Worm gears are used when huge planetary gearbox equipment reductions are needed. It’s quite common for worm gears to possess reductions of 20:1, and actually up to 300:1 or greater.
Many worm gears have an interesting property that no various other gear arranged has: the worm can certainly turn the gear, however the gear cannot turn the worm. That is because the position on the worm is so shallow that when the apparatus tries to spin it, the friction between the equipment and the worm retains the worm in place.
This feature pays to for machines such as for example conveyor systems, in which the locking feature can act as a brake for the conveyor when the motor isn’t turning. An added very interesting utilization of worm gears is usually in the Torsen differential, which can be used on some high-performance cars and trucks.