A Study on Stability Characteristics of Actively Controlled Externally Pressurized Air Journal Bearings

抄録

Results of theoretical investigations of the stability characteristics of an actively controlled externally pressurized air journal bearing are presented.The proportional and derivative control is used for the control algorithm of the active air bearing.The stability characteristics of the actively controlled bearing for zero steady-state eccentricity are investigated with the step jump method.The speed at onset of instability is increased for both proportional and derivative control of the bearing.The proportional control increased the stability threshold without affecting the whirl raito.However, for the derivative control of the bearing, stability threshold increase is accompanied by a parallel reduction of the whirl ratio.Results show the active control of bearing can be adopted for the stability improvement of air journal bearing.