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Remarks on rotor stability (A contribution to discussion during symposium on instability in rotating machinery)Influence of nonlinear factors in fluid lubricated bearings on rotor vibrations is discussed as are computation of threshold of stability for systems with multiple degrees of freedom. The reason for this investigation was to learn more about the influence of tilting pad bearings on vertical rotors. The eigenvalues, the stability threshold, the response on the Heaviside-function and the unbalance response were calculated for a rigid rotor, a Jeffcott rotor and for the finite element model of a real rotor. The comparison of the linear and nonlinear calculations shows the limit of the linear calculations. The computation is supposed to show, that the model of the Jeffcott rotor is not sufficient in most practical cases to determine the stability threshold. This was known for some years, when computed results were compared with the behavior of real machines. That's why a program was developed, which is roughly described.
Document ID
19860020719
Document Type
Conference Paper
Authors
Kraemer, E. (Technische Univ. Darmstadt, Germany)
Date Acquired
August 12, 2013
Publication Date
December 1, 1985
Publication Information
Publication: NASA. Lewis Research Center Instability in Rotating Machinery
Subject Category
MECHANICAL ENGINEERING
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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