Motor contactor
By using a motor-driven gear cam combination mechanism and a magnetic tripping device, the contactor achieves efficient closing self-locking and automatic fault current tripping, solving the problems of insufficient driving force and high power consumption of existing DC contactors, and improving breaking capacity and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-03-06
AI Technical Summary
The electromagnetic system of existing DC contactors has limited driving force, resulting in insufficient breaking capacity, and requires continuous power to maintain the closed state, resulting in high power consumption.
The contactor is closed and self-locked by a combination of motor-driven gear and cam mechanism, which is driven by the motor to move the push rod. Combined with a magnetic tripping device, it is forced to open during fault current.
It improves the contactor's breaking speed and stability, reduces power consumption, and automatically disconnects the circuit during fault current.
Smart Images
Figure CN223977874U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of contactor technology, and to a motor contactor that replaces electromagnetic drive and is driven by an electric motor. Background Technology
[0002] A DC contactor is a mechanical device that uses electromagnetic principles to close and release the moving and stationary iron cores, thereby connecting and disconnecting the moving and stationary contacts. In existing DC contactor electromagnetic systems, the driving force provided by the electromagnetic system within a limited volume is limited, resulting in constraints on its reaction force setting. This makes it unable to meet current requirements for breaking capacity, the ability to prevent the moving and stationary contacts from disengaging during the closing state, and other performance characteristics. Furthermore, the electromagnetic system needs to remain energized after the moving and stationary contacts are closed to maintain the closed state, resulting in relatively high power consumption. Summary of the Invention
[0003] The purpose of this invention is to provide a motor contactor that replaces electromagnetic drive with motor drive, achieving self-locking of the contactor while it is closing, thereby improving the stability of the contactor's operation.
[0004] To achieve the above objectives, the present invention provides a motor contactor, comprising: a moving contact, a stationary contact, a linearly displaceable push rod, a drive motor, a gear-cam assembly mechanism, a locking mechanism, a force-receiving structure, and a limiting structure; a contact spring and the moving contact are disposed at one end of the push rod facing the stationary contact, the moving contact abutting against the contact spring; the force-receiving structure and the limiting structure are spaced apart along the length of the push rod on its outer circumferential surface; the locking mechanism is rotatably disposed relative to the push rod and can be reset under its own elastic force; in normal operating condition, when the circuit is closed, the drive motor drives the gear-cam assembly mechanism to rotate, the gear-cam assembly mechanism abutting against the force-receiving structure, driving the push rod to move the moving contact toward the stationary contact, so that the moving contact closes with the stationary contact. The displacement of the push rod further compresses the contact spring; simultaneously, the push rod carries the limiting structure to displacement. During the displacement, the limiting structure abuts against the locking mechanism, causing it to rotate. After rotating, the locking mechanism resets under its own elastic force, with the end abutting the limiting structure away from the stationary contact limiting the push rod. When the circuit is opened, the drive motor drives the gear cam assembly to continue rotating, disengaging the gear cam assembly from the force-bearing structure. The gear cam assembly drives the locking mechanism to rotate, disengaging from the limiting structure and releasing the limiting of the push rod. Under the elastic force of the contact spring, the push rod carries the limiting structure to displacement away from the stationary contact, opening the circuit between the moving contact and the stationary contact. The locking mechanism resets under its own elastic force.
[0005] Preferably, the gear-cam combination mechanism includes a large cam, a small cam, and a driven gear arranged coaxially. The driving gear meshes with the driven gear. The drive motor drives the driving gear to rotate, thereby causing the large cam and the small cam to rotate synchronously. When the circuit is closed, the large cam acts on the force-bearing structure. When the circuit is opened, the small cam acts on the locking mechanism.
[0006] Preferably, the locking mechanism includes a limiting arm and a return spring. The limiting arm is rotatably disposed on one side of the push rod. One end of the limiting arm can abut against the small cam, and the other end is fixedly connected to one end of the return spring. The other end of the return spring is fixedly disposed. A buckle is fixedly disposed on the side of the limiting arm that is fixedly connected to the return spring facing the push rod. In the open state, the buckle is located outside the end of the limiting structure facing the moving contact. In the closed state, the limiting structure is displaced, causing the buckle to drive the limiting arm to rotate first. Then, under the action of the return spring, the buckle is reset. After reset, the buckle abuts against the end of the limiting structure away from the moving contact, limiting the push rod.
[0007] Preferably, one or both of the end face of the limiting structure facing the moving contact and the end face of the latch away from the moving contact are configured as inclined structures. When the circuit is closed, the limiting structure abuts against the inclined structure of the latch, causing the latch to drive the limiting arm to rotate.
[0008] Preferably, the limiting structure is a limiting protrusion fixedly disposed on the outer periphery of the push rod, and the side of the limiting protrusion facing the moving contact is configured as the inclined surface structure.
[0009] Preferably, a magnetic tripping device is also provided on one side of the push rod. The magnetic tripping device is arranged around the circuit formed by the closing of the moving contact and the stationary contact, or connected in parallel with the circuit formed by the closing of the moving contact and the stationary contact. One end of the limiting arm connected to the reset spring extends toward the magnetic tripping device to form a force arm. The force arm is located on the displacement path of the magnetic tripping device when it trips. When the current in the circuit formed after the moving contact and the stationary contact are closed exceeds a set threshold, the magnetic tripping device trips, driving the force arm to rotate the latch, causing the latch to disengage from the limiting structure and release the limiting. Under the elastic force of the contact spring, the moving contact and the stationary contact are disconnected.
[0010] Preferably, the magnetic tripping device includes an electromagnetic coil and a moving magnetic mechanical component passing through the electromagnetic coil. The force arm is located on the displacement path of the moving magnetic mechanical component. The electromagnetic coil is electrically connected to both ends of the moving contact via a flexible cable. When the magnetic tripping device trips, the moving magnetic mechanical component is displaced under the magnetic force of the electromagnetic coil, driving the force arm to rotate.
[0011] Preferably, the two ends of the moving contact that make conductive contact with the stationary contact are conductive springs.
[0012] Preferably, a reaction spring is sleeved on the push rod. When the circuit is open, the reaction spring is in a compressed state. When the circuit is closed, the displacement of the push rod further compresses the reaction spring. When the push rod is released from its limit, the moving contact and the stationary contact are separated under the combined action of the reaction spring and the contact spring.
[0013] Preferably, a limit support is provided on the push rod, one end of the reaction spring abuts against the support and the other end abuts against the housing of the motor contactor; when the circuit is closed, the push rod is displaced, causing the reaction spring to be further compressed.
[0014] The motor contactor of the present invention uses a motor to mechanically drive a gear cam combination mechanism to rotate, thereby driving a push rod to move in a mechanical way, causing the moving contact and the stationary contact to close. The motor drive increases the driving force, allowing the reaction spring and the contact spring to be sufficiently compressed, thereby increasing the reaction force of the reaction spring and the contact spring, improving the contact resistance of the contactor and increasing the breaking speed.
[0015] By setting a magnetic trip device, when the current in the circuit formed by the contact of the moving contact and the stationary contact exceeds a set threshold, the magnetic trip device trips, forcibly releasing the locking mechanism from the limit of the push rod. Then, through the elastic force of the reaction spring and the contact spring, the moving contact and the stationary contact are separated, and the circuit is opened. This achieves self-disconnection during fault current, enabling the contactor to have the functions of a contactor and a circuit breaker at the same time. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the contactor structure.
[0017] Figure 2 This is a schematic diagram of the push rod and gear cam combination mechanism.
[0018] Figure 3 This is a schematic diagram of the push rod, locking mechanism, and gear-cam combination mechanism.
[0019] Figure 4 This is a schematic diagram of a contactor structure equipped with a magnetic tripping device.
[0020] Figure 5 This is a front view schematic diagram of the magnetic release device combined with the push rod, gear, and cam mechanism.
[0021] Figure 6 This is a three-dimensional structural diagram of the magnetic release device combined with the push rod, gear, and cam mechanism.
[0022] Figure 7 This is a three-dimensional structural diagram of the magnetic release device combined with the push rod, gear, and cam mechanism from another angle.
[0023] Figure 8 This is a schematic diagram of the locking mechanism.
[0024] Figure label:
[0025] Planar support plate 100, push rod 101, stationary contact 102, moving contact 103, contact spring 104, reaction spring 105, force-bearing structure 106, limiting structure 107, driven gear 201, small cam 202, large cam 203, drive motor 301, bevel gear 302, driving gear 303, limiting arm 401, rotating shaft 402, spring fixing shaft 403, return spring 404, buckle 405, force-bearing arm 406, magnetic release device 5, electromagnetic coil 501, moving magnetic mechanical component 502, flexible cable 503. Detailed Implementation
[0026] The motor contactor of the present invention includes: a moving contact, a stationary contact, a linearly displaceable push rod, a drive motor, a gear-cam assembly mechanism, a locking mechanism, a force-receiving structure, and a limiting structure; a contact spring and a moving contact are provided at one end of the push rod facing the stationary contact, with the moving contact abutting against the contact spring; a force-receiving structure and a limiting structure are provided at intervals along the length of the push rod on its outer circumferential surface; the locking mechanism is rotatably disposed relative to the push rod and can be reset under its own elastic force; under normal operating conditions, when the circuit is closed, the drive motor drives the gear-cam assembly mechanism to rotate, the gear-cam assembly mechanism abuts against the force-receiving structure, and drives the push rod to move the moving contact toward the stationary contact, causing the moving contact to close with the stationary contact. The displacement of the push rod further compresses the contact spring; simultaneously, the push rod carries the limiting structure away from the stationary contact. During the displacement, the limiting structure contacts the locking mechanism, causing it to rotate. After rotating, the locking mechanism resets under its own elastic force. The end of the limiting structure away from the stationary contact limits the push rod. When the circuit is opened, the drive motor drives the gear cam combination mechanism to continue rotating. The gear cam combination mechanism disengages from the force-bearing structure and drives the locking mechanism to rotate, disengaging from the limiting structure and releasing the limit on the push rod. Under the elastic force of the contact spring, the push rod carries the limiting structure away from the stationary contact, causing the moving contact to open from the stationary contact. The locking mechanism resets under its own elastic force.
[0027] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solution of this invention.
[0028] See Figures 1 to 3 The motor contactor has a housing, which is divided into two cavities by a flat support plate 100. A push rod 101 is disposed in the cavity below the flat support plate 100. The push rod 101 passes through the flat support plate 100, and its two ends are located in the two different cavities separated by the flat support plate. The stationary contact 102 and the moving contact 103 are located in the cavity at the top of the housing. The moving contact 103 is located at the end of the push rod 101 in the cavity at the top of the housing and is supported by a contact spring 404, which is in a compressed state. In this embodiment, the two ends of the moving contact that contacts the stationary contact are conductive springs with a certain elasticity, which can buffer the impact force when closing the circuit. A reaction spring 105 is sleeved on the push rod 101 and located in the cavity below the planar support plate 100. A support member (not shown) is provided on the outer periphery of the push rod 101. The reaction spring 105 is located between the planar support plate and the support member on the push rod 101. In the initial state, the reaction spring 105 is in a compressed state. The support member can be an annular protrusion structure provided on the outer periphery of the push rod, or other structures that can limit the position of the reaction spring. A force-bearing structure 106 and a limiting structure 107 are provided at intervals on the outer periphery of the push rod 101 below the reaction spring 105. The force-bearing structure 106 is a planar force-bearing plate provided around the outer periphery of the push rod 101. The limiting structure 107 is a limiting protrusion provided around the outer periphery of the push rod 101. The end of the limiting protrusion facing the moving contact is set as a bevel structure, so that the cross-section of the limiting protrusion is a wedge-shaped structure. A support guide seat is provided at the bottom of the cavity at the bottom of the housing. The push rod 101 passes through the support guide seat and the flat support plate. The push rod is guided and limited by the support guide seat and the flat support plate to ensure that the push rod 101 makes linear displacement.
[0029] The gear-cam combination mechanism 2 is rotatably disposed in the cavity at the bottom of the housing. The gear-cam combination mechanism includes a driven gear 201, a small cam 202, and a large cam 203, all coaxially fixed. When the large cam 203 rotates, it only contacts the force-bearing structure 106 on the push rod 101 during closing. This rotational torque is applied to the force-bearing structure 106, driving the push rod 101 to move towards the stationary contact 102 along with the limiting structure 107 and the moving contact 103. This allows the moving contact to make conductive contact with the stationary contact, thus closing the circuit. During the displacement of the limiting structure 107, it contacts the locking mechanism, causing it to rotate. As the limiting structure 107 moves, it passes the locking mechanism and no longer contacts it. The locking mechanism resets under the action of elastic force, located at the end of the limiting structure 107 furthest from the moving contact, thus limiting the displacement of the push rod away from the stationary contact. Only during the opening phase, when the small cam rotates, it can abut against the locking mechanism, causing it to rotate and disengage from the locking mechanism, which in turn disengages from the limiting structure 107. This allows the push rod to displace under the action of the reaction spring 105 and the contact spring. The limiting structure 107 then displaces past the locking mechanism, resetting the locking mechanism and returning the limiting structure to its initial position before closing. There is a certain angle between the line connecting the protrusion of the large cam 203 to the axis and the line connecting the protrusion of the small cam 202 to the axis. In this embodiment, the angle is 180 degrees, ensuring that when the moving and stationary contacts close, the large cam first drives the push rod to displace, while the small cam idles. During the opening phase, the large cam disengages from the force-bearing structure 106 and then idles, while the small cam drives the locking mechanism to rotate, releasing it from the limiting structure 107 and thus releasing the limit on the push rod.
[0030] The motor drive mechanism includes a drive motor 301, a bevel gear 302 mounted on the main shaft of the drive motor 301, a drive gear 303 meshing with the bevel gear 302, and a driven gear 201 meshing with the drive gear 303 on a gear cam assembly mechanism. When the drive motor 301 rotates, it drives the drive gear 303 to rotate, which in turn drives the driven gear 201 to rotate. The rotation of the driven gear 201, in turn, drives the large cam 203 and the small cam 202, which are coaxially arranged, to rotate synchronously.
[0031] A locking mechanism, located on one side of the gear cam assembly mechanism, includes a limiting arm 401. One end of the limiting arm 401 has a rotating shaft 402, and the other end has a spring fixing shaft 403. One end of the limiting arm 401 with the rotating shaft is bent towards the gear cam assembly mechanism and located on the side of the small cam 202 of the gear cam assembly mechanism. The limiting arm 401 is rotatably mounted in the bottom cavity of the housing via the rotating shaft 402. One end of the return spring 404 is fixedly connected to the spring fixing shaft 403, and the other end is fixedly mounted away from the gear cam assembly mechanism. A protruding latch 405 is fixedly mounted on the side of the limiting arm with the spring fixing shaft 403 facing the push rod 101. The end face of the latch 405 away from the moving contact is set as a bevel structure. In the initial position, the latch 405 is located on the bevel structure of the limiting structure 106 of the push rod 101, that is, the latch 405 is located outside the end of the limiting structure 106 facing the stationary contact. When the moving and stationary contacts need to close, the drive motor 301 rotates, driving the bevel gear 302 to rotate, which in turn drives the drive gear 303 to rotate. The drive gear 303, in turn, drives the driven gear 201, which meshes with it, to rotate, thereby driving the gear cam assembly mechanism to rotate. As the gear cam assembly mechanism rotates, the protrusion of the large cam first abuts against the force-bearing structure 106 on the push rod 101, driving the push rod to move the moving contact toward the stationary contact to close the circuit. During the push rod's displacement and closing process, the limiting structure 107 on the push rod abuts against the inclined structure of the latch 405, causing the latch 405 to drive the force-bearing arm and the limiting arm to rotate together around the rotation axis 402. After closing, the limiting structure 106 of the push rod 101 moves to above the locking position of the latch 405, that is, moves to the position of the latch 405. 5. On the outer side of the stationary contact, the limiting structure 106 disengages from the latch 405. Under the elastic force of the return spring 404, the latch 405 returns to its original position. At this time, the locking position of the latch 405 abuts against the end face of the limiting structure 107 away from the moving contact, thus limiting the position of the push rod 101. After closing, the drive motor stops rotating, and the protrusion of the large cam is in a state of about to disengage from the force-bearing structure 106. During the closing process, the reaction spring 105 and the contact spring are further compressed.
[0032] When it is necessary to open the circuit breaker, the drive motor continues to rotate, driving the gear cam combination mechanism to continue rotating. The large cam disengages from the force-bearing structure 106 on the push rod. As the gear cam combination mechanism continues to rotate, the protrusion of the small cam abuts against the bent end of the limiting arm 401, causing the latch 405 to rotate and disengage from the limiting structure 107 on the push rod, releasing the limiting of the push rod. Under the reaction force of the return spring and the contact spring, the push rod moves the moving contact and the limiting structure 107 away from the stationary contact, causing the moving contact to disengage from the stationary contact, thus opening the circuit breaker between the moving and stationary contacts. After opening the circuit breaker, the end face of the limiting structure facing the moving contact moves to the outer side of the latch 405 away from the stationary contact. The latch 405 resets under the elastic force of the return spring 404, placing the latch 405 between the limiting structure 107 on the push rod and the moving contact. The limiting structure 107 resets to its initial position before closing the circuit breaker.
[0033] In this embodiment, the gear cam combination mechanism is driven to rotate by a drive motor, so that the large cam, small cam, locking mechanism and force-bearing structure and limiting structure on the push rod cooperate to realize the closing and opening of the moving contact and the stationary contact under normal current flow conditions. Figure 1 and Figure 3 The structure is insufficient to force the moving and stationary contacts to open when the current in the circuit formed by the moving and stationary contacts is a fault current.
[0034] exist Figures 1 to 3 Based on this, a magnetic tripping device 5 is added, which can force the moving and stationary contacts to open and disconnect the circuit when a fault current occurs in the circuit. (See also...) Figures 4 to 8A force-bearing arm 406 extends from the end of the locking mechanism's limiting arm 401, which is fixedly connected to the return spring 404, away from the gear cam assembly mechanism. A magnetic tripping device is fixedly installed above the force-bearing arm 406. The magnetic tripping device includes an electromagnetic coil 501, a moving magnetic mechanical component 502, and a spring. The electromagnetic coil 501 is electrically connected to both ends of the moving contact 103 via a flexible cable 503, so that the electromagnetic coil 501 is connected in parallel to the circuit formed after the moving contact 103 and the stationary contact 102 are closed. The moving magnetic mechanical component 502 passes through the electromagnetic coil 501, and under the action of the magnetic field force generated by the electromagnetic coil, the moving magnetic mechanical component 502 can be displaced relative to the electromagnetic coil. A spring is provided at one end of the moving magnetic mechanical component 502 for resetting after displacement. The moving magnetic mechanical component 502 is located above the force-bearing arm 406. The current in the circuit formed after the moving and stationary contacts are closed can flow through the flexible cable 503 to the electromagnetic coil 501, causing the electromagnetic coil to generate a magnetic field. When the current in the circuit formed after the moving and stationary contacts are closed is a fault current and exceeds a set threshold, the magnetic field generated can drive the moving magnetic mechanical component 502 to move, driving the force-bearing arm 406 to rotate around the rotating shaft 402, thereby causing the latch to rotate, releasing the limit on the push rod, and opening the circuit under the action of the contact spring and the reaction spring. The magnetic tripping device is existing technology. Alternatively, the magnetic tripping device may include a moving magnetic conductor and a stationary magnetic conductor. The magnetic conductor is arranged around the stationary contact. The moving magnetic conductor is directly linked to the force arm of the locking mechanism. Alternatively, the moving magnetic conductor is linked to the force arm through a driving component. When the current in the circuit formed after the moving and stationary contacts are closed is a fault current and exceeds a set threshold, the magnetic force generated by the stationary magnetic conductor can attract the displacement of the moving magnetic conductor. The moving magnetic conductor drives the force arm to rotate around the rotation axis.
[0035] When the current in the circuit formed after the moving contact 103 and the stationary contact 102 are closed exceeds the set threshold, the electromagnetic coil 501 is energized, the magnetic force generated by the electromagnetic coil 501 increases, the mechanical component 502 that attracts the moving magnetic conductor moves toward the force arm 406, drives the force arm 406 to rotate around the rotating shaft 402, forces the latch 405 away from the push rod, releases the limit on the push rod, and under the elastic drive of the reaction spring 105, drives the push rod to move the moving contact, causing the moving contact to disengage from the stationary contact, and forcibly opens the circuit between the moving contact and the stationary contact.
[0036] In order to improve the reliability of the conductive contact between the moving contact and the stationary contact and to buffer the impact caused by the moving contact and the stationary contact during opening and closing, the two ends of the contact between the moving contact and the stationary contact are respectively set as conductive spring structures.
[0037] In the above embodiments, the opening and closing of the circuit breaker is achieved through the cooperation of the gear-cam combination mechanism, the locking mechanism, and the push rod. In other embodiments, the locking mechanism may be omitted, and the gear-cam combination mechanism may not have a small cam. When the locking mechanism and the small cam are not provided, the gear-cam combination mechanism rotates, and the protrusion of the large cam first abuts against the force-bearing structure of the push rod, pushing the push rod to move the moving contact, so that the moving contact contacts the stationary contact to close the circuit breaker. The drive motor stops rotating, and the position of the push rod is maintained in the closed position by the protrusion of the large cam abutting against the force-bearing structure. When it is necessary to open the circuit breaker, the drive motor continues to drive the gear cam combination mechanism to rotate. The protrusion of the large cam first contacts the force-bearing structure of the push rod and makes a very small displacement before disengaging from the force-bearing structure of the push rod. During this process, the reaction spring and the contact spring are further compressed. Since the moving contact is a conductive spring with a certain elasticity, before the large cam continues to rotate and disengages from the force-bearing structure of the push rod, it pushes the push rod to make a small displacement, causing the moving contact to undergo elastic deformation. The elastic deformation of the moving contact will not have any adverse effect on the stationary contact. Moreover, during this process, the reaction spring and the contact spring are further compressed, increasing the elastic force. When the large cam disengages from the force-bearing structure of the push rod, under the action of the increased elastic force of the reaction spring and the contact spring, the opening speed is increased, and the opening of the moving contact and the stationary contact is quickly achieved.
[0038] In some embodiments, a reaction spring may not be required. When no reaction spring is provided, the circuit breaker is opened by the force of the contact spring, or by the force of the contact spring combined with the gravity of the contact and push rod. The purpose of providing a reaction spring is to increase the opening speed.
Claims
1. Motor contactor, characterized in that, The utility model provides a kind of contactor, including: moving contact, static contact, push rod that can be linearly displaced, drive motor, gear cam combination mechanism, locking mechanism, force structure and limiting structure;The push rod is provided with contact spring and the moving contact towards the static contact one end, the moving contact is arranged in contact with the contact spring;The force structure and the limiting structure are arranged on the outer circumferential surface of the push rod along the length direction of the push rod at intervals;The locking mechanism is rotatably arranged relative to the push rod and can be reset under the action of its elastic force;In normal working condition, when closing, the drive motor drives the gear cam combination mechanism to rotate, the gear cam combination mechanism is in contact with the force structure, drives the push rod with the moving contact to displace towards the static contact, makes the moving contact and the static contact close, and the push rod displacement makes the contact spring be further compressed;At the same time, the push rod displaces with the limiting structure, and the limiting structure is in contact with the locking mechanism during displacement process to make it rotate, and the locking mechanism is reset after rotating under the action of its elastic force, and the end of the limiting structure away from the static contact is in contact with the push rod to limit it;When opening, the drive motor drives the gear cam combination mechanism to continue rotating, the gear cam combination mechanism is out of contact with the force structure, the gear cam combination mechanism drives the locking mechanism to rotate and is out of contact with the limiting structure, to remove the limitation to the push rod, and under the action of the elastic force of the contact spring, the push rod displaces with the limiting structure away from the static contact, the moving contact and the static contact are opened, and the locking mechanism is reset under the action of its elastic force. The gear cam combination mechanism includes coaxially arranged large cam, small cam and driven gear, driving gear is engaged with driven gear, the drive motor drives the driving gear to rotate to drive the large cam and small cam to rotate synchronously, in closing, the large cam acts on the force structure, and in opening, the small cam acts on the locking mechanism.
2. The motor contactor of claim 1, wherein, The locking mechanism includes limiting arm and reset spring, the limiting arm is rotatably arranged on one side of the push rod, one end of the limiting arm can be in contact with the small cam, the other end is fixedly connected with one end of the reset spring, the other end of the reset spring is fixedly arranged, and the buckle is fixedly arranged on the side of the limiting arm and the reset spring fixedly connected end towards the one side of the push rod;In opening state, the buckle is located outside the end of the limiting structure towards the moving contact;In closing, the limiting structure displaces, the buckle drives the limiting arm to rotate first, and then under the action of the elastic force of the reset spring, the buckle is reset, and the reset buckle is in contact with the end of the limiting structure away from the moving contact to limit the push rod.
3. The motor contactor of claim 2, wherein, One or both of the end face of the limiting structure towards the moving contact and the end face of the buckle away from the moving contact are arranged as inclined surface structure, and in closing, the inclined surface structure of the limiting structure and the buckle is in contact to make the buckle drive the limiting arm to rotate.
4. The motor contactor of claim 3, wherein, 5. The motor contactor of claim 4, wherein, The limiting structure is a limiting convex rib fixedly arranged on the outer periphery of the push rod, and one side of the limiting convex rib facing the moving contact is provided with the inclined surface structure.
6. The motor contactor of claim 4, wherein, The push rod is further provided with a magnetic tripping device, which is arranged around the circuit formed by the closing of the moving contact and the static contact, or is connected in parallel with the circuit formed by the closing of the moving contact and the static contact; one end of the limiting arm connected with the return spring extends towards the magnetic tripping device to form a force arm, and the force arm is located on the displacement path of the magnetic tripping device when the magnetic tripping device is tripped; when the current in the circuit formed by the closing of the moving contact and the static contact exceeds a set threshold, the magnetic tripping device is tripped to drive the force arm to drive the buckle to rotate, so that the buckle is disengaged from the abutment with the limiting structure to release the limiting, and the elastic force of the contact spring causes the moving contact and the static contact to open.
7. The motor contactor of claim 6, wherein, The magnetic tripping device comprises an electromagnetic coil and a dynamic magnetic mechanical component penetrating the electromagnetic coil, the force arm is located on the displacement path of the dynamic magnetic mechanical component, and the electromagnetic coil is conductively connected with both ends of the moving contact through a soft cable; when the magnetic tripping device is tripped, the dynamic magnetic mechanical component is displaced under the magnetic field force of the electromagnetic coil to drive the force arm to rotate.
8. The motor contactor of claim 1, wherein, Both ends of the moving contact and the static contact in conductive contact are conductive springs.
9. The motor contactor according to any one of claims 1 to 8, characterized in that, A counterforce spring is sleeved on the push rod, and in the open state, the counterforce spring is in a compressed state; in the closed state, the displacement of the push rod causes the counterforce spring to be further compressed, and when the push rod is released from the limiting, the dynamic contact and the static contact are opened under the combined action of the counterforce spring and the contact spring.
10. The motor contactor of claim 9, wherein, A supporting member for limiting is arranged on the push rod, one end of the counterforce spring abuts against the supporting member, and the other end abuts against the housing of the motor contactor; when the push rod is displaced, the counterforce spring is further compressed.