粘-惯性耦合节流静压气浮轴承微振动特性研究

Study on the micro vibration of viscous and inertial coupling aerostatic bearings

小孔节流气浮轴承因结构简单、刚度较高等优点在超精密加工中获得了广泛的应用。然而由于小孔节流气浮轴承存在微振动,限制了超精密加工表面粗糙度的进一步提升。为了抑制小孔节流气浮轴微振动,文章提出了一种新型粘-惯性耦合节流气浮轴承,通过数值模拟的方法研究了新型节流器的结构参数对气浮轴承微振动特性的影响,在此基础上开发了试验平台对新型气浮轴承振动特性进行测试。研究结果表明,粘-惯性耦合节流气浮轴承均压腔内压力波动低于小孔节流,可以减小气浮轴承微振动;同时,增大渗透率和节流孔直径、降低均压腔高度均能减小粘惯性耦合节流气浮轴承微振动。

Because of the simple structure and high stiffness,the orifice-restrictor air bearings are widely used in ultra-precision machining.However,increasing the roughness of ultra-precision surface is limited due to the micro-vibration in the orifice aerostatic bearings.In order to suppress the micro vibration,a novel viscous and inertial restrictor aerostatic bearing is designed in this paper.By employing the CFD method,the influences of the structure parameters on the stability of the novel aerostatic bearing are studied carefully.And the experimental test-beds are designed to test the bearing performances.The results show that the viscous and inertial restrictor aerostatic bearings can reduce the micro vibration compared with orifice air bearings efficiently.Meanwhile,increasing the permeability of porous materials,increasing the orifice diameter,and reducing the height of the pressure equalizing chamber can also reduce the micro vibration of the viscous and inertial restrictor aerostatic bearings.