Abstract

In recent years, large numbers of patents have been devoted to evaluating the dynamic characteristics of coupled double-rotor spindle system of high speed grinder for significant improvement in both the removal rate and quality of grinding. This study was focused on the theoretical modeling and numerical simulation about the dynamic characteristics of coupled double-rotor spindle system of high speed grinder. The influences of the grinder spindle’s major structural parameters on its critical speed and vibration mode were investigated. The results showed that the critical speeds of coupled double-rotor system were arranged in a similar increasing order as to those of each single rotor. It was thus indicated that the critical speeds of each order for coupled double-rotor system corresponded to those of single rotor. Furthermore, we analyzed the effect of preload of bearing, overhang length, span of bearing, rotor structure and mass of spindle system on critical speeds of various orders for the coupled spindle system. The results showed that increased bearing rigidity could increase critical speeds of each order and the effect of overhang length of coupled rotors was the superimposition of effect of single rotor on critical speeds of each order of the coupled double order system. The critical speeds of spindle system of coupled double-rotor system could be decreased by increasing the mass of its spindle system.

Keywords: Critical speed, double-rotor spindle system, dynamic and static rigidities, high speed grinder, structural parameters, vibration mode, mathematical model, transfer matrix, dynamic characteristics.