Ntn Corporation

Kimihiro Hanai

Yasuhiro Shimizu

Takashi Tsujimoto

Tsukasa Yamakawa

Shiro Ishikawa

Akira Tsutsui

A tapered roller bearing comprises inner and outer and outer rings having raceways, a large flange surface and a small flange surface, tapered rollers between the raceways and each having large and small end faces at the ends, and a retainer for the tapered rollers. The average roughness of the large end faces and the large flange surface is 0.14 &mgr;m Ra or less. The radius of curvature of the large end faces is 75 to 85% of the roller reference radius, and the central angle of the contact positions between the tapered rollers and the large flange surface is to of the roller angle. The center of the contact surface between the tapered rollers and the raceways is offset toward the large end faces from the center of the rolling surfaces of the tapered rollers by 10% or less of the effective length of the tapered rollers.

Tapered roller bearing

The boundary between the rolling surface 3a and the larger end surface 3b of a roller 3 and the boundary between the rolling surface 3a and the smaller end surface 3c are formed with rounded portions Rb and Rc, respectively. The rolling surface 3a and the rounded portion Rb associated with the larger end surface 3b are smoothly continuous with each other through a first arc R1, while the larger end surface 3b and the rounded portion Rb are smoothly continuous with each other through a second arc R2.

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Mie, Japan

Kimihiro Hanai