spur gear

mechanics

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Last updated

July 14, 2026

Quick Summary

A spur gear is a mechanical component with radial teeth that are parallel to its axis. It is a type of toothed wheel used in pairs to transmit and modify rotary motion and torque without slipping. The teeth of one gear engage with the teeth of a mating gear.

When gears have teeth arranged on circles, they maintain constant ratios of rotary speeds and torques. If the smaller gear (pinion) drives the larger gear, it reduces speed and amplifies torque. Conversely, if the pinion is driven by the larger gear, it increases speed and reduces torque. Spur gears are used to connect parallel shafts.1

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gear
…to the shaft axes (spur gears) or by gears with twisted, screwlike teeth (helical gears). Intersecting shafts are connected by gears with tapered teeth arranged on truncated cones (bevel gears). Nonparallel, nonintersecting shafts are usually connected by a worm and gear. The worm resembles a screw, and the gear…
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…to the shaft axes (spur gears) or by gears with twisted, screwlike teeth (helical gears). Intersecting shafts are connected by gears with tapered teeth arranged on truncated cones (bevel gears). Nonparallel, nonintersecting shafts are usually connected by a worm and gear. The worm resembles a screw, and the gear…
Read More