To provide a method for manufacturing consistently and efficiently manufacturing an excellent inner ring for a self-aligning roller bearing.
The outside diameter of an intermediate portion in the axial direction of a material 8a is largest, and both side portions of the intermediate portion in the axial direction are formed in inclined surface parts 16, 16 inclined in the direction in which the outside diameter is gradually reduced toward each end in the axial direction. A working circumferential surface 10 of a forming roll 11 is brought into contact with outer circumferential surfaces of the material 8a. While the material 8a is not plastically deformed yet, the outer circumferential surface of the material 8a is abutted on the working circumferential surface 10 at a part close to a center part in the axial direction from an end of the material 8a. Further, the tangential direction of the abutted part is agreed with the tangential direction of each generatrix of both circumferential surfaces to prevent application of excessive bearing pressure to the abutted part.
COPYRIGHT: (C)2008,JPO&INPIT
KOBAYASHI KAZUTO
YUGAWA KINJI
Takashi Daejeon
Kinzo Koyama
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