Planetary Transmission System

Abstract: A continuously variable transmission (CVT), in theory, has an unlimited number of gear ratios between the highest and lowest settings. But most CVTs are complex, expensive, have poor efficiencies, and aren't scalable. A new type of CVT, CONTINUOSLY VARIABLE PLANETARY TRANSMISSION(CVPT),combines toroidaltraction CVT with the versatility of the planetary gear arrangement to create a low-cost, highly efficient drive for human-powered and motorized vehicles.While the CVPT uses rolling traction to distribute torque like toroidal CVTs, it distributes the transmitted torque over several spheres in an inherently stable configuration. The rotating balls between the input and output section of the CVT tilt to vary transmission speed. As the balls tilt, they change their contact diameters to vary the speed ratio. This lowers contact pressures and improves durability, stability, and torque density. And since it uses a planetary arrangement, torque can be summed or divided.In the present work, a CVPT has been mounted to a bicycle for conducting the experiments. Normally tilting of spheres for changing gear ratios is done manually, however in our case, this has been obtained automatically. For automated shifting, a shift actuator, a controller and a battery to power this circuit is used.Also, results have been obtained with speed variations of a bicycle with and without CVPT. Graphs are plotted using the obtained results and analysed