Contact assembly and circuit breaker

Abstract

The utility model belongs to the field of electrical technology, and particularly relates to a contact assembly and a circuit breaker, and the contact assembly comprises a moving contact which is provided with a moving contact, and the moving contact is located at one end of the moving contact; the static contact is provided with at least two static contact points, the at least two static contact points are sequentially arranged at one end of the static contact at intervals, and the static contact points and the movable contact points are arranged oppositely; wherein the moving contact can move towards the side close to or away from the static contact, so that the moving contact is in contact with the at least two static contacts. Contact resistance can be reduced, the heating phenomenon can be reduced, local energy accumulation can be avoided, and therefore the service life of the circuit breaker is prolonged, and the breaking capacity of the circuit breaker is improved.

Description

Technical Field

[0001] This application belongs to the field of electrical technology, specifically relating to a contact assembly and a circuit breaker. Background Technology

[0002] A circuit breaker is a switching device that can close, carry, and interrupt current under normal circuit conditions and close, carry, and interrupt current under abnormal circuit conditions within a specified time. Inside a circuit breaker, there are two key components: moving contacts and stationary contacts.

[0003] Currently, most mainstream molded case circuit breakers on the market adopt a single static contact structure. However, using a single static contact can easily lead to the vaporization or evaporation of the metal material on the surface of the static contact, as well as dynamic fluctuations in contact resistance. Utility Model Content

[0004] The purpose of this application is to solve the problems in the prior art, such as the easy vaporization or evaporation of the metal material on the surface of the static contact due to a single static contact, and the dynamic fluctuation of the contact resistance.

[0005] A first aspect of this application provides a contact assembly, comprising: a movable contact having a movable point located at one end of the movable contact; and a stationary contact having at least two stationary points arranged sequentially at intervals at one end of the stationary contact, the stationary points being disposed facing the movable contact; wherein the movable contact is movable toward or away from the stationary contact so that the movable contact comes into contact with the at least two stationary contacts.

[0006] In one exemplary embodiment of this application, a heat-conducting layer is provided on the surface of the stationary contact near the moving contact.

[0007] In one exemplary embodiment of this application, a guide groove is provided on the surface of the stationary contact near the moving contact.

[0008] In one exemplary embodiment of this application, the stationary contact includes a tungsten carbide layer and a silver alloy layer, wherein the silver alloy layer is disposed on the side of the tungsten carbide layer near the moving contact.

[0009] In one exemplary embodiment of this application, the stationary contact comprises a silver-tungsten alloy component.

[0010] In one exemplary embodiment of this application, the stationary contact includes a stationary contact body, one end of which is provided with a groove for accommodating the at least two stationary contacts, and the inner surface of the groove is provided with a conductive layer.

[0011] In one exemplary embodiment of this application, the spacing between adjacent static contacts is 0.5-5 mm.

[0012] A second aspect of this application provides a circuit breaker, comprising: a housing; and a contact assembly as described in any of the preceding claims, wherein the moving contact and the stationary contact are disposed within the housing.

[0013] In another exemplary embodiment of this application, the circuit breaker further includes an arc-extinguishing chamber and arc-extinguishing grid plates. The arc-extinguishing chamber is disposed on the moving contact and the stationary contact. A plurality of arc-extinguishing grid plates are arranged at intervals in the arc-extinguishing chamber, and the arrangement direction of the plurality of arc-extinguishing grid plates is parallel to the moving direction of the moving contact.

[0014] In another exemplary embodiment of this application, the circuit breaker further includes an operating component, which includes an operating handle, a transmission rod, and an elastic element. The operating handle extends outside the housing and is connected to a rotating shaft on the moving contact via the transmission rod to drive the moving contact to rotate toward or away from the stationary contact. The elastic element is sleeved on the rotating shaft to provide a spring force for resetting the moving contact.

[0015] The contact assembly and circuit breaker of this application have at least the following beneficial effects:

[0016] The contact assembly in this application includes a moving contact and a stationary contact. The stationary contact includes at least two stationary contact points, which are arranged sequentially at intervals at one end of the stationary contact and face each other. The moving contact can move towards or away from the stationary contact to make contact with the at least two stationary contacts. By having the moving contact contact the at least two stationary contacts, the contact area is increased, the contact resistance is reduced, heat generation is reduced, and thermal conductivity is improved. Furthermore, when breaking the circuit between the moving and stationary contacts, the arc energy can be dispersed to the at least two stationary contacts, reducing the thermal stress and electrodynamic force borne by a single stationary contact, avoiding local energy accumulation, thereby improving the service life and breaking capacity of the circuit breaker.

[0017] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1A schematic diagram of the structure of the stationary contact provided in the embodiment of this application, which has two stationary contacts, is shown.

[0021] Figure 2 A schematic diagram of the structure of the stationary contact provided in the embodiment of this application, which has two stationary contacts, is shown.

[0022] Figure 3 The diagram shows an exploded view of the static contact and groove structure provided in an embodiment of this application.

[0023] Figure 4 A schematic diagram of the circuit breaker provided in an embodiment of this application is shown.

[0024] Figure 5 An exploded view of the circuit breaker provided in an embodiment of this application is shown.

[0025] Figure 6 This illustration shows a schematic diagram of the connection structure between the arc-extinguishing chamber and the arc-extinguishing grid plate, and the moving contact and the stationary contact, provided in an embodiment of this application.

[0026] Figure 7 This illustration shows an exploded structural diagram of the arc-extinguishing chamber and arc-extinguishing grid, along with the moving and stationary contacts, provided in an embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10. Circuit breaker; 100. Contact assembly; 110. Moving contact; 111. Moving contact body; 112. Moving contact; 120. Stationary contact; 121. Stationary contact body; 122. Stationary contact; 123. Groove; 200. Housing; 300. Arc extinguishing chamber; 400. Arc extinguishing grid; 500. Magnetic blow-out coil; 600. Arc ignition grid; 710. Operating handle; 720. Transmission rod. Detailed Implementation

[0029] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0030] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0031] In this application, unless otherwise expressly specified and limited, the terms "assembly," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0033] Figure 1 A schematic diagram of a structure with two stationary contacts is shown. Figure 2 A schematic diagram of a structure with two stationary contacts is shown.

[0034] See Figure 1 and Figure 2 As shown, this application embodiment provides a contact assembly 100, which may include a moving contact 110 and a stationary contact 120. When the moving contact 110 and the stationary contact 120 are in close contact, a conductive path can be formed, allowing current to flow. When an overload, short circuit, or human operation is detected, the moving contact 110 can be quickly disengaged from the stationary contact 120 under the actuation of the operating components described below to cut off the current.

[0035] In the embodiments of this application, see Figure 1 and Figure 2 As shown, the moving contact 110 includes a moving contact body 111 and a moving contact 112 located at one end of the moving contact body 111. The stationary contact 120 includes a stationary contact body 121 and at least two stationary contacts 122 located at one end of the stationary contact body 121. The at least two stationary contacts 122 are arranged sequentially at intervals on one end of the stationary contact body 121, and the stationary contacts 122 and the moving contact 112 are arranged facing each other.

[0036] In this embodiment, the moving contact 110 can move toward or away from the stationary contact 120 so that the moving contact 112 contacts at least two stationary contacts 122 to form a conductive path and allow current to pass through.

[0037] The present application solution increases the contact area and reduces the contact resistance (approximately 20-50 μΩ) by having the moving contact 112 contact at least two stationary contacts 122, thereby reducing heat generation and improving thermal conductivity. Furthermore, when the moving contact 112 and the stationary contacts 122 are disconnected, the arc energy can be dispersed to at least two stationary contacts 122, reducing the thermal stress and electrodynamic force borne by a single stationary contact 122, avoiding local energy accumulation, and thus improving the service life and breaking capacity of the circuit breaker 10.

[0038] An alternative example, see Figure 1 As shown, two stationary contacts 122 can be arranged at one end of the stationary contact body 121 at intervals. The two stationary contacts 122 can reduce the arc energy borne by a single stationary contact 122 by 50%.

[0039] Another alternative example, see Figure 2 As shown, three stationary contacts 122 can be arranged at intervals at one end of the stationary contact body 121. The three stationary contacts 122 can reduce the arc energy borne by a single stationary contact 122 by 67%.

[0040] In this embodiment, a thermally conductive layer (not shown in the figure) is provided on the surface of the stationary contact 122 near the moving contact 112. This thermally conductive layer can be a nanoscale silver-plated layer, and the thickness of the thermally conductive layer can be 3-5 μm, which can reduce the temperature coefficient of contact resistance and improve conductivity stability and reliability.

[0041] In this embodiment, the surface of the stationary contact 122 near the moving contact 112 is also provided with a honeycomb-shaped flow guide groove (not shown in the figure). That is, the side of the stationary contact 122 near the moving contact 112 has both a heat-conducting layer and a honeycomb-shaped flow guide groove. Through the heat-conducting layer and the flow guide groove, the temperature coefficient of the contact resistance can be further reduced, so that the temperature rise of the circuit breaker 10 during continuous current carrying can be reduced by 20-30°C, reducing power loss and heat generation risk, and improving conductivity stability and reliability.

[0042] In this embodiment, the surface of the stationary contact 122 may employ a gradient composite coating design. The stationary contact 122 may include a high-hardness tungsten carbide layer (not shown in the figure) and a low-resistance silver alloy layer (not shown in the figure) to reduce surface wear, improve electrical life, and effectively reduce equipment maintenance costs and replacement frequency.

[0043] In this embodiment, the stationary contact 122 may include a silver-tungsten alloy component (not shown in the figure). For example, the material of the stationary contact 122 may contain a silver-tungsten alloy material, wherein the tungsten content may be 30-80%, to improve the anti-welding and corrosion resistance of the stationary contact 120.

[0044] In this embodiment, the stationary contact body 121 can be made of high-conductivity oxygen-free copper (purity ≥99.97%), and its cross-sectional shape can be designed according to current carrying capacity requirements, for example, it can be U-shaped. The stationary contact 122 can be made of a high-temperature resistant and arc-corrosion resistant alloy material composed of silver-tungsten alloy and silicon carbide particles.

[0045] In this embodiment, the surface of the static contact 122 can also be coated with a 2-3 μm thick silver cadmium oxide (cadmium oxide content 10-15%) composite coating by magnetron sputtering technology to further improve its resistance to arc erosion and conductivity.

[0046] Figure 3 A schematic diagram showing the exploded structure of the stationary contact and the groove is provided.

[0047] In the embodiments of this application, see Figure 3 As shown, one end of the stationary contact body 121 is provided with a groove 123 for accommodating at least two stationary contacts 122. All stationary contacts 122 are fixed inside the groove 123 by riveting. A conductive layer (e.g., a silver layer) is plated on the inner surface of the groove 123 to enhance the bonding force and conductivity between the stationary contact body 121 and the stationary contacts 122.

[0048] In this embodiment, the spacing between adjacent stationary contacts 122 can be 0.5-5mm to ensure electrical performance and mechanical stability. Furthermore, the stationary contacts 122 are strictly calibrated on the same plane, with a flatness error not exceeding 0.02mm, to ensure that the moving contact 112 can contact at least two stationary contacts 122.

[0049] In this embodiment, the moving contact body 111 can also be made of silver-tungsten alloy, and its surface is coated with a silver alloy layer of 0.8-1.2μm thickness by vacuum coating technology to reduce contact resistance.

[0050] In this embodiment, the moving contact body 111 can be connected to the operating component via a high-precision rotating shaft (not shown in the figure). The rotating shaft can be supported by an oil-impregnated bearing, and its surface is nitrided to achieve a hardness of HV800-1000 to reduce the coefficient of rotational friction and ensure that the moving contact body 111 can rotate rapidly under the drive of the operating component to complete the connection or disconnection action between the moving contact 112 and the stationary contact 122.

[0051] Figure 4 A schematic diagram of the circuit breaker is shown. Figure 5 A schematic diagram of the exploded structure of a circuit breaker is shown.

[0052] See Figure 4 and Figure 5As shown, this application embodiment also provides a circuit breaker 10, which may include a housing 200 and a contact assembly 100 described in any of the above.

[0053] The outer casing 200 can be integrally injection molded from high-strength flame-retardant engineering plastic, and its interior forms a closed chamber for installing various functional components (not shown in the figure). This outer casing 200 can effectively prevent dust, foreign objects from entering and liquids from splashing into the outer casing 200, thereby affecting the normal operation of the functional components.

[0054] Figure 6 A schematic diagram of the connection structure between the arc-extinguishing chamber and the arc-extinguishing grid plate and the moving and stationary contacts is shown. Figure 7 A schematic diagram showing the exploded structure of the arc-extinguishing chamber, arc-extinguishing grid, moving contact, and stationary contact is provided.

[0055] In the embodiments of this application, see Figures 5 to 7 As shown, the circuit breaker 10 may further include an arc-extinguishing chamber 300 and arc-extinguishing grid plates 400. The arc-extinguishing chamber 300 is located above multiple stationary contacts 122 and moving contacts 112. Multiple arc-extinguishing grid plates 400 are arranged at intervals within the arc-extinguishing chamber 300. The arc-extinguishing grid plates 400 may be made of a magnetically conductive metal material, and the arrangement direction of the multiple arc-extinguishing grid plates 400 is parallel to the moving direction of the moving contact 110. Thus, the arc generated when the moving contact 110 and the stationary contact 120 separate can be quickly extinguished through the arc-extinguishing chamber 300 and the arc-extinguishing grid plates 400, preventing the arc from continuing to burn and damaging the equipment or causing an accident.

[0056] In the embodiments of this application, see Figure 7 As shown, the circuit breaker 10 may also include a magnetic blow-out coil 500 and an arc-initiating grid 600. Both the magnetic blow-out coil 500 and the arc-initiating grid 600 can be located at the entrance of the arc-extinguishing chamber 300. When the current is interrupted, the magnetic field generated by the magnetic blow-out coil 500 interacts with the arc, forcing the arc to move rapidly towards the arc-extinguishing chamber 300; the asymmetric arc-initiating grid 600 (grid tilt angle 15°-30°) cooperates with the stationary contact 122 to divide the arc into smaller, shorter arcs, shortening the arcing time to 8-12ms, increasing the energy absorption efficiency of the arc-extinguishing chamber 300 by more than 35%, effectively suppressing the flying arc phenomenon, and shortening the flying arc distance from the traditional 200-300mm to within 50mm, significantly improving the safety and application adaptability of the circuit breaker 10.

[0057] In this embodiment of the application, arc-starting angles (not shown in the figure) are also provided on both sides of the arc-extinguishing chamber 300. One end of the arc-starting angle is connected to the stationary contact body 121 of the stationary contact 122, and the other end faces the interior of the arc-extinguishing chamber 300. The arc-starting angles on both sides of the arc-extinguishing chamber 300 can guide the arc to quickly enter the arc-extinguishing chamber 300, enhance the arc-extinguishing effect, and improve the safety performance of the circuit breaker 10.

[0058] In the embodiments of this application, see Figure 4 and Figure 5 As shown, the circuit breaker 10 also includes an operating assembly (not shown in the figure). The operating assembly may include an operating handle 710, a transmission rod 720, and a resilient element (not shown in the figure). The operating handle 710 extends outside the housing 200 and is connected to the rotating shaft of the moving contact 110 via the transmission rod 720. The resilient element is sleeved on the rotating shaft to provide a spring force for the moving contact 112 to reset. In this way, the operating handle 710 can reliably drive the moving contact 110 to operate via the transmission rod 720, and the resilient element can ensure that the moving contact 112 quickly resets after disconnection.

[0059] In this embodiment of the application, the circuit breaker 10 further includes a heating element (not shown in the figure), an overload trip unit (not shown in the figure), a short-circuit trip unit (not shown in the figure), and a tripping element (not shown in the figure).

[0060] The overload trip unit can employ a bimetallic strip structure, with the bimetallic strip connected in series with a heating element, which is then connected to the circuit. When the circuit is overloaded, the heating element heats up, causing the bimetallic strip to bend and triggering the trip unit. The short-circuit trip unit uses an electromagnetic trip structure. When a short circuit occurs, the magnetic field generated by the short-circuit current causes the electromagnetic trip unit to activate, triggering the trip unit.

[0061] The trip unit is connected to the operating component, enabling the operating component to disconnect the moving contact 112 from the stationary contact 122 when the overload / short circuit trip unit operates. Thus, by incorporating overload and short circuit protection functions, the circuit breaker 10 provides comprehensive and effective protection for the circuit, improving its reliability and usability.

[0062] The installation process for each component is as follows:

[0063] Installation and circuit connection of stationary contacts 122: A high-precision positioning fixture is used to install the two stationary contacts 122 into predetermined positions inside the housing 200. The positioning fixture precisely engages with the housing 200 via positioning pin holes, ensuring that the parallelism error of the stationary contacts 122 is controlled within a predetermined range and that the spacing meets preset requirements. Bolts and insulating washers are used to fix the stationary contacts 122, ensuring a secure fixation and electrical insulation. The connection between the stationary contact body 121 of the stationary contact 120 and the external circuit connection terminal employs a dual process of double-bolt crimping and soldering. First, the conductive connector is placed between the stationary contact body 121 and the connection terminal, and initial crimping is performed using bolts. Subsequently, lead-free solder is used to solder the crimped area, with the soldering temperature controlled at 260-280℃, to form a strong electrical connection and ensure that the contact resistance is below 50μΩ.

[0064] Moving contact 112 is assembled with the rotating shaft: The moving contact 112 is mounted on the rotating shaft by an interference fit, with the interference amount controlled within 0.02-0.03 mm. Before assembly, the shaft hole on the moving contact body 111 and the surface of the rotating shaft are cleaned and a thin layer of conductive grease is applied to reduce friction and enhance conductivity. The rotating shaft is supported at both ends by oil-impregnated bearings. The bearings are fitted with the mounting holes on the inner wall of the housing 200 using a transition fit, and the bearings are pressed into the housing 200 to ensure secure installation and flexible rotation.

[0065] Arc-extinguishing system installation: The arc-extinguishing chamber 300 adopts a modular design, pre-positioned with slots on the inner wall of the outer casing 200 using four positioning clips, and then secured with screws. The arc-extinguishing grid plates 400 are nickel-plated to enhance their oxidation resistance. During installation, the arc-extinguishing grid plates 400 are inserted into the slots of the arc-extinguishing chamber 300 in an alternating pattern (adjacent grid plates are offset by 45°). Each arc-extinguishing grid plate 400 must be fully embedded in the slot, and the gap between it and the wall of the arc-extinguishing chamber 300 should not exceed 0.2mm. The arc-starting angle is made of copper alloy and is connected to the stationary contact body 121 of the stationary contact 122 by welding. The welded area must be polished smooth to avoid sharp edges. The other end of the arc-starting angle is fixed to the inlet of the arc-extinguishing chamber 300 by a positioning bracket, ensuring that the deviation between its tip and the central axis of the arc-extinguishing chamber 300 does not exceed ±1°, so as to ensure that the arc can be accurately introduced into the arc-extinguishing chamber 300.

[0066] Operating component installation: The operating handle 710 extends outward through a circular through-hole on the surface of the housing 200. A waterproof and dustproof sealing ring is installed between the operating handle 710 and the through-hole. The transmission rod 720 inside the operating handle 710 is connected to the rotating shaft of the moving contact 110 via a universal joint structure, ensuring reliable transmission of operating force at different angles. The universal joint connection is fixed with pins, which must be coated with thread-locking adhesive to prevent loosening. The elastic element can be a helical compression spring, which needs to be pre-compressed before installation to eliminate plastic deformation. After the spring is fitted onto the rotating shaft, the compression of the spring is adjusted by adjusting the positions of the limit retaining rings at both ends of the spring to ensure that the spring force meets the design requirements.

[0067] Overload Trip Unit Installation: The bimetallic strip of the overload trip unit is rolled from two metals with different coefficients of thermal expansion (such as an iron-nickel alloy and a copper alloy). One end is fixed to a bracket inside the housing 200, and the other end is connected to the trigger rod of the tripping mechanism. The bimetallic strip and the heating element (made of constantan wire, with a resistance value customized according to the rated current) are connected in series by welding. The welding points must be insulated and wrapped with high-temperature resistant insulating sleeves. The heating element is connected to the main circuit through terminals with a quick-plug design to ensure reliable connection and easy maintenance.

[0068] Short-circuit trip unit installation: The electromagnetic tripping structure of the short-circuit trip unit mainly includes a coil, armature, and iron core. The coil is wound with high-strength enameled wire (the wire diameter is selected according to the rated current, such as 0.8mm wire for a 100A specification product). After winding, it needs to be impregnated with enamel to improve insulation performance. The coil is encapsulated in an insulating shell 200 with epoxy resin to ensure isolation from the outside environment. The air gap between the armature and the iron core must be strictly controlled between 0.8-1.0mm, which can be precisely adjusted by adjusting the number of shims. The electromagnetic trip unit is fixed inside the shell 200 by a bracket and connected to the linkage of the tripping mechanism. The connection part uses a spherical bearing to ensure flexible and unobstructed operation.

[0069] Understandably, after each component is installed, its performance must be tested to ensure that each component is working properly and to ensure the protection performance of the circuit breaker 10.

[0070] Work process:

[0071] 1. Circuit connected

[0072] When the operator rotates the operating handle 710 clockwise, the operating handle 710 drives the moving contact 110 to rotate upwards around the axis via the transmission rod 720. During rotation, the moving contact 112 first approaches the stationary contact 122 at a relatively fast speed, then slows down as it approaches the stationary contact 122 to reduce the impact force. After the moving contact 112 contacts multiple stationary contacts 122 simultaneously, a tight electrical connection is formed under the combined action of the spring force and the operating force. At this time, current flows through the multiple stationary contacts 122, the moving contact 112, and the conductive connector to form a complete conductive circuit. The structure of multiple stationary contacts 122 increases the contact area, reduces contact resistance, minimizes heat generation, and ensures good conductivity.

[0073] 2. Overload protection

[0074] When an overload occurs in the circuit, the current passing through the heating element continuously exceeds the rated value. The heat generated by the heating element causes the temperature of the bimetallic strip in the overload trip unit to rise. Due to the different coefficients of thermal expansion of the metals on both sides of the bimetallic strip, the bimetallic strip gradually bends towards the side with the smaller coefficient of thermal expansion after being heated. As the overload current continues, the degree of bending of the bimetallic strip increases. When the bending displacement reaches a set threshold, the bimetallic strip pushes the trigger rod of the trip unit. The trigger rod drives the trip unit to actuate, unlocking the latch of the operating component. Under the action of the elastic element, the operating handle 710 rotates counterclockwise, and the moving contact 112 quickly separates from the stationary contact 122, cutting off the circuit and realizing overload protection.

[0075] 3. Short circuit protection

[0076] When a short circuit occurs, the instantaneously generated powerful short-circuit current passes through the coil of the electromagnetic trip unit, generating an extremely strong magnetic field in the iron core. The magnetic force attracts the armature to move rapidly, and the armature pushes the tripping element through the connecting rod, causing the latch of the operating component to unlock instantly.

[0077] During the breaking process between the moving contact 112 and the stationary contact 122, a high-temperature electric arc is generated between the contacts. Under the influence of the magnetic field generated by the short-circuit current, the arc-ignition angle rapidly guides the arc to the arc-extinguishing chamber 300. The arc-extinguishing grids 400 arranged in an alternating pattern within the arc-extinguishing chamber 300 divide the arc into multiple short arcs, each of which is rapidly cooled and extinguished by the arc-extinguishing grids 400. In this way, the erosion of the contact system by the arc is effectively reduced, improving the breaking capacity and safety performance of the circuit breaker 10.

[0078] This application increases the contact area, reduces contact resistance, reduces heat generation, and improves thermal conductivity by having the moving contact 112 contact with at least two stationary contacts 122. Furthermore, when the moving contact 112 and the stationary contacts 122 are disconnected, the arc energy can be dispersed to at least two stationary contacts 122, reducing the thermal stress and electrodynamic force borne by a single stationary contact 122, avoiding local energy accumulation, thereby improving the service life and breaking capacity of the circuit breaker 10.

[0079] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0080] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A contact assembly, characterized in that, include: A moving contact is provided with a moving contact point, which is located at one end of the moving contact. A stationary contact is provided with at least two stationary contact points, which are arranged sequentially at intervals at one end of the stationary contact, and the stationary contact points are arranged facing the moving contact point; The moving contact can move toward or away from the stationary contact so that the moving contact comes into contact with the at least two stationary contacts.

2. The contact assembly according to claim 1, characterized in that, The surface of the stationary contact near the moving contact is provided with a heat-conducting layer.

3. The contact assembly according to claim 1 or 2, characterized in that, The surface of the stationary contact near the moving contact is provided with a flow guide groove.

4. The contact assembly according to claim 1, characterized in that, The stationary contact includes a tungsten carbide layer and a silver alloy layer, with the silver alloy layer disposed on the side of the tungsten carbide layer near the moving contact.

5. The contact assembly according to claim 1, characterized in that, The stationary contact comprises a silver-tungsten alloy component.

6. The contact assembly according to claim 1, characterized in that, The stationary contact includes a stationary contact body, one end of which is provided with a groove for accommodating the at least two stationary contacts, and the inner surface of the groove is provided with a conductive layer.

7. The contact assembly according to claim 1, characterized in that, The distance between adjacent stationary contacts is 0.5-5mm.

8. A circuit breaker, characterized in that, include: shell; The contact assembly according to any one of claims 1 to 7, wherein the moving contact and the stationary contact are disposed within the housing.

9. The circuit breaker according to claim 8, characterized in that, The circuit breaker further includes an arc-extinguishing chamber and arc-extinguishing grid plates. The arc-extinguishing chamber is disposed on the moving contact and the stationary contact. A plurality of arc-extinguishing grid plates are arranged at intervals in the arc-extinguishing chamber, and the arrangement direction of the plurality of arc-extinguishing grid plates is parallel to the moving direction of the moving contact.

10. The circuit breaker according to claim 8, characterized in that, The circuit breaker also includes an operating assembly, which includes an operating handle, a transmission rod, and an elastic element. The operating handle extends outside the housing and is connected to a rotating shaft on the moving contact via the transmission rod to drive the moving contact to rotate toward or away from the stationary contact. The elastic element is sleeved on the rotating shaft to provide a spring force for resetting the moving contact.

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