MAXIMUM MECHANICAL EFFICIENCY OF INFINITELY VARIABLE TRANSMISSIONS

Equations for the mechanical efficiency of infinitely variable transmi ssions (IVT) are derived. As a result, we conclude that: (1) an IVT is of input-coupled type, (2) the mechanical efficiency of an IVT depend s only on its allowable maximum speed ratio (R(v))aow, (3) the mechani cal efficiency of an IVT can only be improved by increasing (R(v))aow, the efficiency of planetary gear train (eta(pg)) and the efficiency o f continuously variable unit (eta(v)), and (4) an IVT with five-member planetary gear train of type I power flow has maximum mechanical effi ciency. A design example is also presented.