Abstract
A compact V-ribbed(serpentine) belt CVT system for accessory drive (called CVAD: Continuously Variable Accessory Drive System) has been developed. The CVAD has been tested to confirm not only convenience of installation due to its dry nature, but also good controllability and high power transfer efficiency over 90% in the usual region of operation. The basic feature of the CVAD is the application of a movable drive ring in the variable speed pulley. In this paper, the principal, the configuration, and the tested performance of the developed CVAD are presented.