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.

---

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

---

Etymology

Origin of worm gear

First recorded in 1875–80

Example Sentences

In electric cranes the motor is connected to the barrel, either in a similar manner by spur gear or by worm gear.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 6 "Coucy-le-Château" to "Crocodile" by Various

The motion obtained from the worm gear is transferred through suitable gearing to the rack pinion.

From Modern Machine-Shop Practice, Volumes I and II by Rose, Joshua

A spiral spring pressing against one of the journals into which the axle is mounted prevents any lost motion in the worm gear.

From Microscopes and Accessory Apparatus Catalogue No. 40 by Leitz, Ernst

In the worm gear there is no slack to take up and the power can be applied more gradually, thus reducing the chances of spinning the wheels and losing the traction.

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

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.]