A self-monitoring stable gearbox and monitoring method

Abstract

The present invention provides a self-monitoring stable gearbox and a monitoring method, belonging to the technical field of gearboxes. The gearbox comprises a housing, a worm wheel, a worm and a monitoring device. The monitoring device comprises a base, a first piston head, a second piston head, a spring and a displacement sensor. A monitoring hole is arranged on the base. The base is arranged on the housing and at least three installation cavities are evenly arranged on the outer periphery of the monitoring hole. The installation cavity comprises a first cavity and a second cavity which are arranged in communication. The end surface area of ​​the first piston head is larger than the end surface area of ​​the second piston head. The installation cavity is filled with a liquid medium between the first piston head and the second piston head. The displacement sensors are arranged one by one on the outer ring of the second cavity. A main control board is arranged in the base, and each displacement sensor is connected to the main control board. In the present invention, the radial runout of the worm can be accurately monitored in real time through the monitoring device, and preventive maintenance can be performed before a serious failure of the gearbox occurs, thereby reducing downtime and maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of gear boxes, and in particular to a self-monitoring stable gear box and a monitoring method. Background Art

[0002] Gearboxes are important devices in mechanical transmission systems. They transmit and transform power through the meshing of gears. They have the functions of speed change, torque increase, and change of motion direction. They are widely used in industrial equipment, automobiles, wind turbines, and other fields. Among them, the worm gearbox is a special gearbox with a compact structure and smooth operation. It has a high reduction ratio and self-locking function. It is suitable for scenes such as lifting equipment and automation equipment that require high torque output and unidirectional transmission. Its core is composed of a worm and a worm wheel. It realizes power transmission through helical meshing and has the characteristics of good stability and low vibration and noise.

[0003] In a worm gearbox, the worm wheel is usually connected to the output shaft, while the worm is connected to the input shaft as an active component. Since the worm wheel has a large number of teeth and can withstand large torque, it is suitable as an output component; and the worm, with its spiral design, can achieve a high reduction ratio, which is suitable for the input end to drive the worm wheel at high speed. This type of gearbox is often used in large speed reduction scenarios. The worm drives the worm wheel through high-speed rotation and outputs greater torque at a lower speed. However, since radial runout is prone to occur when the worm rotates at high speed, traditional worm gearboxes usually lack the function of monitoring the motion status of the worm, making it difficult to detect and maintain potential problems in a timely manner, thereby affecting the operating safety and reliability of the gearbox. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a self-monitoring stable gearbox and a monitoring method.

[0005] The technical solution adopted by the present invention is as follows: In the first aspect, the present application provides a self-monitoring stable gearbox, including a housing, a worm wheel and a worm, the worm being rotatably arranged at the bottom of the housing, and also including a monitoring device arranged on the worm, the monitoring device being used to monitor the radial runout of the worm, the monitoring device including a base, a first piston head, a second piston head, a spring and a displacement sensor, a monitoring hole being arranged coaxially with the worm on the base, the base being arranged on the housing and at least three mounting cavities being evenly arranged on the periphery of the monitoring hole, the mounting cavity including a first cavity and a second cavity which are arranged in communication with each other, the first cavity being arranged close to the monitoring hole and being matched with the first piston head, the second cavity being located at an end of the first cavity away from the monitoring hole and being matched with the second piston head The first piston head is slidably arranged in the first cavity, and the second piston head is slidably arranged with the second cavity. The end surface area of ​​the first piston head is larger than the end surface area of ​​the second piston head. The mounting cavity is filled with liquid medium between the first piston head and the second piston head. The first piston head is provided with a first piston rod at one end away from the second piston head, and the second piston head is provided with a second piston rod at one end away from the first piston head. The spring is sleeved on the second piston rod and its two ends respectively abut against the second piston head and the second cavity. Under the action of the spring, the first piston rod abuts against the worm. The number of the displacement sensors is the same as the number of the second piston rods and they are arranged one-to-one on their outer rings. A main control board is arranged in the base, and each of the displacement sensors is connected to the main control board.

[0006] In some embodiments, a first annular cavity is coaxially arranged on the base with the monitoring hole, the first annular cavity is located in the outer ring of a plurality of second cavities, one end of the second piston rod extends into the first annular cavity, an annular fixing plate is arranged in the first annular cavity, each of the displacement sensors is arranged on the annular fixing plate, a control cavity is arranged at the lower part of the base, and the main control board is arranged in the control cavity.

[0007] In some embodiments, a second annular cavity is formed between the annular fixing plate and the circumferential outer wall of the first annular cavity, an annular circuit board is disposed in the second annular cavity, each of the displacement sensors is connected to the annular circuit board, a wiring channel connecting the second annular cavity and the control cavity is disposed on the base, and the annular circuit board is connected to the main control board.

[0008] In some embodiments, a limit plate is provided at one end of the second piston rod close to the displacement sensor, an annular limit plate is coaxially provided on the inner ring of the annular fixing plate, and detection holes are provided on the annular limit plate corresponding to each displacement sensor, and the diameter of the detection hole is smaller than the outer diameter of the limit plate.

[0009] In some embodiments, one end of the first piston rod close to the worm is rotatably provided with a ball, or is provided as a dome, or is provided with a roller rotatably provided along the rotation direction of the worm.

[0010] In some embodiments, the worm includes a worm segment and shaft segments located on both sides of the worm segment, and there are two monitoring devices, which are respectively arranged on the two shaft segments.

[0011] In some embodiments, the number of the mounting cavities is at least eight.

[0012] In a second aspect, the present application provides a monitoring method for the self-monitoring stable gearbox, comprising the following steps:

[0013] Step A1: Set the radial runout limit. Each first piston rod forms a measuring point on the worm. The number of measuring points is , set the end surface area of ​​the first piston head to , the end surface area of ​​the second piston head is ,in, , the displacement of the first piston rod , the displacement of the second piston rod , and preset maximum radial runout , then calculate the actual maximum radial runout ;

[0014] Step A2: Real-time monitoring: when the gearbox is running, the actual radial runout is obtained through each displacement sensor. , ； if , a visual signal feedback is given to ensure timely response.

[0015] In some embodiments, in step A2, if , then safety monitoring is carried out, including the following steps:

[0016] Step B1: Establish a coordinate system, establish a two-dimensional coordinate system with the center of the worm as the origin, and calculate the measurement coordinates as , denoise and clean the data, remove outliers, and each measurement coordinate forms a two-dimensional data set: ;

[0017] Step B2: Calculate the coordinates of the center of the jumping circle , use the least squares method to fit and solve the center of the runout circle. First, set the distance error from each measurement point to the center of the circle to:

[0018]

[0019] in,

[0020] Next, by minimizing the total error To find out and :

[0021] ；

[0022] Then, using the partial derivatives and Take partial derivative and set it to zero, get the equation system, solve it to get the coordinates of the center of the circle .

[0023] Step B3: Calculate the deviation value through the center coordinates Calculate the deviation from the origin coordinates , and set the maximum deviation value ;

[0024] Step B4: Data analysis: Process the deviation data in time series to form a time series data set , plot the deviation value data against time as a real-time change curve;

[0025] Step B5: Establish a database, collect several real-time change curves of the gearbox under the same usage scenario to establish a database, and the time segment of the real-time change curve is from the start of operation to the deviation value Reaching the maximum deviation ;

[0026] Step B6: Optimize the curve, integrate and optimize several real-time change curves to form a standard change curve based on machine learning, and Reaching the maximum deviation Set up early warning points before;

[0027] Step B7: Monitoring and comparison: for gearboxes operating in the same usage scenario, compare their real-time change curve with the standard change curve. If they are consistent with the trend, a visual signal feedback is given when the warning point is reached. If they are not consistent with the trend, the machine is shut down for maintenance.

[0028] In some embodiments, in step B5, the worm wear compensation amount is increased according to the service life of the gearbox, and the actual maximum radial runout is gradually increased. , and a structured database is established according to the service life division groups. In step B6, several real-time change curves in each group are integrated and optimized to form a corresponding standard change curve. In step B7, the standard change curve of the adaptation group is retrieved for comparison.

[0029] The beneficial effects of the present invention are as follows: the monitoring device in the present invention can accurately monitor the radial runout of the worm in real time, perform preventive maintenance before a serious failure of the gearbox occurs, and reduce downtime and maintenance costs. At the same time, since the liquid medium is incompressible, the difference in area ratio between the first piston head and the second piston head can amplify the originally smaller radial runout of the worm into a larger displacement of the second piston rod, thereby facilitating monitoring by the displacement sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0031] Figure 1 A schematic diagram of a self-monitoring stable gearbox in the present invention;

[0032] Figure 2 A cross-sectional view of a self-monitoring stable gearbox in the present invention;

[0033] Figure 3 It is a cross-sectional view of the box and the monitoring device in the present invention;

[0034] Figure 4 A partial schematic diagram of the monitoring device in the present invention Figure 1 ;

[0035] Figure 5 A partial schematic diagram of the monitoring device in the present invention Figure 2 . DETAILED DESCRIPTION

[0036] In the description of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms "longitudinal", "transverse", "radial", "length", "width", "thickness", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0037] Secondly, the terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components and should not be understood as limitations on the embodiments of the present application.

[0038] In addition, the terms "installed", "set", "provided with", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components.

[0039] For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Regarding the drawings of the present application, it should be clearly understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of the present specification. It should also be understood that the drawings are not drawn to scale.

[0041] Usually in a worm gearbox, the worm wheel is connected to the output shaft and bears a large torque, and the worm is connected to the input shaft to drive the worm wheel with high-speed rotation to achieve a high reduction ratio. However, the worm is prone to radial runout when rotating at high speed, and the traditional gearbox lacks a monitoring function and cannot detect problems in time, which affects the safety and reliability of operation. The following description provides specific application scenarios and requirements of this specification for the purpose of enabling those skilled in the art to manufacture and use the contents of this specification. It is obvious to those skilled in the art that various local modifications to the disclosed embodiments are obvious, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0042] Based on the above problems, Figures 1 to 5 As shown, the present specification provides a self-monitoring stable gearbox, comprising a housing 1, a worm wheel 2, a worm 3 and a monitoring device arranged on the worm 3, wherein the worm 3 is rotatably arranged at the bottom of the housing 1, the worm 3 comprises a worm segment and shaft segments located on both sides of the worm segment, and the monitoring device is used to monitor the radial runout of the worm 3. Preferably, there are two monitoring devices, and the two monitoring devices are respectively arranged on two shaft segments, such a bilateral arrangement can more comprehensively capture the motion state of the worm 3, avoid the blind spots existing in single-point monitoring, and improve the monitoring accuracy.

[0043] Specifically, the monitoring device includes a base 4, a first piston head 5, a second piston head 6, a spring 7 and a displacement sensor 8. The base 4 is provided with a monitoring hole 40 coaxially with the worm 3. The base 4 is provided on the housing 1 and at least three mounting cavities 41 are evenly provided on the outer periphery of the monitoring hole 40. Usually, the number of the mounting cavities 41 is at least eight, and eight are taken as an example in this specification. Among them, the displacement sensor 8 is preferably a capacitive displacement sensor with good vibration resistance.

[0044] Secondly, the installation cavity 41 includes a first cavity 410 and a second cavity 411 which are connected to each other. The first cavity 410 is arranged close to the monitoring hole 40 and is adapted to the first piston head 5. The second cavity 411 is located at the end of the first cavity 410 away from the monitoring hole 40 and is adapted to the second piston head 6. The first piston head 5 is slidably arranged in the first cavity 410, and the second piston head 6 is slidably arranged with the second cavity 411. The end surface area of ​​the first piston head 5 is larger than the end surface area of ​​the second piston head 6. The installation cavity 41 is filled with liquid medium between the first piston head 5 and the second piston head 6. The end of the first piston head 5 away from the second piston head 6 is provided with a first piston rod 50, and the second piston head 6 is far away from the first piston head 6. A second piston rod 60 is provided at one end away from the first piston head 5, and the spring 7 is sleeved on the second piston rod 60 and the two ends are respectively abutted against the second piston head 6 and the second cavity 411. Under the action of the spring 7, the first piston rod 50 abuts against the worm 3. The number of the displacement sensors 8 is the same as the number of the second piston rods 60 and are arranged one-to-one on the outer ring thereof. A main control board 9 is provided in the base 4, and each of the displacement sensors 8 is connected to the main control board 9. In this arrangement, since the liquid medium is incompressible, the originally smaller radial runout of the worm 3 can be amplified to a larger displacement of the second piston rod 60 through the difference in area ratio between the first piston head 5 and the second piston head 6, thereby facilitating monitoring by the displacement sensor 8.

[0045] Secondly, the parts of the monitoring device are all installed in the base 4, which simplifies the assembly difficulty and isolates it from external influences.

[0046] Secondly, the liquid medium has a certain damping effect, which can filter out some noise signals caused by environmental vibrations and maintain the stability of the monitoring data.

[0047] Secondly, even if the worm 3 is subjected to an instantaneous impact during operation, the liquid medium can mitigate the impact on the piston by dispersing the pressure, thereby protecting the overall structure.

[0048] In addition, the stability of the worm rotation can be improved to a certain extent.

[0049] In some embodiments, a first annular cavity 42 is coaxially arranged on the base 4 with the monitoring hole 40. The first annular cavity 42 is located at the outer circle of a plurality of second cavities 411, making full use of the internal space of the base 4 and avoiding unnecessary waste of space. One end of the second piston rod 60 extends into the first annular cavity 42. An annular fixing plate 43 is arranged in the first annular cavity 42. Each displacement sensor 8 is arranged on the annular fixing plate 43. Each displacement sensor 8 is integrated into the first annular cavity 42 through the annular fixing plate 43, making maximum use of the space of the first annular cavity 42. A control cavity 44 is arranged at the lower part of the base 4. The main control board 9 is arranged in the control cavity 44. An independent chamber is used to install the main control board 9 to reduce interference factors.

[0050] In some embodiments, a second annular cavity 45 is formed between the annular fixing plate 43 and the circumferential outer side wall of the first annular cavity 42, an annular circuit board is arranged in the second annular cavity 45, each of the displacement sensors 8 is connected to the annular circuit board, and a wiring channel 46 connecting the second annular cavity 45 and the control cavity 44 is arranged on the base 4, the annular circuit board is connected to the main control board 9, and each displacement sensor 8 is directly connected through the annular circuit board, which simplifies the traditional point-to-point wiring method, reduces the length and number of cables, and improves the neatness and reliability of the system.

[0051] In some embodiments, a limit plate 600 is provided at one end of the second piston rod 60 close to the displacement sensor 8, and an annular limit plate 47 is coaxially provided on the inner ring of the annular fixing plate 43. A detection hole 470 is provided on the annular limit plate 47 corresponding to each displacement sensor 8. The diameter of the detection hole 470 is smaller than the outer diameter of the limit plate 600. The limit plate 600 arranged at one end of the second piston rod 60 can provide mechanical limitation within the movement range of the piston rod to prevent the excessive displacement of the piston rod from causing physical damage to the displacement sensor 8, thereby effectively extending the service life of the sensor.

[0052] It should be understood that the annular fixing plate 43 and the annular limiting plate 47 are not necessarily annular, and may also be arc-shaped plates provided corresponding to each displacement sensor 8, and each arc-shaped plate is coaxially provided.

[0053] In some embodiments, a ball is rotatably provided at one end of the first piston rod 50 close to the worm 3 . Compared with the traditional sliding contact method, the ball can significantly reduce friction, especially reduce the influence of the axial movement of the worm 3 on the first piston rod 50 .

[0054] It should be understood that the end of the first piston rod 50 close to the worm 3 can also be set as a dome, or the end of the first piston rod 50 close to the worm 3 is provided with a roller rotating along the rotation direction of the worm 3, but the ball structure is preferably used.

[0055] This specification also provides a monitoring method for the self-monitoring stable gearbox, comprising the following steps:

[0056] Step A1: Setting the radial runout limit, each first piston rod 50 forms a measuring point on the worm 3, and the number of measuring points is Three points can determine a circle. Generally, more than eight points are set to fully capture the radial runout of the worm 3 and ensure the accuracy and comprehensiveness of monitoring. The end surface area of ​​the first piston head 5 is set to , the end surface area of ​​the second piston head 6 is ,in, , the displacement of the first piston rod 50 , the displacement of the second piston rod 60 , and preset maximum radial runout , then calculate the actual maximum radial runout The radial runout of the worm 3 causes a slight displacement of the first piston rod 50, which is magnified by the differential structure and the liquid medium. Therefore, the actual maximum radial runout is It also needs to be adjusted according to the area ratio of the first piston head 5 and the second piston head 6;

[0057] Step A2: Real-time monitoring: when the gearbox is running, the actual radial runout is obtained through each displacement sensor 8. , ； if , a visual signal feedback is given to ensure timely response, and the visual signal feedback can be an alarm light, an alarm sound, etc. In this way, the monitoring method can be used to perform preventive maintenance before serious equipment failure occurs through accurate real-time monitoring, thereby reducing downtime and maintenance costs.

[0058] In some embodiments, in step A2, if , safety monitoring can better prevent serious failures of the gearbox, including the following steps:

[0059] Step B1: Establish a coordinate system, establish a two-dimensional coordinate system with the center of the worm 3 as the origin, and calculate the measurement coordinates as , denoise and clean the data, remove outliers, and remove outliers that deviate from the mean through statistical analysis, such as using In principle, digital filtering methods can also be used to remove interference signals, such as moving average or Kalman filtering. Each measurement coordinate forms a two-dimensional data set:

[0060] ;

[0061] Step B2: Calculate the coordinates of the center of the jumping circle , use the least squares method to fit and solve the center of the runout circle. First, set the distance error from each measurement point to the center of the circle to:

[0062]

[0063] in,

[0064] Next, the total error is minimized by gradient descent or closed-form solution To find out and :

[0065] ;

[0066] Then, using the partial derivatives and Taking partial derivatives and setting them equal to zero, we obtain the system of equations:

[0067] ;

[0068] ;

[0069] Solve the problem together and calculate the coordinates of the center of the jumping circle .

[0070] Since the system of equations is nonlinear, an iterative method is usually required to solve it. The following is a simple iterative idea:

[0071] First, initialize the center of the circle ;

[0072] Secondly, using the gradient descent method, the update formula is as follows:

[0073] ; ;

[0074] in, is the learning rate.

[0075] Finally, update until convergence:

[0076] When and Stop iteration when To meet the accuracy requirements.

[0077] Step B3: Calculate the deviation value through the center coordinates Calculate the deviation from the origin coordinates , and set the maximum deviation value ;

[0078] Step B4: Data analysis: Process the deviation data in time series to form a time series data set , plot the deviation value data against time as a real-time change curve;

[0079] Step B5: Establish a database, collect several real-time change curves of the gearbox under the same usage scenario to establish a database, and the time segment of the real-time change curve is from the start of operation to the deviation value Reaching the maximum deviation In this way, the next time the same gearbox is used to work in this scenario, analysis and prediction can be performed through the database.

[0080] Step B6: Optimize the curve, integrate and optimize several real-time change curves to form a standard change curve based on machine learning, such as support vector machine, random forest, long short-term memory network (LSTM), etc., and optimize the deviation value. Reaching the maximum deviation Set up early warning points before;

[0081] Specifically, the data is divided into training set and test set, usually in a ratio of 80:20. The model is then trained on the training set, and the fitting ability of the model is improved by repeatedly adjusting the hyperparameters. The model performance is then verified on the test set, and the generalization ability of the model is evaluated using cross-validation and other techniques. Finally, the trained model is used to optimize the multiple collected curves to generate a standard change curve representing the health status of the gearbox.

[0082] Step B7: Monitoring and comparison: For gearboxes operating in the same usage scenario, compare their real-time change curve with the standard change curve. If they are consistent with the trend, a visual signal feedback is given when the warning point is reached. If they are not consistent with the trend, the machine is shut down for inspection to determine whether it is a product accuracy problem or an assembly problem.

[0083] Among them, the monitoring comparison can use correlation analysis, namely, Pearson correlation coefficient, to evaluate the linear correlation degree of the two curves by calculating the correlation coefficient, or use dynamic time warping to calculate the DTW distance between the real-time change curve and the standard change curve.

[0084] In some embodiments, in step B5, the wear compensation amount of the worm 3 is increased according to the service life of the gearbox, and the actual maximum radial runout is gradually increased. , and a structured database is established according to the service life division groups. In step B6, several real-time change curves in each group are integrated and optimized to form a corresponding standard change curve. In step B7, the standard change curve of the adaptation group is retrieved for comparison, so as to reduce the influence of worm wear on vibration monitoring.

[0085] In summary, by collecting these data and conducting unified analysis later, the worm structure can also be optimized.

[0086] It should be understood that the data processing function may not be set on the main control board 9 of the monitoring device. Only a transmission module needs to be set on the main control board 9 to send the collected data to the terminal for unified processing, thus avoiding excessive cost of each gearbox.

[0087] In summary, after reading this detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure may be presented only by way of example and may not be restrictive. Although not explicitly stated herein, those skilled in the art will appreciate that the requirements of this application encompass various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are intended to be proposed by the present application and are within the spirit and scope of the exemplary embodiments of the present application.

[0088] In addition, it should be understood that in the foregoing description of the embodiments of the present application, in order to help understand a feature and for the purpose of simplifying the present application, the present application combines various features in a single embodiment, drawing or its description. However, this does not mean that the combination of these features is necessary. When reading the present application, it is entirely possible for a person skilled in the art to mark out a part of the devices as a separate embodiment. In other words, the embodiments in the present application can also be understood as the integration of multiple secondary embodiments. This is also true when the content of each secondary embodiment is less than all the features of a single aforementioned disclosed embodiment.

[0089] Finally, it should be understood that the embodiments of the application disclosed herein are explanations of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Therefore, the embodiments disclosed in the present application are merely examples and not limitations. Those skilled in the art can adopt alternative configurations according to the embodiments in the present application to implement the application in the present application. Therefore, the embodiments of the present application are not limited to the embodiments accurately described in the application.

Claims

1. A self-monitoring stable gearbox, comprising a housing, a worm wheel and a worm, wherein the worm is rotatably arranged at the bottom of the housing, characterized in that: It also includes a monitoring device arranged on the worm, the monitoring device is used to monitor the radial runout of the worm, the monitoring device includes a base, a first piston head, a second piston head, a spring and a displacement sensor, a monitoring hole is coaxially arranged on the base with the worm, the base is arranged on the box body and at least three installation cavities are evenly arranged on the outer periphery of the monitoring hole, the installation cavity includes a first cavity and a second cavity which are arranged in communication, the first cavity is arranged close to the monitoring hole and is adapted to the first piston head, the second cavity is located at an end of the first cavity away from the monitoring hole and is adapted to the second piston head, the first piston head is slidably arranged in the first cavity, and the second piston head is slidably arranged with The second cavity, the end surface area of ​​the first piston head is larger than the end surface area of ​​the second piston head, the installation cavity is filled with liquid medium between the first piston head and the second piston head, a first piston rod is arranged at one end of the first piston head away from the second piston head, and a second piston rod is arranged at one end of the second piston head away from the first piston head, the spring is sleeved on the second piston rod and the two ends are respectively abutted against the second piston head and the second cavity, under the action of the spring, the first piston rod abuts against the worm, the number of the displacement sensors is the same as the number of the second piston rods and are arranged one-to-one on the outer ring thereof, a main control board is arranged in the base, and each of the displacement sensors is connected to the main control board.

2. A self-monitoring stable gearbox according to claim 1, characterized in that: A first annular cavity is coaxially arranged on the base with the monitoring hole, the first annular cavity is located in the outer ring of a plurality of second cavities, one end of the second piston rod extends into the first annular cavity, an annular fixing plate is arranged in the first annular cavity, each of the displacement sensors is arranged on the annular fixing plate, a control cavity is arranged at the lower part of the base, and the main control board is arranged in the control cavity.

3. A self-monitoring stable gearbox according to claim 2, characterized in that: A second annular cavity is formed between the annular fixing plate and the circumferential outer side wall of the first annular cavity, an annular circuit board is arranged in the second annular cavity, each of the displacement sensors is connected to the annular circuit board, a wiring channel connecting the second annular cavity and the control cavity is arranged on the base, and the annular circuit board is connected to the main control board.

4. A self-monitoring stable gearbox according to claim 2, characterized in that: A limit plate is provided at one end of the second piston rod close to the displacement sensor, an annular limit plate is coaxially provided on the inner ring of the annular fixing plate, and detection holes are provided on the annular limit plate corresponding to each displacement sensor, and the diameter of the detection hole is smaller than the outer diameter of the limit plate.

5. A self-monitoring stable gearbox according to claim 1, characterized in that: The end of the first piston rod close to the worm is rotatably provided with a ball, or is provided as a dome, or is rotatably provided with a roller along the rotation direction of the worm.

6. A self-monitoring stable gearbox according to claim 1, characterized in that: The worm comprises a worm segment and shaft segments located on both sides of the worm segment. There are two monitoring devices, and the two monitoring devices are respectively arranged on the two shaft segments.

7. A self-monitoring stable gearbox according to claim 1, characterized in that: The number of the mounting cavities is at least eight.

8. A monitoring method, applied to a self-monitoring stable gearbox as claimed in any one of claims 1 to 7, characterized in that: The steps include: Step A1: Set the radial runout limit. Each first piston rod forms a measuring point on the worm. The number of measuring points is , set the end surface area of ​​the first piston head to , the end surface area of ​​the second piston head is ,in, , the displacement of the first piston rod , the displacement of the second piston rod , and preset maximum radial runout , then calculate the actual maximum radial runout ; Step A2: Real-time monitoring: when the gearbox is running, the actual radial runout is obtained through each displacement sensor. , ； if , a visual signal feedback is given to ensure timely response.

9. The monitoring method according to claim 8, characterized in that: In step A2, if , then safety monitoring is carried out, including the following steps: Step B1: Establish a coordinate system, establish a two-dimensional coordinate system with the center of the worm as the origin, and calculate the measurement coordinates as , denoise and clean the data, remove outliers, and each measurement coordinate forms a two-dimensional data set: ; Step B2: Calculate the coordinates of the center of the jumping circle , use the least squares method to fit and solve the center of the runout circle. First, set the distance error from each measurement point to the center of the circle to: in, Next, by minimizing the total error To find out and : ； Then, using the partial derivatives and Take partial derivative and set it to zero, get the equation system, solve it to get the coordinates of the center of the circle ; Step B3: Calculate the deviation value through the center coordinates Calculate the deviation from the origin coordinates , and set the maximum deviation value ; Step B4: Data analysis: Process the deviation data in time series to form a time series data set , plot the deviation value data against time as a real-time change curve; Step B5: Establish a database, collect several real-time change curves of the gearbox under the same usage scenario to establish a database, and the time segment of the real-time change curve is from the start of operation to the deviation value Reaching the maximum deviation ; Step B6: Optimize the curve, integrate and optimize several real-time change curves based on machine learning to form a standard change curve, and Reaching the maximum deviation Set up early warning points before; Step B7: Monitoring and comparison: for gearboxes operating in the same usage scenario, compare their real-time change curve with the standard change curve. If they are consistent with the trend, a visual signal feedback is given when the warning point is reached. If they are not consistent with the trend, the machine is shut down for maintenance.

10. The monitoring method according to claim 9, characterized in that: In step B5, according to the service life of the gearbox, increase the worm wear compensation and gradually increase the actual maximum radial runout. , and a structured database is established according to the service life division groups. In step B6, several real-time change curves in each group are integrated and optimized to form a corresponding standard change curve. In step B7, the standard change curve of the adaptation group is retrieved for comparison.

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