Dynamic design and analysis on helical milling spindle unit using modified whole transfer matrix method

This paper first designs a novel helical milling spindle unit based on the helical milling processing principle. The spindle unit can be used to machine holes on the titanium alloy material in the assembly of the aero-plane with good surface finish. The typical characteristics of the spindle unit are three-rotor, double-eccentricity and rotation with revolution like as a planetary gear phenomenon. The dynamic model of the helical milling spindle unit based on the modified whole transfer matrix method is established. Then the natural frequencies (critical speeds) of the spindle unit are systematically studied by the whole transfer matrix and the finite element methods, and the dynamics analysis based on the sensitivity of the structure parameters is conducted to identify main factors influencing the natural frequencies and the frequency responses using the whole transfer matrix method. The results indicate that the bearing span, the bearing stiffness and the total length of unit are sensitive to the dynamic behaviors. © Copyright 2016 American Scientific Publishers All rights reserved.