Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 International Journal of Applied Mechanics and Engineering

1 2003

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

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

Muraki M., Kurihara I., Igarashi J.

International Journal of Applied Mechanics and Engineering

2003

Vol. 8, no spec.

87-92

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.