Analysis Of Vibration And Sound Characteristics Of Axle Box Bearing Fault Of High-speed Train

High speed train is an important tool for social development and has made great contributions to people’s safe travel and high-speed logistics.Axle box bearing is a key component of rail vehicle,and its working conditions are very poor.Axle box bearing bears and transmits load,and its failure will seriously threaten the safety of passengers and goods.At this stage,there are many researches on bearings,but there are few researches on the vibration and sound characteristics of axle box bearings considering the service environment of axle box bearings,and there are few noise signal diagnosis methods and tests for faulty bearings.Considering the service environment of axle box bearing,this paper analyzes the vibration and noise characteristics of axle box bearing fault and diagnoses the noise signal of axle box bearing fault.The main research work is as follows:(1)Aiming at the problem that it is difficult to identify the fault of axle box bearing under track service conditions,taking the fault axle box bearing of rail vehicle as the research object,based on the research on the dynamic model of rolling bearing by domestic and foreign scholars,the fault shape of axle box bearing and the actual operation state of axle box bearing are simulated,and the factors such as contact relationship of bearing service environment,load and external exciting force are considered,The dynamic model of axle box bearing rotor bearing system considering excitation force is established.The fault impact is established by considering the force relationship of contact area with irregular model.Combined with the dynamic model of rotor bearing system,the irregular fault model of axle box bearing rotor bearing is proposed.(2)According to the established irregular fault model of axle box bearing rotor bearing,the effects of speed,load and excitation on the vibration characteristics of bearing are analyzed.Different speed,load and excitation conditions are set,and the influence of speed on the displacement characteristics,vibration phase diagram characteristics,time domain characteristics and frequency domain characteristics of each component is analyzed.Speed,load and excitation have a great influence on the dynamic characteristics of axle box bearing.(3)Based on the established irregular fault model of axle box bearing rotor bearing,considering the conversion relationship between vibration and noise and the radiation of bearing noise,the fault noise model of axle box bearing is established by using the multi sound source method,the acoustic fault characteristics under different faults are analyzed,and the influence of speed and load on the acoustic characteristics of axle box bearing is analyzed,Under different working conditions,the acoustic parameters of the bearing change regularly.(4)According to the service environment of axle box bearing,the axle box bearing test-bed is improved,different faults are set,axle box bearing fault tests under different working conditions are carried out,and the axle box bearing noise acquisition device suitable for acoustic signal acquisition environment is developed;Finally,the fault feature extraction method of spectrum whitening energy operator is improved,and the demodulation and diagnosis method of spectrum whitening energy operator filtered by de mean band Burg autoregressive model is proposed.The bench test data is verified,which can accurately identify the faults of outer ring,inner ring and roller.This method is used to verify the effectiveness of the model and conclusion of bearing acoustic characteristics.