This work focuses on the theoretical and experimental behavior of rigid rotors controlled by tilting-pad journal bearings with active oil injection. Initially the mathematical model of the active bearing is presented: The equations that describe the dynamics of hydraulic actuators are introduced into the equations of the lubricant, resulting in a new form of Reynolds’ equation for active lubrication. The global model of the system is obtained by coupling the equation of motion of the rigid rotor with the stiffness and damping of the active oil film. This global model is then used to design the control system of the active bearing based on root locus curves. The active system stability is analyzed by calculating its eigenvalues and frequency response curves. The theoretical and experimental results show that this kind of bearing can significantly reduce the vibration level of rotating machinery.

Issue Section:
Gas Turbines: Structures and Dynamics
Keywords:
rotors, lubrication, machine bearings, machine control, control systems, design engineering, eigenvalues and eigenfunctions, frequency response, modelling
Topics:
Bearings, Control systems, Damping, Design, Eigenvalues, Feedback, Lubrication, Rotors, Stiffness, Frequency response, Hydraulic actuators, Displacement, Vibration, Machinery, Pressure
1.
Mohan
,
S.
, and
Hahn
,
E. J.
,
1974
, “
Design of Squeeze Film Damper Supports for Rigid Rotors
,”
ASME J. Eng. Ind.
,
96
, No.
3
, p.
976
976
.
2.
Shiau
,
T. N.
,
Rao
,
J. S.
,
Chang
,
J. R.
, and
Choi
,
S. T.
,
1999
, “
Dynamic Behavior of Geared Rotors
,”
ASME J. Eng. Gas Turbines Power
,
121
, pp.
494
–
503
.
3.
Ulbrich, H., and Althaus, J., 1989, “Actuator Design for Rotor Control,” 12th Biennial ASME Conference on Vibration and Noise, Vol. 1, ASME, New York, pp. 17–22.
4.
Santos, I. F., and Ulbrich, H., 1992, “Actively Controlled Tilting Pad Journal Bearings,” ISROMAC - The International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, Vol. 2, pp. 423–431.
5.
Santos, I. F., 1993, Aktive Kippsegmentlagerung—Theorie und Experiment (Schwingungstechnik, 189), VDI-Verlag, Dusseldorf.
6.
Santos
,
I. F.
,
1995
, “
On the Adjusting of the Dynamic Coefficients of Tilting-Pad Journal Bearings
,”
STLE Tribol. Trans.
,
38
, No.
3
, pp.
700
–
706
.
7.
Santos, I. F., 1994, “Design and Evaluation of Two Types of Active Tilting-Pad Journal Bearings,” IUTAM Symposium on Active Control of Vibration, Bath, England, pp. 79–87.
8.
Santos, I. F., 1995, “Strategien fu¨r die Erho¨hung der Da¨mpfungsreserve von kippsegmentgelagerten Rotorsystemen,” Schwingungen in rotierenden Maschinen, Vol. 3, pp. 3–12.
9.
Santos
,
I. F.
, and
Russo
,
F. H.
,
1998
, ‘
Tilting-Pad Journal Bearings with Electronic Radial Oil Injection,Tilting-Pad Journal Bearings with Electronic Radial Oil Injection
,’
ASME J. Tribol.
,
120
, pp.
583
–
594
.
10.
Santos
,
I. F.
, and
Nicoletti
,
R.
,
1999
, ‘
THD Analysis in Tilting-Pad Journal Bearings Using Multiple Orifice Hybrid Lubrication,THD Analysis in Tilting-Pad Journal Bearings Using Multiple Orifice Hybrid Lubrication
,’
ASME J. Tribol.
,
121
, pp.
892
–
900
.
11.
Bently, D. E., Grant, J. W., and Hanifan, P., 1999, “Active Control Fluid Bearings for a New Generation of Machines,” Orbits, Second/Third Quarters, Vol. 20, No. 2, pp. 15–20.
12.
El-Shafei
,
A.
, and
Hathout
,
J. P.
,
1995
, “
Development and Control of HSFDs for Active Control of Rotor-Bearing Systems
,”
ASME J. Eng. Gas Turbines Power
,
117
, pp.
757
–
766
.
13.
Ulbrich, H., 1993, “Haben aktive Lagerungen Zukunft?,” Schwingungen in rotierenden Maschinen, Vol. 2, Vieweg Verlag, pp. 18–27.
14.
Ulbrich, H., 1998, “Active Vibration Control of Rotors,” Fifth International IFToMM Conference on Rotor Dynamics, Vieweg Verlag, Braunschweig, pp. 16–31.
15.
Scalabrin, A., 1999, “Utilizac¸a˜o de Mancais Segmentados com Injec¸a˜o Electro^nica para Controle de Rotores - Teoria e Experimento,” Master thesis, Department of Mechanical Design, State University of Campinas, Brazil.
Copyright © 2003
 by ASME
You do not currently have access to this content.