The comparison in stability of rotor-aerostatic bearing system compensated by orifices and inherences

This paper studies static and dynamic characteristics of a rigid spindle supported by aerostatic bearings which are compensated by orifices and inherences. Eigen-solution method is used to determine the stability thresholds of both critical inertial force and critical whirl ratio belong to the motion equation of the rigid rotor-aerobearing system which is obtained by perturbation method. Various eccentricities, rotor speeds and restriction parameters are taken into considerations for the comparisons of restriction effect between both orifice and inherence. The influences of the number and the locations of air entries on the aerostatic bearing are also estimated.