A Review of Transmission System for Performance of CVT

The constant rise in fuel prices on a day to day basis, maximum performance with minimum compromise on the front of fuel economy and emissions is highly desirable and expected from a vehicle’s transmission system. These friction drive CVTs were common in automotive use until engines capable of producing higher torques became common and necessitated the move to geared, fixed-ratio transmissions capable of high torque transfer and having better wear characteristics than friction dependent CVTs. Only in the past few years, with the advent of advanced materials and technology, have friction dependent CVTs returned to commercial application in the automotive industry. To provide a foundation and motivation for the research presented, this chapter first presents a definition of a continuously variable transmission.