An adjustable gap worm gear and worm reduction system

Abstract

The present application relates to worm gear technical field, especially a kind of adjustable gap type worm gear reduction system, including, transmission module, adjust gap module, to obtain the load torque of worm and the vibration acceleration monitoring module of shell inner wall, to periodically based on vibration acceleration identification abnormal meshing condition and control adjust gap module operation response module, to periodically determine the stable characteristic value of transmission module data fitting module, to determine the stable category of transmission module based on stable characteristic value and whether the operation cycle of the response module is corrected based on stable category discrimination module and to store the frequency domain characteristics of worm gear normal operation comparison module.The running condition of worm gear is monitored in real time, and the position of worm is adjusted in time for abnormal meshing condition, improve the stability of worm gear meshing precision.

Description

An adjustable clearance worm gear reduction system Technical Field

[0001] This invention relates to the field of worm gear technology, and more particularly to an adjustable clearance worm gear reduction system. Background Technology

[0002] Worm gear reducers are widely used in critical fields requiring high transmission and positioning accuracy, such as robot joints, precision CNC rotary tables, radar pitch devices, and medical devices, due to their large transmission ratio, compact structure, and reverse self-locking. In these applications, the meshing backlash of the transmission pair is one of the core factors affecting motion accuracy, backlash, and dynamic response. With accumulated operating time, the worm gear teeth inevitably wear, leading to increased meshing backlash, decreased transmission accuracy, and increased vibration and noise, directly impacting the overall performance and service life of the machine.

[0003] In existing technologies, the main way to maintain side clearance is to use high-hardness materials and precision manufacturing processes to delay wear, but this is costly and cannot fundamentally eliminate wear.

[0004] Chinese Patent Publication No. CN101025216A discloses a fine-tuning mechanism for adjusting the clearance of a worm gear transmission pair, comprising a worm, bearing, worm gear box, small bearing end cover, screw, worm gear box cover plate, pin, worm gear shaft, bearing end cover, worm gear, and worm gear box. It employs a method of separating the worm gear and worm into two independent housings, and improves the transmission accuracy of the worm gear by adjusting the clearance between the worm gear box assembly and the worm gear box assembly. However, this technical solution has the following problems: it does not consider real-time monitoring of the worm gear's operation, cannot promptly adjust for meshing abnormalities, and affects the stability of the worm gear meshing accuracy. Summary of the Invention

[0005] Therefore, the present invention provides an adjustable clearance worm gear reduction system to overcome the problem in the prior art that the real-time monitoring of the worm gear's operation is not considered, making it impossible to adjust for meshing abnormalities in a timely manner, thus affecting the stability of the worm gear's meshing accuracy.

[0006] To achieve the above objectives, the present invention provides an adjustable clearance worm gear reduction system, comprising:

[0007] shell;

[0008] The transmission module includes a worm gear and a worm with gradually changing tooth thickness, both housed within a housing.

[0009] The gap adjustment module includes a gap adjustment motor for controlling the axial position of the worm;

[0010] The monitoring module includes a torque sensor mounted on the worm input shaft to obtain the load torque of the worm and a vibration acceleration sensor mounted on the inner wall of the housing to obtain the vibration acceleration.

[0011] A response module, which is connected to the monitoring module and the gap adjustment module respectively, is used to periodically identify abnormal meshing conditions based on vibration acceleration and control the operation of the gap adjustment module;

[0012] A data fitting module, which is connected to the monitoring module and the response module respectively, is used to periodically determine the stable characterization value of the transmission module;

[0013] The discrimination module is connected to the data fitting module and the response module respectively, and is used to determine the stability category of the transmission module based on the stability characterization value, and to determine whether to correct the running cycle of the response module based on the stability category.

[0014] The comparison module, which is connected to the response module, is used to store the frequency domain characteristics of the worm gear during normal operation.

[0015] Furthermore, the data fitting module, used to periodically determine the stable characterization values ​​of the transmission module, includes:

[0016] Used to determine the inherent influence value based on the tooth pitch of the worm gear;

[0017] Used to identify overload operation and determine the load impact value based on overload operation;

[0018] Used to determine the hardness influence value based on the operating data of the adjustable gap motor and the running time of the transmission module;

[0019] The weighting coefficients are assigned to the inherent influence value and the load influence value respectively, and the sum is calculated and multiplied by the product of the sum and the hardness influence value to obtain the stability characterization value.

[0020] Furthermore, the discrimination module is used to determine the stability category of the transmission module based on the stability characterization value, including a weak stability category and a strong stability category.

[0021] Furthermore, the discrimination module is used to determine whether to modify the operating cycle of the response module based on the stability category, including adjusting the operating cycle of the response module to the corresponding value based on the stability characterization value when the transmission module is in the weak stability category.

[0022] Furthermore, the discrimination module is used to adjust the operating cycle of the response module to a corresponding value based on the stable representation value, wherein,

[0023] The reduction in the runtime of the response module is negatively correlated with the stable characterization value.

[0024] Furthermore, the response module is used to identify abnormal meshing conditions based on vibration acceleration, including:

[0025] The time-domain signal from the acquired vibration acceleration sensor is periodically converted to the frequency domain using a fast Fourier transform to obtain a spectrum.

[0026] Compare the frequency domain map obtained from the current measurement with the frequency domain features in the comparison module;

[0027] If an amplitude is higher than the preset amplitude at the corresponding frequency point, an abnormal meshing situation is determined to exist.

[0028] Furthermore, the response module is used to adjust the operating power of the adjustable-gap motor to a corresponding value based on the load impact value when an abnormal meshing condition is detected.

[0029] The increase in the operating power of the adjustable gap motor is negatively correlated with the load impact value.

[0030] Furthermore, the response module is used to correct the operating power of the adjustable motor based on the amplitude change value, provided that the operating power of the adjustable motor has been adjusted based on the load influence value.

[0031] The increase in the operating power of the adjustable gap motor is positively correlated with the change in amplitude.

[0032] Furthermore, the response module is used to determine the amplitude change value, including:

[0033] For all abnormal frequency points identified as having amplitudes higher than the preset amplitude for the corresponding frequency point, the ratio of their amplitudes to the preset amplitudes is calculated to obtain the change coefficient for each point;

[0034] The amplitude change value is obtained by calculating the average value of the change coefficient at each abnormal frequency point.

[0035] Furthermore, the response module is used to control the adjustable gap motor to remain in a stopped state when no abnormal meshing is detected.

[0036] Compared with existing technologies, the beneficial effects of this invention are as follows: the data fitting module determines stable characterization values, which comprehensively consider the inherent tooth pitch of the turbine, the operating load of the transmission module, and the historical operating data of the adjustable motor. The historical operating data of the adjustable motor reflects the hardness of the worm gear. The inherent influence value is the ratio of the turbine tooth pitch to the preset tooth pitch, reflecting the influence of the turbine's inherent model on meshing stability. A larger tooth pitch can withstand a larger load, and a larger inherent influence value indicates that the turbine is less likely to experience disengagement under the current operating conditions. The load influence value is the ratio of the stable duration of the transmission module's total running time to the cumulative overload running time, and then to the preset stable duration ratio, reflecting the influence of the operating load on system stability. A larger load influence value indicates a higher proportion of operation under normal load and better stability. The hardness influence value is the ratio of the average adjustment time of the adjustable motor during each run to the preset adjustment time, reflecting the hardness of the worm gear. A larger hardness influence value indicates a stronger worm gear, slower wear due to operation, and better stability. By comprehensively evaluating multiple factors, a characterization value reflecting the stability of the transmission module is obtained, providing a reliable basis for subsequent determination of the stability category of the module, thereby improving the stability of the worm gear meshing accuracy.

[0037] Furthermore, the discrimination module determines the stability category by comparing the stable characteristic value with the preset stable characteristic value. Based on the comparison result, the transmission module is divided into a weakly stable category and a strongly stable category, so that different adjustment strategies can be adopted. The operating cycle of the response module is adjusted according to the stability category of the transmission module. For the weakly stable category, indicating poor stability, more frequent monitoring and adjustment of abnormal meshing conditions are required, thus shortening the operating cycle; for the strongly stable category, the system stability is good, and the current operating cycle can be maintained, reducing unnecessary monitoring and adjustment operations and lowering system energy consumption. The operating cycle of the response module determines the monitoring frequency of abnormal meshing conditions. Dynamically adjusting the operating cycle of the response module according to the actual stability of the system ensures timely detection and handling of abnormal conditions during unstable periods, while avoiding excessive monitoring during stable periods. This improves the monitoring efficiency and energy-saving effect of the worm gear, thereby improving the stability of the worm gear meshing accuracy.

[0038] Furthermore, the discrimination module adjusts the operating cycle of the response module. When the transmission module is classified as weakly stable, it indicates poor system stability, requiring more frequent monitoring of abnormal meshing. A lower stability characteristic value signifies greater system instability, necessitating a more significant reduction in the response module's operating cycle to increase monitoring frequency and promptly identify potential problems. The reduction in the response module's operating cycle is negatively correlated with the stability characteristic value. The initial operating cycle is the cycle initially set for the response module. Dynamically adjusting the response module's operating cycle based on the stability characteristic value increases the monitoring frequency during periods of instability, improving the response speed to abnormal situations and ensuring stable system operation. Simultaneously, it avoids over-monitoring during relatively stable periods, saving computational resources and energy consumption. This, in turn, improves the stability of the worm gear meshing accuracy.

[0039] Furthermore, the response module identifies abnormal meshing conditions. During normal meshing, the frequency domain characteristics of the vibration acceleration of a worm gear exhibit certain regularities. When abnormal meshing occurs and the tooth surface wears, the frequency components and amplitude of the vibration change. By converting the time-domain signal of the vibration acceleration into a frequency-domain signal and comparing it with the frequency-domain characteristics during normal operation, the presence of abnormal vibration, i.e., abnormal meshing, can be accurately determined. The preset amplitude value is the upper limit of the amplitude at the corresponding frequency point during normal operation, serving as the threshold for determining the presence of abnormal vibration. Using frequency domain analysis to identify abnormal meshing conditions improves the accuracy and reliability of monitoring. It enables the timely detection of potential faults, providing a basis for subsequent adjustments and maintenance, preventing further deterioration of the fault, and extending the service life of the worm gear. This, in turn, improves the stability of the worm gear meshing accuracy.

[0040] Furthermore, the response module adjusts the operating power of the adjustable gap motor based on the load impact value. The load impact value reflects the operating load of the transmission module; a lower value indicates that the system has been operating under high load for a longer period. High load operation places greater pressure on the worm gear teeth, leading to accelerated wear, increased tooth backlash, and more severe worm gear wear. This requires greater power to adjust the worm's axial position to restore meshing accuracy. Therefore, the increase in the adjustable gap motor's operating power is negatively correlated with the load impact value. By dynamically adjusting the operating power of the adjustable gap motor according to the actual application of the worm gear, the worm position is adjusted to ensure the restoration of meshing accuracy, thereby improving the stability of the worm gear meshing accuracy.

[0041] Furthermore, the amplitude change value reflects the degree of change in the current vibration amplitude relative to the normal amplitude. A larger amplitude change value indicates more severe abnormal vibration, a greater deviation of the worm gear meshing state from normal conditions, and a larger tooth flank clearance. Increasing the operating power of the adjusting motor more effectively adjusts the worm position; improving the meshing state requires even more power to adjust the worm position and eliminate the abnormality. Therefore, the increase in the operating power of the adjusting motor is positively correlated with the amplitude change value. Further adjusting the operating power of the adjusting motor based on the amplitude change value allows for more precise handling of different degrees of abnormal meshing. Dynamically adjusting the power according to the actual abnormal conditions improves the effectiveness and specificity of the adjustment, thereby enhancing the stability of the worm gear meshing accuracy.

[0042] Furthermore, for a single frequency point, the ratio of its amplitude to the preset amplitude is calculated to obtain a change coefficient, reflecting the degree of change in amplitude at that frequency point relative to the normal amplitude. The average change coefficient for each frequency point is calculated, and considering all abnormal frequency points, an overall amplitude change value is obtained for subsequent correction of the operating power of the adjustable-gap motor. Amplitude changes at different frequency points represent different types of abnormal conditions. By calculating the average value and comprehensively considering the impact of all abnormal frequency points, the severity of abnormal meshing conditions is assessed more comprehensively, making power adjustment more effective. This, in turn, improves the stability of the worm gear meshing accuracy. Attached Figure Description

[0043] Figure 1 is a front view of the transmission module according to an embodiment of the present invention;

[0044] Figure 2 is a side view of the transmission module according to an embodiment of the present invention;

[0045] Figure 3 is a partial enlarged view of the transmission module according to an embodiment of the present invention;

[0046] Figure 4 is a block diagram of the adjustable clearance worm gear reduction system according to an embodiment of the present invention.

[0047] In the diagram: 1. Worm gear; 2. Worm. Detailed Implementation

[0048] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0051] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Please refer to Figures 1, 2, and 3, which are respectively the front view, side view, and partial enlarged view of the transmission module of an embodiment of the present invention. The transmission module of the present invention includes a worm gear 1 and a worm 2 with gradually changing tooth thickness disposed within a housing;

[0053] The worm 2 rotates to drive the worm wheel 1 to rotate. In actual operation, if there is an abnormal meshing of the worm wheel 1 and worm 2, the position of the worm 2 can be adjusted so that the thicker tooth area of ​​the worm 2 contacts the turbine.

[0054] Please refer to Figure 4, which is a block diagram of the adjustable clearance worm gear 1 and worm 2 reduction system according to an embodiment of the present invention. The adjustable clearance worm gear 1 and worm 2 reduction system of the present invention includes:

[0055] Outer shell (not shown in the picture);

[0056] Transmission module;

[0057] The gap adjustment module (not shown in the figure) includes a gap adjustment motor for controlling the axial position of the worm 2;

[0058] The monitoring module (not shown in the figure) includes a torque sensor mounted on the input shaft of the worm 2 to obtain the load torque of the worm 2 and a vibration acceleration sensor mounted on the inner wall of the housing to obtain the vibration acceleration.

[0059] The response module (not shown in the figure) is connected to the monitoring module and the gap adjustment module respectively, and is used to periodically identify abnormal meshing based on vibration acceleration and control the operation of the gap adjustment module.

[0060] The data fitting module (not shown in the figure) is connected to the monitoring module and the response module respectively, and is used to periodically determine the stable characterization value of the transmission module.

[0061] The discrimination module (not shown in the figure) is connected to the data fitting module and the response module respectively, and is used to determine the stability category of the transmission module based on the stability characterization value, and to determine whether to correct the running cycle of the response module based on the stability category.

[0062] The comparison module (not shown in the figure) is connected to the response module and is used to store the frequency domain characteristics of the worm gear 1 and worm 2 during normal operation.

[0063] Specifically, the method for adjusting the position of the worm 2 via the gap adjustment module is not limited. The gap adjustment module may include a gap adjustment motor, a lead screw and nut pair driven by the gap adjustment motor, and a worm bearing seat connected to the nut. The worm 2 is supported in the worm bearing seat by a bearing. The lead screw is driven to rotate by the gap adjustment motor, which drives the nut and the worm bearing seat to move along the axial direction of the worm 2, thereby achieving precise adjustment of the axial position of the worm 2.

[0064] Specifically, when the meshing backlash of the worm 2 and worm wheel 1 increases after a period of use, the original accuracy can be restored by adjusting the axial position of the worm 2.

[0065] Specifically, when the worm gear 1 and worm 2 are in normal meshing, the vibration is relatively stable during operation, and the vibration acceleration value is within a certain range. When the meshing is abnormally worn, the vibration will intensify.

[0066] Specifically, the data fitting module is used to periodically determine the stable characterization values ​​of the transmission module, including:

[0067] Calculate the ratio of the tooth pitch of worm gear 1 to the preset tooth pitch to obtain the inherent influence value;

[0068] The operating state in which the load torque continuously exceeds the preset torque for a cumulative time threshold is defined as overload operation;

[0069] The ratio of the total running time of the transmission module to the stable time of the cumulative overload running time within the total running time is calculated, and the ratio of the stable time ratio to the preset stable time ratio is calculated to obtain the load impact value. The total running time of the transmission module is the cumulative time since the last operation of the adjustable gap motor when the worm gear 1 and worm 2 are in the meshing transmission state, that is, the load torque is greater than zero.

[0070] Obtain historical operating data of the gap-adjusting motor. When the response module has no historical records of controlling the operation of the gap-adjusting module, the hardness influence value is set to 1.

[0071] When the response module has a history of controlling the operation of the gap adjustment module, the operating time interval of each operation of the gap adjustment motor is determined to obtain several adjustment durations; the operating time interval is the cumulative operating time of the transmission module between two adjacent operations of the gap adjustment motor;

[0072] The ratio of the average value of each adjustment time to the preset adjustment time is calculated to obtain the hardness influence value;

[0073] The inherent influence value and the load influence value are assigned corresponding weight coefficients and summed. The product of the sum and the hardness influence value is then calculated to obtain the stable characterization value.

[0074] Specifically, the preset tooth pitch can be the statistical average of the tooth pitch of commonly used worm gear 1 models in the same type, series, or target application scenario. The preset tooth pitch is determined to measure the specific situation of the current tooth pitch of worm gear 1 compared with the tooth pitch under standard conditions. The preset torque is used to define the threshold for overload operation. The preset adjustment time is the estimated average time under standard operating conditions, rated load, and standard tooth pitch, when the backlash of the worm gear 1 pair material increases due to normal wear to the point where the first adjustment is required. The preset stabilization time ratio is the load health benchmark determined through experiments to ensure the ideal stable operation of worm gear 1 and worm 2.

[0075] Specifically, the data fitting module determines stable characterization values, which comprehensively consider the inherent tooth pitch of the worm gear, the operating load of the transmission module, and the historical operating data of the adjustable-gap motor. The historical operating data of the adjustable-gap motor reflects the hardness of worm gear 1 and worm 2. The inherent influence value is the ratio of the turbine tooth pitch to the preset tooth pitch, reflecting the influence of the turbine's inherent model on meshing stability. A larger tooth pitch can withstand a larger load, and a larger inherent influence value indicates that the turbine is less likely to experience disengagement under the current operating conditions. The load influence value is the ratio of the total running time of the transmission module to the stable time of the cumulative overload running time, and then to the preset stable time ratio, reflecting the impact of the operating load on system stability. A larger load influence value indicates a higher proportion of operation under normal load and better stability. The hardness influence value is the ratio of the average adjustment time of the adjustable-gap motor during each run to the preset adjustment time, reflecting the hardness of worm gear 1 and worm 2. A larger hardness influence value indicates stronger hardness of worm gear 1 and worm 2, slower wear due to operation, and better stability. By comprehensively evaluating multiple factors, a characterization value reflecting the stability of the transmission module is obtained, which provides a reliable basis for determining the stability category of the subsequent module, thereby improving the stability of the meshing accuracy of worm gear 1 and worm 2.

[0076] Specifically, in order to comprehensively consider the load conditions of worm gear 1 and worm 2 during operation and the influence of the actual inherent model of worm gear 1, the weighting coefficients corresponding to the inherent influence value and the load influence value are both 0.5.

[0077] Specifically, the discrimination module is used to determine the stability category of the transmission module based on the stability characterization value, including:

[0078] If the stability characterization value is less than or equal to the preset stability characterization value, the transmission module will be classified as a weakly stable category.

[0079] If the stability characterization value is greater than the preset stability characterization value, the transmission module will be classified as a strongly stable category.

[0080] Specifically, the preset stable performance value is selected within the range [0.92, 0.98]. Those skilled in the art can determine this value themselves. This can be achieved through long-term monitoring and experimentation on a large number of worm gear 1 and worm 2 reduction systems of different models and operating conditions. The stable performance value and corresponding operating status of each system can be recorded, including whether abnormal meshing or tooth surface wear occurs. The probability of abnormal meshing under different stable performance values ​​is statistically analyzed. It is found that when the stable performance value is within a specific range, the probability of abnormality is relatively low, while below this range, the probability of abnormality increases significantly. Through analysis and summarization of this data, the range of the preset stable performance value is comprehensively determined. In this embodiment, the preset stable performance value is preferably 0.92.

[0081] Specifically, the discrimination module is used to determine whether to modify the running cycle of the response module based on the stability category, including:

[0082] If the transmission module is of the weakly stable type, the operating cycle of the response module will be adjusted to the corresponding value based on the stability characterization value;

[0083] If the transmission module is of the strongly stable type, then the response module is controlled to continue operating using the current operating parameters.

[0084] Specifically, the discrimination module determines the stability category by comparing the stable characteristic value with the preset stable characteristic value. Based on the comparison result, the transmission module is divided into a weakly stable category and a strongly stable category, so that different adjustment strategies can be adopted. The operating cycle of the response module is adjusted according to the stability category of the transmission module. For the weakly stable category, indicating poor stability, more frequent monitoring and adjustment of abnormal meshing conditions are required, thus shortening the operating cycle; for the strongly stable category, the system stability is good, and the current operating cycle can be maintained, reducing unnecessary monitoring and adjustment operations and lowering system energy consumption. The operating cycle of the response module determines the monitoring frequency of abnormal meshing conditions. Dynamically adjusting the operating cycle of the response module according to the actual stability of the system ensures timely detection and handling of abnormal conditions during unstable periods, while avoiding excessive monitoring during stable periods. This improves the monitoring efficiency and energy-saving effect of worm gear 1 and worm 2, thereby improving the stability of the meshing accuracy of worm gear 1 and worm 2.

[0085] Specifically, when the discrimination module determines that the transmission module belongs to the weakly stable category, it adjusts the operating cycle of the response module to a corresponding value based on the stability characterization value.

[0086] The reduction in the runtime of the response module is negatively correlated with the stable characterization value.

[0087] In this embodiment, optionally,

[0088] Compare the stable characterization value with the first stable comparison value and the second stable comparison value;

[0089] If the stable characterization value is less than or equal to the first stable comparison value, the running cycle of the response module will be adjusted to 0.81 times the initial running cycle.

[0090] If the stable characterization value is less than or equal to the second stable comparison value and greater than the first stable comparison value, the running cycle of the response module will be adjusted to 0.89 times the initial running cycle.

[0091] If the stable characterization value is greater than the second stable comparison value, the running cycle of the response module will be adjusted to 0.94 times the initial running cycle.

[0092] The first stable alignment value is 0.71, and the second stable alignment value is 0.81.

[0093] Specifically, the discrimination module first classifies the transmission module into a strongly stable or weakly stable category based on a preset stability characterization value. When determined to be in the weakly stable category, a first stability comparison value and a second stability comparison value are introduced to further determine the degree of instability, satisfying the condition that the preset stability characterization value > the first stability comparison value > the second stability comparison value. Subsequently, the operating cycle of the response module is adjusted gradient according to the range in which the stability characterization value falls.

[0094] Specifically, the discrimination module adjusts the operating cycle of the response module. When the transmission module is classified as weakly stable, it indicates poor system stability, requiring more frequent monitoring of abnormal meshing. A lower stability characteristic value signifies greater system instability, necessitating a significant reduction in the response module's operating cycle to increase monitoring frequency and promptly identify potential problems. The reduction in the response module's operating cycle is negatively correlated with the stability characteristic value. The initial operating cycle is the cycle initially set for the response module. Dynamically adjusting the response module's operating cycle based on the stability characteristic value increases the monitoring frequency during periods of instability, improving the response speed to abnormal situations and ensuring stable system operation. Simultaneously, it avoids over-monitoring during relatively stable periods, saving computational resources and energy consumption. This, in turn, improves the stability of the meshing accuracy of worm gear 1 and worm 2.

[0095] Specifically, the response module is used to identify abnormal meshing conditions based on vibration acceleration, including:

[0096] The time-domain signal acquired from the vibration acceleration sensor is periodically converted to the frequency domain using a fast Fourier transform to obtain a spectrum.

[0097] Compare the frequency domain plot obtained from the current measurement with the frequency domain characteristics;

[0098] When the amplitude is higher than the preset amplitude at the corresponding frequency point, it is determined that there is a high vibration component, that is, an abnormal meshing situation is determined.

[0099] Specifically, in a frequency domain graph, the horizontal axis represents frequency, and the vertical axis represents the amplitude of the corresponding frequency.

[0100] Specifically, the method for establishing the frequency domain feature library of worm gear 1 and worm 2 during normal operation is not limited. It may include operating under various stable load conditions, including no load, 30%, 60%, and 90% of rated load, when in the optimal meshing state.

[0101] Vibration acceleration signals under each working condition were collected and analyzed using Fast Fourier Transform to obtain a series of spectra.

[0102] Statistical analysis is performed on multiple spectra under each operating condition to calculate the mean and standard deviation of the amplitude at each frequency point, forming the baseline spectrum envelope (mean line) and the upper limit threshold of normal fluctuation (mean + 2 times standard deviation) under that operating condition.

[0103] The reference spectral envelopes and corresponding upper limit thresholds for fluctuations under different load conditions are stored in the comparison module, forming a frequency domain feature library for the normal operation of worm gear 1 and worm 2. During actual comparison, the closest operating condition feature needs to be selected for comparison based on the current load torque.

[0104] Specifically, the frequency domain characteristics during normal operation can be established as follows: After the system is initially installed, the worm 2 is adjusted to its initial set position using the clearance adjustment module to ensure that the meshing clearance of the worm wheel 1 and worm 2 meets the factory standard. This state is defined as the optimal meshing state. In this state, vibration signals are collected under various load conditions, and a reference spectral envelope and fluctuation upper limit threshold are generated and stored in the comparison module.

[0105] Specifically, the response module identifies abnormal meshing conditions. During normal meshing, the frequency domain characteristics of the vibration acceleration of worm gear 1 and worm 2 exhibit certain regularities. When abnormal meshing occurs and the tooth surface wears, the frequency components and amplitude of the vibration change. By converting the time-domain signal of the vibration acceleration into a frequency-domain signal and comparing it with the frequency-domain characteristics during normal operation, the presence of abnormal vibration, i.e., abnormal meshing, can be accurately determined. The preset amplitude value is the upper limit of the amplitude at the corresponding frequency point during normal operation, serving as the threshold for determining the presence of abnormal vibration. Using frequency domain analysis to identify abnormal meshing conditions improves the accuracy and reliability of monitoring. It can promptly detect potential faults, providing a basis for subsequent adjustments and maintenance, preventing further deterioration of the fault, and extending the service life of worm gear 1 and worm 2. This, in turn, improves the stability of the meshing accuracy of worm gear 1 and worm 2.

[0106] Specifically, the response module is used to adjust the operating power of the adjustable-gap motor to a corresponding value based on the load impact value when an abnormal meshing condition is detected.

[0107] The increase in the operating power of the adjustable gap motor is negatively correlated with the load impact value.

[0108] In this embodiment, optionally,

[0109] The load impact value is compared with the first preset load comparison value and the second preset load comparison value;

[0110] If the load impact value is less than or equal to the first preset load comparison value, the operating power of the adjustable gap motor will be adjusted to 1.17 times the initial preset power.

[0111] If the load impact value is less than or equal to the second preset load comparison value and greater than the first preset load comparison value, then the operating power of the adjustable gap motor will be adjusted to 1.12 times the initial preset power.

[0112] If the load impact value is greater than the second preset load comparison value, the operating power of the adjustable gap motor will be adjusted to 1.06 times the initial preset power.

[0113] The first preset load comparison value is 0.73, and the second preset load comparison value is 0.79.

[0114] Specifically, the response module adjusts the operating power of the adjustable gap motor based on the load influence value. This load influence value reflects the operating load of the transmission module; a lower value indicates that the system operates under high load for a longer period. High load operation places greater pressure on the tooth surfaces of worm gear 1 and worm 2, leading to accelerated wear, increased tooth backlash, and more severe wear. This requires greater power to adjust the axial position of worm 2 to restore meshing accuracy. Therefore, the increase in the operating power of the adjustable gap motor is negatively correlated with the load influence value. By dynamically adjusting the operating power of the adjustable gap motor according to the actual application of worm gear 1 and worm 2, the position of worm 2 is adjusted to ensure the restoration of meshing accuracy, thereby improving the stability of the meshing accuracy of worm gear 1 and worm 2.

[0115] Specifically, the initial operating cycle is the factory-preset monitoring cycle of the response module, which can be set according to the importance of the equipment and historical maintenance experience. The initial preset power is the power value required for the adjustable gap motor to reliably drive the worm gear 2 to complete one standard fine adjustment stroke under standard test conditions, at its rated voltage and to overcome the designed estimated average frictional torque. This power value can be obtained through experimental calibration.

[0116] Specifically, the response module is used to correct the operating power of the adjustable motor based on the amplitude change value, provided that the operating power of the adjustable motor has been adjusted based on the load influence value.

[0117] The increase in the operating power of the adjustable gap motor is positively correlated with the change in amplitude.

[0118] In this embodiment, optionally,

[0119] The amplitude change value is compared with the first preset amplitude comparison value and the second preset amplitude comparison value;

[0120] If the amplitude change value is less than or equal to the first preset amplitude comparison value, the operating power of the adjustable motor will be adjusted to 1.11 times the current operating power.

[0121] If the amplitude change value is less than or equal to the second preset amplitude comparison value and greater than the first preset amplitude comparison value, then the operating power of the adjustable gap motor will be adjusted to 1.15 times the current operating power.

[0122] If the amplitude change value is greater than the second preset amplitude comparison value, the operating power of the adjustable motor will be adjusted to 1.21 times the current operating power;

[0123] The first preset amplitude comparison value is 1.3, and the second preset amplitude comparison value is 1.8.

[0124] Specifically, the amplitude change value reflects the degree of change in the current vibration amplitude relative to the normal amplitude. The larger the amplitude change value, the more severe the abnormal vibration, and the more the meshing state of worm gear 1 and worm 2 deviates from the normal condition, with a large tooth flank clearance. Increasing the operating power of the adjusting motor to more effectively adjust the position of worm 2 and improve the meshing state requires more power to adjust the position of worm 2 to eliminate the abnormality. Therefore, the increase in the operating power of the adjusting motor is positively correlated with the amplitude change value. Further adjusting the operating power of the adjusting motor based on the amplitude change value can more accurately respond to different degrees of abnormal meshing conditions. Dynamically adjusting the power according to the actual abnormal situation improves the effectiveness and targeting of the adjustment, thereby improving the stability of the meshing accuracy of worm gear 1 and worm 2.

[0125] Specifically, the response module is used to determine the amplitude change value, including:

[0126] For all abnormal frequency points identified as having amplitudes higher than the preset amplitude for the corresponding frequency point, the ratio of their amplitudes to the preset amplitudes is calculated to obtain the change coefficient for each point;

[0127] The amplitude change value is obtained by calculating the average value of the change coefficient at each abnormal frequency point.

[0128] Specifically, for a single frequency point, the ratio of its amplitude to the preset amplitude is calculated to obtain a change coefficient, reflecting the degree of change in amplitude at that frequency point relative to the normal amplitude. The average change coefficient for each frequency point is calculated, and considering all abnormal frequency points, an overall amplitude change value is obtained for subsequent correction of the operating power of the adjustable-gap motor. Amplitude changes at different frequency points represent different types of abnormal conditions. By calculating the average value and comprehensively considering the impact of all abnormal frequency points, the severity of abnormal meshing conditions is assessed more comprehensively, making power adjustment more effective. This, in turn, improves the stability of the meshing accuracy of worm gear 1 and worm 2.

[0129] Specifically, the response module is used to control the gap-adjusting motor to remain in a stopped state when no abnormal meshing is detected.

[0130] Specifically, the response module is used to determine whether to correct each preset amplitude based on the load influence value, after completing the correction of the operating power of the adjustable motor based on the amplitude change value;

[0131] If the load impact value is less than or equal to the preset impact comparison value, the control comparison module will continue to operate using the current operating parameters.

[0132] If the load impact value is greater than the preset impact comparison value, then the preset adjustment coefficient will be used to adjust each preset amplitude to the corresponding value.

[0133] In this embodiment, optionally, each preset amplitude after adjustment is 0.98 times the corresponding preset amplitude.

[0134] Specifically, the preset influence comparison value is selected within the range [0.81, 0.86]. Those skilled in the art can select and determine this value themselves. Extensive experimental testing can be conducted on the worm gear 1 and worm 2 reduction system to record the system's vibration under different load influence values ​​and the corresponding probability of abnormal meshing. Simultaneously, referencing industry experience data, the preset influence comparison value is comprehensively determined. In this embodiment, preferably, the preset influence comparison value is 0.81.

[0135] Specifically, when the load impact value is less than or equal to the preset impact comparison value, it indicates that the current operating load fluctuates greatly, the output scenarios of worm gear 1 and worm 2 change frequently, and the vibration of worm gear 1 and worm 2 is still within the original normal range. At this time, the control comparison module continues to operate using the current operating parameters, that is, it maintains the existing preset amplitude unchanged. When the load impact value is greater than the preset impact comparison value, the operating load is within a reasonable and small range. Considering the precise usage scenarios of worm gear 1 and worm 2, the precision required for worm gear 1 and worm 2 is higher in this case. After adjusting the position of worm 2, a more precise judgment standard needs to be maintained to ensure stable output of worm gear 1 and worm 2.

[0136] Specifically, a parameter optimization mechanism for each adjustment is adopted, which is determined based on statistical analysis of a large amount of historical test data, so as to set the corresponding preset adjustment multiple values ​​for subsequent adjustments.

[0137] After adjusting each preset amplitude based on the load impact value, the response module will continuously monitor the load impact value. If the load impact value falls below the preset impact comparison value within a subsequent preset number of monitoring cycles, the preset amplitude will be restored to its original value before adjustment.

[0138] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An adjustable clearance worm gear reduction system, characterized in that, include: shell; The transmission module includes a worm gear and a worm with gradually changing tooth thickness, both housed within a housing. The clearance adjustment module includes a clearance adjustment motor for controlling the axial position of the worm; a monitoring module includes a torque sensor mounted on the worm input shaft to obtain the load torque of the worm and a vibration acceleration sensor mounted on the inner wall of the housing to obtain vibration acceleration; a response module connected to the monitoring module and the clearance adjustment module respectively, for periodically identifying abnormal meshing conditions based on vibration acceleration and controlling the operation of the clearance adjustment module; and a data fitting module connected to the monitoring module and the response module respectively, for periodically determining the stable characterization values ​​of the transmission module. The discrimination module is connected to the data fitting module and the response module respectively, and is used to determine the stability category of the transmission module based on the stability characterization value, and to determine whether to correct the running cycle of the response module based on the stability category. The comparison module, which is connected to the response module, is used to store the frequency domain characteristics of the worm gear during normal operation. The data fitting module is used to periodically determine the stable characterization value of the transmission module, including: determining the inherent influence value based on the tooth pitch of the worm gear; identifying overload operation and determining the load influence value based on the overload operation; determining the hardness influence value based on the operating data of the adjustable gap motor and the running time of the transmission module; assigning corresponding weight coefficients to the inherent influence value and the load influence value respectively and summing them to obtain a first fitting value; and calculating the product of the first fitting value and the hardness influence value to obtain the stable characterization value.

2. The adjustable clearance worm gear reduction system according to claim 1, characterized in that, The discrimination module is used to determine the stability category of the transmission module based on the stability characterization value, including the weak stability category and the strong stability category.

3. The adjustable clearance worm gear reduction system according to claim 2, characterized in that, The discrimination module is used to determine whether to modify the operating cycle of the response module based on the stability category, including adjusting the operating cycle of the response module to the corresponding value based on the stability characterization value when the transmission module is in the weak stability category.

4. The adjustable clearance worm gear reduction system according to claim 3, characterized in that, The discrimination module is used to adjust the running cycle of the response module to a corresponding value based on the stable characterization value, wherein the reduction in the running cycle of the response module is negatively correlated with the stable characterization value.

5. The adjustable clearance worm gear reduction system according to claim 4, characterized in that, The response module is used to identify abnormal meshing based on vibration acceleration, including: periodically converting the acquired time-domain signal of the vibration acceleration sensor to the frequency domain through fast Fourier transform to obtain a spectrum; comparing the currently measured frequency domain spectrum with the frequency domain features in the comparison module; and determining that there is an abnormal meshing condition when there is an amplitude higher than the preset amplitude of the corresponding frequency point.

6. The adjustable clearance worm gear reduction system according to claim 5, characterized in that, The response module is used to adjust the operating power of the adjustable motor to a corresponding value based on the load influence value when an abnormal meshing condition is detected. The increase in the operating power of the adjustable motor is negatively correlated with the load influence value.

7. The adjustable clearance worm gear reduction system according to claim 6, characterized in that, The response module is used to adjust the operating power of the adjustable motor based on the amplitude change value after adjusting the operating power based on the load influence value, wherein the increase in the operating power of the adjustable motor is positively correlated with the amplitude change value.

8. The adjustable clearance worm gear reduction system according to claim 7, characterized in that, The response module is used to determine the amplitude change value, including: for all abnormal frequency points identified as having amplitudes higher than the preset amplitude of the corresponding frequency point, calculating the ratio of their amplitudes to the preset amplitudes to obtain the change coefficients of each point; and solving for the average value of the change coefficients of each abnormal frequency point to obtain the amplitude change value.

9. The adjustable clearance worm gear reduction system according to claim 8, characterized in that, The response module is used to control the adjustable motor to remain in a stopped state when no abnormal meshing is detected.

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