Journal of Power Sources, Vol.197, 125-135, 2012
The singular point transition concept: A novel continuously variable transmission comprising planetary gear trains and a variator
The singular point transition concept relates a novel type of continuously variable transmission. This transmission comprises a pair of planetary gear trains and a couple of electric motors, used to control the overall speed ratio. Its singularity lies in the topology of operation, with less than 10% of nominal power circulating through the electric path. This low power level is achieved by segmenting the range of operation of the transmission. To validate this technology, a test bed was built. The transmission presented here is able to provide any output/input speed ratio within the interval of 0:1.55, meaning that it also offers the function of an infinite variable transmission. Description of the system and results of experimental tests are presented. The results showed that the transmission is able to function in the whole range of operation. They also showed that under load conditions the fraction of power transmitted through the electric path is maintained around the design value. (C) 2011 Published by Elsevier B.V.
Keywords:Planetary gear train;Continuously variable transmission;CVT;PGT;Infinite variable transmission;IVT