existing grid plate structures are mostly fixed, and the arc's movement path between the grid plates is singular. When high current is interrupted, arc stagnation or grid plate melting can easily occur, and the effect on removing residual arc and free metal particles is limited. The third category is gas-generating material arc-extinguishing devices, which use the high temperature of the arc to decompose and vaporize the gas-generating material, generating a high-pressure airflow to blow away the arc. However, traditional gas-generating arc extinguishing methods are mostly passive arc blowing, with a large degree of randomness in airflow direction, making it difficult to achieve precise control of the electric arc, and causing severe material ablation, which affects the lifespan of the device.

[0004] To address the aforementioned issues, existing technologies disclose an arc-extinguishing rotor with helical grooves. These grooves, created on an insulated rotor, attempt to guide the arc along the grooves to increase the arc path. However, this prior art does not disclose a mechanism where the rotor is made of a gas-generating material and its rotation is driven by its own vaporization. Therefore, the rotor's rotation still relies on the continuous action of an external magnetic field, making it difficult to achieve a rapid, autonomous response to fluctuations in arc energy.

[0005] Therefore, how to realize the active utilization and rapid response of arc energy by the arc extinguishing structure, and to achieve multi-physics field coordinated dynamic cutting of the arc, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an arc-extinguishing device to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An arc-extinguishing device, comprising: An insulating shell, with a sealed arc-extinguishing chamber formed inside; The stationary contact and the moving contact are disposed opposite to each other in the arc-extinguishing chamber; A magnetic adsorption component is disposed on the inner wall of the arc extinguishing chamber to generate a non-uniform magnetic field to pull the electric arc. Its characteristic is that it further includes: At least one insulated rotor is rotatably mounted on the arc movement path between the stationary contact and the moving contact via a high-temperature bearing, and the rotation axis of the insulated rotor is perpendicular to the movement direction of the moving contact. At least one spiral arc-inducing groove is provided axially on the outer peripheral wall of the insulated rotor. The insulated rotor is made of a high-temperature resistant gas-generating material, and its rotational inertia is configured such that when the arc heat flux density is greater than a preset threshold, the backflow airflow generated by the local vaporization on the surface of the insulated rotor is sufficient to drive the insulated rotor to start rotating from a stationary state, so that the arc is forcibly introduced into the spiral arc-initiating groove, and is spun and cooled under the combined action of rotational centrifugal force and groove wall compression.

[0008] Furthermore, the spiral arc-initiating groove's depth gradually decreases from the opening to the bottom, forming a trapezoidal constriction channel to compress and elongate the arc entering the groove. This invention further enhances the compression and elongation effect on the arc by setting the spiral arc-initiating groove as a trapezoidal constriction channel with a depth gradually decreasing from the opening to the bottom. When the arc enters the spiral groove, as the groove depth decreases, the arc experiences gradually increasing radial compression, the arc cross-section is compressed, the arc resistance increases, and heating intensifies, further promoting the dissipation of arc energy. Simultaneously, the trapezoidal cross-section design causes the arc to be continuously elongated during movement, and the arc voltage continuously increases. When the voltage exceeds the power supply's sustaining voltage, the arc naturally extinguishes. This constriction channel structure, combined with the rotor's rotational motion, creates a dual effect on the arc—both elongating the arc through rotation and further compressing it through constriction, significantly improving arc-extinguishing efficiency.

[0009] Furthermore, a shield to prevent metal vapor condensation is provided on the outer side of the high-temperature bearing. This shield is made of high-temperature resistant insulating material and has a small pressure relief hole communicating with the bearing gap. The diameter of the pressure relief hole is less than 0.5 mm, used to release metal vapor pressure while preventing electric arc from entering. This invention effectively solves the industry problem of bearings easily getting stuck due to metal vapor condensation in existing arc extinguishing devices by providing a shield to prevent metal vapor condensation on the outer side of the high-temperature bearing and opening a small pressure relief hole. During electric arc combustion, a large amount of high-temperature metal vapor is generated. If this vapor enters the bearing gap, it will condense and cause the bearing to seize, preventing the rotor from rotating and rendering the arc extinguishing function ineffective. This solution uses a shield to prevent metal vapor from directly impacting the bearing, while simultaneously releasing the vapor pressure in the bearing area through a small pressure relief hole with a diameter of less than 0.5 mm. Experiments have shown that a diameter of less than 0.5 mm can utilize the near-cathode effect of the electric arc to inhibit the spread of the arc to the bearing gap, ensuring pressure release while preventing electric arc entry, significantly improving the operational reliability and service life of the device.

[0010] Furthermore, the magnetic adsorption assembly includes at least one pair of permanent magnets, which are respectively embedded in the side walls of the arc-extinguishing chamber opposite to the insulated rotor, and the magnetic poles of the pair of permanent magnets are arranged in opposite directions to form a transverse magnetic field around the insulated rotor. This invention effectively enhances the traction capability of the magnetic adsorption assembly for the electric arc by embedding a pair of permanent magnets with opposite magnetic poles into the side walls of the arc-extinguishing chamber opposite to the insulated rotor, forming a transverse magnetic field around the rotor. The direction of this transverse magnetic field matches the direction of arc movement, making it easier for the arc to be driven to the arc-extinguishing area near the rotor under the action of the Lorentz force. At the same time, the arrangement of the permanent magnets embedded in the side walls avoids occupying internal space of the arc-extinguishing chamber, leaving sufficient space for the rotational movement of the rotor, resulting in a compact structure and reasonable layout. Compared with traditional electromagnetic coil solutions, permanent magnets do not require external power supply, have a simple structure, high reliability, and do not have magnetic field saturation problems, making them particularly suitable for high-current applications.

[0011] Furthermore, the permanent magnets are multiple and arranged sequentially along the axial direction of the insulated rotor, with the magnetic field directions of adjacent permanent magnets alternating to form a multi-segment alternating magnetic field region on the surface of the insulated rotor. This invention forms a multi-segment alternating magnetic field region on the rotor surface by arranging multiple permanent magnets sequentially along the axial direction of the insulated rotor and alternating the magnetic field directions of adjacent permanent magnets. This magnetic field layout has the following significant effects: First, the alternating magnetic field causes the arc to be continuously subjected to a Lorentz force with changing direction as it moves along the axial direction, repeatedly stretching and twisting the arc, further increasing the arc path length and arc voltage; second, the multi-segment magnetic field region, combined with the spiral arc-initiating groove, makes it easier for the arc to be guided into the groove and move stably along it; third, the oscillation effect of the alternating magnetic field on the arc helps to disrupt the stable combustion state of the arc and accelerate its extinction.

[0012] Furthermore, there are two insulated rotors, namely a first rotor and a second rotor, which are arranged parallel and spaced apart. The spiral arc-initiating grooves on the first rotor are left-handed, and the spiral arc-initiating grooves on the second rotor are right-handed. The magnetic field generated by the permanent magnets on both sides of the first rotor is opposite in direction to the magnetic field generated by the permanent magnets on both sides of the second rotor, so that the two rotors form opposite rotational directions under the action of the electric arc, which is used to bidirectionally stretch and cut the electric arc between the two rotors. This invention achieves bidirectional stretching and cutting of the electric arc by setting two parallel and spaced insulated rotors, and respectively configuring left-handed and right-handed spiral arc-initiating grooves and opposite magnetic field directions, so that the two rotors form opposite rotational directions under the action of the electric arc. This technical solution has the following significant advantages: First, the two rotors rotating in opposite directions simultaneously apply force to the electric arc, which is stretched in both directions at the same time, resulting in a faster increase in arc voltage; second, the electric arc is repeatedly cut and squeezed between the two rotors, increasing the contact area and interaction time between the electric arc and the arc-extinguishing structure; third, the opposite rotation of the two rotors creates local eddies in the arc-extinguishing chamber, enhancing gas flow and heat exchange, and accelerating the discharge of free metal particles and high-temperature gases.

[0013] Furthermore, an exhaust channel is provided on the insulating shell, with the inlet end of the exhaust channel located close to the insulating rotor. A one-way pressure valve and a metal filter screen are installed within the exhaust channel. This invention effectively solves the problem of residual metal vapor and free particles in the arc-extinguishing chamber by providing an exhaust channel on the insulating shell close to the insulating rotor and installing a one-way pressure valve and a metal filter screen within the channel. The large amount of metal vapor and high-temperature free gas generated during arc extinguishing, if not discharged in time, will lead to slow recovery of the medium strength and may even cause secondary breakdown. In this solution, the one-way pressure valve automatically opens when the pressure in the arc-extinguishing chamber exceeds a threshold, venting the high-temperature gas and metal particles out of the chamber. It automatically closes after the pressure decreases, maintaining the chamber's airtightness. The metal filter screen traps metal particles, preventing them from polluting the external environment or igniting surrounding components after discharge. This exhaust structure ensures timely removal of arc-extinguishing products and prevents external air from entering the chamber and affecting the arc-extinguishing effect, significantly improving the medium recovery speed and anti-reignition capability of the device.

[0014] Furthermore, the surface of the spiral arc-starting groove is coated with a metal oxide ceramic coating to enhance the ablation resistance of the inner wall of the arc-starting groove. This invention significantly enhances the ablation resistance of the inner wall of the arc-starting groove by coating the surface of the spiral arc-starting groove with a metal oxide ceramic coating. When the electric arc moves within the spiral groove, it generates strong thermal shock and electrical erosion on the groove wall. Ordinary insulating materials are prone to burn-out and deformation after repeated interruptions, leading to structural damage to the spiral groove and a decrease in arc-extinguishing performance. The metal oxide ceramic coating has an extremely high melting point and excellent arc-erosion resistance, effectively protecting the base material and extending the rotor's service life. Simultaneously, the surface roughness of the ceramic coating facilitates arc adsorption and cooling, further enhancing the arc-extinguishing effect.

[0015] Furthermore, several magnetic shielding sheets are embedded inside the insulated rotor. These magnetic shielding sheets are located directly below the bottom of the spiral arc-initiating groove, and are used to concentrate and guide the magnetic field to the groove opening region, enhancing the attraction and driving ability of the electric arc. This invention achieves concentrated guidance and optimized utilization of the magnetic field by embedding magnetic shielding sheets inside the insulated rotor directly below the bottom of the spiral arc-initiating groove. The magnetic shielding sheets are made of a high-permeability material, which can guide the magnetic field lines generated by the permanent magnet to the groove opening region, making the magnetic field more concentrated on the path of the electric arc movement. This design has the following effects: First, it enhances the magnetic field strength in the groove opening region, improving the attraction and driving ability of the electric arc, making it easier for the electric arc to be guided into the spiral groove; second, the magnetic shielding sheets reduce the diffusion of the magnetic field into the rotor interior, avoiding the waste of magnetic energy; third, even in an alternating magnetic field scheme, the high-permeability magnetic shielding sheets can effectively concentrate the magnetic field lines, enhancing the magnetic field strength in the groove opening region. This optimized magnetic field design improves the efficiency of the magnetic adsorption components without increasing the amount of permanent magnets used, thus further enhancing the overall performance of the arc extinguishing device.

[0016] Compared with the prior art, the beneficial effects of the present invention are: I. This invention achieves active utilization and dynamic cutting of electric arc energy by using an insulated rotor made entirely of high-temperature resistant gas-generating material and creating spiral arc-initiating grooves on its outer peripheral wall. When the contacts break and generate an arc, the high temperature of the arc acts on the surface of the insulated rotor, causing localized vaporization and generating a backflow. Because the rotor's rotational inertia is configured to start when the arc heat flux density exceeds a preset threshold, the rotor can quickly start rotating from a stationary state without relying on the continuous action of external electromagnetic force. This self-driving mechanism makes the arc-extinguishing device respond to arc energy more quickly and autonomously, ensuring reliable rotor startup even under conditions of arc energy fluctuations or weak magnetic fields.

[0017] II. This invention achieves dynamic arc shearing and forced cooling. When the rotor rotates, the arc is forcibly guided into the spiral arc-initiating groove, and under the action of centrifugal force, it is thrown against the groove wall, simultaneously subjected to compression and friction from the groove wall. This dynamic shearing effect not only effectively lengthens the arc path and increases the arc voltage, but also significantly enhances the heat exchange between the arc and the groove wall, accelerating the dissipation of arc energy and the reduction of temperature.

[0018] Third, this invention realizes the synergistic arc extinguishing of multiple physical fields. It organically combines the non-uniform magnetic field generated by the magnetic adsorption component, the airflow field generated by the rotor rotation, and the temperature field of the spiral groove wall to form a synergistic arc extinguishing mechanism of "electromagnetic arc driving - airflow assisting rotation - groove wall cutting arc", which significantly improves the arc extinguishing efficiency and breaking capability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the internal structure of the present invention.

[0020] Figure 2 This is a cross-sectional view of the spiral arc-inducing groove of the present invention and a schematic diagram of the installation position of the magnetic shielding sheet.

[0021] Figure 3 This is a cross-sectional view of the bearing and shield of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of the magnetic adsorption component with alternating magnetic field of multiple permanent magnets according to the present invention.

[0023] Figure 5 This is a top view of the dual-rotor structure of the present invention.

[0024] In the diagram: 1. Insulating shell; 2. Arc extinguishing chamber; 3. Stationary contact; 4. Moving contact; 5. Permanent magnet; 6. Insulating rotor; 7. High-temperature bearing; 8. Spiral arc-inducing groove; 9. Shielding cover; 10. Micro pressure relief hole; 11. Rotor shaft; 12. Exhaust channel; 13. One-way pressure valve; 14. Metal filter screen; 15. Magnetic shielding sheet. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1: Single rotor foundation structure This embodiment provides an arc-extinguishing device, the structure of which is as follows: like Figure 1 The insulating shell 1 is integrally injection molded from high-temperature resistant thermosetting plastic (phenolic molding compound), forming a sealed arc-extinguishing chamber 2 inside the shell. The dimensions of the arc-extinguishing chamber 2 are 40mm in length, 30mm in width, and 25mm in height.

[0027] The stationary contact 3 and the moving contact 4 are arranged opposite each other in the arc-extinguishing chamber 2. The stationary contact 3 is fixedly installed at one end of the arc-extinguishing chamber 2, and the moving contact 4 is connected to the operating mechanism and can move in a plane perpendicular to the rotor axis. The moving contact 4 moves in a direction parallel to the horizontal plane, and its stroke is 8 mm.

[0028] A magnetic adsorption assembly is disposed on the inner wall of the arc-extinguishing chamber 2. In this embodiment, the magnetic adsorption assembly consists of a pair of ferrite permanent magnets 5, which are respectively embedded on the two side walls of the arc-extinguishing chamber 2 opposite to the insulating rotor 6. The magnetic poles of the two permanent magnets 5 are arranged in opposite directions (the N pole of the left side wall faces the chamber, and the S pole of the right side wall faces the chamber), forming a transverse magnetic field around the insulating rotor 6. The measured magnetic field strength is 0.15T.

[0029] An insulated rotor 6 is rotatably mounted on the arc movement path between the stationary contact 3 and the moving contact 4 via a high-temperature bearing 7. This embodiment uses a single insulated rotor 6. The rotor is integrally injection molded from high-temperature gas-generating polyoxymethylene (POM) material, is cylindrical, with a diameter of 16 mm, a length of 28 mm, and a mass of 9.2 g. Its moment of inertia is calculated to be 1.35 × 10⁻⁶. -7 kg·m 2 The rotor's axis of rotation is perpendicular to the horizontal plane, that is, perpendicular to the direction of movement of the moving contact 4.

[0030] The rotor's outer circumferential wall is provided with helical arc-initiating grooves 8, with a helix angle of 45°, a groove width of 2.5 mm, and a groove depth of 2.0 mm. The arc-initiating grooves are evenly distributed on the circumference, and all are right-handed. The high-temperature bearing 7 is a ceramic ball bearing, model 688-2Z, which can withstand a high temperature of 800℃.

[0031] Working process: When the moving contact 4 breaks with the stationary contact 3, generating an electric arc, the arc temperature can reach 5000-10000℃. The high temperature of the arc acts on the surface of the insulated rotor 6, causing localized vaporization and decomposition of the polyoxymethylene material, generating a high-speed backflow. Experimental measurements show that the rotor in this embodiment achieves an arc heat flux density of 5.2 × 10⁻⁶. 5 W / m 2 The rotor begins rotating, with a startup response time of approximately 1.8 ms. After rotation, the electric arc is forcibly guided into the spiral arc-initiating groove 8, where it is thrown against the groove wall under the centrifugal force of rotation, and simultaneously subjected to compression and friction from the groove wall. The arc is elongated and cooled within the spiral groove, eventually extinguishing. Testing showed that this embodiment achieves a breaking time of 4.2 ms under AC 380V / 10kA conditions, which is superior to traditional arc-extinguishing devices.

[0032] Example 2: Trapezoidal cross-section spiral groove structure This embodiment improves upon Embodiment 1 by modifying the cross-sectional shape of the spiral arc-inducing groove 8. For example... Figure 2 As shown, the depth of the spiral arc-inducing groove 8 gradually decreases from the groove opening to the bottom, with a groove opening depth of 2.2 mm and a bottom groove depth of 1.0 mm, forming a constriction channel with a trapezoidal cross-section. A radius of 0.3 mm is used for the transition between the groove wall and the groove bottom to avoid stress concentration.

[0033] Experimental comparisons showed that, compared to the equal-depth groove in Example 1, the trapezoidal contraction groove in this embodiment exerts a stronger compression effect on the electric arc. As the arc enters the groove, it is gradually compressed as the groove depth decreases, increasing arc resistance, intensifying heating, and accelerating the dissipation of arc energy. Simultaneously, the trapezoidal groove structure causes the arc to be continuously elongated during its movement, resulting in a faster increase in arc voltage. Tests show that, under the same test conditions, the breaking time of this embodiment is 3.5 ms, which is 16.7% shorter than that of Example 1.

[0034] Example 3: Structure with a shield to prevent metal vapor condensation like Figure 1 and Figure 3 In this embodiment, based on embodiment 1, a shield 9 to prevent metal vapor condensation is added to the outside of the high-temperature bearing 7. The shield 9 is made of alumina ceramic material, is annular, and has an inner diameter slightly larger than the outer diameter of the bearing 7, so that it can be fitted onto the outside of the bearing and form a small gap with the outer ring of the bearing; the shield 9 is fixed to the housing groove on the outside of the bearing by high-temperature adhesive.

[0035] The shield 9 has four tiny pressure relief holes 10, each with a diameter of 0.3 mm, that communicate with the bearing clearance and are evenly distributed around the circumference. The pressure relief holes penetrate the wall thickness of the shield 9, with one end communicating with the bearing clearance and the other end communicating with the arc extinguishing chamber 2.

[0036] Experiments have shown that the pressure relief hole design in this embodiment can effectively release the metal vapor pressure in the bearing area. Simultaneously, it utilizes the near-cathode effect of the electric arc—under standard atmospheric pressure, the minimum sustaining diameter of an electric arc in air is approximately 0.5-0.8 mm—when the pressure relief hole diameter is less than 0.5 mm, the electric arc is difficult to stably burn within the hole and spread to the bearing clearance. After 500 cycles of interruption testing, the bearing rotated flexibly without jamming; while in the control group without the shield 9, the bearing jammed after only 200 cycles.

[0037] Example 4: Multi-permanent magnet 5-alternating magnetic field structure like Figure 4 This embodiment improves upon Embodiment 1 by modifying the magnetic adsorption assembly. Five pairs of permanent magnets 5 (neodymium iron boron material, grade N35) are arranged sequentially along the axial direction of the insulated rotor 6. The permanent magnets 5 are 8mm long, 6mm wide, and 3mm thick, and are embedded in mounting grooves on both sides of the arc-extinguishing chamber 2.

[0038] The magnetic field directions of adjacent permanent magnets 5 alternate: the first pair of permanent magnets 5 has a left N pole and a right S pole; the second pair of permanent magnets 5 has a left S pole and a right N pole; the third pair of permanent magnets 5 has a left N pole and a right S pole; and so on. This creates multiple alternating magnetic field regions on the surface of the insulated rotor 6, with the magnetic field strength changing periodically between 0.12T and 0.18T.

[0039] High-speed video footage shows that the alternating magnetic field causes the arc to be continuously subjected to a Lorentz force with changing direction as it moves along the axial direction. The arc is repeatedly stretched and twisted, increasing the path length by approximately 30% compared to the single magnetic field scheme. Simultaneously, the oscillating effect of the alternating magnetic field disrupts the stable combustion state of the arc, accelerating its extinction. Testing showed that the breaking capacity of this embodiment is 22% higher than that of Embodiment 1.

[0040] Example 5: Dual-rotor bidirectional cutting structure This embodiment provides an arc-extinguishing device with a dual-rotor structure.

[0041] like Figure 5 Two insulated rotors 6, designated as the first rotor and the second rotor, are arranged parallel to each other and spaced apart within the insulating housing 1. The center distance between the two rotors is 20 mm, and both are mounted via high-temperature bearings 7. The spiral arc-initiating groove 8 of the first rotor is left-handed with a helix angle of 40°; the spiral arc-initiating groove 8 of the second rotor is right-handed with a helix angle of 40°. Both rotors have a diameter of 14 mm and a length of 25 mm, and are made of polyoxymethylene (POM).

[0042] The magnetic adsorption assembly includes four sets of permanent magnets 5: a pair of permanent magnets 5 (left N pole, right S pole) are embedded in the left side wall of the first rotor; a pair of permanent magnets 5 (left N pole, right S pole) are embedded in the right side wall of the first rotor, consistent with the left side; a pair of permanent magnets 5 (left S pole, right N pole) are embedded in the left side wall of the second rotor; a pair of permanent magnets 5 (left S pole, right N pole) are embedded in the right side wall of the second rotor, consistent with the left side. That is, the magnetic field direction generated by the permanent magnets 5 on both sides of the first rotor is opposite to the magnetic field direction generated by the permanent magnets 5 on both sides of the second rotor.

[0043] When an electric arc is generated, the first rotor rotates clockwise (viewed from above) under the influence of the magnetic field and airflow, while the second rotor rotates counterclockwise. The two rotors rotating in opposite directions simultaneously exert their influence on the electric arc, stretching it in both directions and repeatedly cutting and compressing it between the two rotors. The opposing rotations of the two rotors create localized vortices within the arc-extinguishing chamber 2, enhancing gas flow and heat exchange.

[0044] Tests show that the breaking time of this embodiment under AC 690V / 15kA conditions is 3.8ms, while the breaking time of the single rotor comparison group under the same conditions is 6.2ms, and the arc extinguishing efficiency is improved by about 40%.

[0045] Example 6: Structure with exhaust channel like Figure 1 In this embodiment, based on Embodiment 1, an exhaust channel 12 is provided on the insulating housing 1. The inlet end of the exhaust channel 12 is located at the top of the arc-extinguishing chamber 2, 5 mm above the center of the insulating rotor 6. The exhaust channel 12 is L-shaped, and the outlet end is located on the side of the housing.

[0046] The exhaust channel 12 is equipped with a one-way pressure valve 13 and a metal filter screen 14. The one-way pressure valve 13 adopts a reed-type structure, and the opening pressure is set to 0.2MPa. The metal filter screen 14 is made of 304 stainless steel wire mesh, with 3 layers and mesh sizes of 80 mesh, 120 mesh and 200 mesh respectively, for step-by-step filtration.

[0047] When the pressure inside the arc-extinguishing chamber 2 exceeds 0.2 MPa, the one-way pressure valve 13 automatically opens, allowing high-temperature gas and metal particles to be discharged outside the chamber through the exhaust channel 12; when the pressure drops below 0.15 MPa, the valve automatically closes to maintain the chamber's airtightness. The metal filter screen 14 traps metal particles, preventing them from polluting the external environment after discharge.

[0048] Tests showed that in this embodiment, the pressure in the arc-extinguishing chamber 2 dropped to 0.12 MPa within 10 ms after the interruption, indicating a fast medium recovery speed. In contrast, in the control group without an exhaust channel 12, the pressure in the chamber was still as high as 0.18 MPa 20 ms after the interruption, and there was a secondary breakdown phenomenon.

[0049] Example 7: Rotor structure with ceramic coating This embodiment, based on Embodiment 1, involves coating the surface of the spiral arc-initiating groove 8 with a metal oxide ceramic coating. The coating material is alumina (Al2O3) ceramic with a purity of 99.5%, prepared using a plasma spraying process, and the coating thickness is 0.1-0.15 mm. Before spraying, the rotor surface is roughened by sandblasting to improve the coating's bonding strength.

[0050] Testing revealed that the rotor surface with the ceramic coating achieved a hardness of HV1200 and a melting point as high as 2050℃. After 3000 cycles of interruption life testing under the same conditions, the arc-initiating groove profile remained intact, with a groove depth wear of only 0.12mm. In contrast, the uncoated control rotor showed a groove depth wear of 0.35mm after 1200 interruptions, and the arc-initiating groove structure exhibited significant deformation. This embodiment demonstrates a rotor electrical life improvement of more than 2.5 times.

[0051] Example 8: Structure with magnetic shielding sheet like Figure 2 In this embodiment, based on Embodiment 4 (alternating magnetic field), a magnetic shielding sheet 15 is embedded inside the insulated rotor 6. The magnetic shielding sheet 15 is made of permalloy (1J85), with a thickness of 0.3 mm, and is in the shape of an arc. During rotor injection molding, the magnetic shielding sheet 15 is pre-placed in the mold, positioned directly below the bottom of the spiral arc-inducing groove 8, approximately 1.0 mm from the bottom surface of the groove.

[0052] The function of the magnetic shielding plate 15 is to concentrate and guide the magnetic field lines generated by the permanent magnet 5 to the slot area. Magnetic field simulation analysis shows that after installing the magnetic shielding plate 15, the magnetic field strength in the slot area increased from 0.12-0.18T to 0.18-0.25T, an increase of over 30%. Simultaneously, the magnetic shielding plate 15 reduces the diffusion of the magnetic field into the rotor, avoiding waste of magnetic energy.

[0053] Experiments show that the arc ignition success rate (the probability that the arc is first introduced into the spiral groove) of this embodiment is increased from 78% to 94%, and the arc extinguishing efficiency is further improved.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An arc-extinguishing device, characterized in that, include: An insulating shell (1) has a sealed arc-extinguishing chamber (2) inside it. The stationary contact (3) and the moving contact (4) are disposed opposite to each other in the arc-extinguishing chamber (2); A magnetic adsorption component is disposed on the inner wall of the arc extinguishing chamber (2) to generate a non-uniform magnetic field to pull the electric arc; Its characteristic is that it further includes: At least one insulated rotor (6) is rotatably mounted on the arc movement path between the stationary contact (3) and the moving contact (4) via a high-temperature bearing (7), and the rotation axis of the insulated rotor (6) is perpendicular to the movement direction of the moving contact (4). At least one spiral arc-inducing groove (8) is provided on the outer peripheral wall of the insulated rotor (6) along the axial direction. The insulating rotor (6) is made of a high-temperature gas-generating material, and its moment of inertia is configured such that when the arc heat flux density is greater than a preset threshold, the backflow generated by the local vaporization on the surface of the insulating rotor (6) is sufficient to drive the insulating rotor (6) to start rotating from a stationary state.

2. The arc-extinguishing device according to claim 1, characterized in that: The depth of the spiral arc-inducing groove (8) gradually decreases from the groove opening to the groove bottom, forming a constriction channel with a trapezoidal cross-section.

3. The arc-extinguishing device according to claim 1, characterized in that: The high-temperature bearing (7) is provided with a shield (9) to prevent metal vapor condensation on its outer side. The shield (9) is made of high-temperature resistant insulating material and has a small pressure relief hole (10) that communicates with the bearing gap. The diameter of the pressure relief hole is less than 0.5 mm.

4. The arc-extinguishing device according to claim 1, characterized in that: The magnetic adsorption assembly includes at least one pair of permanent magnets (5), which are respectively embedded on the two side walls of the arc-extinguishing chamber (2) opposite to the insulating rotor (6), and the magnetic poles of the pair of permanent magnets (5) are arranged oppositely to form a transverse magnetic field around the insulating rotor (6).

5. The arc-extinguishing device according to claim 4, characterized in that: The permanent magnets (5) are multiple and are arranged sequentially along the axial direction of the insulated rotor (6). The magnetic field directions between adjacent permanent magnets (5) alternate to form multiple alternating magnetic field regions on the surface of the insulated rotor (6).

6. The arc-extinguishing device according to claim 1, characterized in that: The number of the insulating rotors (6) is two, namely the first rotor and the second rotor, which are parallel and spaced apart. The spiral arc-inducing groove (8) on the first rotor is left-handed and the spiral arc-inducing groove (8) on the second rotor is right-handed. The magnetic field generated by the permanent magnets (5) on both sides of the first rotor is opposite to the magnetic field generated by the permanent magnets (5) on both sides of the second rotor.

7. The arc-extinguishing device according to claim 1, characterized in that: An exhaust channel (12) is provided on the insulating housing (1). The inlet end of the exhaust channel (12) is located close to the insulating rotor (6), and a one-way pressure valve (13) and a metal filter screen (14) are provided in the exhaust channel (12).

8. The arc-extinguishing device according to claim 1, characterized in that: The surface of the spiral arc-starting groove (8) is coated with a metal oxide ceramic coating.

9. The arc-extinguishing device according to claim 4 or 5, characterized in that: The insulating rotor (6) is internally embedded with several magnetic shielding plates (15), which are located directly below the bottom of the spiral arc-inducing groove (8).

Images