Dynamic characteristics analysis of a rub-impact rubber bearing-shaft system

Abstract

Shaft/bearing rubbing systems may undertake a number of quite different responses. Recent experiments on shaft/bearing rubbing have revealed that two or three different responses may exist under the same frequency ratio with different initial conditions and system parameters. In the present paper, the rubber bearing/shaft system is simplified into a general bearing/shaft system with nonlinear elastic support of bearing, which is established based on the classic impact theory and is analyzed by the modern nonlinear dynamics and bifurcation theories. The boundaries for the existence of the no-rub responses are determined analytically, and the synchronous full annular rub solution are derived and the stability is analyzed to determine the region of the synchronous full annular rub response. The results provide an opportunity for a better understanding of the dynamical characteristics, such as the synchronous full annular rub motion, the jump phenomena as well as the transition between the partial rub motion, the dry whip and the full annular periodic rub motion. A systematic study on the influence of the system parameters on the dynamics characteristics is carried out. An overall picture of the response characteristics of this model is then obtained by drawing the existence boundaries in the parameter space. The present results provide a good understanding of the relationship between the different rubbing responses and the system parameters.