Tapered roller bearings are a unique subset of axial roller bearings in which the rollers are tapered rather than straight right cylindrical. The roller shape allows thrust loads to be withstood in addition to the radial loads. A familiar application for tapered roller bearings is the central hub bearings for automobile wheels. When an auto traverses a turn, the wheels must withstand a significant lateral force, so that tapered roller bearings are necessary.
Tapered roller bearings have an intriguing geometry. If all rolling-contact surfaces are projected out to form cones, all cone tips converge at a single point on the central axis of the bearing. This fact enabled early machine designers to have tapered bearings fabricated without CNC equipment. The following two figures show how tapered roller bearing geometry is derived. Note how it is intuitive how the full cones roll about one another.