On-line deflection detection method for gear rotating system based on axis track

Abstract

The invention discloses a gear rotating system deflection online detection method based on an axis track, and relates to the technical field of gear rotating system deflection online detection. After the model is corrected through a small number of tests, part of high-cost or high-risk physical tests can be replaced. The method comprises the following steps: step 1, carrying out an eccentric test on a gear rotating system; 2, performing dynamics simulation on the gear rotating system; 3, correcting the dynamic model in the step 2 based on the step 1; 4, the relation between the working condition and the axis trajectory equation is fitted; and 5, operating the gear box, and performing real-time detection. By monitoring and analyzing the shape, direction and other characteristics of the axis track, the running state of the equipment can be effectively identified, and common mechanical faults can be diagnosed; the purpose of replacing high-cost or high-risk real object tests through a small number of test correction models is achieved.

Description

Technical Field

[0001] This invention relates to the field of online detection technology for gear rotation system skew, and in particular to an online detection method for gear rotation system skew based on shaft center trajectory. Background Technology

[0002] In the operation of rotating machinery, skew detection is a critical quality control step that has a decisive impact on the stability and service life of the equipment. For high-speed rotating components, ensuring that their coaxiality meets standards during operation is paramount. To reduce excessive vibration and component damage caused by skew, and to improve operational smoothness, skew monitoring and adjustment strategies are particularly crucial. To improve equipment reliability and reduce maintenance costs and unplanned downtime losses due to skew, it is necessary to study the correlation between axial misalignment of the gear rotation system under different operating conditions, based on the actual operating conditions of the equipment. Summary of the Invention

[0003] To address the above problems, this invention proposes an online detection method for gear rotation system skew based on shaft center trajectory. After a small number of experiments to correct the model, it can replace some of the high-cost or high-risk physical testing.

[0004] The technical solution of this invention is as follows: It is carried out according to the following steps:

[0005] Step 1: Conduct an eccentricity test on the gear rotation system;

[0006] A test system for a rotating device with adjustable offset was built based on a gear rotation system. The shaft center trajectory test was carried out on the rotating device test system under different offsets. After the shaft center trajectory data was purified and processed, the offset orientation and offset amount were obtained, and the shaft center trajectory equation was fitted.

[0007] Step 2: Perform dynamic simulation on the gear rotation system;

[0008] By performing dynamic simulations of gear rotation systems under different axis offsets, the shaft center trajectory data of the gear rotation system is extracted. Through shaft center trajectory data processing, the offset orientation and offset amount are obtained, and the shaft center trajectory equation is fitted.

[0009] Step 3: Modify the dynamic model from Step 2 based on Step 1;

[0010] The offset orientation and offset amount obtained from the experiment in step 1 are fitted to obtain the axis trajectory equation;

[0011] By fitting the offset orientation and offset amount obtained from the dynamic simulation in step 2, another axis trajectory equation is obtained.

[0012] By comparing and analyzing the two axis trajectory equations, the dynamic model in step 2 is corrected.

[0013] Step 4: Fit the relationship between the working conditions and the axis trajectory equation;

[0014] Experimental design based on response surface methodology is used to test the gear rotation system under preset operating conditions, including but not limited to speed and load.

[0015] The modified dynamic model from step 3 was used to replace the actual gear rotation system for a response surface methodology experiment. The shaft center trajectory equations under various working conditions were obtained, and the relationship between the working conditions and the shaft center trajectory equations was fitted.

[0016] Step 5: Run the gearbox and monitor it in real time;

[0017] Based on the relationship fitted in step 4, during the actual operation of the gear rotation system, the values ​​of the displacement detection sensors at both ends of the driven gear shaft are acquired in real time, the shaft center trajectory data is purified, the shaft center trajectory data is processed, and then the shaft center trajectory equation is fitted based on the offset orientation and offset amount. Then, the abnormal situation in the working condition is analyzed by the real-time fitted shaft center trajectory equation.

[0018] Step 1: After conducting shaft center trajectory tests under different offsets in the rotating device test system, the shaft center trajectory data is purified by digital low-pass filtering, wavelet denoising, empirical mode decomposition denoising, improved EMD filtering denoising, composite EMD denoising, or mathematical morphology filter to obtain the offsets of the two ends of the shaft on the x-axis and y-axis.

[0019] Based on the Lagrange equation, dynamic models of the shaft unit, gear meshing unit, and support unit under different axial offsets are established; the shaft unit is the gear shaft of the driving gear and driven gear in the discretized gear rotation system, the gear meshing unit is the simplified driving gear and driven gear, and the support unit is the simplified bearing.

[0020] The rotating shaft element considers translational degrees of freedom in the x and y directions and rotational degrees of freedom about the x and y directions. The displacement vector of the element nodes in the rotating shaft element is:

[0021]

[0022] Based on the finite element method, the dynamic equations of the shaft element, gear meshing element, and support element are further coupled to establish the following set of shaft system dynamic equations with the displacements of each node in the shaft element as generalized coordinates:

[0023]

[0024] In the formula, the rotor includes a shaft unit, a gear meshing unit, and a support unit; M, C, G, and K are the mass, damping, gyroscope, and stiffness matrices of the rotor, respectively; q is the generalized displacement vector of each node in the shaft unit. This refers to the generalized velocity vector of each node in the rotating shaft element; F is the generalized acceleration vector of each node in the rotating shaft element; u (t), F G (t) represent the unbalanced force and the generalized force vector acting on the rotor, respectively;

[0025] The Newmark-β method is used to solve the system of equations for shaft dynamics to obtain the offsets of the driven gear shaft at both ends on the x and y axes. Then, the shaft offset and offset angle are obtained by the same calculation process as in step 1.

[0026] The axis trajectory data in steps 1 and 2 includes the offsets of the two ends of the axis on the x-axis and y-axis. The initial position of the axis center is the z-axis. Steps 1 and 2 are further obtained by following the steps below to obtain the axis offset and offset angle.

[0027] The first offset and the first offset angle at end a of shaft a are processed according to the following formula:

[0028]

[0029]

[0030] Among them, the first offset at the a-end and the first offset angle ,in and These are the offsets of end a on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end a;

[0031] The second offset and the second offset angle at end b of shaft are processed according to the following formula:

[0032]

[0033]

[0034] Among them, the second offset at the b end of the axis Second offset angle ,in and These represent the offsets of end b on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end b;

[0035] The axis offset and offset angle are processed according to the following formula:

[0036]

[0037] Among them, the offset of the axis and offset angle , where L is the distance from the center of end a to the center of end b of the axis.

[0038] By changing the unbalanced force F in step 2 u (t) and the generalized force vector F G (t) is used to make the offset azimuth and offset obtained from the dynamic simulation in step 2 close to the offset azimuth and offset obtained from the experiment in step 1. The new set of dynamic equations is: ;

[0039] In the formula, F u '(t), F G '(t) are the unbalanced force and generalized force vectors acting on the corrected system, respectively.

[0040] This invention first corrects the mathematical model of the shaft center trajectory based on experimental data of the rotating device shaft center trajectory, and then fits the relationship between the working condition and the orientation and offset based on the response surface methodology to realize online detection of gear rotation system skew based on shaft center trajectory. After correcting the model through a small number of experiments, it can replace some high-cost or high-risk physical tests, reduce losses, and facilitate widespread use.

[0041] Compared with existing technologies, this invention corrects the mathematical model using measured shaft center trajectory data, eliminating errors caused by theoretical assumptions and making the model closer to the actual system. This allows the corrected model to more accurately reflect complex dynamic behaviors. Consequently, even under speed or load conditions not covered by experiments, the mathematical model can still predict the shaft center trajectory through parametric analysis (such as variable speed simulation), reducing the cost of repeated experiments.

[0042] In practical use, by monitoring and analyzing the shape, direction and other characteristics of the shaft trajectory, this invention can effectively identify the operating status of the equipment and diagnose common mechanical faults; it can replace high-cost or high-risk physical tests (such as the overspeed test and extreme load conditions designed in step 4) by modifying the model with a small number of tests. Attached Figure Description

[0043] Figure 1 This is a flowchart of the method of the present invention;

[0044] Figure 2 This is a schematic diagram of the eccentric sleeve adjustment;

[0045] Figure 3 This is an axial cross-sectional view of the eccentric sleeve;

[0046] Figure 4 A schematic diagram showing the arrangement of the axis trajectory detection sensors;

[0047] Figure 5 This is a schematic diagram of shaft deflection;

[0048] Figure 6 This is a schematic diagram showing the offset of one end of the shaft. Detailed Implementation

[0049] To clearly illustrate the technical features of this patent, the following detailed description is provided through specific embodiments and in conjunction with the accompanying drawings.

[0050] like Figure 1 As shown, the present invention includes the following steps:

[0051] Step 1: Based on the rotating device test system with adjustable offset, conduct rotating device shaft center trajectory tests under several offsets. After purifying the shaft center trajectory data, process the shaft center trajectory data to obtain the offset orientation and offset amount, and fit the shaft center trajectory equation.

[0052] The rotating device test system includes a gearbox and a driving gear and a driven gear rotatably connected in the gearbox. The gear shaft of the driving gear is connected to a rotational power source. An eccentricity adjustment mechanism is installed on the gear shaft of the driven gear. A displacement detection sensor is installed in the gearbox to detect the offset of the two ends of the driven gear shaft on the x-axis and y-axis.

[0053] The eccentricity of a rotary device test system with adjustable offset can be achieved by, but is not limited to, wearing an eccentric sleeve on the outside of the rotating body (e.g., Figure 2 As shown, 1 is the gearbox, 2 is the outer eccentric sleeve, 3 is the inner eccentric sleeve, 4 is the bearing, 5 is the shaft, and 6 is the driven gear. This is achieved by changing the size of the eccentric sleeve, thereby actively adjusting the offset of the driven gear shaft.

[0054] During the experiment, the displacement detection sensors were arranged as follows: Figure 4 The arrangement involves vertically placing two sensors at each end of the shaft to measure the offset, in order to obtain the axis trajectory data of the driven gear shaft, that is, the offset of the two ends of the gear shaft in the x-axis and y-axis.

[0055] Step 1: After conducting shaft center trajectory tests under different offsets in the rotating device test system, the shaft center trajectory is purified by digital low-pass filtering, wavelet denoising, empirical mode decomposition denoising, improved EMD filtering denoising, composite EMD denoising, or mathematical morphology filter to obtain the offsets of the two ends of the shaft on the x-axis and y-axis.

[0056] The axis trajectory data includes the offsets of both ends of the axis on the x-axis and y-axis, with the initial position of the axis center on the z-axis. A schematic diagram of the axis deflection is shown below. Figure 5 As shown, where and These are the offsets of the axis center on the x-axis and y-axis, respectively. and These represent the shaft center offset and the offset angle, respectively. A schematic diagram of the shaft end offset is shown below. Figure 6 As shown. The first offset and first offset angle at end a of shaft a include:

[0057] According to the formula:

[0058]

[0059]

[0060] Obtain the first offset at end a of axis a and the first offset angle ,in and These are the offsets of end a on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end a;

[0061] The second offset and the second offset angle at end b of shaft include:

[0062] According to the formula:

[0063]

[0064]

[0065] The second offset at end b of the shaft is obtained. Second offset angle ,in and These represent the offsets of end b on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end b;

[0066] Axis offset and offset angle, including:

[0067] According to the formula:

[0068]

[0069] Obtain the axis offset and offset angle , where L is the distance from the center of end a to the center of end b of the axis;

[0070] Step 2: By performing dynamic simulations of the gear rotation system under different axis offsets, extract the axis trajectory data of the gear rotation system. Through axis trajectory data processing, obtain the offset orientation and offset amount, and fit the axis trajectory equation.

[0071] Based on the Lagrange equation, dynamic models of the shaft unit, gear meshing unit, and support unit under different axial offsets are established; the shaft unit is the gear shaft of the driving gear and driven gear in the discretized gear rotation system, the gear meshing unit is the simplified driving gear and driven gear, and the support unit is the simplified bearing.

[0072] The rotating shaft element considers translational degrees of freedom in the x and y directions and rotational degrees of freedom about the x and y directions. The displacement vector of the element nodes in the rotating shaft element is:

[0073]

[0074] Based on the finite element method, the dynamic equations of the shaft element, gear meshing element, and support element are further coupled to establish the following set of shaft system dynamic equations with the displacements of each node in the shaft element as generalized coordinates:

[0075]

[0076] In the formula, the rotor includes a shaft unit, a gear meshing unit, and a support unit; M, C, G, and K are the mass, damping, gyroscope, and stiffness matrices of the rotor, respectively; q is the generalized displacement vector of each node in the shaft unit. This refers to the generalized velocity vector of each node in the rotating shaft element; F is the generalized acceleration vector of each node in the rotating shaft element; u (t), F G (t) represent the unbalanced force and the generalized force vector acting on the rotor, respectively;

[0077] The Newmark-β method is used to solve the system of equations for shaft dynamics to obtain the offsets of the driven gear shaft at both ends on the x and y axes. Then, the shaft offset and offset angle are obtained by the same calculation process as in step 1.

[0078] Step 3: Fit the offset orientation and offset obtained in Step 1 to obtain the axis trajectory equation;

[0079] By fitting the offset orientation and offset amount obtained from the dynamic simulation in step 2, another axis trajectory equation is obtained.

[0080] By comparing and analyzing the two axis trajectory equations, the dynamic model in step 2 is corrected.

[0081] By changing the unbalanced force F in step 2 u (t) and the generalized force vector F G (t) is used to make the offset azimuth and offset obtained from the dynamic simulation in step 2 close to the offset azimuth and offset obtained from the experiment in step 1. The new set of dynamic equations is: ;

[0082] In the formula, F u '(t), F G '(t) are the unbalanced force and generalized force vectors acting on the corrected system, respectively.

[0083] Step 4: Design an experiment based on the response surface methodology so that the gear rotation system is tested under preset working conditions, including but not limited to speed and load;

[0084] The modified dynamic model from step 3 was used to replace the actual gear rotation system for a response surface methodology experiment. The shaft center trajectory equations under various working conditions were obtained, and the relationship between the working conditions and the shaft center trajectory equations was fitted.

[0085] Step 5: Based on the relationship fitted in Step 4, during the actual operation of the gear rotation system, the values ​​of the displacement detection sensors at both ends of the driven gear shaft are acquired in real time, the shaft center trajectory data is purified, the shaft center trajectory data is processed, and then the shaft center trajectory equation is fitted based on the offset orientation and offset amount. Then, the abnormal situation in the working condition is analyzed by the real-time fitted shaft center trajectory equation.

[0086] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A method for online detection of skewness in a gear rotation system based on shaft center trajectory, characterized in that, Follow these steps: Step 1: Conduct an eccentricity test on the gear rotation system; A test system for a rotating device with adjustable offset was built based on a gear rotation system. The shaft center trajectory test was carried out on the rotating device test system under different offsets. After the shaft center trajectory data was purified and processed, the offset orientation and offset amount were obtained, and the shaft center trajectory equation was fitted. Step 2: Perform dynamic simulation on the gear rotation system; By performing dynamic simulations of gear rotation systems under different axis offsets, the shaft center trajectory data of the gear rotation system is extracted. Through shaft center trajectory data processing, the offset orientation and offset amount are obtained, and the shaft center trajectory equation is fitted. Step 3: Modify the dynamic model from Step 2 based on Step 1; The offset orientation and offset amount obtained from the experiment in step 1 are fitted to obtain the axis trajectory equation; By fitting the offset orientation and offset amount obtained from the dynamic simulation in step 2, another axis trajectory equation is obtained. By comparing and analyzing the two axis trajectory equations, the dynamic model in step 2 is corrected. Step 4: Fit the relationship between the working conditions and the axis trajectory equation; Experimental design based on response surface methodology is used to test the gear rotation system under preset operating conditions, including but not limited to speed and load. The modified dynamic model from step 3 was used to replace the actual gear rotation system for a response surface methodology experiment. The shaft center trajectory equations under various working conditions were obtained, and the relationship between the working conditions and the shaft center trajectory equations was fitted. Step 5: Run the gearbox and monitor it in real time; Based on the relationship fitted in step 4, during the actual operation of the gear rotation system, the values ​​of the displacement detection sensors at both ends of the driven gear shaft are acquired in real time, the shaft center trajectory data is purified, the shaft center trajectory data is processed, and then the shaft center trajectory equation is fitted based on the offset orientation and offset amount. Then, the abnormal situation in the working condition is analyzed by the real-time fitted shaft center trajectory equation.

2. The method for online detection of skew in a gear rotation system based on shaft center trajectory according to claim 1, characterized in that, Step 1: After conducting shaft center trajectory tests under different offsets in the rotating device test system, the shaft center trajectory data is purified by digital low-pass filtering, wavelet denoising, empirical mode decomposition denoising, improved EMD filtering denoising, composite EMD denoising, or mathematical morphology filter to obtain the offsets of the two ends of the shaft on the x-axis and y-axis.

3. The method for online detection of skew in a gear rotation system based on shaft center trajectory according to claim 1, characterized in that, Based on the Lagrange equation, dynamic models of the shaft unit, gear meshing unit, and support unit under different axial offsets are established; the shaft unit is the gear shaft of the driving gear and driven gear in the discretized gear rotation system, the gear meshing unit is the simplified driving gear and driven gear, and the support unit is the simplified bearing. The rotating shaft element considers translational degrees of freedom in the x and y directions and rotational degrees of freedom about the x and y directions. The displacement vector of the element nodes in the rotating shaft element is: ； Based on the finite element method, the dynamic equations of the shaft element, gear meshing element, and support element are further coupled to establish the following set of shaft system dynamic equations with the displacements of each node in the shaft element as generalized coordinates: ； In the formula, the rotor includes a shaft unit, a gear meshing unit, and a support unit; M, C, G, and K are the mass, damping, gyroscope, and stiffness matrices of the rotor, respectively; q is the generalized displacement vector of each node in the shaft unit. This refers to the generalized velocity vector of each node in the rotating shaft element; F is the generalized acceleration vector of each node in the rotating shaft element; u (t), F G (t) represent the unbalanced force and the generalized force vector acting on the rotor, respectively; The Newmark-β method is used to solve the system of equations for shaft dynamics to obtain the offsets of the driven gear shaft at both ends on the x and y axes. Then, the shaft offset and offset angle are obtained by the same calculation process as in step 1.

4. The method for online detection of skew in a gear rotation system based on shaft center trajectory according to claim 1 or 2, characterized in that, The axis trajectory data in steps 1 and 2 includes the offsets of the two ends of the axis on the x-axis and y-axis. The initial position of the axis center is the z-axis. Steps 1 and 2 are further obtained by following the steps below to obtain the axis offset and offset angle. The first offset and the first offset angle at end a of shaft a are processed according to the following formula: ； ； Among them, the first offset at the a-end and the first offset angle ,in and These are the offsets of end a on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end a; The second offset and the second offset angle at end b of shaft are processed according to the following formula: ； ； Among them, the second offset at the b end of the axis Second offset angle ,in and These represent the offsets of end b on the x-axis and y-axis, respectively. Let be the equation of the trajectory of the axis center at end b; The axis offset and offset angle are processed according to the following formula: ； Among them, the offset of the axis and offset angle , where L is the distance from the center of end a to the center of end b of the axis.

5. The method for online detection of skew in a gear rotation system based on shaft center trajectory according to claim 4, characterized in that, By changing the unbalanced force F in step 2 u (t) and the generalized force vector F G (t) is used to make the offset azimuth and offset obtained from the dynamic simulation in step 2 close to the offset azimuth and offset obtained from the experiment in step 1. The new set of dynamic equations is: ； In the formula, F u '(t), F G '(t) are the unbalanced force and generalized force vectors acting on the corrected system, respectively.

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