Abstract
To know the maximum contact pressure that can be usefully applied to the traction rolling surface is the most important subject to the traction drive CVT for automotive use. In this paper, surface observation and fatigue life analysis of the traction rolling disc is presented. It is shown that cleanliness of the steel and carbonitrrding heat treatment, which was developed for long life of rolling bearings are effective to make a long rolling fatigue life. As a result, S-N data on traction rolling elements is shown.