Design, Modeling, and Simulation of a Geared Infinitely Variable Transmission

Abstract

An infinitely variable transmission (IVT) to provide a continuous outputtoinput speed ratio from zero to a certain value is designed, and its working principle is illustrated. It is a geared IVT (GIVT), since its function to achieve the continuously varied speed ratio is implemented by gears. Crankslider systems are used in the GIVT; the outputtoinput speed ratio is changed with the crank length. Racks and pinions, whose motion is controlled by planetary gear sets, are used to change the crank length when the cranks rotate. Oneway bearings are used to rectify output speeds from different crankslider systems to obtain the output speed of the GIVT. Since the crankslider systems can introduce variations of the instantaneous speed ratio, a pair of noncircular gears is designed to minimize the variations. A direction control system is also designed for the GIVT using planetary gear sets. Finally, a vehicle startup simulation and a wind turbine simulation to maintain a constant generator speed are developed based on a GIVT module in the Matlab Simulink environment.