Design of Machine Tool Spindles Based on Transient Analysis

Abstract

This investigation is concerned with the design of machine tool spindles based on transient analysis. The dynamic equation of motion of a lathe spindle has been obtained using finite element analysis along with modal analysis. These equations are solved to obtain the displacement distribution along the spindle-workpiece system and thus the maximum dynamic displacement response. The system design parameters should be chosen in such a way that a combination of these would minimize the maximum dynamic displacement response. The global system matrices are replaced by condensed matrices of lower order, which preserve the lower modes with reasonable accuracy. This is done to economize on the computer memory storage and computation time. The system design parameters used are: (a ) bearing spacing, (b ) bearing stiffness, (c ) location of an external damper, and (d ) the workpiece diameter. The optimum design variables are selected based on single-parameter variation. The objective of this investigation is the minimization of the maximum dynamic response by a suitable choice of design variables.