Influence of axial thrust bearing defects on the dynamic behavior of an elastic shaft

In this work, the non-linear dynamic behavior of a flexible shaft is presented. The shaft is mounted in two journal bearings and axial load is supported by a hydrodynamic thrust bearing, at one end. The coupling between the axial thrust bearing behavior and the bending vibrations of the shaft is especially studied. The shaft is modeled by a typical beam finite element method and includes gyroscopic effects. The dynamic behavior of the journal bearings and the thrust bearing are considered to be non-linear. The dynamic behavior is analyzed with a transient time integration procedure. The thrust bearing provides additional stiffness and additional damping on the flexible shaft. A defect on the thrust bearing rotor excites a critical speed.