Oil film thickness measurements made in the front main bearing of an operating 3.8 L, V-6 engine were compared with rheological measurements made on a series of commercial and experimental oil blends. High-temperature, high-shear-rate viscosity measurements correlated with the film thicknesses of all single-grade and many multigrade oils. However, the film thicknesses provided by some multigrade oils were larger than could be accounted for by their high-temperature, high-shear-rate viscosities alone. Although the pressure-viscosity coefficients of some of the oils were significantly different from those of the majority of oils tested, they were not oils which produced unusual film thicknesses. As a consequence, correcting oil viscosities for the estimated pressures acting within the bearing was unsuccessful in improving the correlations. The correlations were improved, however, by accounting for the elastic properties of the multigrade oils. Measurements of oil relaxation times at high temperatures and shear rates showed large differences in elastic properties-among the test oils. A good correlation (R2 = 0.73) was obtained from a multiple linear regression of film thickness as a function of both high-temperature, high-shear-rate viscosities and relaxation times.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    A Correlation Between Engine Oil Rheology and Oil Film Thickness in Engine Journal Bearings


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE International Congress and Exposition ; 1986



    Publication date :

    1986-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    A Correlation Between Engine Oil Rheology and Oil Film Thickness in Engine Journal Bearings

    Bates,T.W. / Williamson,B. / Spearot,J.A. et al. | Automotive engineering | 1986


    Measuring the Effect of Oil Viscosity on Oil Film Thickness in Engine Journal Bearings

    Spearot,J.A. / Murphy,C.K. / Rosenberg,R.C. et al. | Automotive engineering | 1983


    Measuring the Effect of Oil Viscosity on Oil Film Thickness in Engine Journal Bearings

    Murphy, C. K. / Spearot, J. A. / Rosenberg, R. C. | SAE | 1983


    Relationship Between Oil Film Thickness and Wear of Journal Bearings

    Gervé, Andreas / Katzenmeier, Gustav / Kollmann, Karl | SAE | 1970


    Engine bearings

    Bate, J. | Engineering Index Backfile | 1944