This  conical geometry is used as it gives a larger contact patch, which  permits greater loads to be carried than with spherical (ball) bearings,  while the geometry means that the tangential speeds of the surfaces of  each of the rollers are the same as their raceways along the whole  length of the contact patch and no differential scrubbing occurs. When a  roller slides rather than rolls, it can generate wear at the  roller-to-race interface, i.e. the differences in surface speeds creates  a scrubbing action. Wear will degenerate the close tolerances normally  held in the bearing and can lead to other problems. Much closer to pure  rolling can be achieved in a tapered roller bearing and this avoids  rapid wear.

The  rollers are guided by a flange on the inner ring. This stops the  rollers from sliding out at high speed due to their momentum.

The larger the half angles of these cones the larger the axial force that the bearing can sustain.

Tapered  roller bearings are separable and have the following components: outer  ring, inner ring, and roller assembly (containing the rollers and a  cage). The non-separable inner ring and roller assembly is called the cone, and the outer ring is called the cup. Internal clearance is established during mounting by the axial position of the cone relative to the cup.