Identification of linearized oil-film coefficients in a flexible rotor-bearing system, part I: Model and simulation

The vibration behaviour of a rotor system supported by hydrodynamic bearings is significantly influenced by the dynamic characteristics of the bearings. An identification procedure for estimating bearing oil-film coefficients is developed in this work. Eight linearized oil-film coefficients are identified by fitting the measured complex functions of frequency response to those calculated theoretically. The theoretical model and reliability are examined by computer simulation. From error analysis, some interesting conclusions are reached and a new identification method is suggested in order to reduce the influence of phase measurement errors on estimated results.