Ravigneaux Planetary Gear Set (Animation)
A Ravigneaux planetary gear set is a compound (or double) planetary gear set. It was invented by Pol Ravigneaux. This kind of gear set has two sun gears, a large sun and a small sun, and a single planet carrier, holding two sets of planetary gears, inner planets and outer planets. Furthermore, it has a ring gear. It is commonly used in automatic transmissions.