Diesel Engine Oils Formulated with Hydrocracked and Solvent-Refined Basestocks Have Equal EHD Film Thicknesses
| Autor: | P. R. Ryason, J. A. Mcgeehan, L. D. Wedeven |
|---|---|
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Tribology Transactions. 40:453-460 |
| ISSN: | 1547-397X 1040-2004 |
| DOI: | 10.1080/10402009708983680 |
| Popis: | Change in emissions standards for particulate and NO x have resulted in changes in diesel engine combustion processes and in diesel engine fuels. To meet the standards, injection timing changes and injection pressure changes have been made. Higher injection pressures required by these changes have been attained by using roller followers in valve and injector trains with Hertzian stresses at the injector-cam roller interface in the range of 1.72-2.07 GPa (250, 000-300,000 psi). As a consequence, concerns have arisen regarding the oil film thickness in the injector-cam roller interface. In particular, questions were raised as to differences in film thicknesses of oils formulated with hydrocracked and with solvent-refined basestocks. Blends of two different commercial formulations in hydro cracked and solvent-refined basestocks were prepared. An optical interferometric method was used to measure film thicknesses under EHD conditions for the formulated oils and for the basestock blends corresponding to each formulated oil. No differences in film thicknesses were found among the fully formulated oils, all blended to SAE 15W-40 grade. Differences were found between the basestock blends for the two formulations due to differences in atmospheric pressure viscosities of the basestock blends. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|