The Robust Stability of a Wave Bearing

The purpose of this paper is to compare the stability of a three wave journal bearing with the stability of a hydrodynamic plain circular journal bearing. The study of the stability of a bearing can be reduced to the study of the stability of a fourth order linear system. In this paper, a perturbation method is used to compute the dynamic coefficients of the bearing. The critical mass is determined at every relative eccentricity, for both the circular hydrodynamic wave bearing and the three wave bearing. The influence of the amplitude of the wave on the stability of the wave bearing is also studied. However, not all the phenomena which affects the bearing’s operation can be taken into account, but it is important that the bearing preserves its stability in face of different types of uncertainty. This property is known as robust stability. In this paper, the robust stability of a bearing is evaluated by determining how great the perturbations of the dynamic coefficients could be so that the bearing remains stable. The robust stability is analyzed using the Kharitonov’s theorem.