Dynamical analysis for the motorised spindles of machine tools

The spindle dynamics directly affect the cutting forces, and typically the topography of machined surface of workpieces. In this study, the dynamical behaviours of spindle system are considered in details for accuracy monitoring of CNC machines. Firstly, the rotational model has been established for the spindle with the servo motor. Secondly, the phase portraits of the dynamical models are provided by vector field analysis, depicting rotational behaviours for the spindle operations. In addition, the bifurcation analysis shows that the machining process can be dynamically stable and unstable by changing control parameters. Spindle rotational behaviours are described by the cutting forces which have significant influence on overall machining performance. Finally, it is noted that stability analysis of spindle speed is essential to characterise tool behaviours and machining accuracy while avoiding chattering. Copyright © 2020 Inderscience Enterprises Ltd.