Not all gears have teeth. In a rack and pinion gear, the pinion is the gear wheel and it meshes with the rack, which is a long bar with cogs.
a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion
(When used attributively) Something behaving in similar, jerky, manner as a cogwheel, e.g. cogwheel respiration as a side effect of hyperbaric medicine
Find another word for gear-wheel. In this page you can discover 3 synonyms, antonyms, idiomatic expressions, and related words for gear-wheel, like: gear, geared wheel and cogwheel.