典型数控龙门镗铣床主轴系统抗振性能优化

Optimization of the dynamic behavior of a spindle system for a CNC gantry-type boring and milling machine

为提高主轴系统的抗振性能,以一台典型的主轴升降式数控龙门镗铣床主轴系统为例,研究了轴承和弹性联轴节两种结合面的有限元建模方法,仿真分析了主轴系统的模态和谐响应动力学特性,通过模态实验验证了动力学仿真分析的有效性,提出了提高主轴系统抗振性能的优化设计方案。研究表明:建立合理的结合面模型是提高仿真精度的关键之一,所研究的主轴系统的主要振型是扭转振动,主轴轴承刚度对各阶固有频率和扭转振幅影响很小,通过优化弹性联轴节刚度和套筒长度可以有效提高主轴系统的抗振性能。研究成果对全面了解并优化主轴系统动态性能具有指导意义。

Finite element models were used to investigate two kinds of joints to reduce vibrations in the spindle system of a CNC（computer numerical control） gantry-type boring and milling machine.The joints were a spindle bearing and an elastic shaft coupling in the spindle system.The dynamic behavior,such as the modal and harmonic responses of the spindle system,were analyzed.The validity of the simulations was verified by modal experiments.Two kinds of optimization solution are presented to improve the anti-vibration performance.Reasonable joint modeling was shown to be a key factor in improving the simulation accuracy with torsional vibration as the main mode shape of the spindle system.The spindle bearing stiffness has little influence on the natural frequency and torsional vibration amplitude.Optimization of the torsional stiffness of the elastic shaft coupling and the coupling sleeve length effectively improved the cutting stability.The results provide a better understanding for optimizing the dynamic behavior of spindle systems.