The elastohydrodynamic lubrication of point contacts is examined and results for the minimum film thickness are presented for a wide range of radius ratios and operating conditions. The results are compared with the predictions of the appropriate regime formulae. Although these formulae give a reasonable estimate of the contact's behaviour, the actual clearances are often substantially different, particularly close to the regime boundaries.
Interpolation equations for seven values of radius ratio are given and these should be sufficient to allow the minimum clearance to be estimated for most isoviscous point contacts.
JohnsonK. L.Regimes of elastohydrodynamic lubrication. J. Mech. Engng Sci., 1970, 12, 9–16.
2.
BreweD. E.HamrockB. J.TaylorC. M., Effect of geometry on hydrodynamic film thickness. Trans. ASME, J. Lubric. Technol., 1979, 101, 231–239.
3.
DowsonD.DunnJ. F.TaylorC. M.The piezoviscous fluid, rigid solid regimes of lubrication. Proc. Instn Mech. Engrs, Part C, 1983, 197(C1), 43–51.
4.
HookeC. J.The elastohydrodynamic lubrication of heavily loaded point contacts. J. Mech. Engng Sci., 1980, 22, 183–187.
5.
HookeC. J.Calculation of clearances in soft point contacts. Trans. ASME, J. Lubric. Technol., 1988, 110, 167–173.
6.
HookeC. J.Minimum film thicknesses in lubricated point contacts operating in the elastic piezoviscous regime. Proc. Instn Mech. Engrs, Part C, 1988, 202(C2), 73–84.
7.
HamrockB. J.DowsonD.Minimum film thickness in elliptical contacts for different regimes of fluid-film lubrication. Proceedings of Fifth Leeds-Lyon Symposium on Elastohydrodynamics and related topics, 1979, pp. 22–27 (Mechanical Engineering Publications, London).
8.
GreenwoodJ. A.Film thickness in circular elastohydrodynamic contacts. Proc. Instn Mech. Engrs, Part C, 1988, 202(C1), 11–17.
9.
HookeC. J.An interpolation procedure for the minimum film thickness in point contacts. Proc. Instn Mech. Engrs, Part C, 1990, 204(C3), 199–206.
10.
ESDU. Film thickness in lubricated Hertzian contacts. Part 2: point contact. Engineering sciences data item 89045, Engineering Sciences Data Unit International plc, London, 1989.
11.
HoupertL.The film thickness in piezoviscous-rigid regime: Film thickness lubrication regimes transition criteria. Trans. ASME, J. Lubric. Technol., 1984, 106, 375–385.
HookeC. J.The influence of piezoviscosity on the minimum film thickness in heavily loaded elastohydrodynamic point contacts. Proc. Instn Mech. Engrs, Part C, 1990, 204(C2), 117–125.
14.
HookeC. J.The elastohydrodynamic lubrication of point contacts operating in the piezoviscous region (in preparation).
15.
HamrockB. J.DowsonD.Isothermal lubrication of point contacts—Part II. Ellipticity parameter results. Trans. ASME, J. Lubric. Technol., 1976, 98, 264–276.
16.
HamrockB. J.DowsonD.Elastohydrodynamic lubrication of elliptical contacts for materials of low elastic modulus. 1. Fully flooded conjugation. Trans. ASME, J. Lubric. Technol., 1978, 100, 236–245.
17.
VennerC. H.Multi-level solution of the elastohydrodynamic line and point contact problems. Proefschrift, Universiteit Twente, The Netherlands, 1991.
18.
KapitzaP. L.Hydrodynamic theory of lubrication during rolling. Zh. tekh Fiz., 1955, 25, 759–775.
