Split moving contact for circuit breaker

Abstract

A kind of split moving contact for circuit breaker, including operating handle and moving contact matched with operating handle, the operating handle in the process of rotation brings moving contact and static contact contact or separate, the moving contact includes mechanical cooperation part and contact cooperation part, the contact cooperation part is matched with static contact and is made of copper, the hardness of the mechanical cooperation part is greater than contact cooperation part and the electrical conductivity is weaker than contact cooperation part.The beneficial effects of the utility model are that: by adopting split structure design, moving contact is divided into mechanical cooperation part and contact cooperation part, mechanical cooperation part has higher hardness and lower electrical conductivity, effectively solve the problem that traditional integrated copper moving contact is easily worn under long-term mechanical operation and the rotating shaft part is easily overheat and burns under large current.

Description

Technical Field

[0001] This utility model relates to a circuit breaker accessory, and more particularly to a split moving contact for a circuit breaker. Background Technology

[0002] Molded case circuit breakers (MCCBs) play a crucial role in low-voltage power distribution systems, protecting circuits from short circuits or overloads. The moving contact, its core component, typically consists of a part connected to the operating handle and a part that mates with the stationary contact. During normal operation, the operating handle mechanically drives the moving contact to rotate, bringing it into contact with the stationary contact to establish a circuit. In case of a fault or when manual disconnection is required, the operating handle quickly disengages the moving contact from the stationary contact, thus interrupting the current. This process relies on the reliable rotation and contact stability of the moving contact, ensuring the circuit breaker can respond promptly to operating commands or automatic protection mechanisms. MCBs are widely used in industrial, commercial, and residential electrical systems.

[0003] In existing technologies, moving contacts are mostly manufactured using a one-piece molding process, with the two parts connected by a rotating shaft, and the material is usually copper, which has good conductivity. However, copper is relatively soft, and the end connected to the operating handle is prone to wear under long-term mechanical operation, leading to an increase in the mating clearance and affecting the accuracy and reliability of operation. In addition, when a large current passes through the rotating shaft, the shaft is prone to overheating and burning due to the low melting point of copper, which may even lead to shaft failure. This not only reduces the service life of the circuit breaker but may also cause safety hazards such as poor contact or arcing. Utility Model Content

[0004] In view of the shortcomings of the prior art, this utility model provides a split-type moving contact for circuit breakers that solves the problems of easy wear of moving contacts and overheating of rotating shafts.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a split-type moving contact for a circuit breaker, comprising an operating handle and a moving contact cooperating with the operating handle. During rotation, the operating handle drives the moving contact to contact or separate from the stationary contact. The moving contact includes a mechanical mating part and a contact mating part. The contact mating part cooperates with the stationary contact and is made of copper. The mechanical mating part has a higher hardness than the contact mating part and a lower conductivity than the contact mating part.

[0006] The beneficial effects of this utility model are as follows: By adopting a split structural design, the moving contact is divided into a mechanical mating part and a contact mating part. The mechanical mating part has higher hardness and lower conductivity, effectively solving the problems of easy wear under long-term mechanical operation and overheating and burning of the shaft part under high current in traditional one-piece copper moving contacts. The mechanical mating part bears the main mechanical stress, reduces wear at the mating point with the operating handle, maintains a stable mating clearance, and thus improves the accuracy and reliability of operation. At the same time, its lower conductivity reduces heat concentration under high current, reduces the risk of shaft overheating, extends the service life of the circuit breaker, and reduces safety hazards such as poor contact or arcing failure. As a preferred embodiment, the mechanical mating part is made of iron-based alloy material, which has high hardness and moderate thermal conductivity, can withstand repeated mechanical operation without plastic deformation, and helps to disperse local heat through the thermal conductivity of the material itself. As another preferred embodiment, the mechanical mating part and the contact mating part are connected by a snap-fit ​​structure, using the interlocking of protrusions and grooves to ensure synchronous movement during rotation, while allowing independent material selection to optimize mechanical strength and electrical performance.

[0007] Furthermore, the mechanical mating parts are made of metal.

[0008] By explicitly specifying that the mechanical mating parts are made of metal, the mechanical durability and thermal management capabilities of the moving contacts are further enhanced. Metal materials such as iron or aluminum alloys provide high hardness and strength, effectively resisting wear during long-term operation and maintaining mating precision. Simultaneously, their relatively low conductivity allows them to act as passive heat dissipation components, helping to conduct and dissipate the heat generated by the large current in the contact mating parts, reducing temperature rise in the rotating shaft and thus avoiding burn-out due to overheating. As a preferred option, the mechanical mating parts are made of die-cast aluminum alloy. The die-casting process ensures material density and uniformity, while the lightweight nature of aluminum alloy reduces motion inertia, improving the circuit breaker's operating response speed. Its good thermal conductivity promotes heat diffusion from the contact area to the outside. As another preferred option, the surface of the mechanical mating parts undergoes a hardening treatment, such as nitriding, to form a wear-resistant layer, further improving wear resistance while maintaining a certain level of heat dissipation efficiency.

[0009] Furthermore, the mechanical mating part is provided with a rotating shaft, the contact mating part is provided with a mating hole corresponding to the rotating shaft, the rotating shaft is provided with a fixing hole with a diameter equivalent to the mating hole, and the contact mating part is connected to the rotating shaft by means of fasteners passing through the mating hole.

[0010] This structure achieves reliable connection and synchronous rotation between the mechanical mating parts and the contact mating parts. The design of the shaft and mating hole ensures precise alignment, and the fasteners provide a firm fixation, preventing relative displacement and improving overall stability and operational consistency. In conventional molded case circuit breakers, a tension spring is added to the shaft. One end of the spring is fixed to the shaft, and the other end is connected to the circuit breaker housing. During opening and closing, it provides a reset force, assisting the moving contact to quickly return to its original position when opening, enhancing response speed and reducing operational lag, thereby improving the safety and reliability of the circuit breaker. As a preferred option, the shaft is designed as a stepped shaft with a threaded end, and a corresponding thread is provided in the mating hole. A nut is used as a fastener to lock it in place, achieving a gapless connection and allowing adjustment of the preload. As another preferred option, the tension spring adopts a helical spring structure. Its tension is transmitted to the moving contact through the shaft, maintaining continuous tension during rotation, allowing the moving contact to automatically reset to the open position without external force, reducing the risk of residual current.

[0011] Furthermore, the operating handle is provided with a mating inclined surface on one side of the mechanical mating part, and the mechanical mating part is provided with a mating arc surface corresponding to the mating inclined surface. The mating inclined surface and the mating arc surface are always in contact with each other during the opening and closing of the circuit breaker.

[0012] The continuous contact design of the inclined and curved surfaces ensures smooth force transmission between the operating handle and the mechanical mating parts, reducing impact and vibration, and improving operational smoothness and accuracy. The surface contact method disperses mechanical stress, reducing localized wear and fatigue damage that may result from point contact, extending component lifespan and maintaining a uniform distribution of operating force. As a preferred approach, the inclined surface employs a multi-segment involute profile, and the curved surface is a concave surface with a corresponding curvature, allowing the contact area to change continuously during rotation, achieving a smooth transition and minimizing frictional resistance. As another preferred approach, the curved surface embeds rolling elements such as miniature bearings, converting sliding friction into rolling friction, further reducing operating force and wear, and improving transmission efficiency.

[0013] Furthermore, the mechanical mating part is provided with an indicator at the indicator window corresponding to the housing, which rotates synchronously with the mechanical mating part. The indicator is used to display the opening and closing status of the circuit breaker when the circuit breaker is opened or closed.

[0014] The indicator section provides an intuitive and reliable status display mechanism, allowing users to directly observe the circuit breaker's opening and closing status through the indicator window, facilitating operation, monitoring, and maintenance. Synchronous rotation ensures that the display matches the actual position of the moving contact, avoiding misjudgments. Simultaneously, mechanical linkage reduces the need for additional sensors, simplifying the structure and improving reliability. As a preferred approach, the indicator section is designed as a marked sector-shaped disk, integrally molded with the mechanical mating parts, ensuring no relative rotation. Changing marking colors or patterns enhance visual recognizability. Alternatively, a guide groove is provided on the housing as a limit, allowing the indicator section to slide along the guide groove, preventing it from detaching from the indicator window during rotation, while also limiting the rotation range to ensure display accuracy and stability. Attached Figure Description

[0015] Figure 1 This is an internal view of an embodiment of the present utility model; Figure 2 This is an isometric view of an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the operating handle and the mechanical mating part in an embodiment of the present utility model; Figure 4 This is a schematic diagram of the structure of the contact mating part and the mechanical mating part in an embodiment of the present utility model. Detailed Implementation

[0016] This utility model provides a split-type moving contact for a circuit breaker, such as... Figure 1-4 As shown: The circuit breaker includes an operating handle 1 and a moving contact 2 that cooperates with the operating handle 1. During rotation, the operating handle 1 drives the moving contact 2 to contact or separate from the stationary contact, thereby realizing the opening and closing operation of the circuit breaker. The moving contact 2 adopts a split design, including a mechanical mating part 21 and a contact mating part 22. The contact mating part 22 is made of copper, a material with good conductivity, and is used to directly contact the stationary contact to conduct current. The mechanical mating part 21 is made of a metal material with higher hardness, such as iron or aluminum alloy. Its hardness is greater than that of the contact mating part 22, but its conductivity is weaker. This design not only enhances the overall mechanical strength of the moving contact 2 but also serves as a passive heat dissipation component for the contact mating part 22, improving the service life and reliability of the circuit breaker.

[0017] A rotating shaft 211 is provided on the mechanical mating part 21, and a mating hole 221 is provided on the contact mating part 22 corresponding to the rotating shaft 211. A fixing hole with a diameter equivalent to that of the mating hole 221 is provided on the rotating shaft 211. The contact mating part 22 is fixedly connected to the rotating shaft 211 by inserting a fastener (not shown in the figure) through the mating hole 221, thereby realizing the synchronous rotation of the mechanical mating part 21 and the contact mating part 22. A tension spring (not shown in the figure) is also provided on the rotating shaft 211. One end of the tension spring (not shown in the figure) is fixed to the rotating shaft 211, and the other end is fixed to the circuit breaker housing. The function of the tension spring (not shown in the figure) is to provide the necessary reset force or holding force during the opening and closing process of the circuit breaker, ensuring that the moving contact 2 stays stably in the open or closed position and avoiding malfunction.

[0018] The operating handle 1 has a mating inclined surface 11 on one side corresponding to the mechanical mating part 21, and the mechanical mating part 21 has a mating arc surface 212 corresponding to the mating inclined surface 11. The mating inclined surface 11 and the mating arc surface 212 always abut against each other during the opening and closing of the circuit breaker, so that the rotation of the operating handle 1 can be smoothly transmitted to the mechanical mating part 21 through the mating of the inclined surface and the arc surface, thereby driving the entire moving contact 2 to rotate. The mechanical mating part 21 is also provided with an indicator part 213, which moves according to the synchronous rotation of the mechanical mating part 21, and is used to display the opening and closing status of the circuit breaker at the indicator window of the housing. The housing is provided with a limiting structure that cooperates with the indicator part 213 to prevent the indicator part 213 from disengaging from the indicator window during rotation, ensuring the accuracy and stability of the status display.

[0019] When the circuit breaker is in operation, the operating handle 1 is driven to rotate by the user or the drive mechanism. Through the interaction between the mating inclined surface 11 and the mating arc surface 212, the mechanical mating part 21 is pushed to rotate around the rotating shaft 211. The mechanical mating part 21 drives the contact mating part 22 to move synchronously, so that the contact mating part 22 contacts or separates from the stationary contact, realizing the connection or disconnection of the circuit. The tension spring (not shown in the figure) provides tension assistance during rotation to ensure smooth operation and position locking. The indicator part 213 rotates with the mechanical mating part 21 and displays the opening and closing status intuitively in the indicator window, which is convenient for the user to observe and operate.

[0020] The above embodiments are merely one preferred embodiment of the present utility model. Ordinary changes and substitutions made by those skilled in the art within the scope of the present utility model's technical solution are all included within the protection scope of the present utility model.

Claims

1. A split-type moving contact for a circuit breaker, comprising an operating handle and a moving contact cooperating with the operating handle, wherein the operating handle, during rotation, causes the moving contact to contact or separate from a stationary contact, characterized in that: The moving contact includes a mechanical mating part and a contact mating part. The contact mating part mates with the stationary contact and is made of copper. The mechanical mating part has a higher hardness than the contact mating part and a lower conductivity.

2. The split-type moving contact for a circuit breaker according to claim 1, characterized in that: The mechanical mating parts are made of metal.

3. The split-type moving contact for a circuit breaker according to claim 2, characterized in that: The mechanical mating part is provided with a rotating shaft, the contact mating part is provided with a mating hole corresponding to the rotating shaft, the rotating shaft is provided with a fixing hole with a diameter equivalent to the mating hole, and the contact mating part is connected to the rotating shaft by means of fasteners passing through the mating hole.

4. The split-type moving contact for a circuit breaker according to claim 1, characterized in that: The operating handle has a mating inclined surface on one side corresponding to the mechanical mating part, and the mechanical mating part has a mating arc surface corresponding to the mating inclined surface. The mating inclined surface and the mating arc surface are always in contact with each other during the opening and closing of the circuit breaker.

5. The split-type moving contact for a circuit breaker according to claim 1, characterized in that: The mechanical mating part is provided with an indicator part at the indicator window corresponding to the housing, which rotates synchronously with the mechanical mating part. The indicator part is used to display the opening and closing status of the circuit breaker when the circuit breaker is opened or closed.

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