Torque protection device of electric actuating mechanism

Abstract

The invention relates to a torque protection device of an electric actuating mechanism. The torque protection device comprises a worm, an axial pushing assembly, a supporting and fixing base, a volute spiral spring, a pressing plate and a screw. The axial pushing assembly comprises a bearing sleeve, an elastic buffering section and a jacking column, and the rear end of the worm is in axial limiting running fit with the bearing sleeve; a containing cavity is defined by a mounting flange of the supporting and fixing base and an upper cover body, the containing cavity is divided into an upper containing cavity and a lower containing cavity through a cover plate, a jacking column is in sliding fit with a screw spiral groove through a limiting pin, axial movement can be converted into screw rotation, a torque adjusting component is driven to rotate, torque overload cutting is completed, and resetting is achieved through a volute spiral spring. The device does not need external power supply, can stably operate in extreme environments of high temperature, strong vibration, electromagnetic interference and the like, and is precise in protection and simplified in operation and maintenance.

Description

Technical Field

[0001] This invention relates to the field of valve control technology, and more specifically to a mechanical torque protection device for an electric actuator controlled by an MCC (motor control center). Background Technology

[0002] As the core power component of industrial valve control, the torque protection function of electric actuators directly affects the operational safety and service life of both the valve and the actuator itself. Currently, torque protection solutions for electric actuators mainly employ intelligent control technology. However, in industrial scenarios such as petrochemicals, nuclear power, metallurgy, and thermal power generation, actuators not only need to withstand extreme environments such as high temperatures, strong vibrations, electromagnetic interference, and dust and moisture erosion for extended periods, but also need to cope with sudden operating conditions such as valve jamming and instantaneous overload. This places stringent requirements on the reliability, environmental adaptability, and response accuracy of torque protection devices.

[0003] Electronic electric actuator protection schemes operate on the principle of sensor signal acquisition and control unit judgment, using signals from motor current, magnetic flux, or torque sensors to detect overload and trigger protection actions. While this type of scheme offers some flexibility, it often struggles to meet the stable operation requirements under the aforementioned extreme conditions in practical engineering applications. Specific limitations are as follows: (1) Insufficient adaptability to extreme environments: Sensors are highly susceptible to electromagnetic interference, dust obstruction, or water vapor corrosion, which can cause signal distortion; Electronic components of the control unit (such as capacitors and chips) will age faster at high temperatures and experience performance degradation at low temperatures, resulting in a limited operating temperature range that is difficult to adapt to the wide temperature requirements of industrial scenarios. (2) Reliance on external power supply and special protection: Sensors and control units require continuous power supply. Once a power outage or voltage fluctuation occurs, the protection function will immediately fail, requiring an additional UPS backup power supply, which increases system complexity and cost. At the same time, a protective shell and electromagnetic shielding layer are required; otherwise, the equipment failure rate will increase significantly in harsh environments. (3) High difficulty in troubleshooting: The system includes multiple components such as sensors, signal lines, and control units. Fault points are scattered and require professional tools and technicians for testing. Ordinary maintenance personnel have difficulty quickly locating problems, which affects the efficiency of equipment recovery.

[0004] Therefore, a mechanical torque protection device is needed to ensure the safe and reliable operation of electric actuators and valves in extreme environments. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a torque protection device for electric actuators. This device can operate stably in extreme industrial environments such as high temperature, strong vibration, and electromagnetic interference, without requiring external power supply. It can accurately cut off torque overload and automatically reset, simplifying operation and maintenance.

[0006] The objective of this invention is achieved through the following approach: A torque protection device for an electric actuator includes a worm gear, an axial pushing assembly, a support base, a spiral spring, a pressure plate, and a screw. The axial pushing assembly includes a bearing sleeve, an elastic buffer section, and a top column. The front end of the worm is connected to the motor, and the rear end of the worm extends into the bearing sleeve and forms an axially limited rotational fit with the bearing sleeve. The support and fixing base includes a fixedly connected mounting flange and an upper cover, which together form a through-hole receiving cavity. The top column and the elastic buffer section are both located in the receiving cavity. A cover plate is fixedly installed in the middle of the receiving cavity, which divides the receiving cavity into an upper receiving cavity and a lower receiving cavity. The side wall of the lower receiving cavity is provided with symmetrically distributed limiting grooves. The elastic buffer section is provided with a disc spring assembly, so that one end of the top column extends into the lower receiving cavity and abuts against the limiting pin that is slidably embedded in the limiting groove. One end of the screw is provided with a helical transmission structure, and the limiting pin is slidably engaged with the helical transmission structure to convert the axial movement of the axial pushing component into the rotational movement of the screw. A pressure plate is fixed on the upper cover through a connector, which is used to axially limit the screw. The other end of the screw is connected and fixed to the torque adjustment component, which is used to drive the torque adjustment component to rotate when the screw rotates, so as to realize the torque cut-off control when the output torque of the electric actuator reaches the rated value or when overloaded. The spiral spring is mounted on the screw and is used to drive the axial pushing assembly back to its initial position when the actuator outputs torque and unloads.

[0007] Preferably, the rear end of the worm gear is connected and fixed to the inner side of the bearing sleeve via a bearing, and the bearing is connected and fixed to the rear end of the worm gear via a second locking nut.

[0008] Preferably, the disc spring assembly includes a first washer, a second washer, and a disc spring assembly sandwiched between the first washer and the second washer. One side of the first washer abuts against a first locking nut on the elastic buffer section, and the other side is in contact with the disc spring assembly. One side of the second washer is in contact with the other end of the disc spring assembly, and the other side abuts against the shoulder between the elastic buffer section and the bearing sleeve.

[0009] Preferably, the upper receiving cavity is provided with an annular stepped surface, and the first gasket abuts against the annular stepped surface.

[0010] Preferably, the cover plate is fixedly connected to the upper cover body by circumferentially distributed screws, and a through hole is provided on the cover plate to allow the free end of the top column to extend into the lower receiving cavity, while simultaneously providing radial restraint to the top column.

[0011] Preferably, the helical transmission structure includes a guide hole at the end of the helical segment of the screw and a helical groove through the guide hole wall. The end of the top post extends into the guide hole and abuts against the limiting pin. The axis of the limiting pin is perpendicular to the axis of the top post, and the length of the limiting pin is greater than the inner diameter of the lower cavity of the upper cover, so that both ends of the limiting pin extend out of the guide hole wall and are embedded in the limiting groove, thereby realizing the axial guiding constraint of the limiting pin.

[0012] Preferably, the connector is a plurality of pillars, one end of which is provided with an external thread and is threadedly engaged with the threaded mounting hole at the lower end of the upper cover for fixation, and the other end of which is provided with an internal threaded hole. The pressure plate is engaged with the internal threaded hole by a screw to achieve detachable fixation between the pressure plate and the pillar.

[0013] Preferably, the inner ring of the spiral spring is connected and fixed to the middle of the screw, and the outer ring of the spiral spring is snapped and fixed to any support post.

[0014] Preferably, the torque adjusting component is provided with a flat square through groove, and the other end of the screw is a flat square structure that is adapted to and passes through the flat square through groove. The free end of the flat square structure is provided with an external thread, and the torque adjusting component is fixed to the screw by a nut that is threaded with the external thread.

[0015] Preferably, the torque adjusting component is further provided with a cam plate for touching the torque protection switch of the electric actuator.

[0016] The beneficial effects of this invention are as follows: ① This invention adopts a fully mechanical structure design, involving no electronic components. It relies solely on the physical characteristics of mechanical transmission and elastic elements to achieve its protection function, eliminating the need for external power supply or backup power. Even in the event of power outages, voltage fluctuations, or other emergencies, its torque protection function remains stable and effective. This design not only effectively avoids the risk of protection failure in electronic devices due to power supply issues but also adapts to extreme industrial scenarios such as high temperatures, strong vibrations, radiation, electromagnetic interference, and dust and moisture corrosion. This solves the problem of insufficient adaptability of electronic devices in fields such as petrochemicals, nuclear power, and metallurgy. It eliminates the need for additional protective shells or electromagnetic shielding layers, reducing system costs.

[0017] ② The device described in this invention can be adapted to electric actuators with different rated torques by flexibly adjusting the specifications (quantity, stacking method) of the disc spring group and the preload of the spiral spring, without redesigning the overall structure. It can meet the control needs of various industrial valves and has a wide range of applications.

[0018] ③ The device described in this invention has a simplified number of core components, a clear transmission chain, and concentrated and easily identifiable fault points. Ordinary maintenance personnel can quickly locate problems without the need for professional tools, which greatly reduces the difficulty of troubleshooting and the threshold for maintenance.

[0019] ④ In this invention, the rear end of the worm extends into the bearing sleeve and is fixed by the bearing and the second locking nut, so that the worm and the bearing sleeve form an axially limited rotational fit. This not only strictly limits the relative axial displacement between the two, but also ensures that only the relative rotational degree of freedom is retained. This effectively avoids the transmission deviation caused by axial movement during torque transmission, provides a stable mechanical transmission basis for torque detection, and thus ensures the accuracy and consistency of torque detection.

[0020] ⑤ By configuring a disc spring assembly consisting of shims and disc spring groups, this invention achieves two advantages. First, by utilizing the symmetrical clamping and stable support structure of the disc spring groups with double shims, a precise correspondence is established between the output torque and the axial movement distance, thereby ensuring the accuracy of the protection torque threshold setting and the consistency of overload triggering. Second, for electric actuators with different rated torques, the required preload can be precisely matched by replacing disc spring groups with different specifications (such as quantity and stacking method), greatly enhancing the adaptability of the device to operating conditions and the flexibility of its application.

[0021] ⑥ By setting a cover plate inside the receiving cavity, the present invention divides the receiving cavity into upper and lower independent chambers. This not only limits the axial movement of the screw, but also forms a reliable radial constraint on the top column through the through hole opened on the cover plate, effectively preventing the top column from deflecting or shaking when moving, and ensuring the accuracy of motion guidance.

[0022] ⑦ The spiral spring used in this invention has two advantages. First, its outer ring can be easily adjusted by changing the position of the locking support to adjust the preload of the spiral spring. This allows for flexible adaptation to the opening and closing of the actuator and the reset requirements under different load conditions, greatly improving the adaptability of the structure to complex working conditions. Second, the dual fixing method, where the inner ring of the spiral spring is fixed to the screw and the outer ring is locked to the support, ensures the stability of the elastic force transmission. After the torque is unloaded, a uniform and continuous reset force can be released, driving the axial pushing component to accurately return to its initial position. This effectively ensures the reliability of repeated use, the consistency of action, and the stability of long-term service of the device. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a two-dimensional structural schematic diagram of the present invention; Figure 3 This is a cross-sectional view of the torque protection device of the present invention; Figure 4 for Figure 3 A partial schematic diagram of point A in the middle; Figure 5 This is a schematic diagram of the bottom structure of the upper cover in this invention; Figure 6 This is a schematic diagram of the screw structure in this invention; Figure 7 This is a schematic diagram of the torque adjustment component in this invention; Figure 8 This is a three-dimensional schematic diagram of the bottom connection of the upper cover in this invention; Figure 9 This is a schematic diagram of the structure inside the upper cover of the present invention from another direction.

[0024] In the attached diagram, 1-worm gear, 2-axial jacking assembly, 201-bearing sleeve, 202-elastic buffer section, 203-top column, 3-support fixing seat, 4-volute spring, 5-pressure plate, 6-screw, 601-helical section, 6011-guide hole, 6012-helical groove, 7-mounting flange, 8-upper cover, 801-limiting groove, 9-support column, 10-cover plate, 11-limiting pin, 12-torque adjustment component, 1201-flat square through groove, 1202-cam plate, 13-bearing, 14-second locking nut, 15-first washer, 16-second washer, 17-disc spring assembly, 18-first locking nut, 19-locking plug, 20-retaining ring, 21-mounting through hole. Detailed Implementation

[0025] like Figures 1 to 9 As shown, a torque protection device for an electric actuator includes a worm gear 1, an axial pushing assembly 2, a support fixing seat 3, a spiral spring 4, a pressure plate 5, and a screw 6, and all components are made of metal.

[0026] The axial jacking assembly 2 includes a bearing sleeve 201, an elastic buffer section 202, and a jacking column 203 arranged coaxially. The front end of the worm gear 1 is connected to the motor via a flat section. After the motor starts, it can drive the worm gear 1 to rotate synchronously. The rear end of the worm gear 1 extends into the bearing sleeve 201 and forms an axially limited rotational fit with the bearing sleeve 201. Specifically, the rear end of the worm gear 1 is connected and fixed to the inner side of the bearing sleeve 201 via a bearing 13. A second locking nut 14 is used to abut one end of the bearing 13 against the first shoulder provided at the rear end of the worm gear 1, so that the bearing 13 and the worm gear 1 are fixed to each other, ensuring that the worm gear 1 and the bearing sleeve 201 can only rotate relative to each other without relative axial movement. At the same time, the other end of the bearing 13 is limited and fixed by a locking plug 19 and a retaining ring 20 to prevent the bearing 13 from axially moving within the bearing sleeve 201, further ensuring the stability of the rotational fit and the transmission accuracy. In this embodiment, the bearings 13 are a pair of angular contact bearings installed opposite each other.

[0027] The support mounting base 3 includes a mounting flange 7 and an upper cover 8 fixedly connected by bolts, which together form a through-hole receiving cavity. The top column 203 and the elastic buffer section 202 are both located within this receiving cavity. A cover plate 10 is fixedly installed in the middle of the receiving cavity by circumferentially distributed screws. The cover plate 10 divides the receiving cavity into an upper receiving cavity and a lower receiving cavity. The elastic buffer section 202 is located in the upper receiving cavity. A disc spring assembly is mounted on the elastic buffer section 202. The disc spring assembly includes a first washer 15, a second washer 16, and a disc spring group 17 sandwiched between the first washer 15 and the second washer 16. One side of the first washer 15 abuts against the first locking nut 18 on the elastic buffer section 202. The inner wall of the upper receiving cavity has an annular stepped surface. The first washer 15 abuts against the annular stepped surface, and the other side is in contact with the disc spring group 17. One side of the second washer 16 is in contact with the other end of the disc spring group 17, and the other side abuts against the shoulder between the elastic buffer section 202 and the bearing sleeve 201. Specifically, the mounting flange 7 and the upper cover 8 are bolted together to the housing of the electric actuator, and the second gasket 16 is in close contact with the end face of the housing of the electric actuator, providing a stable support reference for the disc spring assembly and ensuring that the elastic deformation of the disc spring group 17 can accurately reflect torque changes. In practical applications, by setting the number and stacking method of the disc spring groups 17, the rated torque requirements of the actuator can be precisely matched, ensuring a stable and controllable correspondence between the output torque and the axial displacement distance, providing a reliable guarantee for the accurate triggering of torque protection actions. In this embodiment, the combination of the disc springs in the disc spring group 17 is a mating type.

[0028] The lower receiving cavity has symmetrically distributed limiting grooves 801 on its side wall. One end of the top post 203 extends into the lower receiving cavity through a through hole in the cover plate 10. Specifically, the through hole in the cover plate 10 adopts a positive tolerance design, while the outer diameter of the top post 203 adopts a negative tolerance design. The tolerance matching between the two ensures that the top post 203 can be smoothly inserted while reserving axial movement space for the top post 203 and effectively preventing radial displacement during the movement of the top post 203. The end of the top post 203 extending into the lower receiving cavity is fixedly connected to the limiting pin 11. The axis of the limiting pin 11 is perpendicular to the axis of the top post 203, and the length of the limiting pin 11 is greater than the inner diameter of the lower receiving cavity. This allows both ends of the limiting pin 11 to extend out of the top post 203 and embed into the limiting groove 801, forming a reliable axial guiding constraint. This ensures that the limiting pin 11 can only move linearly along the axial direction of the limiting groove 801, avoiding circumferential rotational displacement.

[0029] One end of the screw 6 is provided with a helical transmission structure, which includes a guide hole 6011 at the end of the helical section 601 of the screw 6 and a helical groove 6012 that penetrates the wall of the guide hole 6011. The end of the top post 203 extends into the guide hole 6011 and abuts against the limiting pin 11. The limiting pin 11 penetrates the helical groove 6012 and forms a sliding fit with it. When the top post 203 drives the limiting pin 11 to make axial linear movement, the limiting pin 11, through the guiding effect of the helical groove 6012, converts the axial movement of the axial pushing assembly 2 into the circumferential rotation of the screw 6.

[0030] The lower end of the upper cover 8 is connected and fixed to the pressure plate 5 via four evenly arranged support columns 9. One end of each support column 9 has an external thread that engages with the threaded mounting hole at the lower end of the upper cover 8. The other end of each support column 9 has an internal threaded hole. The pressure plate 5 has four corresponding mounting holes 21. Screws are passed through the mounting holes 21 and detachably fixed to the corresponding internal threaded holes of the support columns 9, thus achieving a detachable and fixed connection between the pressure plate 5 and the support columns 9. The end face of the pressure plate 5 abuts against the fixed section of the screw 6 to axially limit the screw 6 and prevent axial movement of the screw 6 during rotation.

[0031] A fixed section is provided in the middle of the screw 6. A spiral spring 4 is fitted on the fixed section of the screw 6. The inner ring of the spiral spring 4 is connected to the corresponding pin hole of the fixed section of the screw 6 by an elastic pin, so as to achieve a tight connection and fixation between the spiral spring 4 and the screw 6. The outer ring of the spiral spring 4 is fixed to any support 9 by a hook. The preload torque of the spiral spring 4 can be finely adjusted by adjusting the hook position of the outer ring on different support 9 to meet the reset requirements under different working conditions.

[0032] The other end of the screw 6 is a flat rectangular structure. The outer circumference of the flat rectangular structure is adapted to the inner circumference of the flat rectangular through groove 1201. An external thread is provided at the free end of the flat rectangular structure. The flat rectangular structure passes through the flat rectangular through groove 1201. The torque adjustment component 12 is fixed to the screw 6 by a nut that mates with the external thread and the stepped surface between the flat rectangular structure and the fixed section. This ensures that the screw 6 can synchronously drive the torque adjustment component 12 to rotate when it rotates. The torque adjustment component 12 is also provided with two cam plates 1202, which are used to touch the torque protection switches of the valve opening and closing during rotation to realize torque cut-off control.

[0033] The working principle of the above device is as follows: When the electric actuator is working, the worm gear 1 bears the main axial force during torque transmission (considering the force characteristics of the worm gear, the axial force is the core force component). Therefore, when the output torque of the actuator reaches the rated value or is overloaded, the axial force on the worm gear 1 is greater than the preload of the disc spring assembly 17, which in turn pushes the bearing sleeve 201 to move along the axial cavity and causes the elastic buffer section 202 to compress the disc spring assembly 17 to produce elastic deformation. At this time, the axial movement of the elastic buffer section 202 simultaneously pushes the top column 203 to move axially in a straight line along the through hole of the cover plate 10, and the top column 203 drives the limiting pin 11 to move axially along the limiting groove 801. Since the limiting pin 11 and the spiral groove 6012 of the screw 6 maintain a precise sliding fit, the axial movement in the guide hole 6011 caused by the limiting pin 11 can be converted into the circumferential rotational movement of the screw 6. When the screw 6 rotates, the torque adjustment component 12 rotates synchronously. It should be noted that the lead of the spiral groove 6012 can make the axial movement stroke of the top column 203 and the rotation angle of the screw 6 have a fixed transmission ratio. This ensures that when the torque reaches the set threshold, the cam plate 1202 on the torque adjustment component 12 rotates to the preset position that touches the torque protection switch, cuts off the motor power output, realizes torque overload protection, and avoids action delay or false triggering.

[0034] When the output torque of the motor actuator is unloaded, the axial force on the worm 1 disappears, and the disc spring assembly 17 recovers its deformation under its own elasticity, simultaneously driving the worm 1 and bearing sleeve 201 back to their initial positions. Subsequently, the spiral spring 4 releases the preload torque, driving the screw 6 to rotate in the opposite direction. Through the cooperation of the spiral groove 6012 and the limit pin 11, it pushes the top column 203 to move in the opposite direction until the top column 203, bearing sleeve 201 and worm 1 return to their initial positions, preparing for the next torque test.

[0035] In this embodiment, the spiral spring 4 has a certain preload torque in the initial state, which can meet the bidirectional torque detection requirements of the actuator in both the opening and closing directions. No matter which direction the worm 1 is subjected to axial force, torque protection can be achieved through the above transmission process, ensuring reliable protection when bidirectional torque overload occurs.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A torque protection device for an electric actuator, characterized in that The worm (1), the axial pushing assembly (2), the support fixed seat (3), the volute spring (4), the pressing plate (5) and the screw rod (6) are included. The axial pushing assembly (2) includes a bearing sleeve (201), an elastic buffer section (202) and a top column (203), the front end of the worm (1) is connected with a motor, the rear end of the worm (1) extends into the inside of the bearing sleeve (201) and forms an axial limiting rotating fit with the bearing sleeve (201). The support fixed seat (3) includes a fixedly connected mounting flange (7) and an upper cover body (8), both of which surround to form a through accommodating cavity, the top column (203) and the elastic buffer section (202) are located in the accommodating cavity, a cover plate (10) is fixedly arranged in the middle of the accommodating cavity, the cover plate (10) divides the accommodating cavity into an upper accommodating cavity and a lower accommodating cavity, a limiting groove (801) is arranged on the side wall of the lower accommodating cavity and symmetrically distributed, a disc spring assembly is arranged on the elastic buffer section (202), and one end of the top column (203) extends into the lower accommodating cavity and abuts against a limiting pin (11) which is slidingly embedded in the limiting groove (801). One end of the screw rod (6) is provided with a screw transmission structure, the limiting pin (11) is in sliding fit with the screw transmission structure, which is used for converting the axial movement of the axial pushing assembly (2) into the rotating movement of the screw rod (6), a pressing plate (5) is fixed on the upper cover body (8) through a connecting piece, the pressing plate (5) is used for forming axial limiting for the screw rod (6), the other end of the screw rod (6) is connected and fixed with a torque adjusting component (12), which is used for driving the torque adjusting component (12) to rotate when the screw rod (6) rotates, so that the torque cut-off control of the output torque of the electric actuator reaches the rated value or overload. The volute spring (4) is arranged on the screw rod (6) and is used for driving the axial pushing assembly (2) to return to the initial position when the output torque of the actuator is unloaded.

2. The torque protection device according to claim 1, characterized in that The rear end of the worm (1) is connected and fixed with the inside of the bearing sleeve (201) through a bearing (13), and the bearing (13) is connected and fixed with the rear end of the worm (1) through a second locking nut (14).

3. The torque protection device according to claim 1, characterized in that The disc spring assembly includes a first gasket (15), a second gasket (16) and a disc spring group (17) clamped between the first gasket (15) and the second gasket (16), one side of the first gasket (15) abuts against a first locking nut (18) on the elastic buffer section (202), the other side is in contact with the disc spring group (17), one side of the second gasket (16) is in contact with the other end of the disc spring group (17), and the other side abuts against the shaft shoulder between the elastic buffer section (202) and the bearing sleeve (201).

4. The torque protection device according to claim 3, characterized in that The upper accommodating cavity is provided with an annular stepped surface, and the first gasket (15) abuts against the annular stepped surface.

5. The torque protection device according to claim 1, characterized in that The cover plate (10) and the upper cover body (8) are fixedly connected through circumferentially distributed screws, a through hole is arranged on the cover plate (10), the free end of the top column (203) can extend into the lower accommodating cavity, and the cover plate (10) forms radial limiting for the top column (203).

6. The torque protection device according to claim 1, characterized in that The screw transmission structure comprises a guide hole (6011) arranged at the end of the screw segment (601) of the screw rod (6) and a spiral groove (6012) arranged through the hole wall of the guide hole (6011), the end of the jacking post (203) extends into the guide hole (6011) and abuts against the limiting pin (11), the axis of the limiting pin (11) is perpendicular to the axis of the jacking post (203), and the length of the limiting pin (11) is greater than the inner diameter of the lower accommodating cavity of the upper cover body (8), so that the two ends of the limiting pin (11) extend out of the wall of the guide hole (6011) and are embedded into the limiting groove (801), thereby realizing the axial direction constraint of the limiting pin (11).

7. The torque protection device according to claim 1, characterized in that The connecting piece is a plurality of support columns (9), one end of the support column (9) is provided with external threads and is fixed in thread cooperation with the threaded mounting hole at the lower end of the upper cover body (8), and the other end of the support column (9) is provided with an internal threaded hole, the pressing plate (5) is fixed in cooperation with the internal threaded hole through a screw, thereby realizing the detachable fixing of the pressing plate (5) and the support column (9).

8. The torque protection device according to claim 7, characterized in that The inner ring of the volute spring (4) is connected and fixed with the middle part of the screw rod (6), and the outer ring of the volute spring (4) is clamped and fixed with any support column (9).

9. The torque protection device according to claim 1, characterized in that The torque adjusting component (12) is provided with a flat square through groove (1201), the other end of the screw rod (6) is a flat square structure, the flat square structure is adapted to the flat square through groove (1201) and penetrates through the flat square through groove (1201), the free end of the flat square structure is provided with external threads, and a nut in thread cooperation with the external threads is used to fix the torque adjusting component (12) on the screw rod (6).

10. The torque protection device according to claim 1, characterized in that The torque adjusting component (12) is further provided with a cam piece (1202) for touching the torque protection switch of the electric actuator.

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