An explosion-proof motor with double overspeed protection function

Abstract

The application discloses a double super-speed protection function provided anti-explosion motor, relates to the field of BB technology, and comprises a stator assembly, a rotor assembly, an output main shaft and an anti-explosion shell, the rotor assembly contains a rotor center shaft, the output main shaft is arranged on the axial extension line of the rotor center shaft, and a sliding spline is arranged between the rotor center shaft and the output main shaft. The double protection system is arranged, the electrical protection module is used as a normal monitoring means, the response speed is fast, and the control is flexible; the mechanical protection module is used as a bottom-up means, the physical trigger logic only depends on the centrifugal force generated by the rotation of the rotor, when the actual rotating speed climbs to be greater than a limit rotating speed threshold value, the rotating kinetic energy is converted into an axial suction force through a transmission mechanism, the process forces the sliding spline to axially displace, the rotor center shaft and the output main shaft are decoupled in the physical layer, and the load end can be cut off even in the live state of the winding.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof motor safety protection technology, specifically to an explosion-proof motor with dual overspeed protection function. Background Technology

[0002] In industrial fields such as coal mines and petrochemical plants where explosive gas environments exist, explosion-proof motors serve as the core power source, and their operational safety is directly related to the integrity of the entire system. Due to potential energy feedback at the load end or electrical faults in the drive control system, the motor speed may objectively exceed the rated safe range. Once continuous overspeed occurs, it will not only cause fatigue damage to mechanical parts, but may also generate high-energy mechanical sparks due to high-speed friction, or exceed the explosion-proof group limit due to excessively rapid temperature rise, thereby inducing an explosion accident.

[0003] Existing explosion-proof motor overspeed protection mainly relies on a single electrical protection logic. Typically, a speed sensor installed at the end of the spindle collects the signal and feeds it back to the controller; when the monitored value exceeds a set threshold, the controller outputs a command to trip the circuit breaker.

[0004] However, in actual working conditions, the electrical protection system has the risk of failure. For example, sensor signal drift, control circuit logic deadlock, or contact failure of actuators caused by strong electromagnetic interference may occur. If the electrical protection cannot cut off the power in time, the rotor central shaft will continue to transmit power to the output shaft, causing the output shaft speed to tend to exceed the mechanical load limit of the load end. Since the centrifugal force and dynamic unbalanced load generated by high-speed rotation are greater than the material fatigue limit or physical deformation threshold of the transmission components, the output shaft and its connecting mechanism are prone to breakage and damage. At the same time, the high-frequency friction and vibration caused by the continuous overspeed of the output shaft can induce mechanical sparks and abnormal temperature rise of the casing. In application environments with explosive gases, there is a risk of exceeding the explosion-proof safety group limit. Summary of the Invention

[0005] The purpose of this invention is to provide an explosion-proof motor with dual overspeed protection to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An explosion-proof motor with dual overspeed protection includes a stator assembly, a rotor assembly, an output spindle, and an explosion-proof housing. The rotor assembly includes a rotor central shaft, and the output spindle is located on the axial extension line of the rotor central shaft. A sliding spline is provided between the rotor central shaft and the output spindle, and the rotor central shaft and the output spindle are synchronously connected via the sliding spline. A dual overspeed protection system is provided within the explosion-proof housing, consisting of an electrical protection module and a mechanical protection module. The electrical protection module includes a speed sensor and a controller. The controller is configured to trigger a power-off action when the actual speed detected by the speed sensor exceeds a set safe speed threshold. The mechanical protection module... The module includes a centrifugal actuator, a centrifugal constraint spring, and a transmission mechanism. The centrifugal actuator is radially floating, and the centrifugal constraint spring applies an inward radial preload to the centrifugal actuator. The centrifugal actuator is connected to the sliding spline via the transmission mechanism. When the power supply fails and the actual speed continues to rise and exceeds the set limit speed threshold, the centrifugal force generated by the centrifugal actuator is greater than the radial preload of the centrifugal constraint spring. The centrifugal actuator overcomes the preload and moves radially outward, which is then converted into an axial tension force driving the sliding spline via the transmission mechanism. Under the action of the axial tension force, the sliding spline translates axially, and its translational displacement is greater than the spline engagement length, thus physically decoupling the rotor central shaft from the output spindle.

[0007] By adopting the above technical solution and setting up a dual protection system, the electrical protection module serves as a normal monitoring method with fast response and flexible control; the mechanical protection module serves as a bottom-line backup method, and its physical triggering logic relies solely on the centrifugal force generated by the rotor rotation. When the actual speed increases to a level greater than the limit speed threshold, the radial force generated by the centrifugal actuator overcomes the initial preload of the centripetal constraint spring and converts the rotational kinetic energy into axial suction force through the transmission mechanism. This process forces the sliding spline to undergo axial displacement, resulting in physical decoupling between the rotor central shaft and the output main shaft, which can disconnect the load end even when the winding is energized.

[0008] A further improvement of the technical solution of the present invention is as follows: the rotor central shaft includes a drive shaft section and a transmission shaft section connected by a flange. A sliding groove is provided at the end of the transmission shaft section near the flange, and a slider is slidably connected inside the sliding groove. A clearance groove is provided at the end of the drive shaft section near the flange. Guide rods are symmetrically fixedly connected to the side wall of the drive shaft section, and a limit block is fixedly connected at the end of the guide rod away from the rotor central shaft. The centrifugal actuator is a floating component that is slidably sleeved outside the guide rod. A centripetal constraint spring is sleeved outside the guide rod and located between the floating component and the limit block. The transmission mechanism includes a slider that is slidably connected inside the sliding groove, and a connecting rod is hinged between the slider and the floating component. A first spline groove is provided at the end of the transmission shaft section away from the sliding groove, and a sliding spline is slidably connected inside the first spline groove. A linkage rod is slidably passed through the central part of the transmission shaft section. One end of the linkage rod is fixedly connected to the slider, and the other end passes through the interior of the first spline groove and is fixedly connected to the sliding spline. A second spline groove is provided at the end of the output main shaft located inside the explosion-proof housing.

[0009] By adopting the above technical solution, a rigid transmission mechanism consisting of a radial floating component, connecting rod, slider, and coaxial linkage rod is set up, and a second spline groove is set on the output side to achieve the function of automatic disconnection in case of overspeed: when the motor is overspeed triggered, the mechanism is used to force and without delay convert the radial centrifugal variable into axial displacement on the central axis, so that the additional eccentric mass of the actuator during high-speed revolution approaches zero, ensuring the high-speed dynamic balance of the rotor; at the same time, the linkage rod directly pulls the sliding spline to translate axially and completely exit the second spline groove, thereby completely cutting off the power transmission path between the transmission shaft section and the output main shaft, so that the mechanical disconnection action under extreme working conditions exhibits extremely high structural rigidity and physical boundary certainty.

[0010] Furthermore, existing centrifugal mechanisms with pure spring constraints exhibit linear force characteristics (i.e., spring deformation is proportional to the force). When the motor is in the normal speed range below the overspeed trigger threshold, as soon as the rotor rotates, the centrifugal force immediately overcomes part of the spring preload, causing the centrifugal block to produce continuous small radial displacement, which in turn causes the sliding spline at the output end to undergo high-frequency axial micro-movement. This results in the spline teeth being in a state of slight sliding friction during long-term normal operation, which increases mechanical wear and causes local abnormal heating inside the explosion-proof housing, reducing the transmission life.

[0011] A further improvement of the technical solution of the present invention is that: the limiting block is made of a magnetically conductive material; one end of the floating member away from the drive shaft section extends to the other side of the limiting block and is equipped with a second magnet, the second magnet being configured to magnetically attract the limiting block when the floating member is in the initial position, so as to lock the floating member in the initial position; optionally, a flexible block is provided between the second magnet and the limiting block.

[0012] By employing the above technical solution, the limiting block is made of a magnetic material and cooperates with the second magnet. When the motor speed is less than the limit speed threshold, the second magnet and the limiting block attract and adhere to each other. At this time, the magnetic attraction and the preload of the centrifugal constraint spring work together to provide an initial holding force for the floating component. This holding force enables the floating component to effectively resist the pulling caused by centrifugal force fluctuations during normal operation, avoiding frequent micro-movements of the transmission mechanism and sliding spline. Its mechanical wear and heat generation during operation are significantly less than those of conventional progressive spring limiting structures. When the actual speed exceeds the limit speed threshold, the outward centrifugal force overcomes the initial holding force and forcibly pulls the second magnet away from the limiting block. Utilizing the physical characteristic that the magnetic attraction rapidly decreases with increasing distance, the tiny air gap created by the separation of the two causes the inward magnetic pulling resistance to instantly disintegrate. In this state, the resultant force of the inward constraint on the floating component is significantly less than the outward centrifugal force, causing the floating component to exhibit an outward displacement acceleration greater than that of conventional structures, thereby achieving an instantaneous jump in the decoupling action.

[0013] Furthermore, after the overspeed power-off protection is completed, the output spindle enters the free deceleration stage. As the actual speed of the rotor decreases, the centrifugal force on the centrifugal block decreases and approaches zero. At this time, the centripetal constraint spring forcibly pulls the transmission mechanism to reset. However, in the initial stage of power failure, due to the large rotational inertia at the load end, there is still a large relative speed difference between the output spindle and the rotor central shaft. If the sliding spline is forcibly pushed back to the meshing state by the spring at this stage, the spline tooth ends will experience rigid collision and secondary tooth breakage.

[0014] A further improvement of the technical solution of the present invention is that: a first magnet is fixedly connected to the side of the inner wall of the groove away from the slide groove, the slider is made of magnetic material, and a flexible block is provided on the side of the first magnet close to the slider.

[0015] By adopting the above technical solution, a first magnet is set in the relief groove to attract the slider. When the slider is driven by the centrifugal actuator to rush into the end of the relief groove, it enters the effective range of the magnetic force of the first magnet. At the moment when the slider reaches the ultimate decoupling position, the local static magnetic attraction force output by the first magnet is greater than the maximum reset pull of the centrifugal constraint spring, so that the sliding spline and the second spline groove can quickly disengage in the latter half. Even if the motor speed is completely reduced to zero, the mechanism will not spontaneously reset, thus completely eliminating the risk of dynamic tooth breakage during the speed reduction and frequency reduction stage.

[0016] Furthermore, in the case of overspeeding of the explosion-proof motor, the second magnet disengaging from the limit block, but the sliding spline disengaging from the second spline groove, the centripetal constraint spring will push the floating part to vibrate continuously due to the fluctuation of the rotor central shaft speed, which will still cause mechanical wear. In other words, there is a state in which the second magnet disengages from the limit block but the sliding spline disengages from the second spline groove. If the rotor central shaft speed fluctuates in this state, it will cause the sliding spline to vibrate.

[0017] A further improvement of the technical solution of the present invention is that: the floating component is configured as a piston cylinder with one end open and the other end closed; the limiting block has a cylindrical structure, and a sealing ring is embedded on its outer circumferential surface; the limiting block is slidably sleeved inside the floating component through the open end, and the sealing ring is tightly fitted with the inner wall of the floating component to form a variable volume air chamber; an air inlet and an exhaust port are provided through the wall of the floating component to connect the variable volume air chamber with the internal space of the explosion-proof housing, and a one-way valve is independently provided in the air inlet and the exhaust port respectively; the one-way valve in the exhaust port is configured to unidirectionally flow outward when the volume of the variable volume air chamber decreases, and the one-way valve in the air inlet port is configured to unidirectionally flow inward when the volume of the variable volume air chamber increases; the total flow cross-sectional area of ​​the air inlet is strictly smaller than the total flow cross-sectional area of ​​the exhaust port.

[0018] By adopting the above technical solution, a pneumatic damping mechanism with asymmetric fluid resistance characteristics is constructed through the design of a floating component (i.e., piston cylinder, which is the specific form of the floating component in the following text) and an asymmetric one-way valve orifice. Utilizing the structural feature that the total flow cross-sectional area of ​​the exhaust port is larger than that of the inlet port, during the process where the motor overspeeds and causes the floating component to jump outward, the large-section exhaust port ensures that the air inside the air chamber can be quickly emptied, preventing the acceleration of the decoupling action from being weakened by pneumatic damping and ensuring the instantaneous triggering. During the deceleration and reset phase, when the centripetal constraint spring breaks through the tension of the first magnet and forcibly pulls the floating component inward, the large-section exhaust port closes, and the small-section inlet port restricts the airflow replenishment rate, instantly transforming the variable-volume air chamber into a negative pressure damper. This mechanism forcibly converts the rigid rebound force released by the centripetal constraint spring into fluid heat dissipation, avoiding the reciprocating vibration of the floating component, thereby preventing the sliding spline from exhibiting reciprocating vibration.

[0019] A further improvement of the technical solution of the present invention is that: the outer wall of the floating component is provided with a plurality of spiral-shaped guide grooves; the cross-section of the guide rod is elliptical, and the sliding part on the floating component that cooperates with the guide rod is correspondingly set as an elliptical hole.

[0020] By adopting the above technical solution, a spiral guide groove is set on the outer wall of the floating component to make full use of its movement. This makes the structure no longer add load for mechanical monitoring, but has a guiding function. Specifically, during the high-speed revolution of the floating component with the rotor's central axis, the spiral guide groove on its outer wall is given a certain aerodynamic windward angle by a constant motion posture. It cuts through the air to produce an effect similar to centrifugal pump suction. The high-temperature air in the central area of ​​the rotor is forced to be thrown outward radially, forcing a forced convection circulation from the center to the outer shell inside the explosion-proof housing. Furthermore, the non-cylindrical surface mating feature of the elliptical guide rod and the elliptical hole ensures that the floating component retains only the radial translational degree of freedom, locking its circumferential rotational degree of freedom around the radial axis; this ensures the absolute constancy of the floating component's motion posture and avoids circumferential deflection interference of the transmission mechanism.

[0021] By adopting the above technical solution, during the entire cycle of normal motor operation and centrifugal action, along with the high-speed rotation of the main shaft, the spiral guide groove on the surface of the floating part is equivalent to the blade profile of the backward-inclined centrifugal impeller. It continuously draws hot air from the low-pressure area near the rotor's central shaft and uses the superposition of centrifugal force and inclined thrust to guide the airflow to the inner wall of the explosion-proof housing. This process utilizes the original static mass of the floating part to achieve active intervention and temperature homogenization of the internal thermal field of the explosion-proof housing without adding an additional drive source.

[0022] A further improvement of the technical solution of the present invention is that the air inlet is located on the side of the floating part near the drive shaft section, and the exhaust port is directly opposite the inner wall of the explosion-proof housing.

[0023] By adopting the above technical solution, by setting the air inlet in the rotor center area near the drive shaft section, the mechanism can preferentially draw in high-temperature hot air near the central shaft when the piston cylinder volume increases (reset stage or high-frequency micro-vibration stage); in conjunction with the layout of the exhaust port facing the inner wall of the explosion-proof housing, the high-temperature airflow captured by the piston cylinder is directly sprayed in the form of a jet onto the heat dissipation surface of the inner wall of the housing with the highest heat capacity when the piston cylinder volume decreases (centrifugal trigger stage or fine-tuning stage).

[0024] Furthermore, in actual production and manufacturing, due to the stiffness error of the centrifugal constraint spring, the machining quality tolerance of the centrifugal actuator, and the differences in the magnetic circuit environment inside the explosion-proof housing, the actual trigger speed threshold of the centrifugal disengagement mechanism often deviates from the theoretical design value; if the initial gap between the magnet and the armature is a fixed structure, the system lacks the means to fine-tune the trigger threshold.

[0025] A further improvement of the technical solution of the present invention is that: the outer wall of the second magnet is provided with thread teeth, and the inner wall of the floating part away from the drive shaft section is provided with a threaded groove, and the second magnet is connected to the threaded part of the floating part by thread.

[0026] By adopting the above technical solution, and by setting threads on the outer wall of the second magnet and connecting them to the floating part, an overall threshold calibration effect is achieved: utilizing the precise axial displacement control property of the threaded drive, the operator can fine-tune the initial working air gap between the second magnet and the limit block by rotating the second magnet; since the magnetic attraction force is inversely proportional to the square of the air gap distance, the small change in this axial displacement can significantly change the magnitude of the initial static magnetic locking force, thereby achieving precise physical calibration of the limit speed threshold without replacing the spring, and improving the compatibility and operation accuracy of this protection system on explosion-proof motors of different specifications.

[0027] Furthermore, ordinary magnets exhibit magnetic leakage due to the outward dispersion of magnetic field lines, resulting in low magnetic energy utilization in the adsorption direction. In the confined space of an explosion-proof cavity, if the magnet is too large, it is difficult to place it; if it is too small, the output static holding force is insufficient to counteract the centripetal constraint spring, and the dispersed magnetic field may cause electromagnetic interference to the motor windings and sensors.

[0028] A further improvement to the technical solution of the present invention is that both the second magnet and the first magnet are cup-shaped magnets.

[0029] By adopting the above technical solution, by setting both the second magnet and the first magnet as cup-shaped magnets, the magnetic circuit concentration and shielding effects are achieved: the magnetic cup body is used to construct a closed magnetic circuit, which forces the diverging magnetic lines of force to concentrate at the adsorption end face, so that the static holding force output is better than that of ordinary magnets under the same magnet volume; at the same time, the magnetic cup body plays an electromagnetic shielding role, which limits the overflow of the magnetic field to the non-working direction and eliminates magnetic interference to other precision electronic components inside the motor.

[0030] By adopting the above technical solution, the technical effects achieved by this invention compared to the prior art are as follows: 1. This invention provides an explosion-proof motor with dual overspeed protection. By setting up a dual protection system, the electrical protection module serves as a normal monitoring method with fast response and flexible control; the mechanical protection module serves as a bottom-line backup method, and its physical triggering logic relies solely on the centrifugal force generated by the rotor rotation. When the actual speed increases to a value greater than the limit speed threshold, the radial force generated by the centrifugal actuator overcomes the initial preload of the centripetal constraint spring and converts the rotational kinetic energy into axial suction force through the transmission mechanism. This process forces the sliding spline to undergo axial displacement, resulting in physical decoupling between the rotor central shaft and the output main shaft, which can disconnect the load end even when the winding is energized.

[0031] 2. This invention provides an explosion-proof motor with dual overspeed protection. By setting a second magnet and a magnetic armature block, when the motor speed is less than the limit speed threshold, the second magnet and the magnetic armature block are in a zero-distance contact state. The output limit static magnetic attraction force and the preload force of the centrifugal constraint spring form a superimposed rigid constraint threshold, which makes the floating part absolutely locked in the initial position, eliminating the micro-motion wear and heating phenomenon of sliding spline caused by centrifugal force fluctuation under normal operation. Only when the actual speed is greater than the limit speed threshold, the surge in centrifugal force breaks through the initial magnetic attraction force critical point, and the second magnet detaches from the magnetic armature block. With the generation of a small air gap, the magnetic attraction force decreases abruptly to zero. The floating part instantly loses its main resistance force and generates a huge outward jump displacement acceleration under the state of resultant force imbalance.

[0032] 3. This invention provides an explosion-proof motor with dual overspeed protection. By setting a first magnet in the relief groove to attract the slider, when the slider is driven by the centrifugal actuator to rush into the end of the relief groove, it enters the effective range of the magnetic force of the first magnet. At the moment when the slider reaches the ultimate decoupling position, the local static magnetic attraction force output by the first magnet is greater than the maximum reset tension of the centrifugal constraint spring, so that the sliding spline and the second spline groove can quickly disengage in the latter half. Even if the motor speed is completely reduced to zero, the mechanism will not spontaneously reset, thus completely eliminating the risk of dynamic tooth breakage during the speed reduction and frequency reduction stage.

[0033] 4. This invention provides an explosion-proof motor with dual overspeed protection. Through the design of floating components and asymmetrical one-way valve orifices, a pneumatic damping mechanism with asymmetrical fluid resistance characteristics is constructed: Utilizing the structural feature that the total flow cross-sectional area of ​​the exhaust port is larger than that of the inlet port, during the process of the motor overspeeding and causing the floating component to jump outward, the large-section exhaust port ensures that the air inside the air chamber can be quickly emptied, so that the acceleration of the decoupling action is not weakened by the pneumatic damping, ensuring the instantaneous triggering; In the deceleration and reset phase, when the centripetal constraint spring breaks through the tension of the first magnet and forcibly pulls the floating component inward, the large-section exhaust port closes, and the small-section inlet port limits the airflow replenishment rate, instantly transforming the variable volume air chamber into a negative pressure damper, avoiding the reciprocating vibration of the floating component, thereby avoiding the reciprocating vibration of the sliding spline.

[0034] 5. This invention provides an explosion-proof motor with dual overspeed protection. By setting a spiral guide groove on the outer wall of the floating component, its movement is fully utilized, so that the structure no longer increases the load for mechanical monitoring, but has a guiding function. Specifically, during the high-speed revolution of the floating component with the rotor's central axis, the spiral guide groove on its outer wall is given a certain aerodynamic angle of attack by a constant motion posture, which cuts through the air to produce an effect similar to centrifugal pump suction; the high-temperature air in the central region of the rotor is forced to be thrown outward radially, forcing a forced convection circulation from the center to the outer shell inside the explosion-proof housing. Attached Figure Description

[0035] The invention will now be further described with reference to the accompanying drawings.

[0036] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the front cross-sectional structure of the present invention; Figure 3 This is a schematic diagram of the disassembled structure of the present invention; Figure 4 This is a three-dimensional structural diagram of the rotor central shaft of the present invention; Figure 5 This is a schematic diagram of the centrifugal actuator of the present invention; Figure 6 This is a partial top sectional view of the drive shaft section of the present invention. Figure 7 This is a schematic diagram of the structure of the end cap of the explosion-proof housing of the present invention; Figure 8 This is a schematic diagram of the output spindle of the present invention.

[0037] In the diagram: 1. Explosion-proof housing; 2. Stator assembly; 3. Rotor central shaft; 301. Drive shaft section; 302. Transmission shaft section; 303. Clearance groove; 401. Output main shaft; 402. Second spline groove; 5. Transmission mechanism; 501. First spline groove; 502. Sliding spline; 503. Slide groove; 504. Slider; 505. Linkage rod; 506. Connecting rod; 507. First magnet; 601. Guide rod; 602. Floating component; 603. Limiting block; 604. Centripetal constraint spring; 605. Second magnet; 701. Exhaust port; 702. Inlet port; 703. One-way valve; 704. Sealing ring; 8. Guide groove. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the embodiments.

[0039] Example 1 like Figures 1-8As shown, the present invention provides an explosion-proof motor with dual overspeed protection function, including a stator assembly 2, a rotor assembly, an output spindle 401, and an explosion-proof housing 1. The rotor assembly includes a rotor central shaft 3, and the output spindle 401 is disposed on the axial extension line of the rotor central shaft 3. A sliding spline 502 is provided between the rotor central shaft 3 and the output spindle 401, and the rotor central shaft 3 and the output spindle 401 are synchronously connected via the sliding spline 502. The explosion-proof housing 1 is provided with a dual overspeed protection system, which consists of an electrical protection module and a mechanical protection module. The electrical protection module includes a speed sensor and a controller. The controller is configured to trigger a power-off action when the actual speed detected by the speed sensor is greater than a set safe speed threshold. The mechanical protection module includes a centrifugal actuator, a centrifugal constraint spring 604, and a transmission mechanism 5. The centrifugal actuator is radially floating, and the centrifugal constraint spring 604 applies an inward radial preload to the centrifugal actuator. The centrifugal actuator is connected to the sliding spline 502 via the transmission mechanism 5. When the power supply fails and the actual speed continues to rise and exceeds the set limit speed threshold, the centrifugal force generated by the centrifugal actuator is greater than the radial preload of the centrifugal constraint spring 604. The centrifugal actuator overcomes the preload and moves radially outward, which is converted into an axial tension force driving the sliding spline 502 via the transmission mechanism 5. Under the action of the axial tension, the sliding spline 502 translates axially, and its translational displacement is greater than the spline engagement length, so that the rotor central shaft 3 and the output main shaft 401 are physically decoupled.

[0040] In this embodiment, a dual protection system is set up. The electrical protection module serves as a normal monitoring method, which has a fast response speed and flexible control. The mechanical protection module serves as a bottom-line backup method. Its physical triggering logic relies only on the centrifugal force generated by the rotor rotation. When the actual speed increases to a value greater than the limit speed threshold, the radial force generated by the centrifugal actuator overcomes the initial preload of the centripetal constraint spring 604. The rotational kinetic energy is converted into axial suction force through the transmission mechanism 5. This process forces the sliding spline 502 to undergo axial displacement, so that the rotor central shaft 3 and the output main shaft 401 are physically decoupled. Even when the winding is energized, the load end can be cut off.

[0041] In numerous authorized and published documents in the field of industrial control and motor protection, this electrical overspeed protection logic is widely used and can be considered a conventional method that can be implemented without providing specific circuit diagrams. For example, patent CN103248281A explicitly states that "the judgment module is used to determine whether the current speed of the motor is greater than the preset protection speed, and when it is greater than the preset protection speed, the control unit disconnects the connection between the motor controller and the motor." This is because the core inventiveness of the present invention lies in the "mechanical protection module," while the "electrical protection module," which serves as routine protection, is an existing conventional technical means.

[0042] Optionally, the electrical protection module includes a speed sensor and a controller, the controller being electrically connected to a circuit breaker actuator (preferably an AC contactor or an explosion-proof circuit breaker) in the main power supply circuit of the motor; the controller is configured to output a trip control signal to the circuit breaker actuator to trigger a power-off action when the actual speed detected by the speed sensor is greater than a set first safe speed threshold. Furthermore, the speed sensor is preferably a Hall speed sensor or a photoelectric encoder, and the controller is preferably a PLC or a MCU microcontroller. Since the control logic that uses the speed feedback signal to compare with a set threshold and drive the relay or circuit breaker to operate is a conventional technical means in this field, the specific electrical topology of this part will not be described in detail in this embodiment.

[0043] Within the rated speed range, the sliding spline 502 is in the first meshing position, and the torque of the rotor central shaft 3 is transmitted to the output main shaft 401 through the full length of the spline teeth. At this time, the preload provided by the centrifugal constraint spring 604 is greater than the centrifugal force generated by the centrifugal actuator, and the centrifugal actuator is locked in the radially inner position, and the transmission mechanism 5 does not output axial displacement. When a fault causes the motor speed to rise and exceed the safe speed threshold (e.g., 110% of the rated speed), the electrical protection module is activated, and the controller sends a command to attempt to cut off the power. If the electrical circuit is normal, the motor speed is reduced and the motor returns to a safe state. If electrical protection fails and the speed continues to climb to a level greater than the limit speed threshold (e.g., 125% of the rated speed), the centrifugal force breaks through the critical point and becomes stronger than the resultant force of the centrifugal constraint spring 604. The centrifugal actuator is thrown outward radially, driving the transmission mechanism 5 to move. Specifically, the transmission mechanism 5 converts the radial displacement of the centrifugal actuator into the axial movement of the sliding spline 502. Its translation is greater than the meshing length of the spline teeth. At this time, the spline disengages, and the power transmission path is forcibly cut off, thus achieving physical deterministic protection of the explosion-proof motor under extreme overspeed conditions.

[0044] like Figure 2 , Figure 3 and Figure 6 As shown, in this embodiment, preferably, the rotor central shaft 3 includes a drive shaft section 301 and a transmission shaft section 302 connected by a flange. The transmission shaft section 302 has a groove 503 at one end near the flange, and a slider 504 is slidably connected inside the groove 503. The drive shaft section 301 has a clearance groove 303 at one end near the flange. Guide rods 601 are symmetrically fixedly connected to the side wall of the drive shaft section 301. A limit block 603 is fixedly connected to the end of the guide rod 601 away from the rotor central shaft 3. The centrifugal actuator is a floating component 602 that is slidably sleeved outside the guide rod 601. The centrifugal constraint spring 604 is sleeved outside the guide rod 601 and is located between the floating component 602 and the limit block 603. The transmission mechanism 5 includes a slider 504 slidably connected inside the slide groove 503, and a connecting rod 506 hinged between the slider 504 and the floating member 602; a first spline groove 501 is provided at the end of the transmission shaft section 302 away from the slide groove 503, and a sliding spline 502 is slidably connected inside the first spline groove 501; a linkage rod 505 is slidably provided in the central part of the transmission shaft section 302, one end of the linkage rod 505 is fixedly connected to the slider 504, and the other end passes through the interior of the first spline groove 501 and is fixedly connected to the sliding spline 502; a second spline groove 402 is provided at the end of the output spindle 401 located inside the explosion-proof housing 1.

[0045] In this embodiment, a rigid transmission mechanism 5, consisting of a radial floating element 602, a connecting rod 506, a slider 504, and a coaxial linkage rod 505, is set up in conjunction with the second spline groove 402 on the output side. This achieves the function of automatic disconnection during overspeed: when the motor is overspeed triggered, the mechanism is used to force and seamlessly convert the radial centrifugal variable into axial displacement on the central axis, making the additional eccentric mass of the actuator approach zero during high-speed revolution, thus ensuring the high-speed dynamic balance of the rotor; at the same time, the linkage rod 505 directly pulls the sliding spline 502 to translate axially and completely exit the second spline groove 402, thereby completely cutting off the power transmission path between the transmission shaft section 302 and the output main shaft 401, so that the mechanical disconnection action under extreme working conditions exhibits extremely high structural rigidity and physical boundary certainty.

[0046] When the motor is running normally, the floating component 602 is restricted by the preload of the centripetal constraint spring 604 and stays at the initial position close to the rotor central shaft 3. At this time, the connecting rod 506 is in the retracted state, the slider 504 stays on one side of the slide groove 503 of the transmission shaft section 302, and the linkage rod 505 pulls the sliding spline 502 to maintain the normal engagement depth in the first spline groove 501, so that the sliding spline 502 simultaneously bridging and engaging the first spline groove 501 and the second spline groove 402. At this time, the rotational torque of the rotor central shaft 3 is synchronously transmitted to the output main shaft 401 through the rigid bridging of the sliding spline 502.

[0047] When the motor overspeeds and the actual speed exceeds the set limit speed threshold: The centrifugal inertial force generated by the floating component 602 is greater than the elastic resistance of the centripetal constraint spring 604. The floating component 602 overcomes the spring force and moves radially outward along the guide rod 601 towards the limiting block 603. This radial outward movement of the floating component 602 causes the connecting rod 506 to swing, similar to the action mechanism of the crank-slider 504. The swinging of the connecting rod 506 forces the slider 504 to slide axially along the groove 503 towards the drive shaft section 301, and the end of the slider 504 extends into the relief groove 303 of the drive shaft section 301 to achieve [the desired effect]. Taking the limit stroke; the axial translation of slider 504 synchronously drives the linkage rod 505 in the central part to move axially. The other end of linkage rod 505 directly pulls the sliding spline 502 inside the first spline groove 501 to move axially. As the displacement increases, the sliding spline 502 completely exits the second spline groove 402 of the output spindle 401 axially. At this time, the physical connection between the first spline groove 501 and the second spline groove 402 is forcibly broken, and the power transmission path between the rotor center shaft 3 and the output spindle 401 is completely cut off.

[0048] Example 2 like Figure 4 , Figure 5 and Figure 6 As shown, based on Embodiment 1, the present invention provides a technical solution: preferably, the limiting block 603 is made of a magnetically conductive material; one end of the floating member 602 away from the drive shaft segment 301 extends across the limiting block 603 and a second magnet 605 is installed on its other side, the second magnet 605 is configured to magnetically attract the limiting block 603 when the floating member 602 is in the initial position, so as to lock the floating member 602 in the initial position; optionally, a flexible block is provided between the second magnet 605 and the limiting block 603.

[0049] In this embodiment, by setting the limiting block 603 to a magnetic material and cooperating with the second magnet 605, when the motor speed is less than the limit speed threshold, the second magnet 605 and the limiting block 603 are in a zero-distance contact state, and the ultimate static magnetic attraction force output by the magnet and the preload force of the centrifugal constraint spring 604 form a superimposed rigid constraint threshold. This mechanical feature makes the floating part 602 absolutely locked in the initial position, eliminating the micro-motion wear and heat generation phenomenon of the sliding spline 502 caused by centrifugal force fluctuation under normal operation. Furthermore, only when the actual rotational speed exceeds the limit speed threshold, the surge in centrifugal force breaks through the initial magnetic attraction critical point, and the second magnet 605 forcibly detaches from the limiting block 603; with the generation of a tiny air gap, the magnetic attraction force decreases precipitously to zero; the floating part 602 instantly loses its core resistance force and generates a huge outward displacement acceleration under the state of imbalance of the resultant force.

[0050] During the rated operation of the explosion-proof motor, the outward centrifugal force on the floating part 602 is less than the sum of the inward spring preload and the initial static magnetic attraction force of the second magnet 605. Under this state, the floating part 602 does not undergo any radial slippage, and the linkage rod 505 and the sliding spline 502 maintain an absolutely static rigid engagement state, eliminating the generation of heat through unwarranted friction. When the actual speed increases due to loss of control, until the centrifugal force increases to the critical disengagement point, the floating part 602 is forcibly thrown outward. In the initial few millimeters of the disengagement stroke, the magnetic force rapidly approaches zero as the distance increases, causing the outward net driving force on the floating part 602 to reach its peak instantaneously. This mechanical abrupt change mechanism causes the connecting rod 506 and the slider 504 to complete the pull-out action with extremely high initial velocity, directly switching the sliding spline 502 from the fully engaged state to the fully disengaged state, effectively crossing the semi-engaged critical zone that is prone to mechanical tooth breakage.

[0051] Example 3 like Figure 4 , Figure 5 and Figure 6 As shown, based on Embodiment 2, the present invention provides a technical solution: preferably, a first magnet 507 is fixedly connected to the side of the inner wall of the clearance groove 303 away from the slide groove 503, the slider 504 is made of magnetically conductive material, and a flexible block is provided on the side of the first magnet 507 near the slider 504.

[0052] In this embodiment, a first magnet 507 is provided in the relief groove 303 to attract the slider 504. When the slider 504 is driven by the centrifugal actuator to rush into the end of the relief groove 303, it enters the effective range of the magnetic force of the first magnet 507. At the moment when the slider 504 reaches the ultimate decoupling position, the local static magnetic attraction force output by the first magnet 507 is greater than the maximum reset pull of the centripetal constraint spring 604, so that the sliding spline 502 and the second spline groove 402 can quickly disengage in the latter half. Even if the motor speed is completely reduced to zero, the mechanism will not spontaneously reset, thus completely eliminating the risk of dynamic tooth breakage during the speed reduction and frequency reduction stage.

[0053] When the actual speed of the explosion-proof motor exceeds the limit speed threshold and triggers mechanical action, the slider 504 is driven by the transmission mechanism 5 to move axially and accelerate in the direction of the slide groove 503 toward the clearance groove 303. As the slider 504 approaches the decoupling position, its magnetic end face enters the magnetic field capture range of the first magnet 507. Since the magnetic attraction force increases exponentially with the decrease of the air gap, the magnetostrictive force output by the first magnet 507 on the slider 504 is superimposed in the same direction with the axial thrust of the transmission mechanism 5, causing the slider 504 to suddenly jump and accelerate at the end of its movement. The slider 504 instantly impacts and squeezes the flexible buffer block, and finally fits and locks with the first magnet 507. In this physical process, the flexible buffer block undergoes elastic compression deformation to absorb the impact kinetic energy at the end.

[0054] After the power is completely cut off, the motor enters the free-frequency reduction shutdown stage. As the rotor speed gradually decreases, the centrifugal force on the centrifugal actuator decreases and approaches zero. At this time, the centrifugal constraint spring 604, which is in the maximum deformation state, attempts to release its elastic potential energy and outputs an axial force to the transmission system to pull the sliding spline 502 back to its original position. However, since the slider 504 has been attracted by the first magnet 507 with zero air gap (or micro air gap), the closed-loop static magnetic holding force output by the first magnet 507 exhibits mechanical characteristics that are strictly greater than the maximum reset force of the centrifugal constraint spring 604. Under the forced intervention of this extreme unbalanced torque, the axial displacement of the slider 504 and the linkage rod 505 is absolutely locked, and the sliding spline 502 is physically restricted to the extreme position of exiting the second spline groove 402. Even if there is a large residual speed difference between the rotor central shaft 3 and the load-side output main shaft 401 during the deceleration stage, the sliding spline 502 does not undergo any axial springback engagement, thereby using a purely physical magnetic field to block the secondary tooth collision path during the deceleration process. The system will remain in this disconnected state until manual maintenance intervenes and an external force greater than the magnetic force difference is applied to break the fit balance, at which point the initial engagement state can be restored.

[0055] Example 4 like Figure 4 , Figure 5 and Figure 6 As shown, based on Embodiment 3, the present invention provides a technical solution: Preferably, the floating member 602 is configured as a piston cylinder with one end open and the other end closed; the limiting block 603 has a cylindrical structure, and a sealing ring 704 is embedded on its outer circumferential surface; the limiting block 603 is slidably sleeved inside the piston cylinder through the open end, and the sealing ring 704 is tightly fitted with the inner wall of the piston cylinder to form a variable volume air chamber; an air inlet 702 and an exhaust port 701 are provided through the piston cylinder wall to connect the variable volume air chamber with the internal space of the explosion-proof housing 1, and a one-way valve 703 is independently provided in the air inlet 702 and the exhaust port 701 respectively; the one-way valve 703 in the exhaust port 701 is configured to unidirectionally open outward when the volume of the variable volume air chamber decreases, and the one-way valve 703 in the air inlet 702 is configured to unidirectionally open inward when the volume of the variable volume air chamber increases; the total flow cross-sectional area of ​​the air inlet 702 is strictly smaller than the total flow cross-sectional area of ​​the exhaust port 701.

[0056] In the case of overspeeding of the explosion-proof motor, the second magnet 605 disengaging from the limit block 603, but the sliding spline 502 disengaging from the second spline groove 402, the centripetal constraint spring 604 will push the floating part 602 to vibrate continuously as the speed of the rotor central shaft 3 fluctuates, which will still cause mechanical wear. In other words, there is a state in which the second magnet 605 disengages from the limit block 603 but the sliding spline 502 disengages from the second spline groove 402. In this state, if the speed of the rotor central shaft 3 fluctuates, it will cause the sliding spline 502 to vibrate.

[0057] In this embodiment, a pneumatic damping mechanism with asymmetric fluid resistance characteristics is constructed through the design of the floating component 602 (i.e., piston cylinder, both referring to the same feature) and the orifice diameter of the asymmetric one-way valve 703: Utilizing the structural feature that the total flow cross-sectional area of ​​the exhaust port 701 is larger than that of the inlet port 702, during the process where the motor overspeeds and causes the floating component 602 to suddenly jump outward, the large-section exhaust port 701 ensures that the air inside the air chamber can be quickly vented, so that the acceleration of the decoupling action is not weakened by the pneumatic damping, thus ensuring... The triggering is instantaneous; during the deceleration and reset phase, when the centripetal constraint spring 604 breaks through the tension of the first magnet 507 and forcibly pulls the floating part 602 inward, the large cross-section exhaust port 701 closes and the small cross-section air inlet port 702 restricts the airflow replenishment rate, instantly transforming the variable volume air chamber into a negative pressure damper; this mechanism forcibly transforms the rigid rebound tension released by the centripetal constraint spring 604 into fluid heat dissipation, avoiding the reciprocating vibration of the floating part 602, thereby avoiding the reciprocating vibration of the sliding spline 502.

[0058] During the motor overspeed triggering phase, centrifugal force drives the floating component 602 to overcome the initial attraction of the second magnet 605 and quickly throw it out towards the limiting block 603 at the end of the guide rod 601. During this stroke, the volume of the variable volume air chamber between the floating component 602 and the limiting block 603 rapidly shrinks. During this process, the intake one-way valve 703 closes, and the exhaust one-way valve 703 opens under the positive pressure inside the chamber. Due to the extremely large total flow cross-section of the exhaust port 701, the air in the air chamber is instantly discharged into the explosion-proof chamber, and the air flow resistance of the floating component 602 approaches zero, ensuring that the transmission mechanism 5 quickly disengages. During the reset phase after power failure and shutdown, the rotor speed decreases, and the tension of the centrifugal constraint spring 604 eventually exceeds the steady-state attraction of the first magnet 507 and the residual centrifugal force. The floating component 602 is forcibly pulled back towards the rotor's central shaft 3. During this stroke, the volume of the variable-volume air chamber between the floating component 602 and the limiting block 603 begins to increase. At this time, the exhaust check valve 703 closes under negative pressure, and the intake check valve 703 opens. Since the total flow cross-sectional area of ​​the intake port 702 is restricted, the air in the explosion-proof housing 1 cannot quickly fill the ever-increasing volume of the air chamber, thus forming a negative pressure (vacuum suction effect) in the air chamber. This negative pressure damping force directly restrains and counteracts the rigid tension of the centripetal constraint spring 604, forcing the floating component 602 and the sliding spline 502 connected by the connecting rod 506 to exhibit a smooth and slow damped displacement, preventing the floating component 602 from frequently reciprocating relative to the guide rod 601.

[0059] Example 5 like Figure 4 and Figure 6As shown, based on Embodiment 4, the present invention provides a technical solution: preferably, the outer wall of the floating member 602 is provided with a plurality of spiral-shaped guide grooves 8; the cross-section of the guide rod 601 is an elliptical structure, and the sliding part on the floating member 602 that cooperates with the guide rod 601 is correspondingly set as an elliptical hole.

[0060] In this embodiment, by integrating the spiral guide groove 8 with the elliptical anti-rotation structure, during the high-speed revolution of the floating part 602 with the rotor central axis 3, the spiral guide groove 8 on its outer wall is given a certain aerodynamic windward angle by a constant motion posture, which cuts through the air to produce an effect similar to centrifugal pump suction; the high-temperature air in the center area of ​​the rotor is forced to be thrown outward radially, forcing the explosion-proof housing 1 to generate a forced convection circulation from the center to the outer shell; Furthermore, the non-cylindrical surface mating feature of the elliptical guide rod 601 and the elliptical hole allows the floating component 602 to retain only the radial translational degree of freedom, locking its circumferential rotational degree of freedom around the radial axis; this ensures the absolute constancy of the floating component 602's motion posture and avoids circumferential deflection interference from the transmission mechanism 5.

[0061] Throughout the entire cycle of normal motor operation and centrifugal action, along with the high-speed rotation of the main shaft, the spiral guide groove 8 on the surface of the floating part 602 is equivalent to the blade profile of a backward-inclined centrifugal impeller. It continuously draws hot air from the low-pressure area near the rotor central shaft 3 and uses the superposition of centrifugal force and inclined thrust to guide the airflow to the inner wall of the explosion-proof housing 1. This process utilizes the original static mass of the floating part 602 to achieve active intervention and temperature homogenization of the internal thermal field of the explosion-proof housing 1 without adding an additional drive source.

[0062] like Figure 4 , Figure 5 and Figure 6 As shown, in this embodiment, preferably, the air inlet 702 is located on the side of the floating member 602 near the drive shaft section 301, and the exhaust port 701 is directly opposite the inner wall of the explosion-proof housing 1.

[0063] In this embodiment, by setting the air inlet 702 in the rotor center region near the drive shaft section 301, the mechanism can preferentially draw in high-temperature hot air near the central shaft when the piston cylinder volume increases (reset stage or high-frequency micro-vibration stage); in conjunction with the layout of the exhaust port 701 facing the inner wall of the explosion-proof housing 1, the high-temperature airflow captured by the piston cylinder is directly sprayed in jet form onto the heat dissipation surface of the inner wall of the housing with the highest heat capacity when the piston cylinder volume decreases (centrifugal trigger stage or fine-tuning stage). During motor operation, the volume of the variable volume air chamber inside the floating component 602 will change back and forth due to the slight fluctuations in the speed of the rotor central shaft 3 or during the decoupling / reset operation. When the volume of the variable volume air chamber increases, the negative pressure generated draws air from the periphery of the drive shaft section 301 through the air inlet 702 located on the inner side. Since the periphery of the drive shaft section 301 is the concentration of the main heat source of the rotor, the gas drawn in carries the heat energy of the rotor core. When the volume of the variable volume air chamber decreases, the high-temperature air under pressure inside is discharged through the exhaust port 701 on the outer side. Since the exhaust port 701 is directly opposite the inner wall of the explosion-proof housing 1, the high-temperature airflow impacts and contacts the heat dissipation surface with the shortest physical path.

[0064] like Figure 5 and Figure 6 As shown, preferably, the outer wall of the second magnet 605 is provided with threaded teeth, and the inner wall of the floating member 602 on the side away from the drive shaft section 301 is provided with a threaded groove. The second magnet 605 is connected to the threaded part of the floating member 602 by thread.

[0065] In this embodiment, by setting threads on the outer wall of the second magnet 605 and threading it to the floating part 602, an overall threshold calibration effect is achieved: utilizing the precise axial displacement control property of the threaded drive, the operator can fine-tune the initial working air gap between the second magnet 605 and the limiting block 603 by rotating the second magnet 605; since the magnetic attraction force is inversely proportional to the square of the air gap distance, the small change in this axial displacement can significantly change the magnitude of the initial static magnetic locking force, thereby achieving precise physical calibration of the limit speed threshold without replacing the spring, improving the compatibility and operation accuracy of this protection system on explosion-proof motors of different specifications.

[0066] During the calibration phase after the motor is assembled, the testers use a special tool to rotate the second magnet 605. Since there is a threaded fit between the second magnet 605 and the floating part 602, the second magnet 605 makes a slight axial movement along the inner wall of the floating part 602, thereby changing the initial hovering distance of its end relative to the limit block 603. If the actual trigger speed is less than the target threshold, the second magnet 605 is rotated inward to reduce the air gap, thereby increasing the static magnetic attraction force; otherwise, it is rotated outward to reduce the magnetic attraction force.

[0067] Preferably, both the second magnet 605 and the first magnet 507 are cup-shaped magnets.

[0068] In this embodiment, by setting both the second magnet 605 and the first magnet 507 as cup-shaped magnets, the magnetic circuit gathering and shielding effects are achieved: by constructing a closed magnetic circuit using a magnetic cup body, the divergent magnetic lines of force are forcibly gathered at the adsorption end face, so that under the same magnet volume, its output static holding force is better than that of ordinary magnets; at the same time, the magnetic cup body plays an electromagnetic shielding role, limiting the overflow of the magnetic field to the non-working direction and eliminating magnetic interference to other precision electronic components inside the motor.

[0069] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. An explosion-proof motor with dual overspeed protection function, comprising a stator assembly (2), a rotor assembly, an output spindle (401), and an explosion-proof housing (1), wherein the rotor assembly includes a rotor central shaft (3), and the output spindle (401) is disposed on the axial extension line of the rotor central shaft (3); characterized in that: A sliding spline (502) is provided between the rotor central shaft (3) and the output main shaft (401), and the rotor central shaft (3) and the output main shaft (401) are synchronously connected via the sliding spline (502); The explosion-proof housing (1) is equipped with a dual overspeed protection system, which consists of an electrical protection module and a mechanical protection module. The electrical protection module includes a speed sensor and a controller. The controller is configured to trigger a power-off action when the actual speed detected by the speed sensor is greater than a set safe speed threshold. The mechanical protection module includes a centrifugal actuator, a centrifugal constraint spring (604) and a transmission mechanism (5). The centrifugal actuator is radially floating. The centrifugal constraint spring (604) applies an inward radial preload to the centrifugal actuator. The centrifugal actuator is connected to the sliding spline (502) via the transmission mechanism (5). When the power supply fails to cut off and the actual speed continues to rise and exceeds the set limit speed threshold, the centrifugal force generated by the centrifugal actuator is greater than the radial preload of the centripetal constraint spring (604). The centrifugal actuator overcomes the preload and moves outward radially, and is converted into an axial pulling force to drive the sliding spline (502) via the transmission mechanism (5). The sliding spline (502) is translated axially under the action of the axial tension, and its translational displacement is greater than the spline engagement length, so that the rotor central shaft (3) and the output main shaft (401) are physically decoupled.

2. The explosion-proof motor with dual overspeed protection function according to claim 1, characterized in that: The rotor center shaft (3) includes a drive shaft section (301) and a transmission shaft section (302) connected by a flange. The transmission shaft section (302) has a groove (503) at one end near the flange. A slider (504) is slidably connected inside the groove (503). The drive shaft section (301) has a clearance groove (303) at one end near the flange. Guide rods (601) are symmetrically fixedly connected to the side wall of the drive shaft section (301), and a limiting block (603) is fixedly connected to one end of the guide rod (601) away from the rotor central shaft (3); the centrifugal actuator is a floating component (602) that is slidably sleeved outside the guide rod (601); the centrifugal constraint spring (604) is sleeved outside the guide rod (601) and located between the floating component (602) and the limiting block (603); The transmission mechanism (5) includes a slider (504) slidably connected inside the slide groove (503), and a connecting rod (506) is hinged between the slider (504) and the floating member (602); a first spline groove (501) is provided at one end of the transmission shaft section (302) away from the slide groove (503), and the sliding spline (502) is slidably connected inside the first spline groove (501); a linkage rod (505) is slidably provided in the central part of the transmission shaft section (302), one end of the linkage rod (505) is fixedly connected to the slider (504), and the other end passes through the interior of the first spline groove (501) and is fixedly connected to the sliding spline (502); a second spline groove (402) is provided at one end of the output spindle (401) located inside the explosion-proof housing (1).

3. The explosion-proof motor with dual overspeed protection function according to claim 2, characterized in that: The limiting block (603) is made of a magnetically conductive material; the floating member (602) extends from one end away from the drive shaft section (301) to the other side of the limiting block (603) and is equipped with a second magnet (605), the second magnet (605) being configured to magnetically attract the limiting block (603) when the floating member (602) is in the initial position, so as to lock the floating member (602) in the initial position; a flexible block is provided between the second magnet (605) and the limiting block (603).

4. The explosion-proof motor with dual overspeed protection function according to claim 3, characterized in that: A first magnet (507) is fixedly connected to the inner wall of the clearance groove (303) away from the slide groove (503). The slider (504) is made of magnetic material. A flexible block is provided on the side of the first magnet (507) near the slider (504).

5. An explosion-proof motor with dual overspeed protection function according to claim 4, characterized in that: The floating component (602) is configured as a piston cylinder with one end open and the other end closed; the limiting block (603) has a cylindrical structure, and a sealing ring (704) is embedded on its outer circumferential surface; the limiting block (603) is slidably sleeved inside the floating component (602) through the open end, and the sealing ring (704) is tightly fitted with the inner wall of the floating component (602) to form a variable volume air chamber; an air inlet is provided through the wall of the floating component (602) to connect the variable volume air chamber with the internal space of the explosion-proof housing (1). The inlet (702) and outlet (701) are equipped with separate one-way valves (703). The one-way valve (703) in the outlet (701) is configured to open outward when the volume of the variable volume air chamber decreases, and the one-way valve (703) in the inlet (702) is configured to open inward when the volume of the variable volume air chamber increases. The total flow cross-sectional area of ​​the inlet (702) is strictly smaller than the total flow cross-sectional area of ​​the outlet (701).

6. An explosion-proof motor with dual overspeed protection function according to claim 5, characterized in that: The outer wall of the floating component (602) is provided with a plurality of spiral-shaped guide grooves (8); the cross-section of the guide rod (601) is elliptical, and the sliding part on the floating component (602) that cooperates with the guide rod (601) is correspondingly provided with an elliptical hole.

7. An explosion-proof motor with dual overspeed protection function according to claim 6, characterized in that: The air inlet (702) is located on the side of the floating part (602) near the drive shaft section (301), and the exhaust port (701) is directly opposite the inner wall of the explosion-proof housing (1).

8. An explosion-proof motor with dual overspeed protection function according to claim 3, characterized in that: The outer wall of the second magnet (605) is provided with thread teeth, and the inner wall of the floating part (602) away from the drive shaft section (301) is provided with thread grooves. The second magnet (605) is connected to the threaded part of the floating part (602) by thread.

9. An explosion-proof motor with dual overspeed protection function according to claim 8, characterized in that: The second magnet (605) and the first magnet (507) are both cup-shaped magnets.

Images