Dynamic monitoring method and system for connection interference magnitude of motor rotor and main shaft

Abstract

The invention relates to the technical field of mechanical dynamic monitoring, in particular to a dynamic monitoring method and system for the connection interference magnitude of a motor rotor and a main shaft, and the method comprises the steps: obtaining a contact pressure signal, a vibration acceleration signal and a temperature distribution signal of a connection interface of the motor rotor and the main shaft in parallel in the operation process of a motor; integrating to generate a connection monitoring parameter set; constructing a contact state evaluation matrix of a connection interface of the motor rotor and the main shaft according to the connection monitoring parameter set; calculating stress distribution of a connection interface based on the contact state evaluation matrix, and generating a dynamic contact stiffness value representing connection compactness evolution; and inputting the dynamic contact stiffness value into a pre-calibrated dynamic interference response model, and outputting a dynamic equivalent interference magnitude in a motor operation state. According to the invention, the problem that the real-time monitoring of the connection interference magnitude of the motor rotor and the main shaft is not accurate due to the coupling effect of centrifugal force and thermal deformation under the dynamic operation condition of the rotating machine is effectively solved, and the online quantification of the dynamic evolution of the interference magnitude is realized.

Description

Technical Field

[0001] This invention relates to the field of mechanical dynamic monitoring technology, and in particular to a method and system for dynamic monitoring of the interference fit between a motor rotor and a main shaft. Background Technology

[0002] In high-speed rotating electric motor systems, torque transmission between the motor rotor and the main shaft via an interference fit is the core assembly method, and the tightness of this connection directly determines the reliability and lifespan of the transmission system. The interference fit, as a key parameter characterizing the tightness of the fit, is traditionally measured using static methods: either by measuring the fit during the assembly stage using feeler gauges during cold shrinkage or indirectly calculated using strain gauges after the machine has stopped.

[0003] However, under rotating conditions, the rotor experiences enormous centrifugal force, causing dynamic expansion of the inner bore. Simultaneously, high-speed friction generates heat, leading to thermal expansion and deformation of the material. The coupling effect of these two factors causes the actual interference fit to continuously deviate from the initial assembly value. Existing technologies suffer from several limitations: static detection cannot capture real-time changes during operation, resulting in significant delays in interference fit assessment; single physical quantity measurements, such as monitoring only temperature or vibration, are insufficient to decouple the mutual interference between centrifugal force and thermal deformation, causing cumulative errors; and thirdly, the lack of a multi-source signal collaborative analysis mechanism makes it impossible to establish a closed-loop feedback model for dynamic interference fit. These shortcomings expose rotating machinery to the risk of interference fit failure during long-term operation. Insufficient interference fit will cause loose connections leading to abnormal vibration, while excessive interference fit will induce stress concentration and accelerate fatigue fracture. Existing technologies cannot provide early warning of faults or data support for proactive control.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a method and system for dynamically monitoring the interference fit between the motor rotor and the main shaft, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for dynamically monitoring the interference fit between a motor rotor and a main shaft, the method comprising: During motor operation, the contact pressure signal, vibration acceleration signal, and temperature distribution signal at the connection interface between the motor rotor and the main shaft are acquired in parallel and integrated to generate a set of connection monitoring parameters. Construct a contact state evaluation matrix for the connection interface between the motor rotor and the main shaft based on the connection monitoring parameter set; The stress distribution at the connection interface is calculated based on the contact state evaluation matrix to generate a dynamic contact stiffness value characterizing the evolution of connection tightness. The dynamic contact stiffness value is input into a pre-calibrated dynamic interference response model, and the dynamic equivalent interference under motor operating conditions is output.

[0007] Furthermore, the dynamic equivalent interference under the operating state of the output motor includes: Based on the contact state evaluation matrix, the dynamic contact stiffness value is dynamically weighted and updated during motor operation; The dynamic contact stiffness value is input into the dynamic interference response model and iterative numerical solution is performed based on the time step. The initial iterative value in the iterative numerical solution is generated by extrapolating the historical interference data of the previous time step, and the iterative convergence condition is set to stiffness residual less than preset tolerance. The obtained dynamic equivalent interference is compared with the initial interference of the assembly, and the rotor inner hole expansion effect caused by centrifugal force is compensated, and the dynamic equivalent interference compensated by centrifugal force is output.

[0008] Furthermore, compensation for the rotor bore expansion effect caused by centrifugal force includes: Obtain the rotor's geometric parameters and calculate the dynamic expansion of the rotor's inner bore based on the curve of the rotor material's elastic modulus changing with temperature. A dynamic compensation coefficient is generated based on the ratio of the dynamic expansion amount to the initial interference of the assembly, and the dynamic compensation coefficient increases with the square of the rotational speed. Using the initial interference fit as a reference value, the dynamic compensation coefficient is multiplied by the initial interference fit to generate the dynamic compensation value; Subtract the dynamic compensation amount from the dynamic equivalent interference amount to output the compensated dynamic equivalent interference amount.

[0009] Furthermore, iterative numerical solutions are performed, including: Based on the historical data of the interference amount at the previous time step, the initial iteration value for the current time step is generated by extrapolation according to the time series. The dynamic contact stiffness value is solved iteratively. When the stiffness residual decreases linearly after three consecutive iterations, the iteration step size is increased to a fixed multiple of the original step size. The preset tolerance is dynamically adjusted according to the real-time rotational speed of the motor rotor, wherein the preset tolerance is reduced according to the square of the rotational speed. If the dynamic equivalent interference after iteration convergence exceeds the safe range corresponding to the material's yield strength, then the dynamic equivalent interference is corrected to the boundary value of the closest safe range.

[0010] Furthermore, the dynamic over-interference response model is calibrated, including: With the motor stationary, the axial tensile force is gradually increased on the assembly of the motor rotor and the main shaft, while the deformation data at each point of the connection is measured. The stress distribution on the contact surface is calculated based on the deformation data, and the correspondence between the interference and the total pressure under static conditions is determined. While the motor is rotating, the speed is controlled to operate in multiple gears from low to high, and the vibration acceleration signal and temperature distribution signal are collected in real time to simulate and analyze the change in contact stiffness while the motor is rotating. The dynamic interference response model is established by combining the correspondence between the interference amount and the total pressure and the change in contact stiffness.

[0011] Further, the stress distribution at the connection interface is calculated based on the contact state evaluation matrix, including: Obtain the spatial coordinates and normal vectors of the contact points of the connection interface in the contact state evaluation matrix, and generate the geometric feature vectors of each contact point; Based on the geometric feature vector and the real-time contact pressure obtained from the contact pressure signal, the local stress peak value of each contact point is calculated. Thermal expansion compensation is performed on the local stress peak based on the temperature distribution signal to generate the dynamic contact stiffness value characterizing the evolution of contact tightness.

[0012] Further, thermal expansion compensation is performed on the local stress peak based on the temperature distribution signal, including: The temperature change at each contact point is determined based on the temperature distribution signal. Based on the difference in thermal expansion characteristics of the materials of the motor rotor and the main shaft, the thermal deformation effect caused by temperature change is calculated. The thermally induced deformation effect is converted into a corresponding thermal stress compensation amount; The thermal stress compensation amount is applied to the local stress peak to correct it, and a corrected stress value is obtained. The dynamic contact stiffness value is calculated based on the proportional relationship between the corrected stress value and the contact pressure signal.

[0013] Further, the contact state evaluation matrix of the connection interface is constructed, including: Spatial location decoupling processing is performed on the connection monitoring parameter set to separate the contact pressure signal component, vibration acceleration signal component and temperature distribution signal component corresponding to each spatial location of the connection interface; The contact pressure signal component, the vibration acceleration signal component, and the temperature distribution signal component at the same spatial location are fused together. The contact state evaluation matrix is ​​constructed based on the fused data, wherein the row dimension of the matrix corresponds to the circumferential position of the connection interface, and the column dimension corresponds to the axial position of the connection interface.

[0014] A dynamic monitoring system for the interference fit between a motor rotor and a main shaft, the system comprising: The parameter acquisition module acquires the contact pressure signal, vibration acceleration signal, and temperature distribution signal of the connection interface between the motor rotor and the main shaft in parallel during motor operation, and integrates them to generate a set of connection monitoring parameters. The evaluation matrix module constructs a contact state evaluation matrix for the connection interface between the motor rotor and the spindle based on the connection monitoring parameter set. The stress evolution module calculates the stress distribution at the connection interface based on the contact state evaluation matrix and generates dynamic contact stiffness values ​​that characterize the evolution of connection tightness. The equivalent interference module inputs the dynamic contact stiffness value into the pre-calibrated dynamic interference response model and outputs the dynamic equivalent interference amount under the motor's operating state.

[0015] Furthermore, the equivalent interference module includes: The dynamic weighted unit, based on the contact state evaluation matrix, dynamically weights and updates the dynamic contact stiffness value during motor operation; The iterative solution unit inputs the dynamic contact stiffness value into the dynamic interference response model and performs iterative numerical solutions based on the time step. The historical extrapolation unit generates the initial iterative value in the iterative numerical solution by extrapolating the historical interference data of the previous time step, and the iterative convergence condition is set to stiffness residual less than preset tolerance. The compensation output unit compares the solved dynamic equivalent interference with the initial interference of the assembly, and compensates for the rotor inner hole expansion effect caused by centrifugal force, and outputs the dynamic equivalent interference compensated by centrifugal force.

[0016] The technical solution of this invention can achieve the following technical effects: It effectively solves the problem of inaccurate real-time monitoring of the interference fit between the motor rotor and the main shaft caused by the coupling effect of centrifugal force and thermal deformation under dynamic operating conditions of rotating machinery, and realizes online quantification of the dynamic evolution of the interference fit.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating a method for dynamically monitoring the interference fit between a motor rotor and its main shaft. Figure 2 A flowchart illustrating the process of outputting the dynamic equivalent interference. Figure 3 A flowchart illustrating the calibration of the dynamic interference response model; Figure 4 The logic flowchart for calculating the stress distribution at the connection interface. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Example 1; like Figure 1 As shown, this application provides a method for dynamically monitoring the interference fit between the motor rotor and the main shaft. The method includes: During motor operation, the contact pressure signal, vibration acceleration signal, and temperature distribution signal at the connection interface between the motor rotor and the main shaft are acquired in parallel and integrated to generate a set of connection monitoring parameters. Construct a contact state evaluation matrix for the connection interface between the motor rotor and the spindle based on the connection monitoring parameter set; The stress distribution at the connection interface is calculated based on the contact state evaluation matrix, and a dynamic contact stiffness value characterizing the evolution of connection tightness is generated. Input the dynamic contact stiffness value into the pre-calibrated dynamic interference response model, and output the dynamic equivalent interference under the motor operating state.

[0023] Specifically, firstly, during motor operation, highly sensitive sensors are arranged near the interface between the motor's rotor and main shaft to acquire a series of dynamic data. These include, but are not limited to, pressure sensors for measuring contact pressure signals, accelerometers for capturing vibration acceleration signals, and temperature sensors for monitoring temperature distribution. Preferably, these sensors should be combined and installed at key locations on the contact interface to cover as many signal transformation dimensions as possible under different environmental conditions and operating states, and to improve monitoring accuracy. To improve the timeliness and completeness of the acquired signals, the sensors can acquire the above signals in parallel through a high-frequency data synchronization module, and then... A dedicated data processing module integrates and generates a set of connection monitoring parameters for subsequent analysis. Then, through comprehensive analysis of this parameter set, a contact state evaluation matrix for the rotor-spindle connection interface is constructed. In a preferred implementation, this matrix can be built based on data analysis algorithms to analyze the variation patterns of multi-dimensional signals such as contact pressure, vibration acceleration, and temperature distribution, extracting the main characteristic parameters affecting the rotor-spindle connection state. These characteristic parameters can include not only the signal's average value, standard deviation, and instantaneous signal fluctuation, but also deeper features such as the signal's spectral distribution and root mean square value. During this process, machine learning techniques are used to analyze the multi-source data. Feature optimization and dimensionality reduction integrate multi-dimensional parameters into the evaluation matrix. Next, the stress distribution at the connection interface is calculated based on the contact state evaluation matrix. This stress distribution reflects the forces and deformations between the rotor and the main shaft at the contact interface. Preferably, based on the finite element analysis method, the pressure signals in the evaluation matrix can be fitted and calculated to accurately output the stress changes at different locations on the contact interface. Simultaneously, the frequency domain conversion results of the vibration acceleration signal and temperature distribution signal are combined to superimpose the effects of vibration and thermal effects on the stress distribution. Based on this, the dynamic contact stiffness value characterizing the connection tightness of the contact interface is further defined and calculated. This contact stiffness value can dynamically... The dynamic contact stiffness value is characterized by its variation in structural integrity and deformation dimensions at the contact interface under different operating conditions. Finally, the dynamic contact stiffness value is input into a pre-calibrated dynamic interference response model for calculation, thereby outputting the dynamic equivalent interference of the motor under operating conditions. Specifically, the calibration of the dynamic interference response model can be established in a laboratory environment by actually measuring the mechanical behavior under different interference parameters. In practical applications, the current dynamic equivalent interference can be obtained by comparing the real-time changes in the contact stiffness value with the pre-calibrated data of the model. Preferably, the model can also continuously optimize parameters through long-term online monitoring and tuning to enhance the calculation accuracy and adaptability.For example, in the initial stage of motor operation, the stress distribution at the connection interface is uniform, the dynamic contact stiffness remains at a high level, and the dynamic equivalent interference fit matches the calibration value. However, as the operating time increases, the temperature rises, causing slight thermal expansion at the contact interface. Simultaneously, fretting wear caused by vibration increases. Changes in the contact state evaluation matrix will promptly reflect the decreasing trend of dynamic contact stiffness. At this point, model calculations can show that the dynamic equivalent interference fit begins to decrease, indicating that operators need to inspect or maintain the connection interface.

[0024] The technical solution of this invention effectively solves the problem of inaccurate real-time monitoring of the interference fit between the motor rotor and the main shaft caused by the coupling effect of centrifugal force and thermal deformation under dynamic operating conditions of rotating machinery, and realizes online quantification of the dynamic evolution of the interference fit.

[0025] Furthermore, such as Figure 2 As shown, the dynamic equivalent interference of the output motor during operation includes: Based on the contact state evaluation matrix, the dynamic contact stiffness value is dynamically weighted and updated during motor operation; The dynamic contact stiffness value is input into the dynamic interference response model and iterative numerical solution is performed based on the time step. The initial iterative value in the iterative numerical solution is generated by extrapolating the historical data of the interference of the previous time step, and the iterative convergence condition is set to the stiffness residual being less than the preset tolerance. The dynamic equivalent interference obtained by the solution is compared with the initial interference of the assembly, and the rotor inner hole expansion effect caused by centrifugal force is compensated, and the dynamic equivalent interference compensated by centrifugal force is output.

[0026] As a preferred embodiment of the above, firstly, during motor operation, the dynamic contact stiffness value is dynamically adjusted and weighted by continuously acquiring and updating the contact state evaluation matrix. Preferably, a time series analysis model can be used to process the real-time acquired data. This model can identify the trend of stiffness value changes and adjust the proportion of different signal sources through a weighted algorithm to comprehensively calculate the dynamic contact stiffness correction value for each time period. Combining historical data and real-time parameters, refined management of dynamic stiffness changes can be achieved. This weighted update method can better adapt to various non-stationary states during motor operation. Next, the updated dynamic contact stiffness value is input into the dynamic interference response model. The solution is iteratively numerically solved within a pre-defined time step using a finite iteration method. This approximates the analytical results of the nonlinear correlation step by step. Within each time step, the initial iteration value is estimated by extrapolation from the historical interference data of the previous time step. During extrapolation, the initial iteration value of the current time step is predicted and calculated using the dynamic equivalent interference and relevant operating parameters of the previous time step, through an interpolation algorithm based on historical trends or a parameter optimization model. This provides the initial conditions for the iterative solution, ensuring the coherence and continuity of the solution process. To guarantee the accuracy of the solution, convergence conditions for the stiffness residuals are set during the iteration process. Once the stiffness residual decreases to a preset tolerance range during the iteration process, the iteration calculation ends, and the dynamic equivalent interference for that time step is output. This iterative solution method is an optimization scheme for general numerical solution methods that are difficult to obtain stable solutions under complex working conditions, achieving stable operation in complex systems. Finally, the obtained dynamic equivalent interference is compared with the initial interference at the beginning of rotor assembly, and then the compensation amount for the rotor inner hole expansion caused by centrifugal force is calculated. Due to the centrifugal force, the motor rotor will experience radial expansion of the inner hole due to rotational acceleration during rotation. Therefore, by parametrically modeling the influence of centrifugal force, the compensation amount is calculated to correct the dynamic equivalent interference, generating the final interference. The dynamic equivalent interference output is achieved through centrifugal force compensation. This compensation process is typically based on a comprehensive consideration of the rotor's material properties, physical morphology, and current operating parameters. Multiphysics simulation technology is used for modeling and calculation to ensure that the output interference has higher accuracy and reliability. For example, in practical applications, when the motor reaches a certain speed, the slight expansion of the rotor's inner hole due to centrifugal force will cause the directly measured interference to be lower than the true value. At this time, by combining historical operating data and a real-time updated contact stiffness correction model, the accurate dynamic equivalent interference can be quickly obtained. The influence of centrifugal force on the expansion is automatically adjusted in the calculation, thus providing an interference that is closer to the actual operating state at the current moment.

[0027] Furthermore, compensating for the rotor bore expansion effect caused by centrifugal force includes: Obtain the rotor's geometric parameters and calculate the dynamic expansion of the rotor's inner bore based on the curve of the rotor material's elastic modulus changing with temperature. A dynamic compensation coefficient is generated based on the ratio of the dynamic expansion amount to the initial interference of the assembly. The dynamic compensation coefficient increases with the square of the rotational speed. Using the initial interference fit as the baseline value, the dynamic compensation coefficient is multiplied by the initial interference fit to generate the dynamic compensation value. Subtract the dynamic compensation from the dynamic equivalent interference to output the compensated dynamic equivalent interference.

[0028] As a preferred embodiment of the above, firstly, after the motor is turned on, the rotor's geometric parameters are accurately acquired through sensors or preset parameters. These parameters include, but are not limited to, the rotor's inner diameter, outer diameter, and height. These parameters will serve as important basic input data for subsequent compensation calculations. Simultaneously, data on the change of the rotor material's elastic modulus with temperature is combined. This data can be derived from experimental curves or literature on the rotor material at different temperatures. A dynamic curve showing the relationship between the material's elastic modulus and temperature change is generated using interpolation or fitting methods. By acquiring real-time temperature data during rotor operation, for example, by using a temperature sensor to monitor the rotor's surface or internal temperature, the current temperature is substituted into the aforementioned fitted curve to calculate the material's elastic modulus. The real-time value of the modulus; next, based on the material's dynamic elastic modulus and the rotor's geometric parameters, a mechanical model is used to calculate the dynamic expansion of the rotor's inner bore caused by centrifugal force. In the preferred implementation, by considering the positive correlation between the square of the rotational speed and the centrifugal force, the expansion of the rotor's inner bore under rotational acceleration is dynamically quantified into a specific value under the current specific rotational conditions. This calculation of dynamic expansion not only characterizes the direct influence of centrifugal force but also incorporates the change in elastic modulus caused by rotor thermal effects, resulting in high accuracy and engineering applicability of the final calculation results; then, based on the ratio of the aforementioned dynamic expansion to the initial interference fit, a dynamic compensation coefficient is generated. In actual operation, the dynamic compensation coefficient... The mathematical characteristic of the dynamic compensation coefficient is that it increases with the square of the rotational speed. Specifically, the higher the rotational speed, the stronger the centrifugal force, making the expansion effect of the rotor's inner hole more pronounced. Therefore, the calculation of the dynamic compensation coefficient directly increases the correction weight of the compensation amount on the interference fit. To ensure the accuracy of the dynamic compensation coefficient, it is preferable to use a dynamic adjustment mechanism to optimize it, such as by combining long-term operating data or experimental data under specific application scenarios. Next, using the initial interference fit as the baseline value, the dynamic compensation coefficient is multiplied as the adjustment reference to generate the dynamic compensation amount. In this step, the dynamic compensation amount describes the effective influence of the inner hole expansion on the interference fit, and numerically reflects the part that needs to be reduced or corrected under the current operating conditions. For example, when the initial interference fit is a specific value, the multiple corresponding to the dynamic compensation coefficient can be directly quantified into an engineering compensation value, thereby ensuring the logical closed loop of subsequent calculations. Finally, the dynamic compensation amount is subtracted from the dynamic equivalent interference fit to obtain the true dynamic equivalent interference fit after centrifugal force compensation. Preferably, this compensation result is included in the historical database as the correction basis for subsequent iterative calculations. For example, in actual use, when the motor speed gradually increases to a certain operating condition, the negative impact of rotor inner hole expansion on the dynamic equivalent interference fit increases significantly. At this time, after real-time correction through the compensation model, the interference fit at the current moment can be accurately output, avoiding monitoring deviations and structural hazards caused by insufficient compensation.

[0029] Furthermore, iterative numerical solutions include: Based on the historical data of the overshoot in the previous time step, the initial iterative value for the current time step is generated by extrapolation from the time series. The dynamic contact stiffness value is solved iteratively. When the stiffness residual decreases linearly after three consecutive iterations, the iteration step size is increased to a fixed multiple of the original step size. The preset tolerance is dynamically adjusted based on the real-time speed of the motor rotor, wherein the preset tolerance is reduced according to the square of the speed. If the dynamic equivalent interference after iteration convergence exceeds the safe range corresponding to the material's yield strength, the dynamic equivalent interference will be corrected to the boundary value of the closest safe range.

[0030] As a preferred embodiment of the above, firstly, before the iterative calculation begins at a certain time step, an initial iterative value for the current time step is generated based on the historical interference data of the previous time step. Preferably, a time-series-based extrapolation algorithm is used. By analyzing the changing trends of historical data, such as the curve of interference change and the influence of velocity change on stiffness, an initial iterative value that can be used as an initial condition is predicted. This method allows the iterative process to quickly approach the true value, reduces the number of invalid iterations, and thus improves computational efficiency. For example, if the historical data shows a stable downward trend in the previous time step, the initial iterative value can be directly estimated by linear interpolation; while when the changing trend is more complex, a polynomial fitting method can be used for estimation. To ensure the reliability of the initial iterative values, the system proceeds to iteratively solve for the dynamic contact stiffness value. In the preferred implementation, the stiffness residual is set as the core criterion for iterative convergence. Specifically, when the stiffness residual shows a linear decreasing trend after three consecutive iterations, the system automatically adjusts the iteration step size by multiplying the original step size by a fixed factor to accelerate iterative convergence. This optimized design can respond to changes in dynamic operation, concentrating computational resources on the range with higher prediction accuracy while avoiding resource waste. For example, if the original iteration step size is 0.01 units, after three linear decreases in the residual, the step size can be expanded to 0.02 units to improve computational efficiency. For situations where linear decreases cannot continue, such as convergence pauses due to nonlinear response, [further details are needed]. The system automatically resets the step size to the default value to ensure the stability of the iteration process. During iteration, to address the changing accuracy requirements of the dynamic equivalent interference under different speed conditions, the preset tolerance is adjusted in real time to further optimize the iteration effect. The relationship between the square of the rotational speed and the centrifugal force is such that as the rotational speed increases, the centrifugal force increases rapidly in proportion to the square of the rotational speed, thus significantly affecting the dynamic expansion degree of the rotor's inner hole and the material stress distribution. Due to the relationship between the square of the rotational speed and the centrifugal force, the allowable value of the stiffness residual at iteration convergence is dynamically reduced according to the square of the rotational speed to adapt to the high monitoring accuracy requirements of the system during high-speed operation. In addition, the tolerance adjustment mechanism can respond to the transient speed changes of the system to dynamically adapt to the actual working conditions and provide accurate monitoring data for different operating stages. According to the design, the preset tolerance boundary is set by establishing a fixed initial error range, which is dynamically adjusted according to the motor speed. In the initialization phase, a loose boundary is set to accommodate deviations during system startup. As the speed increases, the boundary gradually shrinks according to a square relationship to improve the calculation accuracy during the iteration process and the reliability of the final output. Finally, after the iteration converges, the dynamic equivalent interference value is checked for a safe range to ensure that the model output is within the safe range corresponding to the material yield strength. Once the equivalent interference after iteration exceeds the safe range, the system automatically executes the correction function to adjust the dynamic equivalent interference back to the boundary value of the safe range. This design can effectively avoid structural failure caused by the material strength exceeding the limit, and enhance the safety and stability of operation.

[0031] Furthermore, such as Figure 3 As shown, the calibration of the dynamic interference response model includes: With the motor stationary, the axial tension is gradually increased on the assembly of the motor rotor and the main shaft, while the deformation data at each point of the connection is measured. The stress distribution on the contact surface is calculated based on the deformation data, and the relationship between the interference fit and the total pressure under static conditions is determined. While the motor is rotating, the speed is controlled to operate in multiple gears from low to high, and vibration acceleration signals and temperature distribution signals are collected in real time to simulate and analyze the changes in contact stiffness while the motor is rotating. A dynamic interference response model is established by combining the correspondence between interference and total pressure and the change in contact stiffness.

[0032] As a preferred embodiment of the above, firstly, with the motor stationary, an experiment is conducted by gradually increasing the axial tensile force on the assembly of the motor rotor and main shaft. Preferably, the axial tensile force can be gradually applied using a precision loading device, and deformation data at each point of the connection during the loading process is recorded in stages, provided that the assembly structure is not damaged. This deformation data can be acquired using high-resolution displacement sensors or strain gauges arranged on the contact interface to ensure the accuracy and comprehensiveness of the data. During the test, to avoid the influence of nonlinear changes on the data, it is preferable to allow sufficient time for each stage of the loading process to reach a fully balanced state, and to measure the deformation under different loading amounts. The acquisition of deformation data can accurately reflect the mechanical behavior of the contact surface. Next, the deformation data is converted into stress distribution on the contact surface. Mechanical property calculation and experimental data processing software are used to analyze the collected deformation information. Based on experimentally tested deformation data, the pressure distribution on the contact interface can be calculated point-by-point using the principle of static equilibrium, ensuring that the stress distribution results are consistent with actual working conditions. In the preferred method, the contact surface area can be divided into a network and calculated point-by-point, and the total pressure can be summarized and verified. In this step, the correspondence between the total contact pressure and the interference fit under static conditions is specifically studied. This relationship can be verified using fitting methods. A parameterized model was established to reflect the pressure state corresponding to different interference fits. Subsequently, with the motor rotating, experimental conditions were set with speeds increasing from low to high, and vibration acceleration and temperature distribution signals were collected simultaneously. The preferred method was to specify several fixed speed levels during motor rotation, gradually increasing the speed and maintaining each level for 15 minutes to obtain stable signal data. Accelerometers and temperature sensors installed near the contact interface were used to capture the dynamic fluctuations of interface vibration acceleration and the temperature distribution in the contact area in real time. This reflects the stiffness changes caused by centrifugal force and thermal effects during motor rotation, thus improving data quality. Simultaneously, signal filtering technology can be used to remove environmental interference, thereby ensuring the overall accuracy of vibration acceleration and temperature distribution signals. Then, based on the above experimental data, the vibration acceleration and temperature signals are simulated and analyzed to study the change law of contact stiffness under rotation. Preferably, by constructing a multi-physics coupling model, the elastic influence of vibration acceleration on contact stiffness and the relationship between temperature-induced changes in the material's elastic modulus are incorporated into the calculation framework. This simulation analysis needs to be combined with the motor operating conditions and the actual physical properties of the material to dynamically reflect the sequential characteristics of the contact interface stiffness as a function of vibration and temperature, thereby providing a complete calibration basis for the contact stiffness parameters under rotation.Finally, combining the relationship between the interference and total pressure obtained in the static state, and the change law of contact stiffness in the rotating state, a dynamic interference response model is established through experimental data fitting and parametric modeling. Preferably, this model is constructed by function fitting based on characteristic parameters, which can describe in detail the trend of interference evolution of the motor from static to rotating states. For example, the model parameters may include the total assembly pressure in the static state, the dynamic contact stiffness value in the rotating state, and the parameter sensitivity to the influence of vibration acceleration and temperature. After the model fitting is completed, its accuracy can be verified through subsequent validation experiments, providing basic support for real-time dynamic interference monitoring during motor operation.

[0033] Furthermore, such as Figure 4 As shown, the stress distribution at the connection interface is calculated based on the contact state evaluation matrix, including: Obtain the spatial coordinates and normal vectors of the contact points at the connection interface in the contact state evaluation matrix, and generate the geometric feature vectors of each contact point; Based on geometric feature vectors and real-time contact pressure obtained from contact pressure signals, the local stress peak value at each contact point is calculated. Thermal expansion compensation is performed on the local stress peak based on the temperature distribution signal to generate a dynamic contact stiffness value that characterizes the evolution of contact tightness.

[0034] As a preferred embodiment of the above, firstly, data of the connection interface is extracted from the contact state evaluation matrix. This matrix contains the spatial coordinates and normal vector of each contact point. This basic data can be obtained by high-precision sensors installed at key locations on the motor. These sensors collect information on the interface by measuring the actual position and direction of the contact points. This step ensures that the positional relationship and normal force direction of each contact point are accurately depicted, providing a geometric basis for stress distribution calculation. Next, geometric feature vectors of each contact point are generated based on the extracted data. The geometric feature vectors are the result of combining spatial coordinates and normal vectors, indicating the directionality and coordinate positioning of the contact points. By combining the geometric feature vectors with the real-time contact pressure signal associated with the evaluation matrix, the local stress peak can be calculated at each contact point. The transient pressure signal, as a real-time changing data input, can be integrated into the mechanical calculation model of the geometric feature vectors to determine the local stress concentration at each contact point. Preferably, it can be used as a calibrated reference pressure state to measure the stress distribution under different interference conditions, thereby incorporating the compression effect and stress concentration effect into the calculation framework. Then, the temperature distribution signal is used... Thermal expansion compensation is applied to the local stress peaks at each contact point. Temperature distribution signals are acquired in real time using dedicated temperature sensors, and the sensed temperature information is converted into stress compensation amounts based on the thermal expansion effect of the material. Specifically, thermal expansion compensation considers the influence of temperature on material dimensions and mechanical response. In the stress distribution model, local stress is corrected using the particle thermal expansion coefficient and temperature change rate to achieve dynamic adjustment of the stress state. In the preferred method, experimental data on material thermal expansion and induction signal models can be used to develop calculation compensation models for the temperature range encountered in practice, ensuring that the stress distribution is adjusted in real time according to temperature conditions. Finally, a dynamic contact stiffness value characterizing the evolution of connection tightness is generated by combining the above-mentioned local stress peak compensation results. The dynamic stiffness value accurately describes the interface connection state by analyzing local stress changes and material properties. Preferably, big data analysis technology can be used to reduce the dimensionality of multi-point stress distribution information, highlighting key signal features to reflect the dynamic change rate. This dynamic contact stiffness value not only reflects the direct influencing factors of stress changes but also includes the thermal stress compensation effect, indicating the evolution trend of interface interference over time.

[0035] Furthermore, thermal expansion compensation for local stress peaks based on temperature distribution signals includes: Determine the temperature changes at each contact point based on the temperature distribution signal; Based on the difference in thermal expansion characteristics of the motor rotor and spindle, the thermal deformation effect caused by temperature change is calculated. The thermally induced deformation effect is converted into the corresponding thermal stress compensation amount; The local stress peak is corrected by applying thermal stress compensation to obtain the corrected stress value; The dynamic contact stiffness value is calculated based on the proportional relationship between the corrected stress value and the contact pressure signal.

[0036] As a preferred embodiment, firstly, real-time temperature distribution signals at each contact point are acquired using multi-point temperature sensors installed near the interface between the motor rotor and the spindle. These temperature sensors preferably possess high sensitivity and high resolution, capable of capturing temperature changes in different areas of the interface, covering everything from external temperature changes to localized heat differences caused by friction. Based on the real-time collected data and the interface's geometric features, corresponding temperature changes are generated, thereby defining the temperature gradient for each contact point. Subsequently, based on the differences in thermal expansion characteristics of the motor rotor and the spindle materials, the thermally induced deformation effect caused by temperature changes is calculated. A preferred method is to use the coefficients of thermal expansion of each material, such as the rotor material and the spindle material. The materials may be steel and aluminum, which have significantly different coefficients of thermal expansion. By combining real-time temperature changes, the dimensional changes of the two materials at the interface under different temperature conditions are calculated, i.e., thermally induced deformation. The coefficients of thermal expansion can be obtained from laboratory calibration values ​​or material databases and dynamically adjusted using real-time temperature signals. Furthermore, the combined thermally induced deformation effect of the two materials at the interface needs to be analyzed in conjunction with the interface pressure distribution and heat conduction effects to ensure that the calculation results reflect the actual interface conditions. Next, the thermally induced deformation effect is converted into a corresponding thermal stress compensation amount. The thermal stress compensation calculates the local stress change caused by the interface dimensional change based on the thermally induced deformation amount and assigns specific compensation data to each contact point. Preferably, it can... The influence of material thermal expansion differences on pressure and stress distribution is simulated using a multi-point distribution model, thereby calculating accurate compensation stress values ​​for each contact point. The accuracy of the compensation directly depends on the level of detail in the model design. For example, finite element analysis is used to calculate the stress concentration effect caused by material thermal expansion point by point to ensure that the compensation amount conforms to actual working conditions. Furthermore, thermal stress compensation is applied to the calculated local stress peaks to obtain corrected stress values. The correction process preferably adopts a point-by-point solution method to achieve dynamic adjustment of the compensated pressure value and reflect the stress distribution changes at the interface due to temperature. If the local stress peak at a certain contact point increases significantly due to temperature changes, the pressure is reduced. The proportion of the signal is used to balance its overall relationship with other contact points, and finally the corrected stress value that conforms to the dynamic balance of interface interference is output. Finally, based on the proportional relationship between the corrected stress value and the contact pressure signal, a dynamic contact stiffness value characterizing the evolution of the connection interface state is calculated and generated. The generation of dynamic contact stiffness value needs to comprehensively consider the response of the corrected stress value to the real-time pressure signal, so as to construct the dynamic change process of stiffness evolution on the interface. The preferred method is to introduce nonlinear data fitting technology to classify and model the real-time monitored corrected stress and contact pressure signals to improve the dynamic characteristics of stiffness value generation. The generated dynamic contact stiffness value can not only reflect the interface connection change, but also has the function of predicting the evolution of future working conditions.

[0037] Furthermore, constructing the contact state evaluation matrix of the connection interface includes: Spatial location decoupling processing is performed on the connection monitoring parameter set to separate the contact pressure signal component, vibration acceleration signal component and temperature distribution signal component corresponding to each spatial location of the connection interface; Data fusion is performed on the contact pressure signal components, vibration acceleration signal components, and temperature distribution signal components at the same spatial location; A contact state evaluation matrix is ​​constructed based on the fused data, where the row dimension of the matrix corresponds to the circumferential position of the connection interface and the column dimension corresponds to the axial position of the connection interface.

[0038] As a preferred embodiment of the above, firstly, after acquiring the connection monitoring parameter set, it is necessary to perform spatial position decoupling processing on the sensing signals at different spatial locations of the connection interface. That is, the monitoring parameters are decomposed into three corresponding signal components according to their spatial locations: contact pressure signal component, vibration acceleration signal component, and temperature distribution signal component. A preferred method is to arrange multiple sets of high-density sensors in the circumferential and axial positions of the connection interface to collect dynamic signals in real time. Then, combined with the spatial arrangement information of the sensors, the collected signals are mapped to the corresponding spatial locations to ensure that each spatial location is individually identified. For example, in the axial direction, layered sensing points are arranged at specific intervals, thereby completing the spatial position decoupling of the parameter set and obtaining the components of each acquisition point. This step accurately determines the spatial location of each signal at the connection interface, providing a foundation for data fusion. Next, for the decoupled signal components, the contact pressure signal component, vibration acceleration signal component, and temperature distribution signal component at the same spatial location are fused. The goal of data fusion is to combine the static value of contact pressure, the dynamic characteristics of vibration acceleration, and the compensation effect caused by temperature distribution to form unified data comprehensively reflecting the contact state. A preferred implementation method is to use a multi-source data weighted fusion algorithm, where the contact pressure signal serves as the primary weight, the vibration acceleration signal is assigned a correction weight based on its dynamic fluctuation characteristics, and the temperature distribution signal participates in the fusion as a compensation weight. When multiple signal components show different trends, historical data can be used for trend comparison, and weights can be adjusted for optimization to ensure that the fusion result truly reflects the interface contact state. After data fusion is completed, a contact state evaluation matrix is ​​constructed based on the fused data. By mapping the circumferential position of the connecting interface to the row dimension of the matrix and the axial position to the column dimension, each element in the matrix is ​​the fused data value at that position. For example, for a gridded distribution of interface acquisition points, with the axis divided into upper, middle, and lower layers, an evaluation matrix with 30 circumferential points in the row dimension and 3 axial points in the column dimension can be generated. This matrix comprehensively represents the contact state at different positions of the interface. The row and column dimensions and the acquisition point density can be adjusted according to actual conditions. The operating conditions can be flexibly adjusted, and the value of any element in the matrix directly maps to the combined state of contact pressure, vibration acceleration, and temperature at that location. For example, during the operation of a motor, the signal displayed by connecting to the monitoring parameter collection shows that the contact pressure is significantly increased at the circumferential position and the axial upper layer sensing point nearby, the vibration signal shows peak oscillation, and the temperature distribution is slightly lower than other areas. Through decoupling and fusion calculation, the element value corresponding to this area in the evaluation matrix shows an abnormal weight distribution. Subsequent analysis can reveal that the stress concentration at this point may be due to the locking effect caused by uneven interference distribution during assembly. Therefore, the evaluation matrix can quickly locate abnormal points on the interface, providing maintenance personnel with a clear basis for analysis.

[0039] Example 2; Based on the same inventive concept as the method for dynamic monitoring of interference fit between a motor rotor and a spindle in the foregoing embodiments, the present invention also provides a system for dynamic monitoring of interference fit between a motor rotor and a spindle, the system comprising: The parameter acquisition module acquires the contact pressure signal, vibration acceleration signal, and temperature distribution signal of the connection interface between the motor rotor and the main shaft in parallel during motor operation, and integrates them to generate a set of connection monitoring parameters. The evaluation matrix module constructs a contact state evaluation matrix for the connection interface between the motor rotor and the spindle based on the connection monitoring parameter set. The stress evolution module calculates the stress distribution at the connection interface based on the contact state evaluation matrix and generates dynamic contact stiffness values ​​that characterize the evolution of connection tightness. The equivalent interference module inputs the dynamic contact stiffness value into the pre-calibrated dynamic interference response model and outputs the dynamic equivalent interference amount under the motor's operating state.

[0040] The adjustment system described above in this invention can effectively realize a method for dynamic monitoring of the interference fit between the motor rotor and the main shaft. The technical effects it can achieve are as described in the above embodiments, and will not be repeated here.

[0041] Furthermore, the equivalent interference module includes: The dynamic weighted unit, based on the contact state evaluation matrix, dynamically weights and updates the dynamic contact stiffness value during motor operation; The iterative solution unit inputs the dynamic contact stiffness value into the dynamic interference response model and performs iterative numerical solutions based on the time step. The historical extrapolation unit generates the initial iterative value in the iterative numerical solution by extrapolating the historical interference data of the previous time step, and the iterative convergence condition is set to stiffness residual less than preset tolerance. The compensation output unit compares the solved dynamic equivalent interference with the initial interference of the assembly, and compensates for the rotor inner hole expansion effect caused by centrifugal force, and outputs the dynamic equivalent interference compensated by centrifugal force.

[0042] Similarly, the above-mentioned optimization schemes for the system can also achieve the optimization effects corresponding to the methods in Embodiment 1, which will not be repeated here.

[0043] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for dynamically monitoring the interference fit between a motor rotor and its main shaft, characterized in that, The method includes: During motor operation, the contact pressure signal, vibration acceleration signal, and temperature distribution signal at the connection interface between the motor rotor and the main shaft are acquired in parallel and integrated to generate a set of connection monitoring parameters. Construct a contact state evaluation matrix for the connection interface between the motor rotor and the main shaft based on the connection monitoring parameter set; The stress distribution at the connection interface is calculated based on the contact state evaluation matrix to generate a dynamic contact stiffness value characterizing the evolution of connection tightness. The dynamic contact stiffness value is input into a pre-calibrated dynamic interference response model, and the dynamic equivalent interference under motor operating conditions is output.

2. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 1, characterized in that, The dynamic equivalent interference of the output motor during operation includes: Based on the contact state evaluation matrix, the dynamic contact stiffness value is dynamically weighted and updated during motor operation; The dynamic contact stiffness value is input into the dynamic interference response model and iterative numerical solution is performed based on the time step. The initial iterative value in the iterative numerical solution is generated by extrapolating the historical interference data of the previous time step, and the iterative convergence condition is set to stiffness residual less than preset tolerance. The dynamically equivalent interference obtained by the solution is compared with the initial interference of the assembly, and the rotor inner hole expansion effect caused by centrifugal force is compensated, and the dynamically equivalent interference compensated by centrifugal force is output.

3. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 2, characterized in that, Compensation for the rotor bore expansion effect caused by centrifugal force includes: Obtain the rotor's geometric parameters and calculate the dynamic expansion of the rotor's inner bore based on the curve of the rotor material's elastic modulus changing with temperature. A dynamic compensation coefficient is generated based on the ratio of the dynamic expansion amount to the initial interference of the assembly, and the dynamic compensation coefficient increases with the square of the rotational speed. Using the initial interference fit as a reference value, the dynamic compensation coefficient is multiplied by the initial interference fit to generate the dynamic compensation value; Subtract the dynamic compensation amount from the dynamic equivalent interference amount to output the compensated dynamic equivalent interference amount.

4. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 2, characterized in that, Perform iterative numerical solutions, including: Based on the historical data of the interference amount at the previous time step, the initial iteration value for the current time step is generated by extrapolation according to the time series. The dynamic contact stiffness value is solved iteratively. When the stiffness residual decreases linearly after three consecutive iterations, the iteration step size is increased to a fixed multiple of the original step size. The preset tolerance is dynamically adjusted according to the real-time rotational speed of the motor rotor, wherein the preset tolerance is reduced according to the square of the rotational speed. If the dynamic equivalent interference after iteration convergence exceeds the safe range corresponding to the material's yield strength, then the dynamic equivalent interference is corrected to the boundary value of the closest safe range.

5. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 1, characterized in that, Calibrate the dynamic over-interference response model, including: With the motor stationary, the axial tensile force is gradually increased on the assembly of the motor rotor and the main shaft, while the deformation data at each point of the connection is measured. The stress distribution on the contact surface is calculated based on the deformation data, and the correspondence between the interference and the total pressure under static conditions is determined. While the motor is rotating, the speed is controlled to operate in multiple gears from low to high, and the vibration acceleration signal and temperature distribution signal are collected in real time to simulate and analyze the change in contact stiffness while the motor is rotating. The dynamic interference response model is established by combining the correspondence between the interference amount and the total pressure and the change in contact stiffness.

6. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 1, characterized in that, The stress distribution at the connection interface is calculated based on the contact state evaluation matrix, including: Obtain the spatial coordinates and normal vectors of the contact points of the connection interface in the contact state evaluation matrix, and generate the geometric feature vectors of each contact point; Based on the geometric feature vector and the real-time contact pressure obtained from the contact pressure signal, the local stress peak value of each contact point is calculated. Thermal expansion compensation is performed on the local stress peak based on the temperature distribution signal to generate the dynamic contact stiffness value characterizing the evolution of contact tightness.

7. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 6, characterized in that, Thermal expansion compensation is performed on the local stress peak based on the temperature distribution signal, including: The temperature change at each contact point is determined based on the temperature distribution signal. Based on the difference in thermal expansion characteristics of the materials of the motor rotor and the main shaft, the thermal deformation effect caused by temperature change is calculated. The thermally induced deformation effect is converted into a corresponding thermal stress compensation amount; The thermal stress compensation amount is applied to the local stress peak to correct it, and a corrected stress value is obtained. The dynamic contact stiffness value is calculated based on the proportional relationship between the corrected stress value and the contact pressure signal.

8. The method for dynamically monitoring the interference fit between the motor rotor and the main shaft according to claim 1, characterized in that, Constructing the contact state evaluation matrix of the connection interface includes: Spatial location decoupling processing is performed on the connection monitoring parameter set to separate the contact pressure signal component, vibration acceleration signal component and temperature distribution signal component corresponding to each spatial location of the connection interface; The contact pressure signal component, the vibration acceleration signal component, and the temperature distribution signal component at the same spatial location are fused together. The contact state evaluation matrix is ​​constructed based on the fused data, wherein the row dimension of the matrix corresponds to the circumferential position of the connection interface, and the column dimension corresponds to the axial position of the connection interface.

9. A dynamic monitoring system for the interference fit between a motor rotor and a main shaft, characterized in that, The system includes: The parameter acquisition module acquires the contact pressure signal, vibration acceleration signal, and temperature distribution signal of the connection interface between the motor rotor and the main shaft in parallel during motor operation, and integrates them to generate a set of connection monitoring parameters. The evaluation matrix module constructs a contact state evaluation matrix for the connection interface between the motor rotor and the spindle based on the connection monitoring parameter set. The stress evolution module calculates the stress distribution at the connection interface based on the contact state evaluation matrix and generates dynamic contact stiffness values ​​that characterize the evolution of connection tightness. The equivalent interference module inputs the dynamic contact stiffness value into the pre-calibrated dynamic interference response model and outputs the dynamic equivalent interference amount under the motor's operating state.

10. The dynamic monitoring system for interference fit between the motor rotor and the main shaft according to claim 9, characterized in that, The equivalent interference module includes: The dynamic weighted unit, based on the contact state evaluation matrix, dynamically weights and updates the dynamic contact stiffness value during motor operation; The iterative solution unit inputs the dynamic contact stiffness value into the dynamic interference response model and performs iterative numerical solutions based on the time step. The historical extrapolation unit generates the initial iterative value in the iterative numerical solution by extrapolating the historical interference data of the previous time step, and the iterative convergence condition is set to stiffness residual less than preset tolerance. The compensation output unit compares the solved dynamic equivalent interference with the initial interference of the assembly, and compensates for the rotor inner hole expansion effect caused by centrifugal force, and outputs the dynamic equivalent interference compensated by centrifugal force.

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