Concentrated (or counterformal) contacts are found in many mechanical components that transmit significant power. Traditionally, concentrated contacts can be roughly categorized to point and line contacts. In point contacts, the contact area is small in both principal directions, while in line contacts, it is small in one direction but assumed to be infinitely long in the other direction. However, these two types of geometry are results of simplification that does not precisely cover all the contact conditions in engineering practice. Actually most line contact components are purposely designed to have a crown in the contact length direction in order to accommodate possible non-uniform load distribution and misalignment. Moreover, the contact length is always finite, and at two ends of the contact there usually exist round corners or chamfers to reduce stress concentration. In the present work, the deterministic mixed EHL model developed previously has been modified to take into account the realistic geometry. Sample cases have been analyzed to investigate the effects of contact length, crowning, and end corners (or chamfers) on the EHL film thickness and the stress concentration, and also to demonstrate the entire transition from full-film and mixed EHL down to a practically dry contact under severe operating conditions with real machined roughness. It appears that this modified model can be used as an engineering tool for roller design optimization through in-depth mixed EHL performance evaluation.

References

References
1.
Petrusevich
,
A. I.
, 1951, “
Fundamental Conclusions From the Contact-Hydrodynamic Theory of Lubrication
,”
Izv. Akad. Nauk SSSR, Otd. Tekh. Nauk)
2
, pp.
209
233
.
2.
Dowson
,
D.
, and
Higginson
,
G. R.
, 1959, “
A Numerical Solution to the Elastohydrodynamic Problem
,”
J. Eng. Sci.
,
1
, pp.
6
11
.
3.
Dowson
,
D.
, and
Higginson
,
G. R.
, 1966,
Elastohydrodynamic Lubrication
,
Pergamon Press
,
New York
.
4.
Ranger
,
A. P.
,
Ettles
,
C. M. M.
, and
Cameron
,
A.
, 1975, “
The Solution of the Point Contact Elastohydrodynamic Problem
,”
Proc. R. Soc., London
,
A346
, pp.
227
244
.
5.
Hamrock
,
B. J.
, and
Dowson
,
D.
, 1976, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part 1—Theoretical Formulation
,”
ASME J. Lubr. Technol.
,
98
, pp.
223
229
.
6.
Hamrock
,
B. J.
, and
Dowson
,
D.
, 1976, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part 2—Ellipticity Parameter Results
,”
ASME J. Lubr. Technol.
,
98
, pp.
375
383
.
7.
Hamrock
,
B. J.
, and
Dowson
,
D.
, 1977, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part 3—Fully Flooded Results
,”
ASME J. Lubr. Technol.
,
99
, pp.
264
276
.
8.
Gohar
,
R.
, and
Cameron
,
A.
, 1967, “
The Mapping of Elastohydrodynamic Contacts
,”
ASLE Trans.
,
10
, pp.
215
225
.
9.
Wymer
,
D. G.
, and
Cameron
,
A.
, 1974, “
Elastohydrodynamic Lubrication of a Line Contact
,”
Proc. Inst. Mech. Eng.
,
188
, pp.
221
238
.
10.
Bahadoran
,
H.
, and
Gohar
,
R.
, 1974, “
Oil Film Thickness in Lightly-Loaded Roller Bearings
,”
J. Mech. Eng. Sci.
,
16
, pp.
386
390
.
11.
Mostofi
,
A.
, and
Gohar
,
R.
, 1983, “
Elastohydrodynamic Lubrication of Finite Line Contacts
,”
ASME J. Lubr. Technol.
,
105
, pp.
598
604
.
12.
Kuroda
,
S.
, and
Arai
,
K.
, 1985, “
Elastohydrodynamic Lubrication Between Two Rollers
,”
JSME
,
28
, pp.
1367
1372
.
13.
Xu
,
W.
,
Ma
,
J.
, and
Chen
,
X.
, 1993, “
Elastohydrodynamic Lubrication of Finite Line Contacts, Part I: A Numerical Analysis of EHL for Finite Cylindrical Roller Contacts
,”
Chin. J. Tribol.
,
18
(
1
), pp.
39
44
(in Chinese).
14.
Park
,
T. J.
, and
Kim
,
K. W.
, 1998, “
Elastohydrodynamic Lubrication of a Finite Line Contact
,”
Wear
,
223
, pp.
102
109
.
15.
Chen
,
X.
,
Shen
,
X.
,
Xu
,
W.
, and
Ma
,
J.
, 2001, “
Elastohydrodynamic Lubrication of Logarithmic Profile Roller Contacts
,”
Chin. J. Mech. Eng.
,
14
(
4
), pp.
347
352
.
16.
Liu
,
X.
, and
Yang
,
P.
, 2002, “
Analysis of the Thermal Elastohydrodynamic Lubrication of a Finite Line Contact
,”
Tribol. Int.
,
35
, pp.
137
144
.
17.
Sun
,
H.
, and
Chen
,
X.
, 2006, “
Thermal EHL Analysis of Cylinderical Roller Under Heavy Load
,”
Proceedings IUTAM Symposium on Elastohydrodynamics and Microelastohydrodynamics
,
R. W.
Snidle
and
H. P.
Evans
, eds., Cardiff, Springer, Dordrecht.
18.
Kushwaha
,
M.
,
Rahnejat
,
H.
, and
Gohar
,
R.
, 2002, “
Aligned and Misaligned Contacts of Rollers to Races in Elastohydrodynamic Finite Line Conjunctions
,”
Proc. Inst. Mech. Eng.
,
216
, pp.
1051
1069
.
19.
Zhu
,
D.
, and
Hu
,
Y. Z.
, 1999, “
The Study of Transition From Full Film Elastohydrodynamic to Mixed and Boundary Lubrication
,”
The Advancing Frontier of Engineering Tribology, Proceedings of the 1999 STLE/ASME
,
H. S.
Cheng
, ed., Tribology Surveillance, pp.
150
156
.
20.
Hu
,
Y. Z.
, and
Zhu
,
D.
, 2000, “
A Full Numerical Solution to the Mixed Lubrication in Point Contacts
,”
ASME J. Tribol.
,
122
(
1
), pp.
1
9
.
21.
Wang
,
W. Z.
,
Wang
,
H.
,
Liu
,
Y. C.
,
Hu
,
Y. Z.
, and
Zhu
,
D.
, 2003, “
A Comparative Study of the Methods for Calculation of Surface Elastic Deformation
,”
Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol.
,
217
, pp.
145
153
.
22.
Liu
,
Y. C.
,
Wang
,
Q.
,
Wang
,
W. Z.
,
Hu
,
Y. Z.
, and
Zhu
,
D.
, 2006, “
Effects of Differential Scheme and Mesh Density on EHL Film Thickness in Point Contacts
,”
ASME J. Tribol.
,
128
(
3
), pp.
641
653
.
23.
Zhu
,
D.
, 2007, “
On Some Aspects in Numerical Solution of Thin-Film and Mixed EHL
,”
Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol.
,
221
, pp.
561
579
.
24.
Zhu
,
D.
,
Martini
,
A.
,
Wang
,
W. Z.
,
Hu
,
Y. Z.
,
Lisowsky
,
B.
, and
Wang
,
Q.
, 2007, “
Simulation of Sliding Wear in Mixed Lubrication
,”
ASME J. Tribol.
,
129
, pp.
544
552
.
25.
Ren
,
N.
,
Zhu
,
D.
,
Chen
,
W. W.
, and
Wang
,
Q. J.
, 2010, “
Plasto-Elastohydrodynamic Lubrication (PEHL) in Point Contacts
,”
ASME J. Tribol.
,
132
, p.
031501
.
26.
Ren
,
N.
,
Zhu
,
D.
, and
Wang
,
Q. J.
, 2011, “
Three-Dimensional Plasto-Elastohydrodynamic Lubrication (PEHL) for Surfaces With Irregularities
,”
ASME J. Tribol.
,
133
, p.
031502
.
27.
Jacq
,
C.
,
Nelias
,
D.
,
Lormand
,
G.
, and
Girodin
,
D.
, 2002, “
Development of a Three-Dimensional Semi-Analytical Elastic-Plastic Contact Code
,”
ASME J. Tribol.
,
124
(
4
), pp.
653
667
.
28.
Chen
,
W. W.
, and
Wang
,
Q.
, 2008, “
Thermomechanical Analysis of Elasto-Plastic Bodies in a Sliding Spherical Contact and the Effects of Sliding Speed, Heat Partition, and Thermal Softening
,”
ASME J. Tribol.
,
130
(
4
), p.
041402
.
29.
Hu
,
Y. Z.
,
Barber
,
G. C.
, and
Zhu
,
D.
, 1999, “
Numerical Analysis for the Elastic Contact of Real Rough Surfaces
,”
Tribol. Trans.
,
42
(
3
), pp.
443
452
.
30.
Zhu
,
D.
, and
Wang
,
Q.
, 2011, “
Elastohydrodynamic Lubrication (EHL): A Gateway to Interfacial Mechanics—Review and Prospect
,”
ASME J. Tribol.
,
133
(
4
), p.
041001
.
31.
Zhu
,
D.
, and
Hu
,
Y. Z.
, 2001, “
A Computer Program Package for the Prediction of EHL and Mixed Lubrication Characteristics, Friction, Subsurface Stresses and Flash Temperatures Based on Measured 3-D Surface Roughness
,”
Tribol. Trans.
,
44
, pp.
383
390
.
You do not currently have access to this content.