A control method for low wear debris during the running-in period of the worm and worm gear of an electric actuator

Abstract

The present invention provides a method for regulating low wear debris during the running-in period of a worm gear of an electric actuator, belonging to the technical field of electric actuator devices, and comprising the following steps: S100: Obtain the running-in characteristics of the worm gear during the running-in period in a number of electric actuators with different model parameters, and form corresponding reference running-in curves based on the running-in characteristics; S200: Based on the model parameters of the target electric actuator, match the standard running-in parameters that conform to the target electric actuator according to the experience database; S300: Collect the running-in characteristics in real time and form corresponding target running-in curves; S400: Compare the target running-in curve with the reference running-in curve of the electric actuator with the same model parameters, and evaluate and optimize the running-in effect of the target electric actuator; In the present invention, through the collaborative monitoring and closed-loop feedback of multi-dimensional characteristics, the amount of wear debris generated by the worm gear of the electric actuator during the running-in period is greatly reduced, effectively avoiding tooth surface damage caused by three-body wear.

Description

Technical Field

[0001] The invention relates to the technical field of electric actuators, and in particular to a method for controlling low wear debris during the running-in period of a worm gear of an electric actuator. Background Art

[0002] As the core driving component of industrial automation systems, electric actuators are widely used in petrochemical, power equipment, intelligent machinery and other fields. They achieve high reduction ratio torque transmission and precise position control through worm gear mechanism. The meshing quality of worm gear pair directly affects the transmission efficiency, positioning accuracy and service life of the actuator. Among them, the micro-convexity crushing and contact surface reconstruction process of the friction pair surface during the running-in stage is particularly critical.

[0003] In the existing technology, the following technical difficulties are common in the running-in period of worm gears: abnormal wear caused by the mismatch of the contact surface microstructure during the running-in process will produce a large amount of metal debris (particle size concentrated in 20-50μm), which will form three-body wear after mixing with the lubricating medium, accelerate tooth surface scratches and cause torque fluctuation amplification effect. In particular, when the amount of debris exceeds the critical threshold, it will cause the scratch depth of the worm spiral surface to increase, significantly shortening the actuator maintenance cycle. 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 method for controlling low wear debris during the running-in period of a worm gear of an electric actuator.

[0005] The technical solution adopted by the present invention is as follows: This application provides a method for controlling low wear debris during the running-in period of a worm gear of an electric actuator, comprising the following steps:

[0006] S100: obtaining running-in characteristics of worm gears in electric actuators of different models and parameters during a running-in period, wherein the running-in characteristics include torque characteristics, vibration characteristics, and temperature characteristics, and forming corresponding reference running-in curves based on the running-in characteristics;

[0007] S200: Based on the model parameters of the target electric actuator, matching the standard running-in parameters that meet the target electric actuator according to the experience database, the standard running-in parameters including speed, direction, running-in time and number of running-in times;

[0008] S300: the target electric actuator operates according to the standard running-in parameters, the running-in characteristics of the worm gear in the target electric actuator are collected in real time, and a corresponding target running-in curve is formed;

[0009] S400: Compare the target running-in curve with a reference running-in curve of an electric actuator with the same model parameters, evaluate the running-in effect of the target electric actuator, and adjust the standard running-in parameters according to the running-in effect to form optimized running-in parameters.

[0010] In some embodiments, a step-by-step evaluation strategy is implemented based on the running-in characteristics, and the step-by-step evaluation strategy includes:

[0011] The running-in period is divided into an early running-in period, a middle running-in period and a late running-in period;

[0012] In the early stage of the running-in, forming a running-in curve based on the torque characteristic;

[0013] In the middle stage of the running-in, a running-in curve is formed in combination with the vibration characteristics;

[0014] In the later stage of the running-in, the temperature characteristics are combined to form a running-in curve.

[0015] In some embodiments, in the early stage of the running-in, an early stage score is obtained based on the torque characteristic;

[0016] In the middle stage of the running-in, the torque characteristics and the vibration characteristics are jointly evaluated, and a mid-term score is obtained by data fusion;

[0017] In the later stage of the running-in, a comprehensive evaluation is performed through torque characteristics, vibration characteristics and temperature characteristics, and a later score is obtained through data fusion;

[0018] A running-in curve is formed based on the early scoring, mid-term scoring and late scoring.

[0019] In some embodiments, based on the comparison between the target running-in curve and the reference running-in curve of the electric actuator with the same model parameters, the deviation of each period is extracted, the error parameter causing the maximum deviation is located, and the cause of the error is analyzed based on the error parameter;

[0020] If the cause of the error is to be solved, compare the running-in effects of the standard running-in parameters and the optimized running-in parameters, and update the best ones to the standard running-in parameters;

[0021] If the cause of the error is not resolved, then in step S200 , the latest optimized running-in parameters that meet the target electric actuator are matched according to the experience library.

[0022] In some embodiments, each analysis result is stored in a database to form a mapping relationship between period-error parameter-error cause-solution, a causal network is constructed based on historical data, and the posterior probabilities of different error causes are calculated.

[0023] In some embodiments, in step S400, adjusting the standard running-in parameters according to the running-in effect to form optimized running-in parameters includes:

[0024] If the error parameter is a torque characteristic, reducing the initial rotation speed;

[0025] If the error parameter is a vibration characteristic, a speed amplitude stepwise fluctuation control is implemented;

[0026] If the error parameter is a temperature characteristic, the heat dissipation is accelerated, and forward and reverse rotations are alternately controlled, and the rotation speed maintained during the reverse rotation is different from that during the forward rotation.

[0027] In some embodiments, the lubricating oil parameters of the target electric actuator are obtained by the production end, and the lubricating oil parameters include the lubricating oil level and the lubricating oil type. Based on the running-in effect of the target electric actuator in step S400, the lubricating oil parameters of the target electric actuator are optimized and fed back to the production end.

[0028] In some embodiments, the production end obtains assembly line data of the target electric actuator, where the assembly line data is assembly worker information or assembly equipment parameters. Based on the running-in effect of the target electric actuator in step S400, the cause of the error is analyzed and the assembly quality of the assembly line is evaluated.

[0029] The beneficial effects of the present invention are as follows: In the present invention, through the coordinated monitoring and closed-loop feedback of multi-dimensional characteristics (torque / vibration / temperature), the amount of wear debris generated by the worm gear of the electric actuator during the running-in period is greatly reduced, effectively avoiding tooth surface damage caused by three-body wear. 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 The explosion of the electric actuator in the present invention Figure 1 ;

[0032] Figure 2 The explosion of the electric actuator in the present invention Figure 2 ;

[0033] Figure 3 It is a schematic flow chart of a method for controlling low wear debris during the running-in period of a worm gear of an electric actuator in the present invention;

[0034] Figure 4 It is a logic schematic diagram of a method for controlling low wear debris during the running-in period of a worm gear of an electric actuator in the present invention;

[0035] Figure 5 It is a schematic diagram of the process of forming the running-in curve in the present invention;

[0036] Figure 6 Schematic diagram of the construction of the causal network in the present invention. DETAILED DESCRIPTION

[0037] The following description provides specific application scenarios and requirements of this specification, with the purpose of enabling those skilled in the art to make and use the contents of this specification. Various local modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein may 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The flowcharts used in this application illustrate the operations implemented by the system according to some embodiments in this specification. It should be clearly understood that the operations of the flowcharts may not be implemented in sequence. On the contrary, the operations may be implemented in reverse order or simultaneously. In addition, one or more other operations may be added to the flowchart. One or more operations may be removed from the flowchart.

[0043] 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.

[0044] In the prior art, the abnormal wear of the worm gear of the electric actuator during the running-in period due to the mismatch of the contact surface microstructure will produce a large amount of metal chips, resulting in a shortened maintenance cycle of the electric actuator.

[0045] Based on the above problems, Figures 3 to 6 As shown, this specification provides a method for controlling low wear debris during the running-in period of a worm gear of an electric actuator, comprising the following steps:

[0046] S100: Acquire running-in characteristics of worm gears in electric actuators of different models and parameters during a running-in period, wherein the running-in characteristics include torque characteristics, vibration characteristics, and temperature characteristics, and form corresponding reference running-in curves based on the running-in characteristics.

[0047] Among them, the running-in period refers to the time during which the surface of the worm gear friction pair evolves from the initial processing morphology to the stable service morphology during the first operation of the electric actuator. The running-in period can be judged based on the running-in curve. It can be understood that the running-in period ends when the values ​​of torque characteristics, vibration characteristics and temperature characteristics tend to be flat.

[0048] S200: Based on the model parameters of the target electric actuator, matching the standard running-in parameters that meet the target electric actuator according to the experience database, the standard running-in parameters including speed, direction, running-in time and number of running-in times;

[0049] Among them, the model parameters include worm gear geometric parameters, such as module, number of teeth, helix angle, lead angle, etc., as well as material parameters. It can be understood that the standard running-in parameters of the target electric actuator matched according to the experience library, that is, the standard running-in parameters of the electric actuator with the same model parameters matched in the experience library, can also be understood as the same product.

[0050] S300: the target electric actuator operates according to the standard running-in parameters, the running-in characteristics of the worm gear in the target electric actuator are collected in real time, and a corresponding target running-in curve is formed;

[0051] The running-in characteristics are obtained through a sensor group. For example, the torque characteristics are measured by a non-contact torque sensor, and the general measuring points are: the power input end of the worm shaft, the power input end of the worm shaft, the extended end of the worm shaft, the extended end of the worm shaft, etc. The vibration characteristics are measured by a three-axis accelerometer, and the general measuring points are: the top plane of the worm gear case, the extended end of the worm shaft, the extended end of the worm shaft, etc. The temperature characteristics are measured by an infrared thermal imager, and the general measuring points are: the worm gear and worm meshing area, etc.

[0052] S400: Compare the target running-in curve with a reference running-in curve of an electric actuator with the same model parameters, evaluate the running-in effect of the target electric actuator, and adjust the standard running-in parameters according to the running-in effect to form optimized running-in parameters.

[0053] Through this control method, the coordinated monitoring and closed-loop feedback of multi-dimensional characteristics (torque / vibration / temperature) are adopted to greatly reduce the amount of wear debris generated by the worm gear of the electric actuator during the running-in period, effectively avoiding tooth surface damage caused by three-body wear.

[0054] In some embodiments, a step-by-step evaluation strategy is implemented based on the running-in characteristics, and the step-by-step evaluation strategy includes:

[0055] The running-in period is divided into an early running-in period, a middle running-in period and a late running-in period;

[0056] For example, in the early stages of running-in: , mid-term running-in: , late running-in period: .

[0057] In the early stage of the running-in, a running-in curve is formed based on the torque characteristics, and specifically, an early stage score is obtained based on the torque characteristics;

[0058] In the mid-term of the running-in, a running-in curve is formed by combining the vibration characteristics. Specifically, the torque characteristics and the vibration characteristics are jointly evaluated, and a mid-term score is obtained by data fusion;

[0059] In the later stage of the running-in, the temperature characteristics are combined to form a running-in curve. Specifically, the torque characteristics, vibration characteristics and temperature characteristics are comprehensively evaluated, and a later score is obtained through data fusion;

[0060] A running-in curve is formed based on the early scoring, mid-term scoring and late scoring.

[0061] The torque characteristic may be the torque fluctuation variance, the vibration characteristic may be the sideband frequency modulation ratio, the temperature characteristic may be the temperature rise rate, and of course other parameters with the same characteristics may also be used instead.

[0062] Among them, data fusion includes weight allocation, weighted average, principal component analysis, fuzzy logic, etc. For example, entropy method weight allocation can be used in the later stage of running-in.

[0063] The reference running-in curve or the target running-in curve is formed based on the early stage score, the mid-term score and the late stage score. Specifically, the scores of each stage are integrated in chronological order, and the curve may be generated using interpolation or curve fitting technology.

[0064] Specifically, in the early stage of running-in, an early score is formed based on the high-frequency fluctuation energy proportion of the torque characteristics, and the high-frequency fluctuation energy proportion is calculated by extracting the signal energy in the 2-4kHz frequency band through wavelet packet decomposition.

[0065] In the middle stage of running-in, the weighted average of the peak-to-peak value of the torque fluctuation and the effective value of the vibration forms a mid-term score, with the torque weighting being 60%-70% and the vibration weighting being 30%-40%.

[0066] In the later stage of running-in, the torque fluctuation variance, sideband frequency modulation ratio and temperature rise rate are fused in a preset ratio to calculate the later score, and the fusion ratio range is 4:3:3 to 5:2:3.

[0067] In some embodiments, based on the comparison between the target running-in curve and the reference running-in curve of the electric actuator with the same model parameters, the deviation of each period is extracted, and then the error parameter causing the maximum deviation is located, and the maximum deviation is solved first, which improves the efficiency and pertinence of problem solving, and the cause of the error is analyzed based on the error parameter;

[0068] When comparing curves, multi-scale curve alignment technology can be used through dynamic time warping. The specific formula is:

[0069] ;

[0070] in, is the target running-in curve data point, It is the reference running-in curve data point.

[0071] If the cause of the error is solved, the running-in effects of the standard running-in parameters are compared with those of the optimized running-in parameters, and the best ones are updated to the standard running-in parameters; if the cause of the error is not solved, in step S200, the latest optimized running-in parameters that meet the target electric actuator are matched according to the experience library. In this way, not only can the problem be solved from the root, but it can also be solved through regulation. The dual advantages of solving the problem from the root and solving it through regulation can effectively control the running-in quality regardless of whether the problem is completely solved.

[0072] In some embodiments, each analysis result is stored in a database to form a mapping relationship between period-error parameter-error cause-solution, a causal network is constructed based on historical data, and the posterior probabilities of different error causes are calculated.

[0073] Posterior probability calculation:

[0074] ;

[0075] in, Due to the error, is the observational evidence, i.e., the error parameter.

[0076] Through the calculation of posterior probability, the possibility of different error causes can be determined, the error causes can be found quickly and processed in a priority manner, thereby reducing the time for manual troubleshooting. At the same time, as data accumulates, the model will be continuously updated to improve the accuracy of the prediction.

[0077] In some embodiments, in step S400, adjusting the standard running-in parameters according to the running-in effect to form optimized running-in parameters includes:

[0078] If the error parameter is a torque characteristic, the initial rotational speed is reduced; for example, when the torque deviation ΔT>15%, by reducing the initial rotational speed by 10%-20%, the peak value of the contact stress on the worm gear tooth surface can be effectively reduced to avoid the generation of hard wear chips caused by plastic deformation.

[0079] If the error parameter is a vibration characteristic, a step-by-step fluctuation control of the speed amplitude is implemented, for example, the fluctuation range is from 90% to 110% of the rated value, and the adjustment interval of each level is ≥ 2 minutes, so as to break the resonant frequency locking state.

[0080] If the error parameter is a temperature characteristic, the speed increase and heat dissipation are implemented, and the forward and reverse rotations are alternately controlled, and the speed maintained during the reverse rotation is different from that during the forward operation. Specifically, the speed increase can increase the flow rate of the lubricating oil. Specifically, if the speed reduction reduces the friction power, it also reduces the circulation speed of the lubricating oil, resulting in a decrease in the heat dissipation capacity. If the decrease in heat dissipation exceeds the reduction in heat generation, it will cause the temperature to rise. This happens especially in the boundary lubrication state, because the oil film is incomplete at low speeds, the friction coefficient μ increases, and more heat is generated. On the other hand, although the speed increase increases the friction speed, it maintains or enters the fluid lubrication state. At the same time, the high speed brings an increase in the flow of lubricating oil, and the heat dissipation effect is better.

[0081] Secondly, the forward and reverse alternating control can change the location where friction heat is generated, avoid continuous high temperature in local areas, and promote the reconstruction of the lubricating film by reverse motion. For example, when the temperature gradient ΔT>5℃ / min, the alternating control is started, and the rated speed is maintained at 90% for running-in in the forward stage, and the rated speed is operated at 60% in the reverse stage. Preferably, in the alternating cycle, the time of the forward stage is shorter than that of the reverse stage.

[0082] When analyzing the cause of the error, it may be necessary to consider lubricant parameters and assembly line data, specifically:

[0083] In some embodiments, the lubricating oil parameters of the target electric actuator are obtained by the production end, and the lubricating oil parameters include the lubricating oil level and the lubricating oil type. The production end is the production line end or the design end. Since the lubricating oil parameters are generally determined during production, they can be directly obtained. Based on the running-in effect of the target electric actuator in step S400, the lubricating oil parameters of the target electric actuator are optimized and fed back to the production end. In particular, when the error parameter is a temperature characteristic, the lubricating oil parameter may be the preferred error cause to be considered.

[0084] In some embodiments, assembly line data of the target electric actuator is obtained by the production end, and the assembly line data is assembly worker information or assembly equipment parameters. Based on the running-in effect of the target electric actuator in step S400, the cause of the error is analyzed and the assembly quality of the assembly line is evaluated. If it is manual assembly, an assembly quality evaluation sheet for the corresponding worker can be produced to facilitate the evaluation of his ability and improvement direction. If mechanical automated assembly is adopted, the equipment parameters can be adjusted to improve the assembly quality.

[0085] like Figure 1 and Figure 2 As shown, the present specification also provides an electric actuator that can implement a method for controlling low wear debris during the running-in period of a worm gear of the electric actuator. The electric actuator comprises: a housing 1, a motor 2, a worm wheel 3 and a worm 4. A transmission gear set 5 is arranged between the motor 2 and the worm 4. The worm wheel 3 is meshed with the worm 4, and its front end serves as an output end, and a detection end 6 is arranged at the rear end. A transmission cavity 7 and a control cavity 8 are arranged in the housing, and the detection end extends into the control cavity. Generally, the sensor group is preferably arranged in the control cavity to ensure measurement accuracy.

[0086] 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.

[0087] 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.

[0088] 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 method for controlling low wear debris during the running-in period of a worm gear of an electric actuator, characterized in that: The steps include: S100: obtaining running-in characteristics of worm gears in electric actuators of different models and parameters during a running-in period, wherein the running-in characteristics include torque characteristics, vibration characteristics, and temperature characteristics, and forming corresponding reference running-in curves based on the running-in characteristics; S200: Based on the model parameters of the target electric actuator, matching the standard running-in parameters that meet the target electric actuator according to the experience database, the standard running-in parameters including speed, direction, running-in time and number of running-in times; S300: the target electric actuator operates according to the standard running-in parameters, the running-in characteristics of the worm gear in the target electric actuator are collected in real time, and a corresponding target running-in curve is formed; S400: comparing the target running-in curve with a reference running-in curve of an electric actuator with the same model parameters, evaluating the running-in effect of the target electric actuator, and adjusting the standard running-in parameters according to the running-in effect to form optimized running-in parameters; The method for forming the reference running-in curve and the target running-in curve comprises the following steps: The running-in period is divided into an early running-in period, a middle running-in period and a late running-in period; In the early stage of the running-in, obtaining an early stage score based on the torque characteristic; In the middle stage of the running-in, the torque characteristics and the vibration characteristics are jointly evaluated, and a mid-term score is obtained by data fusion; In the later stage of the running-in, a comprehensive evaluation is performed through torque characteristics, vibration characteristics and temperature characteristics, and a later score is obtained through data fusion; A corresponding running-in curve is formed based on the early-stage scoring, mid-term scoring and late-stage scoring.

2. A method for controlling low wear debris during the running-in period of a worm gear of an electric actuator according to claim 1, characterized in that: Based on the comparison between the target running-in curve and the reference running-in curve of the electric actuator with the same model parameters, the deviation of each period is extracted, the error parameter causing the maximum deviation is located, and the cause of the error is analyzed based on the error parameter; If the cause of the error is to be solved, compare the running-in effects of the standard running-in parameters and the optimized running-in parameters, and update the best ones to the standard running-in parameters; If the cause of the error is not resolved, then in step S200 , the latest optimized running-in parameters that meet the target electric actuator are matched according to the experience library.

3. A method for controlling low wear debris during the running-in period of a worm gear of an electric actuator according to claim 2, characterized in that: The results of each analysis are stored in the database to form a mapping relationship between period-error parameter-error cause-solution. A causal network is constructed based on historical data to calculate the posterior probability of different error causes.

4. The method for controlling low wear debris during the running-in period of the worm gear of an electric actuator according to claim 2, characterized in that: In step S400, adjusting the standard running-in parameters to form optimized running-in parameters according to the running-in effect includes: If the error parameter is a torque characteristic, reducing the initial rotation speed; If the error parameter is a vibration characteristic, a speed amplitude stepwise fluctuation control is implemented; If the error parameter is a temperature characteristic, the heat dissipation is accelerated, and forward and reverse rotations are alternately controlled, and the rotation speed maintained during the reverse rotation is different from that during the forward rotation.

5. The method for controlling low wear debris during the running-in period of the worm gear of an electric actuator according to claim 2, characterized in that: The lubricating oil parameters of the target electric actuator are obtained from the production end, and the lubricating oil parameters include the lubricating oil level and the lubricating oil type. Based on the running-in effect of the target electric actuator in step S400, the lubricating oil parameters of the target electric actuator are optimized and fed back to the production end.

6. The method for controlling low wear debris during the running-in period of the worm gear of an electric actuator according to claim 2, characterized in that: The production end obtains assembly line data of the target electric actuator, where the assembly line data is assembly worker information or assembly equipment parameters. Based on the running-in effect of the target electric actuator in step S400, the error cause is analyzed and the assembly quality of the assembly line is evaluated.

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