Abstract
A coupling calculation method of dynamics and lubrication for rotor and floating bush bearing system has been developed to predict self-excited oscillations and unbalance oscillations using a flexible multibody dynamics technique with hydrodynamic lubrication theory. Based on experimental results of floating bush bearing, an accurate and numerically efficient lubrication model is proposed to calculate the hydrodynamic force, the bush rotating speed and the temperature of the oil film. In the multibody dynamics analysis, the rotor is modeled by a finite element method including bending elasticity and gyroscopic effect. The bearing bush is modeled by a rigid body. The coupling analysis between the rotor dynamics and the oil film force of the bearing is performed by an in-house flexible multibody dynamics solver. Then, the detailed mechanism of the rotor oscillation and the influence of some design parameters are investigated by numerical simulations and experiments.
