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CN-115204213-B - Gear wear uniformity identification method based on vibration response of gear box body

CN115204213BCN 115204213 BCN115204213 BCN 115204213BCN-115204213-B

Abstract

The invention provides a gear wear uniformity identification method based on vibration response characteristics of a gear box. Analyzing constraint relations among elements of a gear box in an actual running process, determining a description mode of boundary conditions of a system, establishing a rigid-flexible coupling model comprising a gear box body and a gear transmission system, calculating dynamic engagement stiffness of gears with uniform and non-uniform abrasion by adopting a numerical calculation method, constructing a system dynamics calculation model to obtain quantitative evaluation of the degree of influence of different abrasion modes on the engagement stiffness and abrasion quantity of the gears, obtaining gear engagement force and a vibration response rule of the gear box body under uniform and non-uniform abrasion by combining the rigid-flexible coupling model, constructing a simulation test bed to collect vibration signals of the gear box body, extracting characteristics and realizing abrasion uniformity identification. The gear box dynamic model is established by a rigid-flexible coupling method and a numerical calculation comprehensive method, and the gear wear uniformity can be accurately calculated by considering the change of meshing stiffness and wear amount and the mutual influence of the shell and the transmission system.

Inventors

  • ZHANG JINJIE
  • ZHANG QIUSHUANG
  • MAO ZHIWEI
  • WANG YAO

Assignees

  • 北京化工大学

Dates

Publication Date
20260508
Application Date
20220525

Claims (5)

  1. 1. The gear wear uniformity identification method based on the vibration response of the gear box body is characterized by comprising the following steps of: 1) The method comprises the steps of establishing a rigid-flexible coupling multi-body dynamics simulation model of a gearbox transmission system, acquiring characteristic parameters and initial working condition parameters of the transmission gearbox, determining a motion constraint relation among various elements and a description mode of gear/box boundary conditions according to the characteristic parameters and the initial working condition parameters, and establishing the rigid-flexible coupling multi-body dynamics model of the gearbox transmission system according to the constraint relation and the description mode of various boundaries; 2) Calculating dynamic engagement stiffness under uniform and non-uniform abrasion, namely calculating the dynamic engagement stiffness of the uniform and non-uniform abrasion gears by adopting an analytic method to obtain quantitative results of the influence degree of different abrasion modes on the gear engagement stiffness and abrasion loss; 3) The characteristic analysis of gear meshing force/box vibration under uniform and non-uniform conditions comprises the steps of inputting a gear meshing stiffness conversion curve as internal excitation in a step 2) by a gear meshing contact unit on a rigid-flexible dynamic model in the step 1), selecting a vibration measuring point, generally selecting a near point close to excitation of a vibration source as the vibration measuring point, and monitoring meshing force/vibration acceleration signals before and after the internal excitation force is applied to the gear/box interface of a gear box and after the internal excitation force is applied, wherein the vibration measuring point is arranged at the interface above a gear shaft hole of a speed-increasing gear/box, and the measured vibration acceleration signals are all gravity directions; 4) And acquiring actual gear box vibration signals and identifying the wear uniformity of the gears, namely constructing a simulation test bed to acquire the gear box vibration signals and extract the characteristics, and realizing the identification of the wear uniformity of the gears.
  2. 2. The method for identifying the wear uniformity of the gear based on the vibration response of the gear box body according to claim 1 is characterized in that in the step 1), the characteristic parameters comprise geometric structural parameters of a gear box speed-increasing spur gear, a rotating shaft and a machine body and used material characteristics, the geometric structural parameters are obtained from drawing files of the gear box, the rotating shaft and the box body, the material characteristics at least comprise material marks and mechanical properties of the gear box, the rotating shaft and the box body, a three-dimensional gear box model is built according to the geometric parameters of the drawing files, a multi-body dynamics model is built by introducing the three-dimensional model into multi-body dynamics analysis software, all parts are rigid bodies, constraint is built between the parts according to the motion relation between the elements, wherein fixed constraint is formed between the gear box and a matched shaft, rotation constraint is formed between the rotating shaft and the machine body around a z-axis, the machine body and the ground, bearing contact is added between the rotating shaft and the machine body to simulate bearing damping and rigidity effects, and the normal contact force f n between contact members is expressed as follows: Wherein k is a contact stiffness coefficient, c is a damping coefficient; to contact penetration depth; derivative of contact penetration depth; 、 、 The method comprises the steps of respectively obtaining a rigidity index, a damping index and a dent index, adding a contact pair to simulate gear engagement constraint between engaged gears, setting gear engagement rigidity, flexibly processing a target gear, a transmission shaft and a gear box body, keeping rigid components of the other components, dividing the analyzed key components into grids through finite element software, using a four-node tetrahedron unit structure grid to create a mass unit at the center of a rotating shaft hole of a machine body, using a central node as a main node, using a point on the hole surface as a slave node, creating rigid connection, introducing a flexible bearing bush containing model node, material and unit type information into multi-body dynamics software to replace an original rigid element, realizing rigid-flexible coupling, completing rigid-flexible coupling model establishment, wherein a model driving form is torque around the axial direction of a driving shaft, and a load form is torsion damping around a power output gear.
  3. 3. The method for identifying the uniformity of gear wear based on the vibration response of the gear housing according to claim 1, wherein in the step 2), the calculation formula of the gear engagement stiffness k t considering the uniformity of wear is expressed as: ; In the above formula, k h is the contact stiffness of the driving wheel, k b1 is the bending stiffness of the gear teeth of the driving wheel, k s1 is the shearing stiffness of the gear teeth of the driving wheel, k a1 is the axial compression stiffness of the driving wheel, k f1 is the elastic stiffness of the matrix of the driving wheel, k b2 is the bending stiffness of the gear teeth of the driven wheel, k s2 is the shearing stiffness of the gear teeth of the driven wheel, k a2 is the axial compression stiffness of the driven wheel, and k f2 is the elastic stiffness of the matrix of the driven wheel; Wherein, the calculation formula of k h is expressed as: wherein E is elastic modulus, v is Poisson's ratio, L is tooth width; the calculation formula of k b 、k s 、k a is expressed as: ; ; in the formula, N is the number of teeth, h w is the abrasion loss of the meshing point A on the abrasion tooth profile of the gear tooth at the coordinate x, R b is the base circle radius of the gear tooth, alpha 0 is the pressure angle at the perfect tooth profile, alpha is the pressure angle at the meshing point A, and alpha 2 is half of the angle occupied by the base circle on a single gear of the driving wheel: α 1 is the perfect tooth profile meshing point angle, α 3 meshing point a angle: ; the calculation formula of k f is expressed as: ; In the above formula, u f represents the distance between the intersection point of the meshing line and the symmetry line of the gear teeth and the base circle, S f represents the arc length of the single tooth profile, L * 、M * 、P * 、Q * represents four parameters related to the number of gears and the modulus, the rigidity of the driven wheel is completely consistent with the driving wheel, and the values of L, M, P and Q can be obtained by polynomial fitting: a i 、B i 、C i 、D i 、E i 、F i is a coefficient, h fi ＝R r /R int ,R r represents the radius of a root circle, R int represents the aperture of a gear shaft, and theta f represents the angle occupied by a single tooth profile; And calculating the dynamic engagement stiffness of the gears with uniform and non-uniform abrasion, so as to obtain quantitative result curves of the influence degree of different abrasion modes on the gear engagement stiffness and the abrasion loss.
  4. 4. The method for identifying the uniformity of gear wear based on the vibration response of a gear housing according to claim 1, wherein in said step 3), the dynamic equation of the gear train model is expressed as: In the above-mentioned steps, ; ; ; ; ; ; ; ; The above formula is further deduced and rewritten as: Wherein, the , Is that Finally, the method can be as follows: ; In the above-mentioned steps, ; ; ; Is a bit linear differential equation, the right end of which can be divided into two parts, one part is composed of gear rigidity excitation and error excitation The other part is composed of gear engagement impact excitation force ; The gear meshing contact unit on the rigid-flexible dynamic model in the step 1) inputs the gear meshing stiffness transformation curve calculated in the step 2) as internal excitation, the gear box body is selected to be close to an excitation source and used as a measuring point, meshing force and vibration acceleration signals of the same measuring point under uniform and non-uniform abrasion are collected, and then a sample is subjected to Fourier transformation uniformly to obtain a frequency domain signal characteristic value, so that the gear dynamic meshing force/box vibration acceleration signal characteristic value of the gear box under uniform and non-uniform abrasion is quantized.
  5. 5. The method for identifying the uniformity of the gear wear based on the vibration response of the gear housing according to claim 1, wherein in the step 4), a gear housing wear simulation fault test bed is built, an actual gear housing vibration signal is acquired through a vibration acceleration sensor, the acquired signal is subjected to Fourier transformation to acquire a frequency domain signal, the frequency domain signal is compared with the characteristic value of the gear housing vibration signal under the condition of simulation uniform and nonuniform wear in the step 3), and if the frequency domain component of the actual signal is consistent with the frequency domain component of the gear housing vibration signal under the condition of uniform wear, the gear wear is considered to be in a uniform state at the moment, otherwise, the gear wear is considered to be nonuniform.

Description

Gear wear uniformity identification method based on vibration response of gear box body Technical Field The invention belongs to the technical field of fault diagnosis of mechanical transmission systems, and particularly relates to a method for distinguishing wear uniformity of gears in a dynamic transmission process of a mechanical system by internal excitation. Background Gearboxes are the most important power transmission system for engines and are the key subject of mechanical dynamics research. Failure types of multi-stage gear transmission systems include tooth breakage, plastic deformation, tooth surface contact fatigue wear, etc., wherein the highest proportion (more than 60%) of tooth surface contact fatigue wear faults is caused, and tooth breakage is caused when the wear is serious. The fault of the key component is necessarily related to other mechanisms, if the fault is not prevented and eliminated in time, the probability of potential risk is greatly increased, and even the whole unit is crashed, so that a malignant accident is caused. Therefore, how to effectively catch the response change caused by the dynamic abrasion of the gears has important significance for guaranteeing the long-term safe operation of the unit. Currently, there are relatively few studies of the dynamic response of gear systems to continuous wear progression, and no consideration is given to the changes in gear dynamics caused by uniform, non-uniform gear wear position changes. Therefore, aiming at the current situation that the dynamic response rule of the gear system is not clear due to tooth surface abrasion, based on a rigid-flexible coupling model, the influence study of the meshing stiffness and accumulated abrasion quantity of the gear tooth surface under different abrasion modes on the dynamic response of the system is carried out by combining numerical calculation and finite element analysis, and the meshing stiffness change rule and dynamic characteristic change trend of the gear under different abrasion fault states are obtained. Disclosure of Invention The invention aims to provide an effective wear uniformity identification method for analyzing early wear fault diagnosis, extracts envelope characteristic frequency domain characteristics based on a box vibration acceleration signal, can quantitatively and accurately evaluate vibration response and wear uniformity of endogenous excitation in a gear system, can analyze and research a fault mechanism, and has important significance for tracing faults of a mechanical system. The method comprises the following steps of firstly analyzing constraint relations among elements of a gear box in an actual running process, determining a description mode of boundary conditions of a system, establishing a rigid-flexible coupling model comprising a gear box body and a gear transmission system, then calculating dynamic engagement stiffness of gears which are uniformly and unevenly worn by a numerical calculation method, constructing a system dynamics calculation model, obtaining quantitative evaluation of influence degree of different wear modes on the gear engagement stiffness and wear amount, obtaining gear engagement force and a vibration response rule of the gear box body under uniform and non-uniform wear by combining the rigid-flexible coupling model, and finally constructing a simulation test bed to collect vibration signals of the gear box body and extract characteristics to realize identification of wear uniformity of the gear box. The gear wear uniformity identification method based on the vibration response of the gear box body is characterized by comprising the following steps of: 1) The method comprises the steps of establishing a rigid-flexible coupling multi-body dynamics simulation model of a gearbox transmission system, obtaining characteristic parameters and initial working condition parameters of the transmission gearbox, determining motion constraint relations among elements and description modes of gear/box boundary conditions according to the characteristic parameters and the initial working condition parameters, and establishing the rigid-flexible coupling multi-body dynamics model of the gearbox transmission system according to the constraint relations and the description modes of the boundaries. 2) Calculating dynamic engagement stiffness under uniform and non-uniform abrasion, namely calculating the dynamic engagement stiffness of the uniform and non-uniform abrasion gears by adopting an analytic method to obtain quantitative results of the influence degree of different abrasion modes on the gear engagement stiffness and abrasion loss; 3) The characteristic analysis of gear meshing force/box vibration under uniform and non-uniform conditions comprises the steps of inputting a gear meshing stiffness conversion curve as internal excitation in a step 2) by a gear meshing contact unit on a rigid-flexible dynamic model in the step 1), selecting a vibratio