A novel dynamic modeling method of defective four-row roller bearings considering the spatial contact correlation between the roller and defect zone

Dynamic modeling is an effective method of researching dynamic characteristics of the four-row roller bearing (FRRB) containing localized defects. A novel dynamic modeling method considering the spatial contact correlation between the roller and defect zone is proposed to investigate the dynamic changes of contact force, displacement as well as vibration response as the roller passes through the defect zone. The interaction form is classified based on the spatial dimension correlation between the roller and defect zone. Contact force, displacement and vibration response are compared according to the variation of defect size. The analysis results indicate that the dynamic responses of defective FRRB are closely related to the defect zone width and depth on the axial segment and the length of the radial section. Magnitude and time interval of the multi-impulse are related to the roll's radial load and the rotational speed. The simulated outcomes closely match the results of the experiment.