In statically indeterminate rotor bearings systems, where the rotor is supported by one or morehydrodynamic bearings, the reactions at each hydrodynamic bearing, and hence its stiffness anddamping properties depend not only on the bearing type, the operating conditions and the bearingdimensions but also on the relative lateral alignment between the journal and the bearing housing; thealignment, therefore, has a significant influence on the system stability and unbalance response.Additional complications arise if nonsymmetric bearing types such as elliptic or tilting pad bearingsare present. An iterative procedure is outlined which enables the bearing reactions to be determined atany speed, thereby enabling even large systems such as turbomachinery to be rapidly analyzed inconjunction with existing linear rotor bearing vibration analysis software. Sample numericalexamples show how misalignment and bearing type can affect the natural frequencies, the stabilitythreshold, and the unbalance response of such statically indeterminate systems.
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