Vibration Characteristics Of Hub Bearings With Outer Ring Raceway Indentation

As a key component of automobile,the performance of hub bearing directly affects the overall movement performance,comfort performance and safety performance of the automobile.Defects in hub bearings may cause vehicle vibration,abnormal sound and other phenomena,and even lead to safety accidents,which may affect the normal operation of automobiles.Therefore,it is of great engineering significance to study the vibration characteristics of hub bearings with raceway defects.In order to study the excitation and vibration response mechanism of the hub bearing caused by the defect of the raceway,the relationship between vibration characteristics and defects of hub bearing is analyzed.In this paper,the nonlinear dynamic model of hub bearing is established,and the vibration characteristics of the hub bearing are studied through simulation.A feature extraction method based on optimal resonance component is proposed,and a frequency-weighted energy operator was introduced to process vibration signals.The characteristic extraction of the vibration simulation signal and the vibration test signal of the defective wheel bearing is carried out respectively,and the vibration characteristics of the outer ring raceway defect bearing are studied.The main contributions are as follows:(1)Aiming at the structural characteristics of the third generation hub bearing and taking into account the factors such as bearing rotation speed,the number and distribution of the raceway defects,relative sliding and preloading between components,a non-linear dynamic model of out ring raceway defective hub bearings is established applied by Hertz contact theory and elastohydrodynamic lubrication theory.(2)Using MATLAB software to simulate the vibration signal of the hub bearing based on the established nonlinear dynamic model of the hub bearing,and study the effect of different working conditions on the vibration response of the hub bearing.The results show that the increase of the rotational speed will increase the characteristic frequency of the indentation.The number of defects,depth of indentations,load parameters and other factors do not affect the numerical change of characteristic frequency,but have an impact on kurtosis value and root mean square value.Comparing the simulation results with the theoretical calculations,the validity of the nonlinear dynamic model built in this paper is preliminarily verified.(3)Considering the complexity of the vibration signal of the hub bearing,it is difficult to extract the characteristics of the weak vibration signal caused by the defect in the background of the strong noise of the hub bearing test.A feature extraction method based on the optimal resonance component is proposed.The genetic algorithm is applied to the quality factor in the optimal resonance sparse decomposition,and the frequency weighted energy operator is introduced to process the optimal component of the vibration signal to highlight the impact characteristics of the signal.By processing the rolling bearing simulation signal,the rolling bearing test signal and the wheel bearing simulation signal given in the classic literature,it is verified that the new method can be effectively applied to the vibration signal feature extraction caused by defects.(4)On the hub bearing vibration test system,the vibration characteristics of the hub bearing were tested and the indentations of spindle speed and indentation depth on vibration characteristics are studied.The results show that the faster the spindles speed is,the greater the characteristic frequency of hub bearing is,the larger the RMS of the signal will be,and the kurtosis value will decrease.The depth of the indentation does not affect the variation of the characteristic frequency,but it affects the RMS and kurtosis of the signal.The validity of the proposed nonlinear dynamic model and feature extraction method of hub bearing are verified by comparing the actual measured data with the simulation data.The research results of the vibration characteristics of automobile hub bearings can be used for defect analysis of hub bearing vibration test and data analysis.