Authors Notes
Gear Mechanisms

What is a gear?

A gear can be described as a wheel with teeth around its edges. Gears can be fixed to a shaft so that it turns at the same speed as the shaft. A gear is a mechanism for transferring and changing movement, speed and force.


One gear wheel, known as the input, is able to drive another gear wheel, known as the output. This occurs when two gear wheels are put next to each other, so that their teeth can be made to interlock. When one wheel is turned it will make the other wheel turn.f both wheels are the same size, the wheels turn at the same speed. If one wheel is larger than the other wheel, then the gears can be used to speed up or slow down movement. They can also be used to increase or decrease a force.