Simpson compound planetary gear set

This animation shows a Simpson compound planetary gear set, used in automatic transmissions. It is made of two planetary gear sets sharing the same sun gear (colored orange in the movies). The green planet carrier turns together with the green ring gear. Each movie shows a different transmission ratio (see table below). Number of teeth: Sun Gears 24 Planets 12 Ring Gears 48 1st Gear: Input: Yellow Ring Gear Output: Green Planet Carrier/Ring Gear Blue Planet Carrier held stationary Ratio: 2.2 : 1 2nd Gear: Input: Yellow Ring Gear Output: Green Planet Carrier/Ring Gear Red Sun Gear held stationary Ratio: 1.5 : 1 3rd Gear: Input: Yellow Ring Gear Output: Green Planet Carrier/Ring Gear All parts turn together Ratio: 1 : 1 Reverse: Input: Red Sun Gear Output: Green Planet Carrier/Ring Gear Blue Planet Carrier held stationary Ratio: -2 : 1