Rheological properties of mineral base oils and polymer solutions for engine lubricants

• Autorzy: Muraki M. , Kurihara I. , Igarashi J.
• Konferencja: Second International Conference on Engineering Rheology ICER 2003
• Języki publikacji: EN

Abstrakty

EN

Viscosity-pressure-temperature relations of paraffinic mineral base oils at a pressure up to 0.7GPa were determined with a falling ball type viscometer. The viscosity at a higher pressure condition than that of the viscometer was derived from traction curves determined with a disk-on-ball type EHD tester. When the viscosity were plotted against pressure, for the oils with higher viscosity index than 120, the viscosity derived from traction measurements followed the extrapolated curve to the high pressure region by the Yasutomi formula using the parameters obtained with the viscometer. Then, traction characteristics and oil film formability were determined for polymer solutions compared to their base oils. The addition of polymer had little effect on traction but shows a slight increase in film thickness compared to the results for its base oil. This is because the viscosity-pressure coefficient governing traction is little affected by the addition of polymer. Moreover, it was shown that the EHD inlet viscosity of polymer solutions derived by applying the Hamrock-Dowson formula to the film thickness measurements revealed a much lower value than its atmospheric viscosity at low shear rates.

Słowa kluczowe

EN

traction; elastohydrodynamic lubrication; mineral oil; polymer solution

PL

polimery; olej mineralny; smarowanie

• Wydawca: Oficyna Wydawnicza Uniwersytetu Zielonogórskiego
• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2003
• Tom: Vol. 8, no spec.
• Strony: 87--92
• Opis fizyczny: Bibliogr. 6 poz., rys., wykr.

Twórcy

autor

Muraki M.

• Shonan Institute of Technology, 1-1-25, Tsujido Nishikaigan, Fujisawa, Kanagawa, 251-8511, JAPAN

autor

Kurihara I.

• Nippon Oil Corporation, 8, Chidori-Cho, Naka-Ku, Yokohama, Kanagawa, 231-0815, JAPAN

autor

Igarashi J.

• Nippon Oil Corporation, 8, Chidori-Cho, Naka-Ku, Yokohama, Kanagawa, 231-0815, JAPAN

Bibliografia

• [1] Gohar R. (1988 ): Elastohydrodynamics. - Market Cross House, Chichester, West Sussex, England, Ellis Horwood Ltd.
• [2] Korcek S., Jensen R.K. and Johnson M.D. (2000): Additive systems for engine oils-future challenges. - Proc. Int. Tribol. Conf. Nagasaki, October 29-November 2, pp.71-78.
• [3] Muraki M. and Dong D. (1999): Derivation of basie rheological parameters from experimental elastohydrodynamic lubrication traction curves of low viscosity lubricants. - Proc. Instn. Mech. Engrs, Part J, J. Eng., Tribol., vol.213, pp.53-61.
• [4] Muraki M., Sano T. and Dong D. (2000): Determination of EHD film thickness and traction characteristics of polyol ester under an EHD contact in some refrigerant environments. - STLE Tribology Trans., vol.43, No.l, pp. 15-20.
• [5] Muraki M. and Wada H. (2002): Influence of alkyl group of ZnDTP on frictional characteristics of MoDTC under sliding conditions. - Tribology International, vol.35, pp.857-863.
• [6] Yasutomi S., Bair S. and Winer W. (1984): An application of a free volume model to lubricant rheology. - ASME Journal of Tribology, vol.l06, No.2, pp.294-298.