ELEVATOR

A worm and worm gear, also known as a worm drive, is a type of gear arrangement where a worm (which is a screw) meshes with a worm gear (which is similar in appearance to a spur gear). This setup is commonly used when a high reduction ratio is needed, allowing for the transmission of motion and power between non-parallel and non-intersecting shafts, typically at a right angle.

A gear train is a mechanical system composed of multiple gears that work together to transmit motion and power from one part of a machine to another. Gear trains are used to change the speed, torque, and direction of a power source.