worm gear

American  

Or wormgear

noun

1. a mechanism consisting of a worm engaging with and driving a worm wheel, the two axes usually being at right angles, used where a relatively low speed and a relatively large amplification of power are desired.

2. Also called worm wheel.  a gear wheel driven by a worm.

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worm gear British  

noun

1. a device consisting of a threaded shaft ( worm ) that mates with a gearwheel ( worm wheel ) so that rotary motion can be transferred between two shafts at right angles to each other

2. Also called: worm wheel.  a gearwheel driven by a threaded shaft or worm

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Etymology

Origin of worm gear

First recorded in 1875–80

Example Sentences

Such a worm gear will, I fancy, outwear a dozen of the scientific sort.

From Scientific American Supplement, No. 643, April 28, 1888 by Various

It was therefore easier in rebuilding to include than to omit the pump, even though this required the addition of a cross shaft and worm gear combination.

From The Wright Brothers' Engines and Their Design by Hobbs, Leonard S.

By way of reply Mr. Barr went to the starboard wall of the cabin and pulled a lever connecting with a worm gear.

From The Boy Scouts for Uncle Sam by Goldfrap, John Henry

Tom frantically worked the worm gear that opened the tower.

From Tom Swift and His Submarine Boat, or, under the Ocean for Sunken Treasure by Appleton, Victor [pseud.]

The chain drive also allows the replacement of the sprocket with one of a larger or smaller diameter thereby giving a higher or lower gear ratio, which cannot be done with the worm gear.

From Motor Truck Logging Methods Engineering Experiment Station Series, Bulletin No. 12 by Knapp, Frederick Malcolm