Friction characteristics between metal contacting surfaces from antiwear additives with application to metal V-belt type continuously variable transmission lubricants

Abstract

This study has focused on the application of lubricating oil additives in metal V-belt pushing type continuously variable transmission fluids (B-CVTFs) achieve higher friction coefficient and more stable lubricant film formation between the metal-metal contacting surfaces. The metal-metal tribological characteristics of various kinds of antiwear additives and a detergent were experimentally investigated using a ball on plate reciprocating tribometer (Plint TE77), which enables lubricant film formation to be monitored during a rubbing test. Zinc-dithio phosphates (ZnDTPs), a significant difference in instantaneous film formation was observed between primary and secondary type ZnDTP at the moment of increasing step load, due to the variation of the antiwear activity of different ZnDTPs. ZnDTPs in the presence of over-based calcium sulphonate detergent demonstrated slightly less tribofilm formationcompared with ZnDTP alone due to the competition for the rubbing surface. Very interestingly, in the case of phosphonic ester with calcium sulphonate, synergism was observed with more stable film formation and 8 per cent higher friction coefficient than without calcium sulphonate, a positive outcome for a B-CVTF. From surface analysis, it is hypothesized that the tribofilms species composed of iron phosphate, calcium phosphate, and calcium carbonate were generated by the reaction between phosphonic ester and calcium sulphonate, and that the resulting tribofilm plays a dual role in preventingwear and inhibiting the entrainment of lubricant into the interface, resulting in higher friction.

Keywords

belt continuously variable transmission transmittable torque capacity lubricant additives film formation synergism

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References

Murakami

Half a century of automatic transmissions for vehicles

J. Jpn. Soc. Tribol., 2005, 50 (9), 665–670.

Fewkes

Gunsing

Sumiejski

J. L.

Lubricants as a construction element in the VDT push-belt CVT system. SAE paper 932848, 1993.

Mitsui

Trends and requirements of fluids for metal pushing belt type CVTs

J. Jpn. Soc. Tribol., 2000, 45 (6), 13–18.

Narita

Priest

Improvement of the transmission efficiency of a metal V-Belt type CVT by lubricants. In Proceedings of the 15th International Colloquium Tribology, Automotive and Industrial Lubrication, Techniche Akademie Esslingen, 2006, 6 pp. (available on CD-ROM).

Ishikawa

Murakami

Yautibara

Sano

The effect of belt drive CVT fluid on the friction coefficient between metal components. SAE paper 972921, 1997.

Spikes

H. A.

History and mechanism of ZDDP

Tribol. Lett., 2004, 17 (3), 469–489.

Bec

Tonck

Georges

J. M.

Coy

R. C.

Bell

J. C.

Roper

G. W.

Relationship between mechanical properties and structures of zinc dithiophosphate antiwear films

Proc. R. Soc. Lond., 1999, A455, 4181.

Yin

Kasrai

Fuller

Bancroft

G. M.

Fyfe

Tan

K. H.

Application of soft X-ray absorption in chemical characterization of antiwear films generated by ZDDP Part I: The effects of physical parameter

Wear, 1999, 202, 172–191.

Martin

J. M.

Grossiord

Monge

T. L.

Bec

Tonck

The two-layer structure of Zndtp tribofilms. Part I: AES, XPS and XANES analyses

Tribol. Int., 2001, 34, 523–530.

10.

Bennet

P. A.

A surface effect associated with the use of oils contacting Zinc Dialkyl Dithiophosphate

PASLE Trans., 1959, 2, 78–90.

11.

Taylor

Spikes

H. A.

Friction-enhancing properties of ZDDP antiwear additive: Part I - friction and morphology of ZDDP reaction films

Tribol. Trans., 2003, 46 (3), 303–309.

12.

Taylor

Spikes

H. A.

Friction-enhancing properties of ZDDP antiwear additive: Part 2-influence of ZDDP reaction film on EHD lubrication

Tribol. Trans., 2003, 46 (3), 310–314.

13.

Minami

Ichihashi

Kubo

Nanao

Mori

Tribochemical approach toward mechanism for synergism of lubricant additive on antiwear and friction reducing properties.

In Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Leeds, 2004, pp. 259–268 (Elsevier, Amsterdam).

14.

Wada

Iwanami

Xanes study on boundary lubrication films generated from belt-drive continuously variable transmission fluids. Synopses of International Tribology Conference, Kobe, 2005, p. 319.

15.

Aktary

McDermott

M. T.

McAlpine

G. A.

Morphology and nanomechanical properties of ZDDP antiwear films as a function of tribological contact time

Tribol. Lett., 2002, 12 (3), 155–162.

16.

Demmou

Bec

Loubet

J. L.

Martin

J. M.

Temperature effects on mechanical properties of zinc dithiophosphate tribofilms

Tribol. Int., 2006, 39, 1558–1563.

17.

Fujita

Spikes

H. A.

The study of ZnDTP antiwear film formation kinetics. In Proceedings of 15th International colloquium Tribology, Automotive and Industrial Lubrication, Technische Akademie Esslingen, 2006, 6 pp. (available on CD-ROM).

18.

Masuko

Ohkido

Suzuki

Effect of formulation of dispersant or dispersant on the anti-wear characteristics of deteriorated ZnDTP in model engine oil. In Esslingen Proceedings of 15th International colloquium Tribology, Automotive and Industrial Lubrication, Technische Akademie Esslingen, 2006, 10 pp (available on CD-ROM).

19.

Sato

Mechanism of additives in belt type CVT contact area. In Proceedings of International Tribology Conference, Nagasaki, 2000, Vol. 2, pp. 1379–1384.

20.

Narita

Priest

Boundary lubrication film formation from belt type CVT fluids. IPDS2006

Integrated powertrain & driveline systems, 2006, pp. 39–49 (Woodhead Publishing in Mechanical Engineering, Cambridge).

21.

Furey

M. J.

Metallic contact and friction between sliding surfaces

ASLE Trans., 1961, 4, 1–11.

22.

Bovington

C. H.

Chemistry and technology of lubricants, 2nd edition, 1997, ch. 12, pp. 337–338 (Blackie Academic & Professional, Glasgow).

23.

Bhushan

Principles and application of tribology, 1999, p. 450 (Wilky-Interscience, Chichester).

24.

Fujita

Spikes

H. A.

The formation of zinc dithiophosphate antiwear film

Proc. Instn Mech. Engrs, Part J: J. Engineering Tribology, 2004, 218, 265–277.

25.

Kugimiya

Effects of additives for ATF on μ-V characteristics. In Proceedings of International Tribology Conference, Nagasaki, 2000, Vol. 2, pp. 1355–1360.

26.

Giasson

Espinat

Palermo

Study on microstructural transformation of overbased calcium sulphonate during friction

Lubr. Sci., 1993, 5 (2), 91–111.

27.

Rounds

F. G.

Additive interactions and their effect on the performance of a zinc dialkyldithiophosphate

ASLE Trans., 1978, 21 (2), 91–101.

28.

Kasrai

Fuller

M. S.

Bancroft

G. M.

X-ray absorption study of the effect of calcium sulphonate on antiwear film formation generated from natural and basic ZDDPs Part I: Phosphorus species

Tribol. Trans., 2003, 46 (4), 534–542.

29.

Inoue

Watanabe

Interactions of engine oil additives

ASLE Trans., 1983, 26 (2), 189–199.

30.

Harrison

Kikabhai

Thermogravimetric analysis of zinc and leads bis(O,O'-Dialkyldithiophosphate) and their complexes with nitrogen donor molecules

Wear, 1987, 116, 25–31.

31.

Zhang

Kasrai

Bancroft

G. M.

Yamaguchi

E. S.

Study of the interaction of ZDDP and dispersants using X-ray absorption near edge structure spectroscopy Part I: Thermal chemical reactions

Tribol. Lett., 2003, 15 (4), 377–384.

32.

Zhang

Kasrai

Bancroft

G. M.

Yamaguchi

E. S.

Study of the interaction of ZDDP and dispersants using X-ray absorption near edge structure spectroscopy Part II: Tribochemical reactions

Tribol. Lett., 2003, 15 (4), 385–394.

33.

Narita

Priest

Tribological characteristics of dispersant additives with application to metal V-belt CVT lubricants. Conference Volume of Tribology 2006

Surface engineering and tribology for future engines and drivelines, London, 2006, 4 pp. (IMechE, London).

34.

Handbook of X-ray photoelectron spectroscopy, JOEL, 1991.