Finite Element Analysis and Multi-parameter Optimization of the BMT Driving ASS'Y in CNC Lathe

Abstract

BMT turret is one of the indispensable parts in CNC lathe turning center. The driving ASS’Y assembled in BMT turret transfers driving force generated by motor to the rotary tools mounted on BMT turret. A good driving ASS’Y can provide faster tool positioning and improve productivity by reducing tool changeover time. With this in mind, it is essential to design the BMT turret including its driving ASS’Y to meet the ever-increasing demand of precision machine tools. The wide application of driving ASS'Y in BMT turret is limited due to its high vibration and generated noise. In this study, a simulation-based multi-objective design optimization methodology is implemented to improve the efficiency of BMT driving ASS’Y. First, a three-dimension finite element model of driving ASS'Y and solution methods are determined. Then the static characteristics, dynamic characteristics and fatigue behaviors of the driving ASS'Y are analyzed. Dynamic characteristics, which depend on the stiffness, mass, damping and boundary conditions of driving ASS'Y, are consisted of the natural frequencies and modal shapes of driving ASS'Y. By modulating these frequencies, resonance at high rotational speed can be avoided, thus the vibration level of driving ASS'Y can be reduced. Moreover, optimum design through analysis-evaluation-modification cycles has been performed. The purpose of this study is to study and predict the behaviors of driving ASS'Y under actual working conditions and the aim of this study is to determine the optimal geometrical parameters of driving ASS'Y with higher efficiency and stability.