Dynamic Analysis Of Faulty Bearing Of Harmony Electric Locomotive

Axle box bearings are crucial components of electric locomotives that operate in complex and harsh working conditions.If these bearings fail,it can have serious safety implications and potentially lead to traffic accidents.Currently,research on roller bearings primarily focuses on fault detection,while understanding the mechanism of bearing faults and the motion law of internal parts is insufficient.This study aims to investigate the influence of different damage positions of the inner ring raceway on bearing internal dynamic behavior.The main research contents of this study include:Mechanical analysis of bearings based on Hertz contact theory and elastic fluid dynamic lubrication theory to obtain the contact load between rollers and raceway by "slicing method." The dynamics model of double row tapered roller bearings is established by ADAMS and ABAQUS.The error analysis method is used to validate the model by comparing theoretical and simulation values of component speed and simulation results of the fault characteristic frequency.The rigid-flexible coupling analysis method is used to study the dynamic characteristics of defect-free bearings during operation.The displacements of the whole defective bearing,cage,and roller are analyzed first.Then,the speed and force of the defect-free bearing are analyzed.By comparing the speed of adjacent rollers,the overall motion of the bearing is analyzed,and the force of each part of the bearing is analyzed,providing a theoretical basis for subsequent experimentation and bearing improvement.Finally,the working stability of the bearing is analyzed,checking the stiffness,strength,and stability,and simulating the vibration mode and vibration frequency of the bearing system.Through the analysis,the resonant speed of the bearing system is obtained,and the dangerous working speed is identified,providing an effective basis for bearing fault research and analysis.Building on the research on the rigid-flexible coupling vibration characteristics of the defection-free bearing,the dynamic load is extracted according to the dynamic characteristics of the bearing.Then,the displacement and stress analysis of the faulty bearing in the inner ring is carried out by ADAMS and ABAQUS co-simulation method.The dynamic response analysis of the faulty bearing is carried out under multiple working conditions,including different position fault,different degree of fault,and different working speed conditions.The dynamic response analysis of key bearing components investigates the deformation and raceway contact force of several measuring points,including the outer ring,the inner ring,and the cage.The response of the center of mass fluctuation of the cage and the rolling body under normal and fault operation is also studied.Based on the research results,it is concluded that with the increasing degree of inner ring stripping fault,the unstable state of each bearing component gradually shifts from the inner and outer rings to the cage.It is important to note that while the current study focuses on the internal raceway stripping fault,common faults of bearings include outer ring faults and rolling body faults,and there are various types of faults such as spalling,adhesion,indentation,and wear that exhibit different fault characteristic frequencies and dynamic response characteristics under different working conditions.Therefore,future research should conduct simulations and experiments from multiple perspectives and conduct comprehensive and diversified comparative analyses.In terms of modeling design,considering the balance between computational accuracy and cost,the model aims to minimize the number of grids,especially due to the size relationship of the bearings.However,even with a reduced grid number,the model still requires high computer hardware requirements,and the computational cost is relatively high.Therefore,this study only analyzes roller bearings with a single inner ring defect to ensure research feasibility.