Traction Drive With Reduced Spin Losses

Abstract

The paper focuses on the effect of spin motion upon elastohydrodynamic (EHD) traction in a CVT traction drive. The effect of the spin is determined upon the traction curves, traction coefficient and the slope of linear section of the traction curves. A kinematic study of a standard EHD contact leads to the general formula that governs the spin motion within the area of contact. Subsequently, this equation is applied to a traction drive with conical discs, balls and support ring. Furthermore it is determined that the spin motion at the contacts between balls and supporting ring creates additional loss. A new, original type of supporting ring that may ameliorate the spin loss is presented. This new support ring changes the type of contact between balls and supporting ring by replacing one heavily loaded contact between a ball and the ring with two spin-optimized contacts.