Planetary gear definition
Planetary gears mean that the axis of rotation is not fixed and is mounted on a rotatable bracket (blue) (the black part is the housing and the yellow is the bearing). Planetary gears (green) can rotate around their own axis of rotation (BB) like fixed-axis gears, and their axes of rotation follow the axes of other gears (AA) with blue brackets (called planet carriers). Turn. The rotation around its own axis is called "rotation", and the rotation around the other gear axes is called "revolution", just like the planets in the solar system, hence the name.