Describe the main operating features of any one of the following: Worm and wheel mechanism - Leaving Cert Engineering - Question i - 2016

A worm and wheel mechanism consists of a gear arrangement in which a worm, shaped like a screw, drives a wheel, similar to a spur gear. This setup is primarily used to change the direction of rotation through 90°, reduce rotational speed, and increase torque.

The further design often seen in projects utilizes the high speed of DC electrical motors. When the wheel attempts to turn the worm, the design ensures that the worm locks in place to prevent back-driving. This feature is crucial in applications needing high torque and safety.