Development of High Damping Hydrostatic Air Slider

研究结果如下：（1）在一维槽形轴承模型分析中，发现在σ = 0时，槽数N_g、槽深G和槽宽L_g对静刚度的影响很小。低σ区阻尼B随N_g、G和L_g的增大而减小。而在高σ区，B随G的增大而增大，并在σ_处有一极值B_<opt><opt>，该极值对应于局部挤压数σ ′ = 10。通过尽可能减小L_g，选择N_g，使σ_f<opt>与相应的固有频率相匹配，并在低σ区将G增大到使B为正值的极限值，可以实现共振频率处的高阻尼轴承。(2)本文在分析一维静压气浮轴承模型的基础上，提出了一种新型的梳形槽静压气浮滑块，它具有高刚度和高阻尼的特点。在高频区域增加空气膜阻尼的基本思想是通过梳状凹槽来减小空气膜的压缩效应。据发现，可以实现0.23的zeta，同时确保0.3的无量纲刚度。(3)We制作一个带有四个梳状凹槽轴承的静压空气滑块。该滑块具有很高的静刚度，是传统槽式空气轴承静刚度的1.2倍。其阻尼比为0.065，是常规槽式空气轴承阻尼比的2.0倍，只要实现更高精度的间隙和进给孔径，并采用刚性更强的材料，就可以实现阻尼比在0.2以上的静压空气滑块。

The results of this research is as follows ;(1) In analysis of one dimensional grooved bearing model, it is found that groove number N_g, depth G and width L_g have little effect on static stiffness at sigma = O. The damping B in low sigma region decreases when N_g, G and L_g respectively become large. But B in high sigma region increases with the increase in G and has an extremum value B_<opt> at sigma_<opt> which corresponds to the local squeeze number sigma' of ten in the divided region. We can realize a high damping bearing at resonance frequency by decreasing L_g as small as possible, choosing N_g so as to tune sigma_<opt> to the corresponding natural frequency and increasing G to the limiting value which keeps B positive in low sigma region.(2) We propose a new hydrostatic air bearing slider with comb-shaped grooves based on the analysis of one dimensional bearing model which can provide high damping ratios at resonances as well as high stiffnesses. The basic idea to increase the air film damping at a high frequency region is to reduce the compressive effect of the air film by comb-shaped grooves. It is found that the zeta of 0.23 can be realized while assuring 0.3 non-dimensional stiffness.(3)We fabricate a hydrostatic air slider with four comb-shaped grooved beaxings. The fabricated slider has a high static stiffness which is 1.2 times the conventional grooved air bearing's one. Damping ratio is 0.065 which is 2.0 times the conventional grooved air bearing's one.We can realize the hydrostatic air slider whose damping ratio is above 0.2 if we will realize the higher accuracy clearance and feeding hole diameter and use more rigid material.