Analysis of Cylindrical Journal Bearing With Viscoelastic Bush

Abstract

Stationarily loaded cylindrical journal bearings with viscoelastic deformable bearing bush is analyzed in this paper. FEM is used to calculate the deformation of bush induced by the pressure of the oil film, which is in its turn influenced by this deformation causing an increment of the oil film thickness. The simultaneous solution of distributions of oil film pressure and thickness is used to obtain the static performances of the bearing. In the analysis of dynamic behavior of the system under small harmonic vibrations, the effect of linear viscoelastic dynamic deformation of bush is taken into consideration. The frequency method is used to obtain the distributions of the derivatives of complex amplitudes of dynamic pressure increment in the oil film with respect to amplitudes of variation of journal eccentricity and attitude angle, and the simultaneously coexisting distributions of derivatives of dynamic deformation amplitudes with respect to the same, wherefrom the linear dynamic coefficients of the viscoelastically supported oil film are obtained. Unbalance response properties and stability threshold speeds of the rotor-bearing system are calculated. Numerical results enable conclusions to be made that suitable viscoelastic property of the bush will effectively improve the dynamic behavior, both in unbalance response and stability.