Modelling and characteristic investigation of spindle-holder assembly under clamping and centrifugal forces

Spindle-holder interface is the weakest part of the spindle system, and to some extent, determines the dynamics of spindle systems and strongly affects the cutting process stability. In order to improve the spindle system during the design stage and predict the tool point dynamics, this paper proposes modelling of spindle-holder assembly and presents an investigation on the contact characteristic under clamping and centrifugal forces. Modal test results show a good agreement with the simulated results. After that, contact pressure distribution under different clamping and centrifugal forces are investigated, which indicates a decrease of natural frequency of spindle-holder assembly caused by rotational speed. In the last, an improvement of holder dimensions based on the deformations of spindle and holder is presented, and the results show a significantly improved performance of spindle-holder assembly under the rotating condition.