This paper presents a new approach for modeling flexure-pivot journal bearings (FPJB) employing a three-dimensional (3D) elasto-hydro-dynamic (EHD) lubrication model. The finite element (FE) method is adopted for an analysis of the (1) pad-pivot dynamic behavior and the (2) fluid force. The isoviscosity Reynolds equation is utilized to calculate the fluid force acting on a flexure-pivot pad bearing and spinning journal. Computational efficiency is achieved utilizing modal coordinate transformation for the flexible pad-pivot dynamic analysis. Fluid film thickness plays a critical role in the solution of Reynolds equation and is evaluated on a node-by-node basis accounting for the pad and web deflections. The increased fidelity of the novel modeling approach provides rotating machinery designers with a more effective tool to analyze and predict rotor–bearing dynamic behavior.

References

1.
Lund
,
J. W.
,
1964
, “
Spring and Damping Coefficients for the Tilting-Pad Journal Bearing
,”
ASLE Trans.
,
7
(
4
), pp.
342
352
.
2.
Nilsson
,
L.
,
1978
, “
The Influence of Bearing Flexibility on the Dynamic Performance of Radial Oil Film Bearings
,”
5th Leeds-Lyon Symposium on Tribology
, Lyon, France, pp.
19
22
.
3.
Lund
,
J. W.
, and
Pedersen
,
L. B.
,
1987
, “
The Influence of Pad Flexibility on the Dynamic Coefficients of a Tilting Pad Journal Bearing
,”
ASME J. Tribol.
,
109
(
1
), pp.
65
70
.
4.
Earles
,
L. L.
, Palazzolo, A. B., and Armentrout, R. W.,
1990
, “
A Finite Element Approach to Pad Flexibility Effects in Tilt Pad Journal Bearings: Part I—Single Pad Analysis
,”
ASME J. Tribol.
,
112
(
2
), pp.
169
176
.
5.
Desbordes
,
H.
, Fillon, M., FrêNe, J., and Wai, C. C. H.,
1995
, “
The Effects of Three-Dimensional Pad Deformations on Tilting-Pad Journal Bearings under Dynamic Loading
,”
ASME J. Tribol.
,
117
(
3
), pp.
379
384
.
6.
Armentrout
,
R. W.
, and
Paquette
,
D. J.
,
1993
, “
Rotordynamic Characteristics of Flexure-Pivot Tilting-Pad Journal Bearings
,”
Tribol. Trans.
,
36
(
3
), pp.
443
451
.
7.
Chen
,
W. J.
,
1995
, “
Bearing Dynamic Coefficients of Flexible-Pad Journal Bearings
,”
Tribol. Trans.
,
38
(
2
), pp.
253
260
.
8.
San Andres
,
L.
,
1996
, “
Turbulent Flow, Flexure-Pivot Hybrid Bearings for Cryogenic Applications
,”
ASME J. Tribol.
,
118
(
1
), pp.
190
200
.
9.
Walton
,
N. V.
, and
San Andres
,
L.
,
1997
, “
Measurements of Static Loading Versus Eccentricity in a Flexure-Pivot Tilting Pad Journal Bearing
,”
ASME J. Tribol.
,
119
(
2
), pp.
297
304
.
10.
Al-Ghasem
,
A. M.
, and
Childs
,
D. W.
,
2006
, “
Rotordynamic Coefficients Measurements Versus Predictions for a High-Speed Flexure-Pivot Tilting-Pad Bearing (Load-Between-Pad Configuration)
,”
ASME J. Eng. Gas Turbines Power
,
128
(
4
), pp.
896
906
.
11.
Rodriguez
,
L. E.
, and
Childs
,
D. W.
,
2006
, “
Frequency Dependency of Measured and Predicted Rotordynamic Coefficients for a Load-on-Pad Flexible-Pivot Tilting-Pad Bearing
,”
ASME J. Tribol.
,
128
(
2
), pp.
388
395
.
12.
Hensley
,
J. E.
, and
Childs
,
D.
,
2008
, “
Measurements Versus Predictions for Rotordynamic Characteristics of a Flexure Pivot-Pad Tilting Pad Bearing in an LBP Condition at Higher Unit Loads
,”
ASME
Paper No. GT2008-50066.
13.
Kepple
,
W. E.
,
Read
,
D. W.
,
Zeidan
,
F. Y.
,
Paraskevakos
,
C.
, and
Dawson
,
M. P.
,
1998
, “
Experience in the Use of Flexure Pivot Tilt Pad Bearings in Boiler Feed Water Pumps
,” 15th International Pump User Symposium provide link for
15th International Pump User Symposium
, Texas A&M University, College Station, TX, Mar. 3–5, pp.
77
84
.
14.
Pettinato
,
B. C.
, and
De Choudhury
,
P.
,
2002
, “
Rotordynamic Tests of a Flexible Rotor on Flexure Pivot Journal Bearings and Stability Correlation With Frequency Dependent Characteristics
,”
31st Turbomachinery Symposium
, Texas A&M University, College Station, TX, pp.
39
47
.
15.
Kim
,
J.
,
Palazzolo
,
A.
, and
Gadangi
,
R.
,
1995
, “
Dynamic Characteristics of TEHD Tilt Pad Journal Bearing Simulation Including Multiple Mode Pad Flexibility Model
,”
ASME J. Vib. Acoust.
,
117
(
1
), pp.
123
135
.
16.
Boedo
,
S.
, and
Booker
,
J. F.
,
1997
, “
Surface Roughness and Structural Inertia in a Mode-Based Mass-Conserving Elastohydrodynamic Lubrication Model
,”
ASME J. Tribol.
,
119
(
3
), pp.
449
455
.
17.
Boedo
,
S.
, and
Booker
,
J. F.
,
2000
, “
A Mode-Based Elastohydrodynamic Lubrication Model With Elastic Journal and Sleeve
,”
ASME J. Tribol.
,
122
(
1
), pp.
94
102
.
18.
Boedo
,
S.
, and
Booker
,
J. F.
,
2001
, “
Finite Element Analysis of Elastic Engine Bearing Lubrication: Theory
,”
Rev. Eur. Élém.
,
10
(
6–7
), pp.
705
724
.
19.
Boedo
,
S.
, and
Booker
,
J. F.
,
2001
, “
Finite Element Analysis of Elastic Engine Bearing Lubrication: Application
,”
Rev. Eur. Élém.
,
10
(
6–7
), pp.
705
724
.
20.
Boedo
,
S.
, and
Booker
,
J. F.
,
2005
, “
Modal and Nodal EHD Analysis for Gas Journal Bearings
,”
ASME J. Tribol.
,
127
(
2
), pp.
306
314
.
21.
Suh
,
J. H.
, and
Palazzolo
,
A.
,
2015
, “
Three-Dimensional Dynamic Model of TEHD Tilting-Pad Journal Bearing—Part I: Theoretical Modeling
,”
ASME J. Tribol.
,
137
(
2
), p.
041703
.
22.
Cook
,
R. D.
,
1994
,
Finite Element Modeling for Stress Analysis
,
Wiley
,
New York
.
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