The projections at both the raceway and roller apex meet at a common point on the main axis of the bearing. This tapered geometry provides true coaxial rotation and prevents sliding motion between the raceway and roller, which reduces wear and fatigue on the components.
Tapered roller bearings are capable of carrying both radial and axial loads, whereas other types of bearings are primarily designed to carry one type of load. Whether the load on the bearing is radial, axial, or a combination of both, the tapered design creates a resultant force that pushes the rollers against the flange or rib of the cone. This force holds the rollers against the flange and keeps the rollers aligned. Engineers typically design systems using tapered roller bearings to accommodate equal axial forces in both directions.
Another advantage of tapered roller bearings is adjustable clearance. The outer and inner ring assemblies are separable, so end play (axial play) or preload (axial interference) is created during installation by axially moving the outer or inner ring. In many applications, a slight preload will maximize bearing performance and life. However, it should be noted that excessive preload can greatly shorten bearing life or generate high temperatures that can quickly lead to bearing failure.
A third advantage of tapered roller bearings is the ability to support higher load capacities than ball bearings of the same size. The line contact between each roller and raceway provides a wider load-bearing surface than the point contact of the balls - so for the same load capacity, a tapered roller bearing will be smaller than a ball bearing.
Despite the advantages of tapered roller bearings, disadvantages do exist. These bearings have speed limitations and are very sensitive to misalignment, so engineers should consider other types of bearings for applications with high misalignment or high-speed requirements.
Tapered roller bearings are typically used in medium-speed, heavy-load applications with multi-directional loads. Examples include gearboxes, differentials, wheel hubs and railroad axles, as well as agricultural, construction and mining equipment.
