Frae Wikipedia
Lowp tae: navigation, rake
Twa meshin gears transmittin rotational motion. Note that the smawer gear is rotatin faster. Syne the lairger gear is rotatin less quickly, its torque is proportionally greater. Ane subtlety o this pairticular arrangement is that the linear speed at the pitch diameter is the same on baith gears.

A gear is a rotatin machine pairt haein cut teeth, or cogs, which mesh wi anither tuithed pairt tae transmit torque. Geared devices can change the speed, torque, an direction o a pouer soorce.