An all - new 111 - kW electric drive unit uses two electric motors working with planetary gear sets to mix - n - match power delivery depending on need. (Autoweek.com)
Another goal was to implement the nine gears with a minimal number of planetary gear sets and shift elements. (greencarcongress.com)
The gear ratio is determined by the number of teeth on the smaller, planetary gears in ratio to the number of teeth on the larger, sun gear. (yourmechanic.com)