Effect of Dynamic Misalignment on the Stiffness Characteristics of a Double-Row Self-Aligning Rolling-Element Bearing

Rolling element bearings are the key component of every rotating machinery and are prone to various type of imperfections e.g. localized spalls, waviness, misalignment etc. Different rolling element bearings, such as deep-groove ball bearings, tapered bearings, needle bearings etc. are used in industry for specific applications. Spherical rolling-element bearings being one such category, are used to counter dynamic misalignment between two shafts. During misalignment, the stiffness characteristics of the bearing also change and thus characterize the system’s internal dynamics. In this study, a mathematical model is presented for a double-row self-aligning rolling-element bearing to analyze its nonlinear contact stiffness characteristics. A stiffness matrix of order three is constructed and the coefficients are evaluated for variation with respect to change in radial-load, axial-load and misalignment angle. Also, the time-varying stiffness coefficients are presented. The results show the variation of bearing’s contact stiffness with change in radial load and shaft speed. The time variations of contact stiffness have also been presented.