Bearing (mechanical)

A bearing is a device to permit fixed direction motion between two parts, typically rotation or linear movement. Bearings may be broadly grouped by the way they work. The most common of the many types are plain bearings and rolling-element bearings.

The two main types of rolling-element bearings are ball bearings and roller bearings. In ball bearings, the rolling elements are spherical balls. In roller bearings, the rolling elements are cylindrical, taper or spherical rollers. Ball bearings are shown in the pictures.

Other websites

Comprehensive article on bearings Archived 2016-01-23 at the Wayback Machine
How Bearings Work - Animations and functioning
How Bearings Work - - Animations on www.mechanismen.be
Early Bearing Failure Detection Archived 2008-02-08 at the Wayback Machine - Case study
Catalogs, CAD files and more Bearings information from Bosch Rexroth^{[permanent dead link]}