What type of worm gear eliminates reverse?

The correct answer is based on the functioning of the gear system known as the worm gear. A quadruple worm gear uses a design that effectively prevents reverse motion due to the way the threads engage with the worm wheel. In this configuration, there are multiple threads that create engagement points, which significantly enhances the grip and ensures that torque is transferred in only one direction.

This unique setup allows for a locking mechanism where the load on the gear keeps it engaged in a way that prohibits unintended reverse movement. As the load increases, the friction between the worm and the wheel actually increases, further locking the system in place.

In contrast, other types of worm gears, such as single, double, or triple configurations, do not incorporate enough threads to fully eliminate the possibility of reverse motion under certain conditions. These arrangements may still allow for some backward motion if not adequately loaded or if the system is not aligned perfectly. The quadruple design stands out because it not only manages load but also optimizes the mechanical advantage and locks the motion, reinforcing its primary function of offering one-way driving capability without reverse.