Nonlinear Dynamic Analysis of Rotor Supported by Finite Journals With a new Unsteady Nonlinear Oil-Film Force Model

摘要

A new approximate method for evaluating oil-film force acting on a finite journal bearing with unsteady and larger perturbed motion is presented. The nonlinear dynamic analysis of rotor supported by finite oil-film bearings is carried out by the new oil-film force model. Unsteady and large perturbed motion of journal is considered. From the numerical results the following conclusions are obtained: 1. At very low speed, oil-film force can be ignored, the motion is synchronous whirl. It is unbalance response motion. 2. At very high speed or lager eccentricity, unbalance force prevails over the influence of oil-film force. The motion is also synchronous and stable. 3. In the middle interval of speed, oil-film force and unbalance force have the same order of magnitude, or oil-film force play the main role, the motion is much complex. The running danger of the rotor would be happened in this running interval.