This paper presents a numerical study of the effects of inlet supply starvation on film thickness in EHL point contacts. Generally this problem is treated using the position of the inlet meniscus as the governing parameter; however, it is difficult to measure this in real applications. Thus, in this paper an alternative approach is adopted whereby the amount of oil present on the surfaces is used to define the degree of starvation. It is this property which determines both meniscus position and film thickness reduction. The effect of subsequent overrollings on film thickness decay can also be evaluated. In the simplest case a constant lubricant inlet film thickness in the Y direction is assumed and the film thickness distribution is computed as a function of the oil available. This yields an equation predicting the film thickness reduction, with respect to the fully flooded value, from the amount of lubricant initially available on the surface, as a function of the number of overrollings n. However, the constant inlet film thickness does not give a realistic description of starvation for all conditions. Some experimental studies show that the combination of side flow and replenishment action can generate large differences in local oil supply and that the side reservoirs play an important role in this replenishment mechanism. Thus the contact centre can be fully starved whilst the contact sides remain well lubricated. In these cases, a complete analysis with a realistic inlet distribution has been carried out and the numerical results agree well with experimental findings.

1.
A˚stro¨m
H.
,
O¨stensen
J. O.
, and
Ho¨glund
E.
,
1993
, “
Lubricating Grease Replenishment in an ElastoHydrodynamic Point Contact
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
115
, pp.
501
506
.
2.
Bayada
G.
,
Chambat
M.
, and
El Alaoui
M.
,
1990
, “
Variational Formulations and Finite Element Algorithms for Cavitation Problems
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
112
, pp.
398
403
.
3.
Brandt
A.
, and
Lubrecht
A. A.
,
1990
, “
Multilevel Matrix Multiplication and Fast Solution of Integral Equations
,”
J. of Comp. Phys.
, Vol.
90
, No.
1
, pp.
348
370
.
4.
Cann
P. M.
, and
Spikes
H. A.
,
1992
, “
Film Thickness Measurements of Greases Under Normally Starved Conditions
,”
NLGI Spokesman
, Vol.
56
, pp.
21
26
.
5.
Chevalier, F., Lubrecht, A. A., Cann, P. M. E., Colin, F., and Dalmaz, G., 1994, “Starved Film Thickness: A Qualitative Explanation.” Proceedings of the 21st Leeds-Lyon Symposium on Tribology, pp. 249–257.
6.
Chevalier, F., Lubrecht, A. A., Cann, P. M. E., Colin, F., and Dalmaz, G., 1995, “Starvation Phenomena in EHL Point Contacts: Influence of Inlet Flow Distribution,” Proceedings of the 22nd Leeds-Lyon Symposium on Tribology.
7.
Chevalier, F., 1996, “Mode´lisation des Conditions d’Alimentation en Lubrifiant dans les Contacts Elastohydrodynamiques Ponctuels,” PhD. thesis, INSA de Lyon, France, under preparation.
8.
Chiu
Y. P.
,
1974
, “
An Analysis and Prediction of Lubricant Film Starvation in Rolling Contact Systems
,”
ASLE Trans.
, Vol.
17
, No.
1
, pp.
22
35
.
9.
Dalmaz, G., 1978, “Film Thickness and Traction measurements in small Elasto-hydrodynamic Elliptical Contacts,” Proceedings of the 5th Leeds-Lyon Symposium on Tribology, pp. 71–80.
10.
Dowson
D.
, and
Higginson
G. R.
,
1959
, “
A Numerical Solution to the Elasto-Hydrodynamic Problem
,”
J. of Mech. Eng. Science
, Vol.
1
, No.
1
, pp.
6
15
.
11.
Elrod, H. G., and Adams, M. L., 1974, “A Computer Program for Cavitation and Starvation Problems,” Proceedings of the 1st Leed-Lyon Symposium on Tribology, pp. 37–41.
12.
Elrod
H. G.
,
1981
, “
A Cavitation Algorithm
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
103
, pp.
350
354
.
13.
Gadallah
N.
, and
Dalmaz
G.
,
1984
, “
Hydrodynamic Lubrication of the Rib-Roller End Contact of a Tapered Roller Bearing
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
106
, pp.
265
274
.
14.
Guangteng
G.
,
Cann
P. M.
, and
Spikes
H. A.
,
1992
, “
A Study of Parched Lubrication
,”
Wear
, Vol.
153
, pp.
91
105
.
15.
Hamrock
B. J.
, and
Dowson
D.
,
1976
, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, part I, Theoretical Formulation
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
98
, pp.
223
229
.
16.
Hamrock
B. J.
, and
Dowson
D.
,
1977
a, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, part III, Fully Flooded Results
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
99
, pp.
264
276
.
17.
Hamrock
B. J.
, and
Dowson
D.
,
1977
b, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, part IV, Starvation Results
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
99
, pp.
15
23
.
18.
Kingsbury
E.
,
1973
, “
Cross Flow in a Starved E.H.D. Contact
,”
ASLE Trans.
, Vol.
16
. No.
4
, pp.
276
280
.
19.
Lubrecht, A. A., 1987, “Numerical Solution of the EHL Line and Point Contact Problem Using Multigrid Techniques,” PhD. thesis. University of Twente, Enschede, The Netherlands. ISBN 90-9001583-3.
20.
Nijenbanning
G.
,
Venner
C. H.
, and
Moes
H.
,
1994
, “
Film Thickness in Elastohydrodynamically Lubricated Elliptic Contacts
,”
Wear
, Vol.
167
, pp.
217
229
.
21.
Pemberton
J.
, and
Cameron
A.
,
1976
, “
A Mechanism of Fluid Replenishment in ElastoHydrodynamic Contacts
,”
Wear
, Vol.
37
, pp.
184
190
.
22.
Venner, C. H., 1991, “Multilevel Solution of the EHL Line and Point Contact Problems,” PhD. thesis, University of Twente, Enschede, The Netherlands. ISBN 90-9003974-0.
23.
Wedeven
L. D.
,
Evans
D.
, and
Cameron
A.
,
1971
, “
Optical Analysis of Ball Bearing Starvation
,”
ASME JOURNAL OF TRIBOLOGY
, F, Vol.
93
, pp.
349
363
.
24.
Wolveridge
P. E.
,
Baglin
K. P.
, and
Archard
J. P.
,
1970-1971
, “
The Starved Lubrication of Cylinders in Line Contact
,”
Proc. Inst. Mech. Engrs.
, Vol.
181
, pp.
1159
1169
.
This content is only available via PDF.
You do not currently have access to this content.