Abstract
Modelling and analysis of a rotor--bearing system with a new type of active oil bearing is presented. The active bearing is supplied with a flexible sleeve whose deformation can be changed during operation of the rotor. The flexible sleeve is also a part of a hydraulic damper whose parameters can be controlled during operation as well.Finite Element Method (FEM) and the Guyan condensation technique was utilised to create mathematical model of both, the rotor and the flexible sleeve. The hydrodynamic pressure distribution in the oil film, for the instantaneous position of the flexible sleeve and rotor, was approximated by Reynolds equation.The mathematical model of motion of a rotor system with the described active bearing developed in this paper allowed the influence of the introduced hydraulic damper on stability of the rotor-bearing system to be investigated. Results of the computer simulation shows that within a large region of configuration parameters of the rotor bearing system, the self exciting vibration can be eliminated or greatly reduced during operation by properly controlled deformation of the flexible sleeve and optimal choice of the hydraulic damper parameters.