Fluid-film bearings can suffer from flow-induced instabilities known as ‘whirl’ and ‘whip,’ especially when supporting lightly-loaded shafts. This phenomenon can lead to large rotor (self-excited) vibrations, which eventually result in rotor-bearing failure. In this paper, we introduce a new active hydrodynamic bearing to mitigate such vibrations in lightly loaded rotating machines. The system contains a rotating bushing, actuated by a motor, that serves as the control input. This input is used to control the mean flow velocity in the bearing and thereby the journal vibration. A simple feedback control law is proposed for the bushing velocity, and numerical simulations are presented to evaluate the active bearing.
AdamsMLGuoJS (1996) Simulations and experiments of the non-linear hysteresis loop for rotor-bearing instability. Proceedings of the IMechE International Conference Vibration in Rotating Machinery, 309–319.
2.
BentlyDE (2000) In pursuit of better bearings. Orbit21(2): 33–42.
3.
BookerF (1965) A table of the journal bearing integral. Journal of Basic Engineering87: 533–535.
4.
BrancatiRRoccaERussoR (1996) Non-linear stability analysis of a rigid rotor on tilting pad journal bearings. Tribology International29: 571–578.
5.
CaiZDe QueirozMSKhonsariMM (2004) On the active stabilization of tilting-pad journal bearings. Journal Sound and Vibration273: 421–428.
6.
CouzonP-YDer HagopianJ (2007) Neuro-fuzzy active control of rotor suspended on active magnetic bearing. Journal of Vibration and Control13: 365–384.
7.
CrandallSH (1980) Heuristic explanation of journal bearing instability. In: Proceedings of the Workshop on Rotordynamic Instability Problems in High-Performance Turbomachinery, College Station, TX, 274–283.
8.
CrandallSH (1995) The instability mechanism responsible for oil whirl and oil whip. In: Proceedings of the Greek National Congress on Mechanics, Xanthi, Greece, 659–672.
9.
De CastroHFCavalcaKLNordmannR (2008) Whirl and whip instabilities in rotor-bearing system considering a nonlinear force model. Journal Sound and Vibration317: 273–293.
10.
DecklerDCVilletteRJ (2004) Simulation and control of an active tilting-pad journal bearing. STLE Tribology Transactions47: 440–458.
11.
Den HartogJP (1985) Mechanical Vibrations, Mineola, NY: Dover.
12.
De QueirozMSPradhanangaS (2007) Control of magnetic levitation systems with reduced steady-state power losses. IEEE Transactions on Control Systems Technology15: 1096–1102.
13.
FayollePChildsDW (1999) Rotordynamic evaluation of a roughened-land hybrid bearing. ASME Journal of Tribology121: 133–138.
14.
FlackRDZuckCJ (1988) Experiments on the stability of two flexible rotors in tilting pad bearings. STLE Tribology Transactions31: 251–257.
15.
GongXCaoD (2010) Active control of an unsymmetrical rotor system with tilting pad journal bearings. Journal of Vibration and Control17: 1582–1590.
16.
GuijosaJMMFengZC (2000) Stability analysis of a rigid rotor on tilting-pad journal bearings. Journal of Engineering Tribology214: 243–251.
17.
HaggAC (1946) The influence of oil-film bearings on the stability of rotating machines. Transactions of the ASME68: A211–A220.
18.
HamrockBJ (1994) Fundamentals of Fluid Film Lubrication, New York, NY: McGraw-Hill.
19.
HarnoyA (1966) Composite Bearing — Rolling Element with Hydrodynamic Journal. MSc Thesis, Technion, Israel Institute of Technology, Haifa, Israel.
20.
HaugaardMASantosIF (2010) Elastohydrodynamics applied to active tilting-pad journal bearings. ASME Journal of Tribology132: 021702–021702.
21.
HolmesMH (1995) Introduction to Perturbation Methods, New York, NY: Springer-Verlag.
22.
HoriY (1959) A theory of oil whip. ASME Journal of Applied Mechanics26: 189–198.
23.
LeeJBKimKW (1999) Effects of synchronous vibration of bearing on stability of externally pressurized air journal bearings. ASME Journal of Tribology121: 830–835.
24.
LieYLou-BaiXJunZDamouQ (1989) Experiments on the destabilizing factors in tilting pad bearings. Tribology International22: 329–334.
25.
MakiEREzzatHA (1980) Thermally induced whirl of a rigid rotor on hydrodynamic journal bearing. ASME Journal of Lubrication Technology102: 8–14.
26.
MuszynskaA (1986) Whirl and whip – rotor/bearing stability problems. Journal of Sound and Vibration110: 443–462.
27.
MuszynskaAFranklinWDBentlyDE (1988) Rotor active “anti-awirl” control. ASME Journal of Vibration, Acoustics, Stress, and Reliability in Design110: 143–150.
28.
MuszynskaABentlyDE (1989) Anti-swirl arrangements prevent rotor/seal instability. ASME Journal of Vibration, Acoustics, Stress, and Reliability in Design111: 156–162.
29.
NewkirkBLLewisJF (1956) Oil Film whirl – an investigation of disturbances due to oil films in journal bearings. Transactions of the ASME78: 21–27.
30.
NewkirkBLTaylorHD (1925) Shaft whipping due to oil action in journal bearings. General Electric Review28: 559–568.
31.
NicolettiRSantosIF (2003) Linear and non-linear control techniques applied to actively lubricated journal bearings. Journal of Sound and Vibration260: 927–947.
32.
NicolettiRSantosIF (2007) Control system design for flexible rotors supported by actively lubricated bearings. Journal of Vibration and Control14: 347–374.
33.
OlssonKO (1996) Some fundamental aspects on the dynamic properties of journal bearings. In: Proceedings of the IMechE International Conference on Vibrations in Rotating Machinery, 31–40.
34.
ParkS-HLeeC-W (2009) Design and control of hybrid-type three-pole active magnetic bearings using redundant coordinates. Journal of Vibration and Control16: 601–614.
35.
Petchenev A, Bently DE, Muszynska A, and Goldman P (1999) Experimental study of a fluid film bearing with a oating ring. In: SPIE Proceedings of the International Modal Analysis Conference, Kissimmee, FL, vol. 3727(2), pp. 283–289.
36.
PinkusO (1953) Note on oil whip. ASME Journal of Applied Mechanics75: 450–451.
37.
PinkusO (1956) Experimental investigation of resonant whip. Transactions of the ASME78: 975–983.
38.
PoritskyH (1953) Contribution to the theory of oil whip. Transactions of the ASME75: 1153–1161.
39.
RobertsonD (1933) Whirling of a journal in a sleeve bearing. Philosophical Magazine7: 113–130.
SantosIF (1994) Design and evaluation of two types of active tilting pad journal bearings. In: BurrowsCRKeoghPS (eds) The Active Control of Vibration, London: Mechanical Engineering Publications Limited, pp. 79–87.
42.
SantosIF (1995) On the adjusting of the dynamic coefficients of tilting-pad journal bearings. STLE Tribology Transactions38: 700–706.
43.
SantosIFRussoFH (1998) Tilting-pad journal bearings with electronic radial oil injection. Journal of Tribology120: 583–594.
44.
SantosIFUlbrichH (1993) Zur anwendung von regelungskonzepten für aktive kippsegmentlager. ZAMM – Zeitschrift für Angewandte Mathematik und Mechanik4: 241–244.
45.
SantosIFWatanabeFY (2004) Compensation of cross-coupling ctiffness and increase of direct damping in multirecess journal bearings using active hybrid lubrication: part I—theory. ASME Journal of Tribology126: 146–155.
46.
ShawMCNussdorferTJJr (1947) An analysis of the full-floating journal bearing. NACA Report866: 95–107.
47.
SimõesRCSteffenVJrDer HagopianJMahfoudJ (2007) Modal active vibration control of a rotor using piezoelectric stack actuators. Journal of Vibration and Control13: 45–64.
48.
SunLKrodkiewskiJM (2000) Experimental investigation of dynamic properties of an active journal bearing. Journal of Sound and Vibration230: 1103–1117.
49.
UlbrichHAlthausJ (1989) Actuator design for rotor control. ASME Design Technical Conference: Proceedings of the 12th Biennial Conference on Mechanical Vibration and Noise, Canada: Montreal, pp. 17–22.
50.
van de VorstELBFeyRHBde KrakerAvan CampenDH (1996) Steady-state behaviour of flexible rotordynamic systems with oil journal bearings. Nonlinear Dynamics11: 295–313.
51.
WangYKMoteCDJr (1996) Active and passive vibration control of an axially moving beam by smart hybrid bearings. Journal of Sound and Vibration195: 575–584.
52.
WuACaiZDe QueirozMS (2007) Model-based control of active tilting-pad bearings. IEEE/ASME Transactions on Mechatronics12: 689–695.
53.
WuADe QueirozM (2010) A new active tilting-pad bearing: nonlinear modeling and feedback control. Tribology Transactions53: 755–763.
54.
WuWXPfeifferF (1998) Active vibration damping for rotors by a controllable oil-film bearing. IFToMM International Conference on Rotor Dynamics, Germany: Darmstadt, pp. 431–443.
