Grease passing through an elastohydrodynamic contact under pure rolling conditions

Abstract

Using optical interferometry in a standard ball-and-disc apparatus and a high-speed video camera with light enhancer, thickener particles entering a grease-lubricated elastohydrodynamic (EHD) contact were traced as they passed through the contact in pure rolling. In previous studies, it has not been possible to track specific particles but, due to the short exposure time and high recording rates used here, sharp images of a passing particle could be captured. Two greases, based on the same synthetic poly(α-olefin) but thickened with Li-12-OH and lithium complex respectively were studied and for a freshly lubricated track it could be documented that the lithium complex thickener causes fewer, but larger, particles to pass the contact. The influence of the base oil bleeding on film formation is also discussed in the paper.

Keywords

elastohydrodynamics (EHD)elastohydrodynamic lubrication (EHL)grease lubrication interferometry bearing

Get full access to this article

View all access options for this article.

References

Baker

A. E.

Grease bleeding—a factor in ball bearing performance

NLGISpokesman, September 1958, 18, 271–277.

Scarlett

N. A.

Use of grease in rolling bearings

Proc. Instn Mech. Engrs, 1967, 182 (3A), 167–171.

Cann

P. M.

The influence of temperature on the lubrication behavior of a lithium hydroxystearate grease. In Fifth Annual European Lubricating Grease Institute Conference, Budapest, Hungary, 1994.

Wikström

Rolling bearing lubrication at low temperature. PhD thesis 1996:186 D, Lulea University of Technology, Lulea, Sweden, 1996.

Åström

Grease in elastohydrodynamic lubrication. PhD thesis 1993:132 D, Luleå University of Technology, Luleå, Sweden, 1993.

Palacios

J. M.

Cameron

Arizmendi

Film thickness of grease in rolling contacts

ASLE Trans., 1981, 24 (4), 474–478.

Cann

P. M.

Spikes

H. A.

In lubro studies of lubricants in EHD contacts using FTIR absorption spectroscopy

STLE Tribology Trans., April 1991, 34 (2), 248–256.

Cann

P. M.

Spikes

Film thickness measurements of lubricating greases under normally starved conditions

NLGI Spokesman, 1992, 56 (2), 21–27.

Cann

P. M.

Chevalier

Lubrecht

A. A.

Track depletion and replenishment in a grease lubricated point contact: A quantitative analysis.

In Proceedings of the 23rd Leeds-Lyon Symposium on Tribology, Leeds, 10-13 September 1996, 1997, pp. 405–413 (Elsevier, Amsterdam).

10.

Åström

Isaksson

Höglund

Video recordings of an EHD point contact lubricated with grease

Tribology Int., 1991, 24 (3), 179–184.

11.

Dalmaz

Nantua

An evaluation of grease behavior in rolling bearing contacts

Lubric. Engng, 1987, 43 (12), 905–915.

12.

ASTM Standard D 1742-88, Standard test method for oil separation from lubricating grease during storage. Annual Book of ASTM Standards, 1988 (American Society for Testing and Materials, Philadelphia, Pennsylvania).

13.

Gow

G. M.

The CEY to grease rheology. In Institution of Engineers Australia: Preprints of the Third International Tribology Conference, Brisbane, Australia, 3-5 December 1990, pp. 202–205.

14.

Hamnelid

Amazing grease, or finding the right way to consistency. 57th Annual NLGI Meeting, Denver, Colorado, 1990.

15.

Aström

Irregular film thickness fluctuations in elastohydrodynamic lubrication of a point contact lubricated with lubricating grease

Tribologia, 1992, 11 (4), 115–122.

16.

Larsson

P. O.

Larsson

Jolkin

Marklund

Pressure fluctuations as grease soaps pass through an EHL contact. In Proceedings of the Australian Tribology Conference on

Tribology at Work, Brisbane, Australia, December 1998 pp. 413–418.

17.

Larsson

P. O.

Lubricant replenishment in the vicinity of an EHD contact. PhD thesis 1996:201 D, Luleå University of Technology, Luleå, Sweden, 1996.