To provide a manufacturing method which can stably form the inner race and the outer race of a rolling bearing.
A partially fabricated item 3 includes a large diameter outer race portion 4 and a small diameter inner race portion 5. The outer circumference of one end portion of the inner race portion 5 is connected to the inner circumference of one end portion of the outer race portion 4. A bottom 6 is provided on the inner circumference of the other end portion of the inner race portion 5. The partially fabricated item 3 is separated into the outer race portion 4 and the inner race portion 5 by cutting off the connecting portion between the outer race portion 4 and the inner race portion 5, and the bottom 6 of the inner race portion 5 is punched out. Then, the separated outer race portion 4 and the separated inner race portion 5 are formed into required shapes by rolling respectively. In the outer race portion 4 to be processed by the rolling process, one first end portion 4a connected to the inner race portion 5 is formed into a tapered shape such that the inner circumferential edge of the end face approaches toward the other second end portion 4b. Further, in the inner race portion 5 to be processed by the rolling process, one first end portion 5a connected to the bottom 6 is formed into a tapered shape such that the inner circumferential edge of the end face approaches toward the other second end portion 5b.
KOYAMA HIROSHI
Hironori Honda
Toshimitsu Ichikawa
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