Nonlinear Transient Response of Tilting 4 Pad Bearings: Turbocharger Systems

High speed and high performance engines are often equipped with turbochargers to increase power density over the operating speed range. Tilting pad bearings are now much more applied in many types of rotor systems. This paper presents nonlinear dynamical behavior of a typical turbocharger supported by two tilting 4 pad bearings. The bearing oil-film force was calculated by a database method and the influence of both pad offset and preload were studied. The nonlinear transient vibration is represented by bifurcation diagrams. The results directly show that pad offset and preload greatly influence the nonlinear vibrations of the turbocharger-tilting pad bearings system. In some certain speed range, the motions of the bearing pads are different from that of the bearing journal centerline.