Axle

An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported.

In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle.
Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.

Back to How Gears, Wheels & Axles Work →

Source: Wikipedia · Image: Wikimedia Commons · CC BY 2.5

LEVERLAB

How things move — simple machines, mechanics, and hands-on STEM.

Get new guides by emailOccasional emails. No spam. Unsubscribe anytime.

InformationAbout Contact Privacy Policy Terms of Service Disclaimer Affiliate Disclosure Cookie Policy

Museum entries, images, and facts are drawn from Wikipedia and Wikimedia Commons, used under public-domain and Creative Commons licenses.