A Fault Identification Method of Rear Axle Bearing Under Lateral Dynamic Load of Vehicle

As an important component of automobile, rolling bearing has a great impact on the safety of vehicle and occupants. At present, most of the literatures have studied the damaged bearing on the bench, and there is little research on the bearing failure resulted from the change of the vehicle posture. In this paper, taking the abnormal noise of the rear axle hub bearing induced by the axial load of rear axle in steering condition as an example, a method of fault identification and data analysis for the rolling bearing in the whole vehicle state is presented. First of all, the subjective evaluation of vehicles is carried out and the fault location is analyzed with the transfer path of the abnormal noise. Then, an objective test is designed to collect the vibration acceleration data of the rear axle bearings and the data is analyzed by wavelet packet. The appropriate wavelet base function and the number of decomposition level are selected to decompose the signal into different frequency bands. The frequency band containing the most information of bearing fault is determined by calculating the energy distribution of frequency bands. Envelope analysis for the fault frequency band is used to extract the characteristic frequency of the fault bearing. The correctness of the analysis results is verified by disassembling the hub bearing, and it also shows that this method can be effectively used to judge the fault location and identify the fault type of rolling bearing under the condition of the whole vehicle.