Pinion

Pinion and annular gear

Rack and pinion animation

A pinion is a round gear used in several applications:

• usually the smaller gear in a gear drive train, although in the first commercially successful steam locomotive (the Salamanca), the pinion was rather large.^[1] In many cases, such as remote controlled toys, the pinion is also the drive gear.
• the smaller gear that drives in a 90-degree angle towards a crown gear in a differential drive.
• the small front sprocket on a chain driven motorcycle.
• the round gear that engages and drives a rack in a rack and pinion mechanism and against a rack in a rack railway.
• in the case of radio-controlled cars with an engine (i.e. nitro) this pinion gear can be referred to as a clutch bell when it is paired with a centrifugal clutch.^[2]

See also

• List of gear nomenclature

References

Look up pinion in Wiktionary, the free dictionary.