Comparison study regarding bearing performance on 3 types of air bearingsusing Dyrobes software

Abstract

The gas bearings have low load capacity and high stiffness requirements beside the high precision which all are a concern in their development. The 2 large categories of gas bearings have each of them a drawback: the static gas bearing have the performances depending by the system which maintain the pressure, while the dynamic one's performances are increasing with speed. The article creates a comparison between 3 different type of dynamic gas bearing, using air as lubricant. While all 3 types of bearing having similar performances at max speed in term of eccentricity ratio vs. rpm, minimum film thickness and equilibrium locus, the cross-coupled damping and stiffness shown a rotor destabilization tendency. The 3 lobe rotor presented the highest pressure profiles at every speed. The pressure profiles present same shapes after 80000 rpm. The results shown potentially a multilobe rotor can over perform the plain bearing also in low speed.