There are three types of thin-section bearings: deep groove, four-point contact, and angular contact. Compared with standard-section ball bearings, all three offer advantages in reduced space requirements and low cost. They are used primarily where shaft location is the major requirement.
As structural components, thin-section bearings behave differently than standard bearings because their bearing rings are quite flexible. Under load, the rings follow the imperfections of shaft and bores, so these components must be geometrically accurate.
The four-point contact bearing supports thrust loads in either direction and is much more effective in resisting moment loads than the deep-groove design.
Two other designs use an axial split in the outer ring to increase ball complement and radial capacity without sacrificing thrust capacity. One is a full-complement design, the other uses alternating full-size balls and spacer balls. The latter type also has high shoulders on the outer ring to provide integral shields for grease lubrication. Both types are held together with wire bands after assembly.