INFLUENCE ON INSTABILITY OF ASYMMETRIC SHAFTS, PART IV - EFFECTS OF FLUID-FILM BEARINGS

The influence of fluid-film bearings on the parametric instability of asymmetric shafts is investigated. Since fluid-film bearings may have non-isotropic stiffness and damping, the system equations are time-var ying coefficients in a rotating reference frame and the complete solut ion of transition curves includes coupled modes. Thus, the analytical modal method provided by our previous studies has been modified in thi s part for the determination of approximate solutions from a truncated Hill's determinant. In numerical examples, a plain cylindrical type a nd a tilting four-pad type are considered to estimate the effects of b earing parameters concerning static load, oil viscosity, and clearance on unstable regions. (C) 1997 Published by Elsevier Science Ltd.