Ball Bearings
- shares

A ball bearing is an antifriction bearing consisting of a hardened inner and outer race with a series of hardened steel balls separating the two. "Sealed" bearings have plastic dust seals and are greased only at the time of manufacture. They are often found in gearsets like car transmissions between gears, and between the housing and the rotating shafts. The helical gears used in most transmissions have angled teeth -- this causes a thrust load that must be supported by a bearing.