An analytical model to predict vibrations of a cylindrical roller bearing with a localized surface defect

The main failure mode of cylindrical roller bearings (CROBs) is localized surface defects (LSDs) such as spalls and pits on the surface of its races or rollers. However, it is difficult to describe the time-varying deflection excitation (TVDE) generated by a LSD and time-varying contact stiffness excitation due to the changes in contact conditions between the roller and defect by using the previous defect models. In this paper, a new dynamic analysis method is proposed to formulate a LSD more accurately for a CROB dynamic modeling. A two-degree of freedom dynamic model for a CROB with a LSD on its races is proposed, which considers both the TVDE and time-varying contact stiffness coefficient produced by the defect. The load-deflection relationship between the roller and race is considered as non-Hertzian one, which can be used to determine the load-deflection relationship between the logarithmic-profile roller and races of the CROB. The numerical results are compared with the available results from the previous defect models in the literature. Effects of the radial load, defect sizes and types on the contact deformation and contact force between the roller and race are investigated, as well as the vibrations characteristics of the CROB. The results show that the proposed method can describe more accurately a real excitation produced by a LSD located at anywhere in the contact zone between the roller and race, which cannot be captured by the previous model in the literature.