Moving contact assembly

Abstract

A kind of movable contact assembly, including shell and movable contact rotationally arranged in shell, the movable contact is provided with contact point towards static contact side, and suspension assembly is also arranged in the shell, when the movable contact is separated from contact due to repulsion between large current and static contact, the suspension assembly is used to maintain the separation state between movable contact and static contact at this time.The beneficial effects of the utility model are: by setting suspension assembly, when movable contact is automatically bounced off due to the repulsion of large current, its separation state is immediately maintained, re-contact caused by delay of release device is avoided, so as to effectively reduce the risk of contact temperature rise and material damage, improve the response efficiency and reliability of circuit breaker.

Description

Technical Field

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

[0002] The moving contact in a circuit breaker is a critical protective component in power systems, widely used in low-voltage and high-voltage distribution networks. It enables rapid circuit opening and closing to handle faults such as overloads and short circuits. Under normal operating conditions, the moving contact maintains close contact with the stationary contact via an operating mechanism (such as a spring or electromagnetic drive), ensuring normal current flow. When an abnormally large current occurs in the circuit, the trip unit (such as a thermomagnetic or electronic type) detects the current change and triggers the trip mechanism, causing the moving contact to move rapidly and separate from the stationary contact, thereby disconnecting the circuit and preventing equipment damage or safety accidents. This process relies on the accurate sensing of the trip unit and the mechanical response of the moving contact, and is commonly found in residential, commercial, and industrial electrical protection devices.

[0003] However, existing moving contact assemblies have significant drawbacks. When a large current is generated between the moving and stationary contacts, the trip unit must first sense the current before initiating the tripping action, a process with an unavoidable time delay. During this period, the large current continues to flow through the contacts, causing a rapid increase in contact temperature, which may lead to welding, ablation, or permanent damage to the contact material. This time difference not only reduces the response efficiency and reliability of the circuit breaker but may also exacerbate the consequences of a fault, such as triggering an electric arc or equipment failure, affecting the safe operation of the entire system. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a moving contact assembly that solves the problem of delayed separation between moving and stationary contacts under high current conditions.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a moving contact assembly, comprising a housing and a moving contact rotatably disposed within the housing, wherein the moving contact has a contact point on the side facing the stationary contact, and a suspension assembly is also disposed within the housing, wherein when the moving contact disengages from the stationary contact due to repulsion generated between the moving contact and the stationary contact by a large current, the suspension assembly is used to maintain the disengaged state between the moving contact and the stationary contact at this time.

[0006] The beneficial effects of this invention are as follows: By setting a hovering component, when the moving contact automatically springs open due to the repulsive force generated by a large current, it can immediately maintain its disengaged state, avoiding re-contact caused by the delay of the trip unit. This effectively reduces the risk of contact temperature rise and material damage, improving the response efficiency and reliability of the circuit breaker. Furthermore, this design simplifies the operating mechanism, reduces the probability of failure, helps prevent arcing and equipment failure, and enhances the safe operation of the entire system. As a preferred embodiment, the hovering component may include a lever mechanism pivotally mounted on the housing. This lever contacts the moving contact through a trigger point. When the moving contact moves due to the repulsive force, the lever is pushed to a locked position, mechanically interlocking to keep the moving contact away from the stationary contact. The trigger point of the lever is designed with a beveled structure, generating sliding contact when the moving contact moves, ensuring a smooth transition to the locked state. As another preferred approach, the hovering assembly can employ a spring-loaded slider system. The slider is housed within the housing and linked to the moving contact. When the moving contact is displaced due to repulsive force, the slider moves to the locking point under the action of the spring force, forming a physical barrier to prevent the moving contact from returning. The preload of the spring is adjustable to adapt to different current conditions.

[0007] Furthermore, after the moving contact is disengaged from the stationary contact due to the repulsive force generated between the large current and the stationary contact, the hovering component drives the moving contact to move away from the stationary contact.

[0008] By actively moving the moving contact further away from the stationary contact using a hovering assembly, the safe distance between them is increased, thereby more effectively preventing accidental contact caused by residual current or vibration, and improving isolation and fault protection capabilities. This reduces the risk of arcing and equipment damage, while optimizing the spatial layout of the circuit breaker, making the assembly more compact and efficient. As a preferred approach, the hovering assembly can integrate a linear actuator, such as an electromagnetic coil or pneumatic piston. When the moving contact is detected to disengage, the actuator is activated, acting directly on the moving contact via a push rod to apply an additional force, accelerating it away from the stationary contact. The actuator's control signal comes from a current sensor to ensure synchronized operation. Alternatively, the hovering assembly can be designed as a rack and pinion mechanism. The rack is fixed to the moving contact, and the gear is driven by a small motor. When the moving contact initially moves due to repulsive force, the motor starts, and the rotation of the gear pushes the rack to extend, thereby increasing the disengagement distance. The gear mechanism is equipped with a clutch that engages only when repulsive force is generated.

[0009] Furthermore, the hovering assembly includes a rocker arm, and the moving contact is provided with a force-applying end that is always in contact with the rocker arm. The force-applying end is located closer to the end of the moving contact that contacts the stationary contact than the hinge point between the moving contact and the housing.

[0010] The optimized rocker arm and force-applying end design improves force transmission efficiency, allowing the hovering assembly to act more directly and efficiently on the critical parts of the moving contact. This facilitates rapid force application to drive movement when repulsive forces are generated, reducing energy loss and mechanical lag. This enhances the assembly's response speed and stability while reducing wear and extending its service life. As a preferred embodiment, the rocker arm can be an L-shaped lever, with one end hinged to the housing and the other end in contact with the force-applying end, which is a protrusion on the moving contact. When the moving contact moves, the protrusion pushes the rocker arm to rotate, amplifying the force through the lever ratio, thus easily driving the moving contact. Alternatively, the rocker arm can employ a rocker arm mechanism, with the rocker arm mounted on the housing via bearings. The force-applying end is a roller on the moving contact, always in rolling contact with the rocker arm surface. The roller's design reduces friction, and the rocker arm's profile optimizes the force direction, ensuring smooth and efficient motion transmission.

[0011] Furthermore, the hovering assembly also includes elastic elements at both ends that abut against the rocker and the housing, respectively. The elastic elements abut against one end of the rocker so that the rocker always generates a torque to drive the moving contact to move away from the stationary contact.

[0012] The introduction of the elastic element provides a continuous preload torque, ensuring that the rocker will not move unexpectedly when stationary, but responds immediately when repulsive force is generated, driving the moving contact away, thereby enhancing reliability and safety while avoiding interference with normal operation. This achieves automatic reset and stable holding, reducing the need for external intervention. As a preferred embodiment, the elastic element can be a compression spring, mounted between a fixed seat on the housing and a groove on the rocker. The spring's compression force is set to be less than the operating mechanism torque, but when repulsive force occurs, the spring's stored energy is released to assist the rocker's rotation; the spring is made of a high-elasticity alloy to withstand frequent cycles. Alternatively, the elastic element can be a torsion spring, fitted onto the rocker's hinge shaft, with one end fixed to the housing and the other hooked onto the rocker. The torque of the torsion spring always tends to push the rocker away from the moving contact; the installation angle of the torsion spring is adjustable to optimize torque output.

[0013] Furthermore, the housing is provided with a limiting groove that forms a clearance fit with the elastic element.

[0014] The design of the limiting groove constrains the movement range of the elastic element through clearance fit, preventing it from falling off or shifting during operation. This improves the structural stability and durability of the component, reduces maintenance requirements, and ensures that the elastic element always operates in the predetermined position, avoiding performance deviations. As a preferred embodiment, the limiting groove can be a U-shaped channel formed on the inner wall of the housing. One end of the elastic element is inserted into the groove, and the width of the groove is slightly larger than the diameter of the elastic element, allowing for minor movement but preventing it from falling out. A guide ramp is provided at the entrance of the channel for easy installation and alignment. Alternatively, the limiting groove can employ a ring-shaped clamp structure, fixed inside the housing. The elastic element passes through the center of the clamp, and the inner diameter of the clamp matches the outer diameter of the elastic element, forming a sliding fit. The clamp is made of wear-resistant plastic to reduce friction and noise. Attached Figure Description

[0015] Figure 1 This is an overall structural diagram of an embodiment of the present utility model; Figure 2 This is a partial enlarged view of the rocker section of this utility model; Figure 3 This is a schematic diagram of the moving contact and hovering assembly in an embodiment of the present invention. Detailed Implementation

[0016] An embodiment of this utility model provides a moving contact assembly, such as... Figure 1-3 As shown: The device includes a housing 1 and a movable contact 2 rotatably disposed within the housing 1. The movable contact 2 is connected to the housing 1 via a hinge shaft 22 to achieve rotation. A contact point 3 is provided on the side of the movable contact 2 facing the stationary contact for conducting electricity. A suspension assembly 4 is also provided within the housing 1. The suspension assembly 4 is used to maintain the movable contact 2 in a disengaged state from the stationary contact when the movable contact 2 loses contact due to repulsion generated between it and the stationary contact caused by a large current, thereby improving the response speed.

[0017] The hovering assembly 4 includes a rocker arm 41. A force-applying end 21, which is always abutted against the rocker arm 41, is provided on the moving contact 2. This force-applying end 21 is positioned closer to the end of the moving contact 2 that contacts the stationary contact than the hinge point between the moving contact 2 and the housing 1, to facilitate the application of force by the rocker arm 41. The hovering assembly 4 also includes an elastic element 42, which is a spring or other elastic component. Its two ends abut against the rocker arm 41 and the housing 1, respectively. The elastic element 42 abutting against one end of the rocker arm 41 ensures that the rocker arm 41 always generates a torque that drives the moving contact 2 to move away from the stationary contact. However, this torque will not exceed the torque applied to the moving contact 2 by the operating mechanism, ensuring reliable contact between the moving and stationary contacts during normal operation.

[0018] The housing 1 is provided with a limiting groove 11 that forms a clearance fit with the elastic element 42. The limiting groove 11 is used to accommodate and position the elastic element 42, preventing the elastic element 42 from detaching from the housing 1 and the rocker plate 41, thus ensuring stability.

[0019] When a large current appears in the circuit, the moving contact 2 and the stationary contact are separated due to the current repulsion force. At this time, under the torque of the elastic element 42, the rocker plate 41 of the suspension assembly 4 drives the moving contact 2 to move away from the stationary contact through the force application end 21, increasing the safe distance between the moving contact 2 and the stationary contact, and keeping it in the disengaged state, waiting for the trip unit to act, thereby quickly responding to the fault current.

[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 moving contact assembly, comprising a housing and a moving contact rotatably disposed within the housing, wherein the moving contact has a contact point disposed on the side facing the stationary contact, characterized in that: The housing is also equipped with a suspension component. When the moving contact is disengaged from the stationary contact due to the repulsive force generated between the moving contact and the stationary contact by the large current, the suspension component is used to maintain the disengaged state between the moving contact and the stationary contact.

2. The moving contact assembly according to claim 1, characterized in that: After the moving contact is disengaged from the stationary contact due to the repulsive force generated between the large current and the stationary contact, the hovering component drives the moving contact to move away from the stationary contact.

3. The moving contact assembly according to claim 2, characterized in that: The hovering assembly includes a rocker arm, and the moving contact is provided with a force-applying end that is always in contact with the rocker arm. The force-applying end is located closer to the end of the moving contact that contacts the stationary contact than the hinge point between the moving contact and the housing.

4. The moving contact assembly according to claim 3, characterized in that: The hovering assembly also includes elastic elements at both ends that abut against the rocker and the housing, respectively. The elastic elements abut against one end of the rocker so that the rocker always generates a torque to drive the moving contact in a direction away from the stationary contact.

5. The moving contact assembly according to claim 4, characterized in that: The housing is provided with a limiting groove that forms a clearance fit with the elastic element.

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