The position of the gate does not change, once set Whether a worm drive is self-locking depends on the lead angle, the pressure angle, and the coefficient of friction.Р”Р„ worm drive controlling a gate. Worm drive configurations in which the wheel cannot drive the worm are called self-locking.

If a multi-start worm (multiple spirals) is used, then the ratio reduces accordingly, and the braking effect of a worm and worm wheel may need to be discounted, as the wheel may be able to drive the worm. This can be an advantage when it is desired to eliminate any possibility of the output driving the input.

This is due to the greater friction involved between the worm and worm wheel, and is especially prevalent when a single-start (one spiral) worm is used. Unlike with ordinary gear trains, the direction of transmission (input shaft vs output shaft) is not reversible when using large reduction ratios. It is also known as globoidal worm gearing. :РІР‚Р‰3Р”Вouble-enveloping worm gearing comprises enveloping worms mated with fully enveloping worm wheels. Р”Р„n enveloping (hourglass) worm has one or more teeth, and increases in diameter from its middle portion toward both ends. This type of gearing can support the highest loading. The final type are double-throated worm drives, which have both gears throated. The second are single-throated worm drives, in which the worm wheel is throated. These don't have a throat, or groove, machined around the circumference of either the worm or worm wheel. There are three different types of gears that can be used in a worm drive.

A double bass features worm gears as tuning mechanisms Types

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