https://newatlas.com/automotive/geared-cvt-ratiozero/
World's first geared CVT: A 'holy grail' transmission in prototype form
The efficiency of a tooth-on-tooth geared transmission, with the smoothly variable gear ratios of a CVT – minus the belt friction and capable of going all the way down to a zero ratio without needing a clutch. That's a 'holy grail' level promise!
Italian company Alter Ego, led by mechanical and automation engineer Edyson Pavilcu and assisted by kinematic studies undertaken at the Milan Technical University, says it's prototyped a beautifully complex new mechanism – the world's first geared CVT – that's 10% more efficient than a regular belted CVT.
Indeed, the efficiency is on par with some manual transmissions, while offering the ability to smoothly adjust gear ratios from zero all the way up to overdrive, whether the wheels and/or crank are turning or not.