Sage Journals: Discover world-class research

Abstract

This work compares the friction between two contacting discs with the friction between gear teeth, using a mixed film lubrication model developed for the evaluation of contact pressure and shear stress fields [5]. Such model is used to analyse twin-disc contacts with smooth surfaces and gear teeth contacts with rough surfaces, both lubricated with an additive-free ISO VG 150 mineral oil.

Experimental lubricant traction curves [4], measured in a twin-disc machine under full film elastohydrodynamic (EHD) lubrication (Λ > 2), were used to evaluate the lubricant rheological parameters, taking into account the surface roughness of the contacting discs. Experimental power loss measurements, made during gear efficiency tests performed in a Forschungsstelle für Zahnräder und Getriebebau (FZG) test rig [4], were used to evaluate the average friction coefficient between gear teeth along the meshing line, considering the surface roughness of the tooth flanks.

The experimental friction coefficients between gear teeth were compared with predictions obtained using three different approaches: (a) values directly extrapolated from the experimental lubricant traction curves, (b) values calculated using a full film EHD lubrication model, considering surface roughness, and (c) values from a mixed film lubrication model. These analysis were performed at three different scales, from the roughness peaks (inside contact) to the entire gear meshing line, passing through the contact dimension.

The results obtained show that the mixed film lubrication model is able to evaluate accurately the friction between gear teeth in power transmission equipment whatever the lubrication regime, boundary, mixed or full film.

Keywords

mixed film lubrication gear friction

Get full access to this article

View all access options for this article.

References

Sottomayor

Campos

Seabra

Flamand

Nélias

Experimental evaluation and numerical simulation of MIL-L-23699 traction curves.

In Proceedings of the 30th Leeds-Lyon Symposium on Tribology, Lyon, France, 2-5 September 2003, Tribology Series 43, 2004, pp. 651–661 (Elsevier, Amsterdam, The Nertherlands).

Winter

Michaelis

FZG gear test rig - description and test possibilities. Co-ordinate European Council Second International Symposium on The Performance Evaluation of Automotive Fuels and Lubricants, Wolfsburg, West Germany, 5-7 June 1985, pp. 29–42.

Castro

Gripagem de engrenagens FZG lubrificadas com óleos base. Novos critérios de gripagem globais e locais. PhD Thesis, Demegi, FEUP, November 2004.

Hohn

B.-R.

Michaelis

Doleschel

Frictional behaviour of synthetic gear lubricants In Tribology research: from model experiment to industrial problem. (Eds Dalmaz

), 2001, pp. 759–768 (Elsevier Science B. V., Amsterdam, The Nertherlands).

Castro

Campos

Sottomayor

Seabra

Gear friction coefficient in mixed lubrication. In Proceedings of Leeds-Lyon Symposium on

Tribology and interface engineering, Tribology Series 48, Life Cycle Tribology, 2005, pp. 525–536 (Elsevier).

Höhn

B.-R.

Michaelis

Vollmer

Thermal rating of gear drives balance between power loss and heat dissipation. AGMA Technical Paper, October 1996, 96FTM8, 12 pp.

Sottomayor

Seabra

Campos

Ferreira

Thermal and non-Newtonian analysis of EHD line contacts.

In Proceedings of the 21st Leeds-Lyon Symposium on Tribology, Tribology Series 30, Lubricants and Lubrication, 1995, pp. 229–247.

Robbe-Valoire

Theoretical prediction and experimental results for mixed lubrication between parallel surfaces In Boundary and mixed lubrication: science and applications (Eds Dowson

), Tribology series 40, 2002, pp. 129–137 (Elsevier Science, Amsterdam, The Netherlands).

Williams

J. A.

Advanced in the modeling of boundary lubrication In Boundary and mixed lubrication: science and applications (Eds Dowson

), Tribology series 40, 2002, pp. 37–48, (Elsevier Science, Amsterdam, The Netherlands).

10.

ASME Tribology Division Technical Committee.

Life ratings for modern rolling bearings: a design guide for the application of international standard ISO 281/2 (Ed. Barnsby

), 2003 (ASME Int., New York).

11.

Gelinck

E. R.M.

Shipper

D. J.

Calculation of Stribeck curves for line contacts

Tribol. Int., 33, 2000, 175–181.

12.

Hamrock

B. J.

Fundamentals of fluid film lubrications In Mechanical engineering series, 1994 (McGraw-Hill International).

13.

Horng

J. H.

Contact analysis of rough surfaces under transaction conditions in sliding line lubrication

Wear, 1998, 219, 205–212.

14.

Zhu

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

STLE Tribol. Trans., 2001, 44 (3), 383–309.

15.

Ciulli

Friction in lubricated contacts: From macro to microscale effects In Fundamentals of tribology and bridging the gap between the macro and micro/nanoscales (Ed. Bhushan

), 2001, pp. 725–734 (Kluwer Academic Publishers, Dordrecht, The Netherlands).

16.

Winter

Michaelis

Scoring load capacity of gears lubricated with EP-oils. AGMA Fall Technical Meeting, Montreal, Canada, October 1983.

17.

Cheng

H. S.

A transient EHL analysis for line contacts with measured surface roughness using multigrid technique

ASMEJ. Tribol., 1994, 116, 549–558.

18.

Barral

Modélisation du champ de pression, du film de lubrifiant et des contraintes tangentielles dans un contact EHD rugueux. Premières études des contraintes engendrées dans les massifs. Rapport technique T03, Etude du pitting de matérieux d'engrenages de boites de vitesses manuelles - approche théorique et pratique, RVBV 10 (RENAULT - DIMAT) e 98.21.01 (INEGI - CETRIB), 1999.

19.

Dowson

Higginson

G. R.

Elastohydrodynamic lubrication, S.I. edition, 1997 (Pergamon Press Ltd, Oxford).

20.

Gohar

Elastohydrodynamics In Ellis Horwood series in mechanical engineering, 1988 (John Wiley & Sons, New York, USA).

21.

Bair

Winer

A rheological model for elastohydrodynamic contacts based on primary laboratory data

ASME J. Lubr. Technol., 1979, 101, 258–265.

22.

Tevaarwerk

J. L.

Traction calculations using the shear plane hypothesis.

In Proceeding of the 6th Leeds-Lyon Symposium on Tribology, Lyon, September 1979, pp. 201–213.

23.

Cheng

H. S.

Gears In Modern tribology handbook (Ed. Bhushan

), vol. 2, 2001, ch. 29 (CCR Press, Boca Raton, Florida, USA).

24.

Cheng

Analytical modeling of mixed lubrication performance In Boundary and mixed lubrication: science and applications (Eds. Dowson

), Tribology Series 40, 2002, pp. 19–33 (Elsevier Science, Amsterdam, The Netherlands).

25.

Epstein

Wang

Keer

Cheng

Liu

An efficient method of analysing the effect of roughness on fatigue life in mixed EHL contact

STLE, Tribol. Trans., 2003, 46 (2), 273–281.

26.

Seabra

Berthe

Influence of surface waviness and roughness on the normal pressure distribution in a Hertzian contact

J. Tribol., 1987, 109, 462–470.

27.

Seabra

Influence de l'ondulation des surfaces sur le comportement des contacts Hertziens secs ou lubrifíes. PhD Thesis, no 8ISAL0018, INSA, Lyon, 1988.

28.

Campos

Determinação da geometria do filme lubrificante, da distribuição de pressão e das tensñoes de corte num contacto elastohidrodinâ mico. Aplicação a rolamentos de rolos. MSc Thesis, Demegi, FEUP, 1994.

Coefficient of friction in mixed film lubrication: Gears versus twin-discs

Abstract

Abstract

Keywords

Get full access to this article

References