Gear

machines · mechanical · engineering

Teeth that grip. A gear is a rotating wheel covered in teeth. Those teeth lock into the teeth of another gear so they can push each other around.

Passing the spin. Gears transmit rotational motion and torque, which means they hand off spinning power from one part of a machine to another.

Cogs and pegs. Sometimes the teeth are separate pegs stuck into the wheel. Then it's called a cogwheel, and each peg can be called a cog.

Teamwork train. When two or more gears mesh together, the whole group is called a gear train, working as a team.