EXPERIMENTAL RESULTS FOR A TWO-MODE SPLIT-WAY CVT Prof

The present work is articulated in two phases. Firstly, an extensive theoretical insight addresses the category of split-way CVT's, where V-belt mechanical variators are arranged inside complex drives including one or more epicyclic trains, in order to spread the output speed range as far as including neutral and reverse. All the arrangements are planned for the two-mode operation, where the switch from one mode to the other occurs in rotational synchronism of the connecting/disconnecting shafts. The most promising schemes are then selected basing on the concept of variator "class", aiming at the minimum variator size for fixed input power. In the second phase, the experimentation is carried out on each of the two modes of a particular drive prototype, recording torque and angular speed on the various branches in several operative conditions, in order to estimate the overall performance in terms of efficiency and power capacity. Simple and reliable formulas are proposed for the CVT efficiency in dependence on the various working conditions.