Analysis of Dynamic Characteristics for Elastic Cylindrical Journal Bearing : 2nd Report, Results of Analysis and Experiment

Abstract

This paper describes theoretical results and experimental investigation on the stabilizing effect of a flexible cylindrical journal bearing which is composed of a thin sleeve simply supported at three angular points. Numerical analysis method was developed in the previous paper to compute the instability threshold of a rigid rotor and flexible bearing system by solving simultaneously the equation of motion of the rotor, sleeve deflection equation and modified Reynolds equation which includes film rupture effect in the negative pressure region. It is found from the calculated results that a thin sleeve journal bearing has a stabilizing effect in a large eccentricity ratio, as the flexibility of the sleeve increases. From the experimental study on instability of a flexible rotor supported by the flexible thin sleeve bearing a remarkable increase in threshold speed can be found in the large eccentricity ratioregion as predicted by the theory.