Alignment Identification of Multi-Bearing Rotor Systems
A general approach has been developed for on-site identification of the actual configuration (alignment) of multi-bearing rotor systems (e.g. a turbogenerator unit). Identification procedure is based on the monitored trajectories of the relative motion of rotor journals with respect to the bearings and a nonlinear mathematical model of the system considered. The mathematical model includes the dynamic properties of rotors, their foundation and supporting structures as well as the nonlinear properties of the oil bearings. Time integration of the nonlinear equations of motion along the measured trajectories yields the desired configuration parameters (relative transverse positions of the bearing centers). The derived procedure of the identification was verified by means of a computer simulation as well as an experimental investigation on a four-bearing rotor test installation. Results may be used for diagnosis of vibrations of rotating machinery as well as their vibration response correction or optimization.
KeywordsHydrodynamic Force Journal Bearing Radial Clearance Nonlinear Simulation Numerical Verification
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