Development of High Damping Hydrostatic Air Slider

点击翻译按钮获取中文摘要

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.