Dynamics Analysis And Simulation Of Vehicle Hub Bearing Assemblies With Double Row Angular Contact Ball Bearings

As a key part of vehicles, the dynamic characteristics of hub bearings are directlyrelated to kinematic performance, comfort, security and reliability of vehicles. Theobject of study in this paper is vehicle hub bearing assemblies with double row angularcontact ball bearings. First, the hub bearing load spectrum is studied and a loadspectrum is made for a certain car. Then the interaction forces between bearingcomponents are analyzed systematically and the dynamic analysis model of doublerow angular contact ball bearings is established on the basis of dynamics analysis ofrolling bearings. The calculation models are built to describe fatigue life, dynamicstiffness and friction torque of hub bearings considering rolling bearing life theory,Hertz contact theory, elastic-hydrodynamic lubrication theory and analysis on causesof friction in rolling bearings. Finally, the virtual prototype of vehicle hub bearingassemblies with double row angular contact ball bearings is created using ADAMS.The user subroutines are compiled by means of FORTRAN, and then, the dynamic linklibrary(*.dll) is generated to link to the ADAMS/Solver module. So, the dynamicsimulation of vehicle hub bearing assemblies with double row angular contact ballbearings is achieved.Taking a vehicle hub bearing assembly with a double row angular contact ballbearing as example, the effects of bearing working conditions and structuralparameters on load distribution, fatigue life, dynamic stiffness, friction torque andvibration characteristics of the bearing are analyzed. The results show that: lateralacceleration plays a decisive role in load distribution of hub bearings; both wheeloffset and axial preload have effects on load distribution and operational performance,and the latter is more important; a proper axial preload contributes to prolongingbearing life, increasing dynamic stiffness and decreasing vibration, while excesspreload will result in increases in friction torque and vibration and a decline in fatigue life; with the increase of groove radius coefficients of curvature, the axial stiffness,angular stiffness and friction torque decrease, while the radial stiffness changesslightly; the increase of ball number can promote dynamic stiffness and reduce frictiontorque and vibration, so, on the premise that the strength of cage is met, the number ofballs should be designed as many as possible; higher rotating speed and bigger axialload both lead to the increase of friction torque.