Parameter sensitivity analysis of axial vibration for lead-screw feed drives with time-varying framework

This paper establishes a dynamic model of lead-screw feed drives by means of the finite element and lumped-parameter and analyzes the effects of changeable table position and workpiece mass on the first three axial modes of the free vibration. The results indicate that the natural frequency of the first mode focusing on table vibration is sensitive to both changeable table position and workpiece mass to a certain extent; the natural frequency of the second mode focusing on rotor vibration is unsensible to changeable table position and workpiece mass; the natural frequency of the third mode focusing on screw vibration is sensitive to the table position whereas unsensible to the workpiece mass. In the second stage of research, the results display that the enhancement of the axial stiffness of the back screw bearing can effectively reduce the sensitivity of the first nature frequency on the changeable table position.