Over the last two decades, significant research effort has been directed towards developing vehicle transmissions that reduce the energy consumption of an automobile. Good ride performance is one of the most important key attributes of a passenger vehicle. One of the methods to achieve this is by using Continuously Variable Transmission (CVT). A CVT offers a continuum of gear ratios between desired limits, which consequently enhances the fuel economy and dynamic performance of a vehicle by better matching the engine operating conditions to the variable driving scenarios. As CVT development continues, costs will be reduced and the performance will continue to improve, which will make further development and application of the CVT technology desirable. The paper deals with the design and synthesis of novel cam-based CVT. It consists of threedimensional cams/camoids and flat face oscillating followers. Camoids have profiles of constant velocity and are mounted on input shaft, and followers are mounted on output shaft. Oscillating followers are mounted on the shaft with the help of unidirectional clutches which convert the oscillating motion of followers into pure rotary motion. Speed control for the CVT is achieved by linearly traversing camoids and changing the profile of contact with followers so that transmission ratio changes.

A Continuously Variable Transmission (CVT) or step-less transmission is suitable for the situations where frequent speed ratio changes are necessary to obtain more output power and to decrease fuel consumption. The cam-based CVT system is one such solution which offers advantages such as simplicity in design, reliability in operation and moderate efficiency.

Beachley and Frank (1979) demonstrated the concept, mechanism, advantages and disadvantages of Hydrostatic CVT. Hickmana and Chang (2013) illustrated the working, advantages and disadvantages of friction type V-Belt Pulley CVT. Kluger and Fussner (1988) illustrated the flat belt CVT developed and patented by Kumm Industries. Srivastava and Haque (2009) reviewed belt and chain CVTs. Delkhosh et al. (2011) explained geometrical optimization of half toroidal CVT using particle swarm optimization. Rockwood et al. (2014) suggested Electronic CVT (ECVT) for efficient urban transportation. Fallbrook Technologies (www.fallbrooktech.com) developed a geometry modification type CVT called NuVinci CVT. Kazerouniana and Furu-Szekelvb (2006) developed a parallel disc type CVT using three discs and rollers in between. Hickmana and Chang (2013) developed a geometry modification type CVT with the help of cam and follower system. Lahr and Hong (2006) explained the mechanism of CVT using cam and followers along with epicyclic gear train.

Mechanical Engineering Journal, Continuously Variable Transmission (CVT), Cam CVT, Eccentric cam, Oscillating flat face followers, 3D cam, Camoid, Autodesk inventor, Unidirectional bearings, My rio.