noun Machinery.
- a bearing consisting of a number of hard balls running in grooves in the surfaces of two concentric rings, one of which is mounted on a rotating or oscillating shaft or the like.
- any of the balls so used.
noun
- a bearing consisting of a number of hard steel balls rolling between a metal sleeve fitted over the rotating shaft and an outer sleeve held in the bearing housing, so reducing friction between moving parts while providing support for the shaft
- a metal ball, esp one used in such a bearing
- A ring-shaped track containing hard metal balls that roll freely, used to reduce friction where a rotating element (such as an axle) is attached to a fixed point.
- A hard ball used in such a track.