ABSTRACT
Turbocharger rotordynamic modelling usually neglects thrust bearing coupling effects on lateral oscillations. However, using thrust bearings in turbochargers is mandatory, due to the compressor and turbine gas flows axial force imbalances. Furthermore, approximating the bearings dynamic characteristics by linear coefficients is not suitable in this rotor-bearing system, because of the high rotational speeds achieved by a typical automotive turbocharger. This paper brings a model of the entire turbocharger, considering the nonlinear behaviour of both thrust and floating ring bearings, with thermal effects, analysing the turbocharger response to an axial harmonic excitation and the thrust bearing influence on lateral vibrations.
