A gear with teeth designed to mesh with the threads of the gear and cause it to rotate
Worm Gear
They are utilized to reduce the speed of something
Spur Geara gear having
radial teeth parallel to the axle
also a spur wheel
Used in
Crown GearA gear in which the gears project at right angles to each other causing motion
Used in mechanical clocks
Rotary MotionThe act of rotating as if on an axis
Gears are an example
When one is moving in linear motion and the other in rotary motion