Case Study: Infinitely variable transmissions with automatic regulation

Abstract

An infinitely variable transmission (IVT) is a continuously variable transmission with an infinite ratio range, which means that the transmission ratio may be zero. IVTs are generally made up of three elements: a continuously variable transmission (CVT), a planetary gear train and a fixed ratio mechanism. Automatically regulated CVTs offer the advantage of automatically changing the transmission ratio without requiring sophisticated control systems. In this work the possibility of realizing an automatically regulated IVT is appraised, i.e. with automatic regulation of the transmission ratio, in relation to operational conditions. The use of the automatically regulated V-belt CVT, endowed with simple devices of axial force, is hypothesized. For the different types of devices the characteristic curves of operation, the power flows and the efficiency of the automatically regulated IVT are determined.