文档介绍：Available online at hanism
and
Machine Theory
Mechanism and Machine Theory 43 (2008) 411–426
ate/mechmt
Identification of clearances and stability analysis for a
rotor-journal bearing system
Chris A. Papadopoulos a,*, Pantelis G. Nikolakopoulos a, e D. Gounaris b
a Machine Design Laboratory, University of Patras, 26500 Patras, Greece
b Hellenic Register of Shipping, R&D Department, Piraeus 18535, Greece
Received 7 November 2006; received in revised form 31 January 2007; accepted 11 April 2007
Available online 11 June 2007
Abstract
Significant wear occurs on the surface of bearings, which support rotating shafts for long periods of time. Therefore, the
need for a new clearance identification method is required. Furthermore, having identified these new clearances, the inves-
tigation of gauging reliable future operation with regards to stability is also an important task.
The rotor is modeled here using the finite element method with 4DOF’s per node, including the gyroscopic effect. The
dynamic coefficients of the bearing are calculated by solving the Reynolds equation, thus obtaining the pressure distribu-
tion of the oil film, and by finding the equilibrium position. The 4 · 4 stiffness and damping matrices, including the force-
moment and displacement-rotation relations with all non-diagonal coupling terms, are taken into account for the analysis.
Here, an identification method for the bearing radial clearances is presented theoretically, using response measurements
of the rotor at a particular point (usually the midpoint of the rotor). These ‘‘measurements’’ should be taken at two dif-
ferent speeds and from different wear effects. The present theoretical work on this particular problem needs to be verified
experimentally as well.
The sum of the squares of the differences between the measured and puted responses at the abovementioned
particular point and for two different speeds is used as an objective function to be minimized.
The stabili