Temporary Viscosity Loss and Its Relationship to Journal Bearing Performance

Abstract

<div class="htmlview paragraph">To determine the correlation between journal bearing performance and viscosity loss in a capillary, viscosities of eleven base oil-polymer blends were measured in a high-shear, pressurized capillary viscometer (High-Shear Capillary Viscometer, HSCV) at shear rates from 100 to nearly 1 000 000 s<sup>-1</sup>. Although low-shear kinematic viscosities do not predict bearing performance differences found by Rosenberg with the same oil blends, HSCV viscosities at shear rates near 500 000 s<sup>-1</sup> correlate well with the bearing performance data. Differences among polymers are strongly related to molecular weight.</div>