Dynamic analysis of the column-spindle system considering the nonlinear characteristics of kinematic joints

Abstract

The nonlinear characteristics of kinematic joints for the column-spindle system have a significant influence on machining accuracy. This paper proposes a comprehensive dynamic model of the column-spindle system considering the nonlinear characteristics of kinematic joints. First, the nonlinear restoring forces of kinematic joints are derived as the functions of the corresponding vibration displacements. The lumped mass method is applied to model the ball screw feed system with nine DOFs including the spindle head, and the spindle system is modeled applying finite element method. Then, the two developed models are coupled with each other through the contact forces and moments of spindle bearings to construct an integral dynamic model. Additionally, the proposed dynamic model is verified by static loading tests, modal hammering tests and vibration response experiments. Finally, the effects of the spindle bearing preload, the pre-deformation and number of effective loaded rollers in each row of raceways, and the installation parameters of ball screw feed system on dynamics are analyzed. The potential value of this research is to guide the optimization of column-spindle system at the design stage.