A ball bearing is a common type of rolling-element bearing, a kind of bearing. The term ball bearing means a bearing assembly, which uses spherical bearings as the rolling elements. It also means an individual ball for a bearing assembly. Ball bearings typically support both axial and radial loads and can tolerate some misalignment of the inner and outer races. Ball bearings tend to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact area that spherical shapes provide.
Ball bushings operating on hardened steel shafts provide many of the low friction, minimal characteristics of radial rolling bearings. The ball bushings, which provides linear travel along the shaft, limited only by built-in motion stoppers, contains three or more oblong circuits of recirculating balls. One portion of the oblong ball complement supports the load on the rolling balls while the remaining balls operate with clearance in the return track. Ball bushings can be lubricated with medium-heavy weight oils or with a light grease to prevent wear and corrosion for high linear speeds, light oils are recommended. Seals can be provided; however, friction is increased significantly.