Electric actuator with variable speed and overspeed protection functions

By designing an electric actuator with variable speed and overspeed protection functions, the problem of valve speed adjustment under different flow rates was solved, achieving efficient control and equipment protection.

CN223908924UActive Publication Date: 2026-02-13CASTO INTELLIGENT TECH JIANGYIN CO LTD
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Patent Information

Application Number
CN202520224605.2
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-02-13
Publication Date
2026-02-13
Estimated Expiration
2035-02-13

AI Technical Summary

Technical Problem

Existing electric actuators cannot adjust the valve opening and closing speed according to the flow rate in the pipeline, resulting in wasted resources or low efficiency. At the same time, the high speed of the input shaft may damage the internal parts of the actuator.

Method used

An electric actuator with speed change and overspeed protection functions was designed, including a power component, a speed change component, and an overspeed protection component. The valve speed is adjusted by start/stop sensors and measurement sensors, and the input shaft is protected to prevent axial movement when the worm gear speed is too high.

Benefits of technology

It enables valve speed adjustment based on flow rate, avoiding resource waste, extending actuator life, and protecting internal parts from damage.

✦ Generated by Eureka AI based on patent content.

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    Figure CN223908924U_ABST
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Abstract

An electric actuator with variable-speed and over-speed protection functions comprises a power assembly, a variable-speed assembly and an over-speed protection assembly. The power assembly is arranged on one side of the speed change assembly and drives the speed change assembly, and the lower end of the overspeed protection assembly is slidably connected to the power assembly. The utility model has the following advantages: the valve is closed or opened through the power assembly, the speed change assembly, the central information processor and the motor for controlling the valve, and the closing or opening speed of the valve is divided into a high-speed gear, a middle-speed gear and a low-speed gear under the action of the speed change assembly; for different flow speeds in the pipeline, a motor for controlling the valve is controlled to close or open the valve at a corresponding speed by adjusting gears of the speed change assembly, and the problem that resources are wasted due to the fact that the flow speed in the pipeline is too high and the valve cannot be closed in time is solved. Meanwhile, when the difference between the collection amount in the container and the preset amount is small, the valve is slowly closed, so that the preset amount can be collected, and the time of continuously adjusting the opening degree of the valve by an operator to do other work can be saved. The overspeed protection assembly can effectively prevent the input shaft from moving in the electric actuator to damage internal weak parts due to too high rotating speed and the action of axial force through the measurement sensor.
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Description

TECHNICAL FIELD

[0001] The utility model relates to electric actuator field, concretely relates to a kind of electric actuator with variable speed and over speed protection function. BACKGROUND

[0002] Electric actuator controls the opening and closing of valve through some devices, in application scene, the valve needing electric actuator control is mostly enclosed in pipeline, and the pipeline end is generally connected to the container of liquid or gas collection, if the collection amount in container reaches predetermined amount, it needs to reduce the opening of valve or directly close valve;The speed of electric actuator to valve closing or opening is only one, when collection amount reaches predetermined amount, but the flow rate in pipeline is faster, if valve cannot be closed quickly, it will cause resource waste;Or the flow rate in pipeline is very slow, after closing valve, collection amount does not reach predetermined amount, it needs to open valve again, so it will affect the efficiency of collection work;In addition, the input shaft of electric actuator is driven by gear or other transmission member and external motor output shaft, the rotation speed of external motor output shaft is very fast, the rotation speed of electric actuator end is basically consistent with the speed of valve opening and closing, but the opening and closing speed of valve is too fast, which will affect service life, so, to reduce the speed inside electric actuator, the first transmission in electric actuator generally adopts worm gear meshing transmission, i.e. SUMMARY

[0003] The utility model provides a kind of electric actuator with variable speed and over speed protection function to solve the technical problem mentioned above.

[0004] The utility model discloses a technical scheme of a kind of electric actuator with variable speed and overspeed protection function, to achieve the above-mentioned purpose, which comprises power component, variable speed component, overspeed protection component;Power component sets variable speed component side, power component drives variable speed component, overspeed protection component is set in power component top;Power component includes first gear, second gear, wherein first gear is power component input end and is engaged with external motor gear, and second gear is power component output end;The variable speed component includes emergency stop component, variable speed gear set, wherein emergency stop component is set between variable speed gear set, second gear;The emergency stop component includes emergency stop gear, and the emergency stop gear is engaged with second gear, the input gear of variable speed gear set or disengaged from engagement respectively;The variable speed component further includes the start-stop sensor that sends opening or closing valve to central information processor, and start-stop sensor is set in variable speed gear set side, and variable speed gear set output end is slidably connected with start-stop sensor;The overspeed protection component includes overspeed measuring rod, overspeed measuring piece, measurement sensor, and one end of overspeed measuring rod is clamped in two spiral blocks on worm, and the axis of overspeed measuring rod is perpendicular to the axis of worm;The other end of overspeed measuring rod is fixedly connected with one end of overspeed measuring piece, and the included angle between overspeed measuring rod and overspeed measuring piece is greater than 0 and less than 180 °;Measurement sensor is set on the shell and is located in the side of overspeed measuring rod;The other end of overspeed measuring piece is slidably connected in measurement sensor.

[0005] Further, the electric actuator with variable speed and overspeed protection function further comprises a shell, and the power component, the variable speed component and the overspeed protection component are all arranged on the shell;The power component comprises a worm, a worm wheel and a transmission rod, the first gear is arranged at one end of the worm and the axis thereof is parallel to the axis of the worm, and the worm is rotatably arranged on the shell;The worm wheel is arranged at the end of the transmission rod and the axis thereof is parallel to the axis of the transmission rod, the worm wheel is engaged with the worm, and the axis of the worm wheel is perpendicular to the axis of the worm;The transmission rod is rotatably arranged on the shell, and the axis of the transmission rod is perpendicular to the axis of the worm;The second gear is sleeved on the transmission rod, and the axis of the second gear is parallel to the axis of the transmission rod and the second gear is arranged on the side of the worm wheel.

[0006] Further, the emergency stop assembly comprises an emergency stop assembly support shaft, a spring, a spring support plate, an emergency stop button and a connecting block; the emergency stop assembly support shaft is vertically arranged on the shell, the spring support plate is arranged on the emergency stop assembly support shaft, and one end of the spring is fixedly arranged on the spring support plate; the emergency stop gear is slidably connected to the emergency stop assembly support shaft, and the axis of the emergency stop gear is parallel to the axis of the emergency stop assembly support shaft; the other end of the spring is fixedly arranged on one side of the emergency stop gear; the connecting block is fixedly connected to the other side of the emergency stop gear; the emergency stop button is arranged on one side of the emergency stop gear, and the lower end of the emergency stop button is rotatably connected to the connecting block. Preferably, when the transmission fails in the variable speed gear set and behind the variable speed gear set, the power transmitted to the variable speed gear set can be disconnected by immediately pressing the emergency stop button, thereby protecting the weak parts inside the electric actuator.

[0007] Further, the variable speed assembly further comprises a shifting block, the shifting block is fixedly arranged on the output gear of the variable speed gear set, and the end of the shifting block is provided with a cam; further, the start-stop sensor comprises a pushing block, and the pushing block is fixedly connected or slidably connected to the start-stop sensor;

[0008] The cam on the shifting block is slidably connected to the pushing block or is disconnected from the pushing block. Preferably, the shifting block has three rotating speeds, and the shifting block slides on the pushing block of the start-stop sensor while rotating; after the start-stop sensor senses the rotating speed of the shifting block, the start-stop sensor sends the rotating speed information to the central information processor; the central information processor matches the motor of the control valve to close or open the valve at the same speed as the shifting block.

[0009] The electric actuator with the variable speed and overspeed protection functions further comprises a terminal, and the terminal is fixedly connected to the shell; the lead of the start-stop sensor is connected to the terminal;

[0010] The lead of the measuring sensor is connected to the terminal; and the lead of the central information processor is also connected to the terminal. Preferably, the start-stop sensor and the measuring sensor send information to the central information processor through the terminal, and the central information processor processes corresponding tasks through the received information.

[0011] The electric actuator with the variable speed and overspeed protection functions further comprises a terminal, and the terminal is fixedly connected to the shell; the lead of the start-stop sensor is connected to the terminal;

[0012] 1. The utility model discloses a power assembly, variable speed assembly, central information processor and the motor of control valve realize closing or opening valve, and under the action of variable speed assembly, the speed of closing or opening valve is divided into fast gear, medium speed gear and slow gear, and the motor of control valve is adjusted the gear of variable speed assembly to realize corresponding speed to close or open valve to solve the problem of resource waste caused by too fast flow rate in pipeline to close valve in time, when the collection amount in container and the difference of predetermined amount are not much, slow closing valve can not only collect predetermined amount but also save the time of operating personnel to adjust the valve opening degree to do other work.

[0013] 2. The utility model discloses the overspeed protection assembly on the input shaft of electric actuator is added, and the overspeed protection assembly can effectively prevent the input shaft from moving in the inside of electric actuator and damaging the inside weak parts under the action of too fast rotating speed and axial force through the measurement sensor. ACCURACY

[0014] Figure 1 It is the whole structure schematic diagram of the utility model;

[0015] Figure 2 It is the internal whole structure schematic diagram of the utility model;

[0016] Figure 3 It is the power assembly structure schematic diagram of the utility model;

[0017] Figure 4 It is the variable speed assembly structure schematic diagram of the utility model;

[0018] Figure 5 It is the emergency stop subassembly structure schematic diagram of the utility model;

[0019] Figure 6 It is the variable speed assembly gear drive route schematic diagram of the utility model;

[0020] Figure 7 It is the start-stop sensor structure schematic diagram of the utility model Figure 1 ;

[0021] Figure 8 It is the overspeed protection assembly structure schematic diagram of the utility model;

[0022] Figure 9 It is the start-stop sensor structure schematic diagram of the utility model Figure 2 .

[0023] In the figure: the housing 40, power assembly 10, speed change assembly 20, overspeed protection assembly 30, first gear 11, worm 12, transmission rod 13, worm gear 14, second gear 15, guard frame 42, partition 41, terminal 43, speed change gear set 21, emergency stop assembly 22, emergency stop assembly support shaft 23, emergency stop gear 24, spring 25, spring support plate 26, emergency stop button 27, connecting block 28, speed change lever 29, push block 210, start-stop sensor 211, push spring 213, fixed block 214, overspeed measuring rod 31, overspeed measuring piece 32, measuring sensor 33, disc spring 34, sliding slot 35. DETAILED DESCRIPTION

[0024] Referring to Figure 1 , Figure 2 , Figure 8 , an electric actuator with speed change and overspeed protection functions includes a housing 40, a speed change assembly 20, an overspeed protection assembly 30, and a power assembly 10. The speed change assembly 20, the overspeed protection assembly 30, and the power assembly 10 are installed on the housing 40. The speed change assembly 20 controls the opening and closing of a valve and the speed of the opening and closing of the valve through some devices. The overspeed protection assembly 30 is used to prevent the input shaft from moving inside the electric actuator due to the effect of too fast rotation speed and axial force. The housing 40 is also provided with a terminal 43. The lead of a start-stop sensor 211 in the speed change assembly 20 is connected to the terminal 43. The terminal 43 is also connected to the lead of a central information processor, the power line of the electric actuator, and the lead of a measuring sensor 33 in the overspeed protection assembly 30. The start-stop sensor 211 and the measuring sensor 33 can send signals to the central information processor through the terminal 43.

[0025] Referring to Figures 2-4 , the housing 40 includes a partition 41. The partition 41 is arranged in the housing 40. The overspeed protection assembly 30 and the speed change assembly 20 are installed on the partition 41. The power assembly 10 includes a first gear 11, a worm 12, a transmission rod 13, a worm gear 14, and a second gear 15. The first gear 11 is engaged with the gear of an external motor. The first gear 11 is coaxial with the worm 12. The worm 12 is arranged to rotate on the housing 40. The worm 12 is engaged with the worm gear 14. The axes of the worm 12 and the worm gear 14 are perpendicular to each other. The worm gear 14 is arranged at one end of the transmission rod 13. The transmission rod 13 is arranged to rotate on the housing 40 through the partition 41. The partition 41 seals the worm gear 14 and the worm 12 in the housing 40 to prevent dust from entering. The first gear 11 is engaged with the gear of an external motor to transmit power to the worm 12. The worm 12 transmits power to the transmission rod 13 through engagement with the worm gear 14. The second gear 15 is arranged on the transmission rod 13. The transmission rod 13 transmits power to the speed change assembly 20 through the second gear 15.

[0026] With reference to Figures 2-5 As shown in the figure, the transmission assembly 20 includes a transmission gear set 21, an emergency stop assembly 22, which is arranged on the shell 40 through the partition plate 41; the emergency stop assembly 22 includes an emergency stop assembly support shaft 23, an emergency stop gear 24, a spring 25, a spring support plate 26, an emergency stop button 27, and a connecting block 28, wherein the emergency stop assembly support shaft 23 is rotationally arranged on the shell 40, a spring support plate 26 is fixedly arranged on the emergency stop assembly support shaft 23, one end of the spring 25 is fixedly arranged on the spring support plate 26, the other end of the spring 25 is fixedly arranged on one side of the emergency stop gear 24, the emergency stop gear 24 is slidingly connected on the emergency stop assembly support shaft 23, the center of the emergency stop gear 24 is provided with a groove, the emergency stop assembly support shaft 23 is a prism, and the emergency stop gear 24 is respectively engaged with the second gear 15 on the transmission rod 13 and the input gear of the transmission gear set 21, and the transmission rod 13 transmits power to the transmission gear set 21 through the second gear 15 and the emergency stop gear 24; the other end of the connecting block 28 is rotationally connected with the lower end of the emergency stop button 27. When a fault occurs in the transmission gear set 21, the operator presses the emergency stop button 27, the emergency stop button 27 presses the emergency stop gear 24 downward through the connecting block 28 connected with the emergency stop gear 24, and when the emergency stop button 27 is pressed to the bottom, the emergency stop gear 24 is disengaged from the second gear 15 and the transmission gear set 21, at this time, the transmission gear set 21 does not lose power, and the transmission gear set 21 and the rear device are all stopped running. If the emergency stop button 27 is released, the emergency stop gear 24 is released by the spring 25 and returns to the position of being engaged with the second gear 15 and the transmission gear set 21.

[0027] With reference to Figure 2 , Figure 4 , Figure 6 As shown in the figure, the transmission gear set 21 includes a transmission lever 29 and a shifting block 210, and in this embodiment, the transmission gear set 21 has one input end and two output ends, the input end of the transmission gear set 21 is engaged with the emergency stop gear 24, and one shifting block 210 is fixedly arranged on each of the two output ends; in this embodiment, one end of the shifting block 210 is fixedly connected with the output end of the transmission gear set 21, and the other end of the shifting block 210 is provided with an arc-shaped block extending to one side. The transmission gear set 21 is provided with a transmission lever 29, which can adjust the rotating speed of the input gear to the output gear of the transmission gear set 21; in the position shown in the figure, there are five levels of speed reduction between the input gear and the output gear of the transmission gear set 21, and the rotating speed of the shifting block 210 is the slowest; if the transmission lever 29 is raised by one level, there are three levels of speed reduction between the input gear and the output gear of the transmission gear set 21, and the rotating speed of the shifting block 210 is neither fast nor slow; if the transmission lever 29 is raised by another level, there is one level of speed reduction between the input gear and the output gear of the transmission gear set 21, and the rotating speed of the shifting block 210 is the fastest.

[0028] With reference toFigure 1 , Figure 2 , Figure 4 , Figure 6 , Figure 7 The transmission assembly 20 further includes a start / stop sensor 211, which includes a push block 212 and a push spring 213. The housing 40 also includes a protective frame 42, which is detachably connected to the housing 40 and is used to protect the internal components of the electric actuator. In this embodiment, two start / stop sensors 211 are provided and respectively located on one side of two actuating blocks 210. The push block 212 is slidably connected inside the start / stop sensor 211, with one end connected to the push spring 213. The other end of the push spring 213 is connected inside the start / stop sensor 211 and connected to the internal information transmitting device. The two actuating blocks 210 rotate at the same speed and in the same direction, but one actuating block 210 always lags behind the other actuating block 210 by half a turn. When one actuating block 210 is in contact with the push block 212, the other actuating block 210 is in an idle state. One start / stop sensor 211 is set to open, and the other sensor is set to closed. The valve is set to "closed". Only when one toggle block 210 is in contact with the start / stop sensor 211 set to "open" and the other toggle block 210 is out of contact with the start / stop sensor 211 set to "closed" will the start / stop sensor 211 send a signal to the central information processor. The central information processor will then send a start signal to the valve motor to open the valve. Similarly, only when one toggle block 210 is out of contact with the start / stop sensor 211 set to "open" and the other toggle block 210 is in contact with the start / stop sensor 211 set to "closed" will the valve be closed. This provides an extra layer of protection for the electric actuator controlling the valve, preventing the valve from being accidentally opened or closed. When the actuating block 210 rotates, it slides on the pushing block 212 while pushing the pushing block 212 to move on the start / stop sensor 211. The start / stop sensor 211 is equipped with a sensing device that senses the moving speed of the pushing block 212. The sensing device in the start / stop sensor 211 senses the moving speed of the pushing block 212 and then transmits the information of the moving speed of the pushing block 212 to the information transmitting device in the start / stop sensor 211. The information transmitting device then transmits the information to the central information processor. The central information processor then matches the corresponding speed of the control valve motor to close or open the valve. Finally, the speed of the control valve motor is matched to be consistent with the speed of the actuating block 210.

[0029] Reference Figure 9 As shown, the start / stop sensor 211 also has the following embodiments. In the second embodiment of the start / stop sensor 211, the start / stop sensor 211 includes a fixing block 214. The fixing block 214 is fixedly disposed on one side of the start / stop sensor 211. The fixing block 214 is an inner arc block that matches the rotation trajectory of the toggle block 210. When the toggle block 210 makes a full rotation, half of it slides in the fixing block 214 and the other half is suspended in the air.

[0030] Referring to Figure 4 , Figure 8 The overspeed protection assembly 30 includes an overspeed measuring rod 31, an overspeed measuring piece 32, a measuring sensor 33, and disc springs 34. The slide groove 35 is arranged on the partition plate 41, and the overspeed measuring rod 31 is slidably arranged in the slide groove 35. One end of the overspeed measuring rod 31 is clamped on two spiral blocks on the worm 12, and the other end is fixedly connected to one end of the overspeed measuring piece 32. The other end of the overspeed measuring piece 32 is slidably connected to the measuring sensor 33. In this embodiment, the axis of the worm 12 is perpendicular to the axis of the overspeed measuring rod 31, and the axis of the worm 12 is parallel to the long axis of the overspeed measuring piece 32. When the worm 12 rotates, the lower end of the overspeed measuring rod 31 slides along the spiral wall of the spiral block and pushes the overspeed measuring piece 32 to slide in the measuring sensor 33. When the worm 12 does not move, the value of the overspeed measuring rod 31 moving in the measuring sensor 33 does not exceed the measuring range set by the measuring sensor 33. If the worm 12 moves, the value of the overspeed measuring rod 31 moving in the measuring sensor 33 exceeds the measuring range set by the measuring sensor 33. When the measuring range is exceeded, the measuring device inside the measuring sensor 33 sends an interrupt signal to the alarm device, and the alarm device inside the measuring sensor 33 immediately sends a power-off instruction to the central information processor and a valve closing instruction to the central information processor. One end of the worm 12 is fixedly connected to the first gear 11, and the other end is provided with a plurality of pairs of disc springs 34. The disc springs 34 are used to buffer the movement of the worm 12 to prevent the impact force generated by the sudden movement of the worm 12 from damaging the weak parts inside the electric actuator.

[0031] The utility model discloses a working principle: first, according to the demand, first gear shifting component 20 is changed, namely the gear lever 29 is taken up or pressed down, the lowest is slow gear, the middle is medium speed gear, the top is fast gear, and the higher the gear, the faster the valve closes or opens, then starts electric actuator, and the first gear 11 in electric actuator is engaged rotation of external motor gear, the first gear 11 is coaxial with worm 12, and the transmission rod 13 is equipped with worm wheel 14, and worm 12 is engaged with worm wheel 14, and the transmission rod 13 is equipped with second gear 15, and the second gear 15 is engaged with the emergency stop gear 24 in emergency stop component 22, and the emergency stop gear 24 is engaged with the variable speed gear set 21 again, and the output end of variable speed gear set 21 is used to move the block 210 for moving start-stop sensor 211, and after receiving the signal of being moved, start-stop sensor 211 sends the signal to central information processor, and central information processor sends the instruction of closing valve or opening valve to the motor of control valve, and if when finding that the abnormal situation appears in variable speed gear set 21, directly presses the emergency stop button 27, and the power that is transmitted to variable speed gear set 21 can be interrupted to protect the weak parts in electric actuator, and the output shaft of external motor is transmitted to the worm 12 axle through the first gear 11, but the rotating speed of external motor output shaft is very high, and the rotating speed of worm 12 axle is also very high, when the rotating speed of worm 12 axle is too high, under the action of worm 12 axle's axial force, will move in electric actuator, and one end of overspeed measuring rod 31 is clamped in the two spiral blocks on worm 12, and the other end is fixedly connected overspeed measuring piece 32 one end, and the other end of overspeed measuring piece 32 is slidably connected in measuring sensor 33, if worm 12 moves in the inside, measuring sensor 33 will send an alarm, then electric actuator stops immediately, and the valve controlled closes immediately.

[0032] The above, only for the utility model preferred specific implementation, but the protection scope of the utility model is not limited to this, any familiar with the technical field of the technical personnel in the utility model disclosed technical range, according to the utility model technical scheme and the utility model concept are equivalent to replace or change, all should be covered in the protection scope of the utility model.

Claims

1. An electric actuator with variable speed and over speed protection, characterized in that, The power assembly (10), the speed change assembly (20), and the overspeed protection assembly (30) are arranged on the housing (40). The power assembly (10) is arranged on one side of the speed change assembly (20), and the power assembly (10) drives the speed change assembly (20). The power assembly (10) comprises a first gear (11) and a second gear (15), wherein the first gear (11) is an input end of the power assembly (10) and is engaged with an external motor gear, and the second gear (15) is an output end of the power assembly. The speed change assembly (20) comprises an emergency stop assembly (22) and a speed change gear set (21), wherein the emergency stop assembly (22) is arranged between the speed change gear set (21) and the second gear (15). The emergency stop assembly (22) comprises an emergency stop gear (24), which is engaged with or disengaged from the second gear (15) and the input gear of the speed change gear set (21) respectively. The speed change assembly (20) further comprises a start-stop sensor (211) for sending an opening or closing signal to a central information processor, which is arranged on one side of the speed change gear set (21) and is in sliding connection with the output end of the speed change gear set (21). The overspeed protection assembly (30) comprises an overspeed measuring rod (31), an overspeed measuring sheet (32), and a measuring sensor (33), wherein one end of the overspeed measuring rod (31) is clamped in two spiral blocks on the worm (12), and the axis of the overspeed measuring rod (31) is perpendicular to the axis of the worm (12). The other end of the overspeed measuring rod (31) is fixedly connected to one end of the overspeed measuring sheet (32), and an included angle greater than 0° and less than 180° is arranged between the overspeed measuring rod (31) and the overspeed measuring sheet (32). The measuring sensor (33) is arranged on the housing (40) and located on one side of the overspeed measuring rod (31). The other end of the overspeed measuring sheet (32) is in sliding connection with the measuring sensor (33).

2. The electric actuator with variable and over speed protection function according to claim 1, characterized in that, The power assembly (10), the speed change assembly (20), and the overspeed protection assembly (30) are arranged on the housing (40). The power assembly (10) comprises a worm (12), a worm gear (14), and a transmission rod (13), wherein the first gear (11) is arranged at one end of the worm and has an axis parallel to the axis of the worm, and the worm (12) is rotatably arranged on the housing (40). The worm gear (14) is arranged at the end of the transmission rod (13) and has an axis parallel to the axis of the transmission rod (13), the worm gear (14) is engaged with the worm (12), and the axis of the worm gear (14) is perpendicular to the axis of the worm (12). The transmission rod (13) is rotatably arranged on the housing (40), and the axis of the transmission rod (13) is perpendicular to the axis of the worm (12). The second gear (15) is sleeved on the transmission rod (13), the axis of the second gear (15) is parallel to the axis of the transmission rod (13), and the second gear (15) is arranged on one side of the worm gear (14).

3. The electric actuator with variable and over speed protection function according to claim 1, characterized in that, The emergency stop assembly (22) comprises an emergency stop assembly support shaft (23), a spring (25), a spring support plate (26), an emergency stop button (27), and a connecting block (28). The emergency stop assembly support shaft (23) is vertically rotatably arranged on the shell (40), the spring support plate (26) is arranged on the emergency stop assembly support shaft (23), and one end of the spring (25) is fixedly arranged on the spring support plate (26); The emergency stop gear (24) is slidably connected on the emergency stop assembly support shaft (23), and the axis of the emergency stop gear (24) is parallel to the axis of the emergency stop assembly support shaft (23); The other end of the spring (25) is fixedly arranged on one side of the emergency stop gear (24); The other side of the emergency stop gear (24) is fixedly connected with the connecting block (28); The emergency stop button (27) is arranged on one side of the emergency stop gear, and the lower end of the emergency stop button (27) is rotatably connected with the connecting block (28).

4. The electric actuator with variable and over speed protection function according to claim 1, characterized in that, The variable speed assembly (20) further comprises a shifting block (210), which is fixedly arranged on the output gear of the variable speed gear set (21), and the end of the shifting block (210) is provided with a cam.

5. The electric actuator with variable and over speed protection according to claim 1 or 4, characterized in that, The start-stop sensor (211) comprises a pushing block (212), which is fixedly connected or slidably connected on the start-stop sensor (211); The cam on the shifting block (210) is slidably connected with the pushing block (212) or is disconnected therefrom.

6. The electric actuator with variable and over speed protection according to claim 1, wherein, Further comprising a terminal, the terminal (43) is fixedly connected on the shell (40); The lead of the start-stop sensor (211) is connected on the terminal (43); The lead of the measuring sensor (33) is connected on the terminal (43); The lead of the central information processor is further connected on the terminal (43).