Roller bearing, transmission using the same and differential gear

摘要

In order to improve a seizure resistance as well as restricting of a dispersion of a rotation torque, surface roughness of a large diameter side end face (4A) of a tapered roller (4) is defined as a value satisfying both the following conditional expressions (1) and (2). 0.04 mu m≤Ra(r)≤0.1 mu m 0.8≤Ra(r)/Ra(c)≤1.1 where, Ra(r) is an arithmetic average of roughness in a radial direction on the large diameter side end face of the tapered roller, and Ra(c) is an arithmetic average of roughness in a peripheral direction on the large diameter side end face of the tapered roller.