Receptance coupling of multi-subsystem connected via a wedge mechanism with application in the position-dependent dynamics of ballscrew drives

An accurate model of the feed drive׳s high-order position-dependent dynamics is crucial for the analysis and controller design of a high-performance machine tool. In this paper, a new dynamic substructuring condition-multi-subsystem connected via a wedge mechanism is introduced, which is originated from the ballscrew-nut dynamic coupling interface. Receptance coupling equations were derived for the condition, and a dynamic modeling approach is developed for the ballscrew drive system based on the equations. The developed model accounts for the ballscrew׳s rotational and axial flexibilities and the dynamic couplings among these flexibilities and that of the sliding component. The model explicitly describes the dynamics variation with respect to the table position, and is particularly suitable for sensitivity based analysis. Based on the model, the position-dependent dynamics of an example ballscrew drive was analyzed, by using the frequencies distribution, the modal shape, and especially the sensitivity of the frequency response functions with respect to the table position.