Stability analysis of a disk-spindle system supported by coupled journal and thrust bearings considering five degrees of freedom

This paper investigates the stability of a disk-spindle system supported by coupled journal and thrust bearings considering the five degrees of freedom of a rotor-bearing system. The Reynolds equations and their perturbed equations of the coupled bearings were solved by FEM to calculate the stiffness and damping coefficients. The critical mass of the rotor-bearing system was determined by solving the linear equations of motion. As a result, the tilting motion was a major design consideration to determine the stability of the rotor-bearing system. Additionally, the stability without the tilting motion was overestimated, as compared to that with the tilting motion.