Worm Gears Explained
Worm gears are highly useful gear types that allow for enormous control over the speed and movement of a gear system. These gears can provide a large amount of gear reductions in a system, from about 20 to 1 to over 300 to 1, which is highly useful in delicate systems that require precise control. Worm gears are designed so that the worm part of the system can turn the gear, but the gear cannot turn the worm part on its own. This makes the gear safer, and will prevent forcible breaks and turns in the gear system if the gear tries to shift or move on its own.
A worm gear has a typical gear on the bottom half of the gear, but on top, instead of the top gear looking like another traditional cog gear, the top gear is a spiral shape that looks somewhat like a mix between a corkscrew and a wall screw. The ridges on the worm gear are designed to fit perfectly between the bottom gear cogs, turning the gear at a precise rate that moves the gear at a precise, predetermined speed.
Worm gear systems are used in a variety of places, but the most common place to see the gears used is as a safety feature in conveyor systems. When the motor is turned off, the braking power of the top worm gear prevents the conveyor from moving at all until the motor is turned back on. This prevents safety risks and other potential problems that could injure humans or cause damage to products or goods. You may also find a worm gear system used in the very unique Torsen differential system, which some high-performance vehicles use for extra control and safety in the system under extreme conditions.