Simulation Based Optimization of a Motorcycle Drive Train by the Integration of a Novel Continuously Variable Planetary Transmission

Meeting upcoming emission limits such as EURO 5 with comparatively simple and low-cost vehicles will be very challenging. On the engine side, a big effort in terms of fuelling, combustion optimization as well as exhaust gas aftertreatment will be necessary without any doubt. Besides that, additional system optimization potential can be gained by a systematic adaptation of the drive train. One approach is to use a CVT (Continuously Variable Transmission) system to run engines in specific ranges with good fuel economy. However, existing belt driven CVTs show comparatively poor efficiencies. To overcome this drawback, the integration of a novel Continuously Variable Planetary Transmission (CVP), designed and developed by Fallbrook Technologies, was investigated in detail. For this purpose, a longitudinal dynamics simulation in Matlab-Simulink was carried out to compare a standard mass production vehicle drive train with several CVP setups.