Lateral Vibration Analysis of Flexible Shafts Supported on Elliptical Journal Bearings

• Published in: Tribology letters Vol. 48; no. 2; pp. 217 - 227
• Main Authors: Miranda, W. M., Faria, M. T. C.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-11-2012; Springer Nature B.V
• Subjects: Beam theory (structures); Chemistry and Materials Science; Corrosion and Coatings; Dynamic response; Finite element method; Impellers; Journal bearings; Linearization; Lubrication; Materials Science; Mathematical models; Nanotechnology; Original Paper; Perturbation methods; Physical Chemistry; Reynolds equation; Rotating disks; Rotating shafts; Rotation; Rotors; Surfaces and Interfaces; Theoretical and Applied Mechanics; Thin Films; Time integration; Timoshenko beams; Tribology; Unbalance; Vibration analysis; Rotor-bearing systems; Hydrodynamic bearings; Unbalance response; Journal bearings; Flexible rotors; Finite element
• ISSN: 1023-8883; 1573-2711
• DOI: 10.1007/s11249-012-0018-5

This paper presents the development of a finite element procedure for the dynamic analysis of flexible rotors supported on fluid-film elliptical journal bearings operating under several operating conditions. The rotating shaft is modeled by using Timoshenko beam theory and the coupled rotating components, such as disks and impellers, are modeled by using lumped masses. The modeling of the elliptical journal bearings is performed by solving the lubrication equations generated from the application of a linearized perturbation method on the classical Reynolds equation. The bearing carrying-load capacity and the linearized dynamic force coefficients can be predicted for elliptical bearings with different preloads and journal eccentricities. The rotor transient whirling unbalance response is estimated by performing the time integration of the finite element equations using Newmark method. Experimental whirling unbalance response of a rotating shaft supported at two identical journal bearings is used to validate the finite element procedure. A comparative analysis of the dynamic response of flexible rotors supported on both cylindrical and elliptical journal bearings is performed to show that some elliptical bearings are capable of attenuating the rotor unbalance response more efficiently than cylindrical bearings are.