Bifurcations in the response of a rigid rotor supported by load sharing between magnetic and auxiliary bearings

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Auxiliary bearings are utilized in practical installations of magnetically suspended rotating machines with the main functions to provide support to the rotating machines during their non-operational period, and to protect the magnetic bearings and the rotating assembly from being damaged due to power loss during operation. The relatively small clearances of these bearings, which are typically half of that of the magnetic bearings, may at time cause contact between the rotor and these bearings to occur even during normal operation of the rotating machines. The work presented herein examines the bifurcations in the response of a rigid rotor supported by load sharing between magnetic and auxiliary bearings, which occurs during contact between the rotor and the auxiliary bearings. Numerical results revealed the occurrence of period-doubling bifurcation resulting in vibrations of period-2, -4, -8, -16 and -32, as well as quasi-periodic and chaotic vibrations. The results further showed that for a relatively small rotor imbalance magnitude, which is within the prescribed level of certain classes of practical rotating machinery, such nonlinear dynamical phenomena would not have been discovered had the auxiliary bearings forces been omitted in the model of the rotor-bearing system. As these bearings are essential elements in practical installations of magnetically supported rotating machines, failure to include them in the rotor-bearing model may result in incorrect prediction of the rotor's vibration response.

Original languageEnglish
Pages (from-to)1341-1351
Number of pages11
JournalMeccanica
Volume46
Issue number6
DOIs
Publication statusPublished - Dec 2011

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Bearings (structural)
Rigid rotors
magnetic bearings
rigid rotors
rotors
Rotors
Magnetic bearings
vibration
installing
period doubling
power loss
machinery
Rotating machinery
clearances
assembly
occurrences

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Mechanics of Materials
  • Condensed Matter Physics

Cite this

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title = "Bifurcations in the response of a rigid rotor supported by load sharing between magnetic and auxiliary bearings",
abstract = "Auxiliary bearings are utilized in practical installations of magnetically suspended rotating machines with the main functions to provide support to the rotating machines during their non-operational period, and to protect the magnetic bearings and the rotating assembly from being damaged due to power loss during operation. The relatively small clearances of these bearings, which are typically half of that of the magnetic bearings, may at time cause contact between the rotor and these bearings to occur even during normal operation of the rotating machines. The work presented herein examines the bifurcations in the response of a rigid rotor supported by load sharing between magnetic and auxiliary bearings, which occurs during contact between the rotor and the auxiliary bearings. Numerical results revealed the occurrence of period-doubling bifurcation resulting in vibrations of period-2, -4, -8, -16 and -32, as well as quasi-periodic and chaotic vibrations. The results further showed that for a relatively small rotor imbalance magnitude, which is within the prescribed level of certain classes of practical rotating machinery, such nonlinear dynamical phenomena would not have been discovered had the auxiliary bearings forces been omitted in the model of the rotor-bearing system. As these bearings are essential elements in practical installations of magnetically supported rotating machines, failure to include them in the rotor-bearing model may result in incorrect prediction of the rotor's vibration response.",
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Bifurcations in the response of a rigid rotor supported by load sharing between magnetic and auxiliary bearings. / Inayat Hussain, Jawaid Iqbal.

In: Meccanica, Vol. 46, No. 6, 12.2011, p. 1341-1351.

Research output: Contribution to journalArticle

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