| 摘要 |
A tapered roller bearing (1A) includes an outer ring (11), an inner ring (12), a plurality of tapered rollers (13), and a holder (20). The outer ring (11), the inner ring (12) and the tapered roller (13) each are made of steel containing 0.6 mass% or more and 1.50 mass% or less of carbon, 0.15 mass% or more and 2.50 mass% or less of silicon, 0.30 mass% or more and 1.50 mass% or less of manganese, and 0.20 mass% or more and 2.00 mass% or less of chromium, with the rest made up of impurities. A nitrogen concentration in a surface layer portion under a contact surface is 0.3 mass% or more. The holder (20) includes a small annular portion, a large annular portion, and a plurality of column portions. A pocket has a trapezoidal shape in which a portion housing a small diameter side of the tapered roller (13) is located on a reduced width side while a portion housing a large diameter side of the tapered roller (13) is located on an increased width side. Each of the column portions on the reduced width side of the pocket is provided with a cutout. |
