Worm and Worm Gears are used when large gear reductions are needed. It is common for worm gears to have reductions of 20:1, and even up to 300:1 or greater. The reduction ratio is determined by the number of starts of the worm, and number of teeth on the worm gear. For instance, if the gear has 20 teeth and the worm has a single thread, the ratio is 20:1.
Many worm gears have an interesting property that no other gear set has: the worm can easily turn the gear, but the gear cannot turn the worm. This is because the angle on the worm is so shallow that when the gear tries to spin it, the friction between the gear and the worm holds the worm in place. It is self locking.
This feature is useful for machines such as conveyor systems, in which the locking feature can act as a brake for the conveyor when the motor is not turning. It acts as a safety feature.
Worm gears have sliding contact which is quiet but tends to produce heat and have relatively low transmission efficiency.
The Threaded part is the Worm and the part with gear teeth is the Worm Gear. We can make both in Bronze, Plastics, Aluminums, Steels and Stainless Steels.
The most common materials for a Set is to have the Worm in Steel and the Worm Gear in Bronze. But each application may have different requirements.
Next Day Gears can manufacture Worm Gears very quickly. We offer seven different delivery options to choose from.