Effect of boundary position and defect shape on the mechanical properties of ball bearings

Abstract

This paper presents a mechanical model of angular contact ball bearing with local and extended defects in the outer raceway and the analytical formulations of varying stiffness under combined loads are obtained. The effects of radial load and clearance on variable stiffness of the bearing at the boundary positions are analyzed. Results show that the load distribution is not necessarily continuous and the maximum and minimum stiffness of the angular contact ball bearing can be located at either of the two boundary positions or even at non-boundary position under the effect of the contact angle. Meanwhile, the effects of defect depth and loads on the mechanical properties and varying stiffness of the bearing under localized and extended defects are studied, respectively, and the mechanism of “limit depth” and “critical load” is analyzed. These results are useful for quantitative fault diagnosis and reliability analysis of rotor-bearing systems.