空气静压主轴有限元建模及动态特性研究

Finite Element Modeling and Dynamic Characteristics of Aerostatic Spindle

为提高空气静压轴承支撑的空气静压主轴的动态工作性能,文章利用Fluent计算出了空气静压轴承在不同供气压力下气膜刚度,利用Ansys Workbench中的轴承单元和弹簧—阻尼单元模拟轴承支承,对主轴系统进行了模态分析和动态响应分析,得到不同供气压力下主轴系统的固有频率、振型以及激振力作用下的位移幅频动态响应曲线。结果表明,随着供气压力的增加,轴承气膜刚度增加,且对主轴系统的低阶模态和高阶模态影响不同。另外随着气膜刚度增加,谐振频率逐渐增大、振幅减小,系统抵抗受迫振动能力逐渐增强。研究结果为提高空气静压主轴的动态性能提供了一定的理论依据。

In order to improve the dynamic working performance of the aerostatic bearing spindle system supported by the aerostatic bearing,this paper uses Fluent to calculate the air film stiffness of the aerostatic bearing under different air supply pressures,Simulating bearing support using bearing units and spring-damper units in Ansys Workbench,the modal analysis and dynamic response analysis of the spindle system is carried out,and under different air supply pressures,the natural frequency,vibration mode and the dynamic response curve of the displacement amplitude-frequency under exciting force are obtained.The results show that with the increase of the supply pressure,the stiffness of the bearing film increases,and the influence of the low-order mode and the high-order mode of the spindle system is different.In addition,as the stiffness of the air film increases,the resonant frequency increases gradually and the amplitude decreases,and the system′s resistance to forced vibration gradually increases.The research results provide a theoretical basis for improving the dynamic performance of the aerostatic main spindle.