Spherical roller bearing is a rolling-element bearing that permits rotation with low friction, and permits angular misalignment. Typically these bearings support a rotating shaft in the bore of the inner ring that may be misaligned in respect to the outer ring. The misalignment is possible due to the spherical internal shape of the outer ring and spherical rollers. Despite what their name may imply, spherical roller bearings are not truly spherical in shape. The rolling elements of spherical roller bearings are mainly cylindrical in shape, but have a profile that makes them appear like cylinders that have been slightly over-inflated.
Double-row spherical roller bearing with central flange
Single-row spherical roller bearing (barrel bearing)
The internal design of the bearing is not standardized by ISO, so it varies between different manufacturers and different series. Some features that may or may not exist in different bearings are:
lubrication features in inner or outer ring
central flange
guide ring or center ring
integrated seals
cage.
External dimensions of spherical roller bearings are standardized by ISO in the standard ISO 15:1998. Some of the common series of spherical roller bearings are: 213, 222, 223, 230, 231, 232, 238, 239, 240, 241, 248, 249.
Spherical bearings are used in countless industrial applications:
gearboxes
wind turbines
continuous casting machines
material handling
pumps
mechanical fans and blowers
mining and construction equipment
pulp and paper processing equipment
marine propulsion and offshore drilling
off-road vehicles.