Planetary Gear Set
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The planetary gear set, the generator motor, and the traction motor are internal to the electronically controlled CVT. The planetary gear set mechanically links the internal combustion engine, the electric traction motor, and the electric generator together. It distributes power between the three elements that it connects. The engine is connected to the carrier, the generator motor is connected to the sun gear, and the traction motor is connected to the ring gear of the planetary gear set.