Investigation on the angular displacements influence and nonlinear effects on thrust bearing dynamics

Abstract

This paper presents a model of a turbocharger fixed geometry thrust bearing, considering the shaft collar axial translation and angular displacements. The work investigates the differences of a purely hydrodynamic model, modeled by Reynolds equation, and a full 3D thermo-hydrodynamic model, modeled by the generalized Reynolds equation and the 3D Energy equation, in terms of the thrust bearing supported load and restoring moments. The main point of the work is the estimate of the equivalent force and moment dynamic stiffness coefficient and the comparison of the full nonlinear terms with the linearized ones. It is shown the linearization is suitable for the restoring moments estimation, but not for the axial supported load