DOUBLE ROW TAPERED ROLLER BEARING, RACE RING AND METHOD OF MANUFACTURING DOUBLE ROW TAPERED ROLLER BEARING

摘要

PROBLEM TO BE SOLVED: To provide a double row tapered roller bearing having suppressed manufacturing cost.SOLUTION: The double row tapered roller bearing comprises an outer ring 2 being a race ring having an annular shape, an inner ring 5 arranged at an inner periphery side of the outer ring 2 and being a race ring having an annular shape and rollers 6. Two rows of grooves 19 having bottom surfaces acting as rolling contact surfaces are formed in the outer circumferential surface opposing the outer ring 2, of the inner ring 5. The rollers 6 are arranged inside the grooves 19 so as to come in contact with the rolling contact surface of the inner ring 5 and are the tapered rollers in contact with the outer ring 2. A region adjacent to the grooves 19 in the outer circumferential surface of the inner ring 5 includes a hardened region 15 extending from the inner circumferential surface of the grooves 19 to the region adjacent to the grooves 19 and a non-hardened region 18 arranged at a position spaced apart from the grooves 19 rather than the hardened region 15 and at the same time having a lower hardness than that of the hardened region 15.SELECTED DRAWING: Figure 9