Fatigue life and reliability analysis of support bearings in double rotary tables

The YRT bearing, as a key component of double rotary tables, is essential to maintaining the precision and stability of the equipment, with its fatigue life and reliability serving as critical determinants of overall performance. In this study, a five-degree-of-freedom (5-DOF) model for YRT bearings is established. Sparrow search algorithm (SSA) is employed to obtain the global optimum of the nonlinear equation system. The Newton-Raphson method is subsequently applied for local refinement, effectively reducing sensitivity to the choice of initial values. The effectiveness of the proposed model is demonstrated through a comparison of its load distribution results with simulation outcomes from the Romax and Harris models. To further analyze the fatigue life of the bearings, an adaptive Kriging method combined with Monte Carlo simulation is employed. Based on the Lundberg–Palmgren (L–P) fatigue life theory, a reliability model for the fatigue life of YRT bearings is established. Finally, the effects of bearing clearance on contact characteristics and fatigue life are examined, along with a corresponding reliability analysis. The proposed analytical model provides theoretical guidance for the optimal design of YRT bearings and helps improve their fatigue life and overall reliability.