KINEMATIC ANALYSIS AND DESIGN OF A CONTINUOUSLY-VARIABLE TRANSMISSION

This paper presents a kinematic analysis of an innovative transmission . The mechanism belongs to the class of continuously-variable transmis sion (CVT) or infinitely-variable transmission (IVT), and consists of conventional components such as a pinion, a cam, and several racks tha t mesh with the pinion and externally slide within pairs of parallel g uideways. The speed ratio of the transmission can be varied continuous ly during operation, simply by changing the offset between the input ( pinion) axis and the output (guideway-body) axis. A kinematic model is developed in the paper from which the speed transmission characterist ics of the device can be studied. An approach is presented through whi ch the required cam profile can be analytically represented. Also, tor que transmission can be studied with the same model, under constant po wer conditions and when inertia effects are negligible. Computer simul ations have been carried out and typical results are summarized in the paper. Originally, a two-slider transmission was built without the be nefit of the present analysis. Subsequently, a three-slider transmissi on was built according to a cam profile and other kinematic parameters that were specified on the basis of the present analysis and computer simulations. The behavior of both transmissions was found to be consi stent with the results obtained through analysis and computer simulati on.