A nonsteady problem for an elastohydrodynamically lubricated (EHL) journal bearing is considered. It is shown that under certain circumstances contact pressure and shaft normal velocity are discontinuous functions of time. The initial normal velocity of the shaft has a certain value which is predetermined by the shaft initial position and applied load. Therefore, the EHL solution cannot accommodate any different initial normal velocity of the shaft. These defects pertain to any nonsteady EHL problem in the “classic” formulation. The main goal of this paper is to propose a modified formulation of the EHL problem free from the above defects. For purely squeezed lubrication film an analytical and numerical analysis of a dynamic bearing response to abrupt changes in external load is performed based on the classic and “modified” problem formulations leading to discontinuous and smooth solutions, respectively.

Issue Section:
Technical Briefs
Topics:
Journal bearings, Stress, Bearings, Lubrication, Numerical analysis, Pressure
1.
Allaire, P. E., and Flack, R. D., 1980, “Journal Bearing Design for High Speed Turbomachinery,” Bearing Design—Historical Aspects, Present Technology and Future Problems, Proceedings of the International Conference “Century 2—Emerging Technology” W. J. Anderson, ed., ASME, New York, pp. 111–160.
2.
Cha
E.
, and
Bogy
D. B.
,
1995
, “
A Numerical Scheme for Static and Dynamic Simulation of Subambient Pressure Shaped Rail Sliders
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
117
, No.
1
, pp.
36
–
46
.
3.
Ghosh
M. K.
,
Hamrock
B. J.
, and
Brewe
D.
,
1985
, “
Hydrodynainic Lubrication of Rigid Non-Conformal Contacts in Combined Rolling and Normal Motion
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
107
, No.
1
, pp.
97
–
103
.
4.
Hamrock, B. J., 1991, Fundamentals of Fluid Film Lubrication, NASA Reference Publication 1255, Washington, D.C.
5.
Hashimoto
H.
, and
Mongkolwongrojn
M.
,
1994
, “
Adiabatic Approximate Solution for Static and Dynamic Characteristics of Turbulent Partial Journal Bearings With Surface Roughness
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
116
, No.
4
, pp.
672
–
680
.
6.
Kudish
I. I.
, and
Panovko
M. Ya.
,
1992
, “
Oscillations of Deformable Cylinder Rolling on Lubricated Rigid Half-Space
,”
Soviet Journal of Friction and Wear
, Vol.
13
, No.
5
, pp.
1
–
11
.
7.
Lin
C. R.
, and
Rylander
H. G.
,
1991
, “
Performance Characteristics of Compliant Journal Bearings
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
113
, No.
3
, pp.
639
–
644
.
8.
Peiran
Yang.
, and
Shizhu
Wen.
,
1991
a, “
Pure Squeeze Action in an Isothermal Elastohydrodynamically Lubricated Spherical Conjunction. Part 1. Theory and Dynamic Load Results
,”
Wear
, Vol.
142
, No.
1
, pp.
1
–
16
.
9.
Peiran
Yang.
, and
Shizhu
Wen.
,
1991
b, “
Pure Squeeze Action in an Isothermal Elastohydrodynamically Lubricated Spherical Conjunction. Part 2. Constant Speed and Constant Load Results
,”
Wear
, Vol.
142
, No.
1
, pp.
17
–
30
.
10.
Safa
M. M. A.
, and
Gohar
R.
,
1986
, “
Pressure Distribution Under a Ball Impacting a Thin Lubricant Layer
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
108
, No.
3
, pp.
372
–
376
.
11.
San Andres
L. A.
, and
Vance
J. M.
,
1987
, “
Effect of Fluid Inertia on Squeeze Film Damper Forces for Small Amplitude Motions About an Off-Center Equilibrium Position
,”
ASLE Transactions
, Vol.
30
, No.
1
, pp.
63
–
68
.
12.
Teplyi, M. 1., 1983, “Contact Problems for Regions with Circular Boundaries,” State Lvov University, Lvov, Ukraine (in Russian).
This content is only available via PDF.
Copyright © 1999
 by The American Society of Mechanical Engineers
You do not currently have access to this content.