Performances of a series infinitely variable transmission with type I power flow

The infinitely variable transmissions (IVT) allow the transmission ratio to vary with continuity, offering the possibility of also reaching zero values for the transmission ratio and the motion inversion. In this work the experimental results related to the performances of an IVT, obtained through the joining of a V-belt continuously variable transmissions (CVT), a planetary gear and a transmission with a constant ratio, are shown. The prototype in examination is a series-IVT with a type I power flow. Using a special test rig, the input and output IVT powers as well as the power circulating in the CVT are measured. The experimental results are compared with those obtained through a theoretical model. The torques and powers of the component CVT and those related the IVT are compared in order to evaluate their potentialities. The IVT efficiency curves, in relation to the torque and the transmission ratio variation, are finally reported and compared with those of an equivalent CVT. (C) 2002 Elsevier Science Ltd. All rights reserved.