气体静压高速电主轴稳定性研究

Study on the stability of high-speed aerostatic motorized spindle

空气静压电主轴是高速精密数控加工机床的关键部件之一,其稳定性是影响高速数控机床的加工质量和切削性能的重要因素。主要研究空气静压电主轴的气锤振动与涡动失稳的机理和判定方法:以电主轴的静压止推轴承为例,推导了止推轴承产生气锤振动的判别式,利用软件仿真分析了止推轴承的节流孔直径、气腔半径、供气压力三个结构参数对气锤振动的影响规律;分析了涡动失衡的原理,从数值分析的角度,研究了涡动比与偏心率的关系,阻尼系数与涡动速度,阻尼系数与主轴的轴颈转速的关系,并提出了防止气锤振动和涡动失衡的有效措施。

Aerostatic motorized spindle is one of the key components of high - speed precision CNC machine tool, and its stability is an important factor that affects the processing quality and cutting performance of high - speed CNC machine tool. This paper mainly studies the mechanism and judgment method of hammer vibration and eddy unbalance of aerostatic motor- ized spindle. Taking the spindle of the thrust bearing as an example, the discriminant of hammer vibration produced by thrust bearing is derived;the influences of orifice diameter, gas cavity radius and gas pressure of the thrust bearing on the hammer vibration are simulated. From the view of numerical analysis, the relationship between the whirl ratio and eccentrici- ty, the damping coefficient and the eddy velocity, the damping coefficient and the shaft neck speed of the spindle are studied. And the effective measures to prevent air hammer vibration and eddy imbalance are put forward.