Estimating unbalance and misalignment of a flexible rotating machine from a single run-down

Earlier studies have suggested that the reliable estimation of the state of unbalance (both amplitude and phase) at multiple planes of a flexibly supported rotating machine from measured vibration data is possible using a single machine run-down. This paper proposes a method that can reliably estimate both the rotor unbalance and misalignment from a single machine run-down. This identification assumes that the source of misalignment is at the couplings of the multi-rotor system, and that this will generate constant synchronous forces and moments at the couplings depending upon the extent of the off-set between the two rotors, irrespective of the machine rotating speed. A flexible foundation model is also estimated. The method is demonstrated using experimental data from a machine with two bearings and a flexible coupling to the motor. A sensitivity analysis has also been carried out for the proposed approach with perturbation errors in the rotor and bearing models, to confirm the robustness of the method.

[1]  Eric J. Hahn,et al.  Including foundation effects on the vibration behaviour of rotating machinery , 1995 .

[2]  A. W. Lees,et al.  Fault diagnosis of rotating machinery , 1998 .

[3]  Fredric F. Ehrlich,et al.  Handbook of Rotordynamics , 2004 .

[4]  Arthur W. Lees,et al.  The evaluation of rotor unbalance in flexibly mounted machines , 1997 .

[5]  A. W. Lees,et al.  Estimating the unbalance of a rotating machine from a single run-down , 2001 .

[6]  Jyoti K. Sinha,et al.  The identification of the unbalance of a flexible rotating machine from a single run-down , 2002 .

[7]  A G Parkinson,et al.  Balancing of Rotating Machinery , 1991 .

[8]  A. W. Lees,et al.  The Estimation of Foundation Models of Flexible Machines , 2002 .

[9]  R. D. Marangoni,et al.  Vibration Analysis Of A Motor-Flexible Coupling-Rotor System Subject To Misalignment And Unbalance, Part I: Theoretical Model And Analysis , 1994 .

[10]  B. Hamrock,et al.  Fundamentals of Fluid Film Lubrication , 1994 .

[11]  Arthur W. Lees,et al.  EXPERIMENTAL IDENTIFICATION OF EXCITATION AND SUPPORT PARAMETERS OF A FLEXIBLE ROTOR-BEARINGS-FOUNDATION SYSTEM FROM A SINGLE RUN-DOWN , 2000 .

[12]  E. J. Gunter,et al.  Review: Rotor balancing , 1998 .

[13]  Arthur W. Lees,et al.  Estimating turbogenerator foundation parameters: model selection and regularization , 2000, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[14]  G Simon.  Prediction of Vibration Behaviour of Large Turbo-Machinery on Elastic Foundations Due to Unbalance and Coupling Misalignment , 1992 .

[15]  L. D. Mitchell,et al.  Detection of a Misaligned Disk Coupling Using Spectrum Analysis , 1984 .

[16]  A. S. Sekhar,et al.  Effects of coupling misalignment on vibrations of rotating machinery , 1995 .

[17]  Charles R. Farrar,et al.  A summary review of vibration-based damage identification methods , 1998 .

[18]  A. Muszynska,et al.  Rotor-To-Stationary Element Rub-Related Vibration Phenomena in Rotating Machinery -- Literature Suryey , 1989 .

[19]  A. W. Lees,et al.  The Identification of the Unbalance of a Flexible Rotating Machine From a Single Rundown , 2004 .

[20]  Jyoti K. Sinha.  Health monitoring techniques for rotating machinery , 2002 .

[21]  Per Christian Hansen,et al.  REGULARIZATION TOOLS: A Matlab package for analysis and solution of discrete ill-posed problems , 1994, Numerical Algorithms.

[22]  Jyoti K. Sinha,et al.  THE IDENTIFICATION OF THE UNBALANCE AND THE FOUNDATION MODEL OF A FLEXIBLE ROTATING MACHINE FROM A SINGLE RUN-DOWN , 2002 .

[23]  R. D. Marangoni,et al.  Vibration Analysis Of A Motor-flexible Coupling-Rotor System Subject To Misalignment And Unbalance, Part II: Experimental Validation , 1994 .

[24]  Andrea Vania,et al.  THE EXTENDED KALMAN FILTER IN THE FREQUENCY DOMAIN FOR THE IDENTIFICATION OF MECHANICAL STRUCTURES EXCITED BY SINUSOIDAL MULTIPLE INPUTS , 2000 .

[25]  C. Gibbons,et al.  Coupling Misalignment Forces , 1976 .