Spherical bearing

Typically these bearings support a rotating shaft in the bore of the inner ring that must move not only rotationally, but also at an angle.

The outer surface of the inner ring and the inner surface of the outer ring are spherical and are collectively considered the raceway and they slide against each other, either with a lubricant, a maintenance-free (typically polytetrafluoroethylene or PTFE) based liner, or they incorporate a rolling element such as a race of ball-bearings, allowing lower friction.

Spherical bearings are used in car suspensions, engines, driveshafts, heavy machinery, sewing machines, robotics and many other applications: wherever rotational motion must be allowed to change the alignment of its rotation axis.

An example, although this is rarely used in practice, is the drive axle bearings of a vehicle control arm (or A-arm) suspension.

This is a simple concept that illustrates a possible application of a spherical bearing.