抄録
Practical toroidal-type continuously variable transmissions (CVT) for automobile are subject to extremely severe operating conditions, namely, the maximum contact pressure is very high at 3 GPa or higher, the rolling speed exceeds over 30 m/s, and the lubricant temperature goes up over 120°C. The objective of this research is to grasp the traction characteristics of extremely severe EHL (Elastohydrodynamic Lubrication) contact conditions. The bulk moduli of a synthetic traction oil at quasi-static conditions were evaluated using a phase diagram. Next, the EHL traction was measured by a two-disc machine and a four-disc machine. It was verified that the traction coefficients were based on the phase diagram of traction oil.
