2013 Volume 58 Issue 8 Pages 581-588
The friction properties of wet clutches were investigated using lubricant oils containing polybutenyl succinimide (PBSI) as a dispersant and oleyl sarcosine (OS) as an oiliness agent in base oils such as paraffinic mineral oil and polyalpha-olefin. The concentration of the additives in lubricant film at sliding contacts was measured by in-situ observation with a micro Fourier transform infrared spectroscopy (FT-IR). It was found that the concentration of additives was increased at sliding contacts and was dependent on load, sliding speed and additives. The friction coefficients were changed by the addition of the additives and dependent on sliding conditions. The friction coefficient was decreased at lower sliding speed by the addition of OS, whereas it was increased at higher sliding speed by the addition of PBSI. A friction mechanism was proposed on the basis of the lubricant film viscosity which is dependent on the concentration of additives.
