With the introduction of spherical plain bearings, both those that require maintenance as well as those that do not require maintenance,
since more than a half a century ago, it has been possible, thanks to their application, to obtain notable advantages,
such as: the transmission of movement and load in the absence of cups and therefore in the absence of radial loads and flexion tension
in the structural elements.
The use of spherical plain bearings is extremely varied because it covers every sector of the construction of a machine, plants and vehicles.
Normally when one speaks about spherical plain bearings, one intends coupled steel/steel,
products particularly used in the presence of alternating loads, dynamic and crash type solicitation.
The spherical plain bearings with steel/steel coupling are products which use precious steel of revolving bearings;
together the rings are polished, tempered and rectified on all sides, the successively treated on the sliding surface
using (phosphate to manganese) procedure, adopted long ago, then successively protected with layers of bisulphide of
molybdenum This procedure insures excellent resistance to wear, given the bearings are lubricated at the foreseen intervals.
The steel/steel spherical plain bearings can be divided into 3 categories based on the direction of the load: radial, axial and angular contact.