Load distribution and deformation of tapered roller bearing-spindle system

To improve the modeling accuracy of the tapered roller bearing-spindle system under various operating conditions, this paper proposes a bearing modeling method based on a 5 + 3n-DOF formulation, combined with one-dimensional finite element theory to establish a coupled bearing–spindle model. The model comprehensively accounts for roller profiling, tilting, and the nonlinear contact characteristics between rollers and raceways. By introducing spatial degrees of freedom for each roller, the model enables independent solutions for contact load, contact deformation, and roller angular displacement. Under typical loading conditions, the proposed model and an existing shaft system model were compared with Romax commercial software. The results show the model outperforms existing ones in spindle analysis and matches Romax closely on key contact parameters like load and deformation, with under 8% error, confirming its accuracy and practicality.