An active hybrid tilting-pad bearing, together with the rotor and the hydraulic system, is modeled and simulated. The main objective of the active device is the reduction of vibration amplitude in rotating machinery. The active action is based on injecting pressurized oil into the bearing gap through orifices machined in the pads. Numerical results show an effective vibration reduction in unbalance and frequency response analyses, by applying a PI controller. The active system managed to eliminate instability phenomena (whirl), which appeared at high Sommerfeld number operational conditions.1 589594Glattfelder, A.H., Grein, H., Dörfler, P.K., Intense system vibrations in hydro plants (1981) Water Power & Dam Construction, pp. 34-37. , marchSchweitzer, G., Lange, R., Characteristics of a magnetic rotor bearing for active vibration control (1976) IMechE Conf. Vibrations in Rotaring Machinery, C239 (76), pp. 301-306Palazzolo, A.B., Lin, R.R., Kaskak, A.F., Alexander, R.M., Active control of transient rotordynamic vibration by optimal control methods (1989) ASME - J. Eng. Gas Turbines and Power, 111, pp. 264-270Lee, C.W., Kim, J.S., Modal testing and sub-optimal vibration control of flexible rotor bearing system by using a magnetic bearing (1992) ASME - J. Dyn. Sys. Meas. and Control, 114, pp. 244-252Burrows, C.R., Keogh, P.S., Tasaltin, R., Closed-loop vibration control of flexible rotors - An experimental study (1993) Proc. IMechE, 207, pp. 1-17Ulbrich, H., Althaus, J., Actuator design for rotor control (1989) 12th Biennial ASME Conf. on Vibration and Noise, pp. 17-22. , Montreal, CanadaPalazzolo, A.B., Jagnnathan, S., Kascak, A.F., Montague, G.T., Kiraly, L.J., Hybrid active vibration control of rotorbearing systems using piezoelectric actuators (1993) ASME - J. Vibration and Accoustics, 115, pp. 111-119Althaus, J., Stelter, P., Feldkamp, B., Adam, H., Aktives hydraulisches lager für eine schneckenzentrifuge (1993) Schwingungen in rotierenden Maschinen II, pp. 28-36. , Wiesbaden, GermanyUlbrich, H., Haben aktive lagerungen zukunft? (1993) Schwingungen in rotierenden Maschinen II, pp. 18-27. , Wiesbaden, GermanyStanway, R., Burrows, C.R., Active vibration control of a flexible rotor on flexibly-mounted journal bearings (1981) ASME - J. Dyn. Sys, Mens. and Control, 103, pp. 383-388Santos, I.F., (1993) Aktive Kippsogmentlagerung - Theorie und Experiment, (189). , VDI-Verlag GmbH, Düsseldorf, Germany, Fortschritt-Berichte VDI, series 11Santos, I.F., Design and evaluation of two types of active tilting-pad journal bearings (1994) IUTAM Symposium on Active Control of Vibration, pp. 79-87. , Bath, EnglandWang, Y.K., Mote C.D., Jr., Active and passive vibration control of an axially moving beam by yin art hybrid bearings (1996) J. of Sound and Vibration, 195 (4), pp. 575-584Wu, W.X., Pfeiffer, F., Aktive schmierfilmbeeinflussung bei radialen gleitlageren (1997) Schwingungen in rotierenden Maschinen IV, pp. 61-68. , Wiesbaden, GermanySantos, I.F., Russo, F.H., Tilting-pad journal bearings with electronic radial injection (1998) ASME - J. of Tribology, 120 (3), pp. 583-594Santos, L.F., Nicoletti, R., THD analysis in tilting-pad journal bearings using multiple orifice hybrid lubrication (1999) ASME - J. of Tribology, 121 (4), pp. 892-900Santos, I.F., Nicoletti, R., Influence of orifice distribution on the thermal and static properties of hybridly lubricated bearings (2001) Int. J. of Solids and Structures, 38 (10-13), pp. 2069-2081Santos, I.F., Scalabrin, A., Control system design for active lubrication with theoretical and experimental examples (2000) ASME/IGTI Int. Gas Turbine and Aeroengine Congress and Exhibition, 2000 GT-643. , Munich, GermanyThayer, W.J., Transfer functions for MOOG servevalves (1965) MOOG Technical Bulletin, 103Rashidi, M., Dirusso, E., Design of a hydraulic actuator for active control of rotating machinery (1993) ASME - J. Eng. Gas Turbines and Power, 115, pp. 336-340Watton, J., (1989) Fluid power systems - Modeling, simulation, analog and microcomputer control, , Prentice-Hall, New York, NYRowe, W.B., (1983) Hydrostatic and hybrid bearing design, , Butterworths & Co, London, EnglandFlack, R.D., Zuck, C.J., Experiments on the stability of two flexible rotors in tilting-pad bearings (1988) STLE Tribology Trans., 31 (2), pp. 251-257Lie, Y., You-Bai, X., Jun, Z., Damou, Q., Experiments on the destabilizing factors in tilting-pad bearings (1989) Tribology International, 22 (5), pp. 329-334White, M.F., Chan, S.H., The subsynchronous dynamic behavior of tilting-pad journal bearings (1992) ASME - J. of Tribology, 114 (1), pp. 167-173Olsson, K.O., Some fundamental aspects on the dynamic properties of journal bearings (1996) 6th IMechE Int. Conf. on Vibrations in Rotating Machinery, pp. 31-40. , London, UK