空气静压止推轴承自激微振动数值分析及实验研究  

Numerical analysis and experimental research on self-excited micro-vibration of aerostatic thrust bearings

作　　者：龙威[1] 王继尧 李法社[2] 吴蜜蜜 邓伟 LONG Wei;WANG Jiyao;LI Fashe;WU Mimi;DENG Wei(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;Faculty of Metallurgy and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Xiyi Industrial Co.,Ltd.,Kunming 650114,China)

机构地区：[1]昆明理工大学机电工程学院,昆明650500 [2]昆明理工大学冶能工程学院,昆明650093 [3]云南西仪工业股份有限公司,昆明650114

出　　处：《振动与冲击》2019年第16期224-232,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51766006);清华大学摩擦学国家重点实验室开放基金(SKLTKF16B02);昆明理工大学课外学术科技创新基金(2018YB106)

摘　　要：随着控制精度和工作稳定性要求的不断提高,空气静压轴承气膜内部的自激振动成为制约气浮系统进一步发展的关键问题。以圆盘型中心供气小孔节流空气静压轴承气膜内的三维自激微振动为研究对象,基于流体润滑理论和修正的速度滑移边界建立了气膜的动力学模型和自激振动方程;基于平面流函数和大涡模拟方法,在确定气膜微振动形成机理的基础上,分析了三维气旋涡量分布特征和速度场变化规律;通过实验测试了气膜自激微振在三轴方向上的时域和频域特性,并分析了各轴向自激微振动的影响因素。研究表明:空气静压止推轴承的自激振动是气膜流场内三维气旋共同形成的,且沿气膜高度方向(z方向)的振动强度显著大于水平面内(x,y方向)的振动;轴承气膜内三个方向的自激振动强度都随着供气压力的增加而增加,且x,y方向自激振动的强度较z方向更为敏感;轴承气膜内三个方向自激振动的固有频率会随着供气压力的变化而改变,其中x,y方向自激振动的固有频率随供气压力增加而增长,而z方向自激振动的固有频率随供气压力的增大基本不变。With the continuous improvement of control accuracy and working stability,the self-excited vibration in the air film of aerostatic bearing has become the key problem restricting the further development of air flotation system.Taking the three-dimensional self-excited micro-vibration in the film of disc type central air supply orifice throttle air hydrostatic bearing as the research object,the dynamic model and self-excited vibration equation of the film were established based on the fluid lubrication theory and the modified velocity slip boundary.Based on the plane flow function and the large eddy simulation method,the characteristics of three-dimensional gas vortex vorticity distribution and the variation of velocity field were analyzed on the basis of determining the formation mechanism of gas film microvibration.Finally,the time domain and frequency domain characteristics of gas film self-excited micro-vibration in triaxial direction were tested by experiments,and the influencing factors of each axial self-excited micro-vibration were analyzed.The results showed that the self-excited vibration of the aerostatic thrust bearing is formed by three-dimensional gas vortexs in the film flow field,and the vibration intensity along the film height direction(z direction)is significantly higher than that in the horizontal plane(x,y direction).The intensity of self-excited vibration in the three directions of bearing film increases with the increase of gas supply pressure,and the intensity of self-excited vibration in x and y directions are more sensitive than that in z direction.The natural frequency of the self-excited vibration in the x and y directions will increase with the increase of the gas supply pressure.While that in z direction is basically unchanged with the increase of gas supply pressure.

关 键 词：空气静压轴承 自激微振动 大涡模拟 三维气旋 涡量分布 

分 类 号：TH133.36[机械工程—机械制造及自动化]