Ball Bearings
 
Ball Bearings are a type of rolling-element bearing that uses balls to maintain the separation between the moving parts of the bearing. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. Radial Ball bearings can support moderate radial loads and moderate axial loads (parallel to the shaft). They can operate at high speeds (400,000 RPMs and higher). Ball bearings with shields or seals for protection can be lubricated to last for the operating life. Sometimes ball bearings are also called deep groove ball bearings.
 
Generally speaking, precision ball bearings comply to ABEC-1 and ABEC-3 tolerances while high-precision ball bearings comply to ABEC-5, ABEC-7, or ABEC-9 tolerances.
 
Ball bearings are the most popular of all the ball bearing types because they are available in a wide variety of seal, shield and snap-ring arrangements.
 
The bearing ring grooves are circular arcs made slightly larger than the radius of the ball. The balls make point contact with the raceways (elliptical contact when loaded). The inner ring shoulders are of equal height (as the outer ring shoulders).
 
Ball bearings can sustain radial, axial, or composite loads and because of simple design, this bearing type can be produced to provide both high-running accuracy and high-speed operation.