There's a more specific type of gear that allows your automatic gearbox to operate. It's called the planetary gear set and the way it works will have your head swimming in concentric circles.

More and more modern cars only offer automatic transmissions, some of them conventional, and some of them CVTs. What's the difference between them?

Planetary gears fall into this category, and as a technology that has been around for thousands of years, it’s fun to think about them turning away in most modern automatic transmissions.

A modern automatic transmission uses one or more sets of epicyclic or planetary gears (consisting of a sun, planets, and a ring gear) to achieve many different (typically between two and ten) gear ...

The automatic transmission is made up of three parts: the torque converter, the planetary gears, and the brake bands and clutches. As the engine runs, it spins the torque converter's impeller ...

The gear ratio and the direction of travel depend on which element is performing each function. Most transmissions have more than one planetary gear set to provide a variety of gear ratios.

Seung Cheal Jung, Seung Gyun Ahn, Hak Jin Kim, Young Woo Kim, Effect of Normalized Microstructure in Alloy Steel on the Performance of Planetary Gear Set of Automatic Transmission, SAE Transactions, ...

Despite all the benefits of a CVT transmission, it does have some drawbacks. A gear-based CVT is looking to address these drawbacks, but how does it work?

One of the most common applications of planetary (epicyclic) gear sets is found in automotive transmissions. A planetary gear set typically total torque applied to be shared by multiple planets making ...

The downside to the CVT is that its behavior to accomplish this lies at direct odds with the proper behavior of an automatic transmission. With over one hundred years of having a set number of gears ...

Multiple speed transmissions use multiplication of gears to create different speeds. The first gear set is multiplied by the next, which is multiplied by any subsequent gears sets to eventually ...

The FMX’s time-proven Ravigneaux planetary gear set, known for extreme durability, is the heart of all AOD, AOD-E, and 4R70W transmissions.