Acoustic Characteristics Analysis of Rail Transit Vehicle Bogie Axle Box Bearing Faults

Abstract

Objective To address the challenge of difficult fault identification in rail transit vehicle bogie axle box bearings under rail service conditions, it is necessary to investigate the acoustic characteristics of these faults. Method Focusing on the faulty axle box bearings of rail transit vehicle bogies as research object, by adding external loads and excitations and introducing irregular faults, a dynamics model of the axle box bearing system is established in conjunction with the rotor-bearing system. Based on the pulsating point sound source radiation method, numerical simulation software is used to construct an irregular fault sound signal model for the inner and outer rings of the bearings. The fault characteristics of inner and outer rings of axle box bearings under rail service conditions, the impact of load and rotational speed on the fault characteristics parameters of bearing sound signals are explored. Experiments are conducted on an axle box bearing test bench under different working conditions to capture the acoustic sound signals of faulty bearings, and the results are analyzed. Result & Conclusion The sound signals of both faulty and normal bearings of inner and outer rings exhibit corresponding characteristic frequencies and harmonics. However, there are modulation frequencies of the rotational frequencies near the harmonics of the inner ring fault bearing sound signals. As the rotational speed increases, the characteristic parameters of both inner and outer ring faulty and normal bearings exhibit a distinctive and obvious positive correlation trend. Specifically, the time-domain waveform indicators decrease with increasing rotational speed, while the amplitude of the characteristic frequencies increases linearly with rotational speed. As the load increases, the characteristic parameters of both inner and outer ring faulty and normal bearings also all show a distinctive and obvious positive correlation, among which the time-domain variance indicators increase with higher loads, and the amplitude of the characteristic frequencies increases linearly as load increases.

Keywords

• rail transit
• vehicle
• bogie
• axle box bearing fault
• acoustic characteristics