ELI5: Explain Like I'm 5

Ravigneaux planetary gearset

Have you ever seen a toy car with wheels that spin, and when you turn the handle, the car moves forward or backward? That's how a Ravigneaux planetary gearset works! Let me explain in simpler terms.

Imagine a big circle (we'll call it the sun gear), with small circles (we'll call them planet gears) spinning around it, all inside a ring-shaped gear (we'll call it the ring gear). The sun gear is connected to the engine, and the ring gear is connected to the wheels of the car.

Now, if we want the car to go forward, we need to make sure the sun gear spins faster than the ring gear. The planet gears help with that. They have teeth on the outside that mesh with the sun gear and teeth on the inside that mesh with the ring gear. By spinning around the sun gear (like spinning around the playground), they transfer power to the ring gear and make the car move forward.

But wait, there's more! To make the car go faster or slower, we can add another set of planet gears (called the "wheels"). These wheels spin around the first set of planet gears and have teeth on the outside that mesh with the sun gear and teeth on the inside that mesh with the ring gear. By adding more planet gears, we get a twisted gear train that can change the speed of the car without changing the direction of the movement.

So, in summary, a Ravigneaux planetary gearset is a set of gears that help transfer power from the engine to the wheels of a car, using a system of circles with teeth on the outside and inside that mesh together. By adding more gears, we can change the speed of the car without changing direction.