Roller bearings are rolling bearings with cylindrical, needle, tapered or barrel rollers as rolling elements. Certain series can support not only radial forces but also axial forces in one or both directions.
A cylindrical rolling element is in contact with a flat support surface not at one point only but over its surface line. As opposed to the ball, line contact is thus present.
In contrast to the ball, the roller has a larger contact area perpendicular to the roller axis. It can therefore transmit higher forces, has greater rigidity and allows smaller rolling elements under the same load. The shape and size of the contact area depends, in the case of the roller, only on the magnitude of the load and the length of the contact line. If the roller diameter remains unchanged, the load carrying capacity of the roller increases with length.
The bearings generally consist of these components:
inner and outer rings with rolling element raceways
seals on one side or both sides of the bearing
lubricant in the case of grease lubrication.