US 12,409,488 B2
Method for manufacturing bearing ring member
Nobuyuki Hagiwara, Takasaki (JP); and Kenji Tezuka, Takasaki (JP)
Appl. No. 18/712,254
Filed by NSK Ltd., Tokyo (JP)
PCT Filed Nov. 16, 2022, PCT No. PCT/JP2022/042611
§ 371(c)(1), (2) Date May 22, 2024,
PCT Pub. No. WO2023/095702, PCT Pub. Date Jun. 1, 2023.
Claims priority of application No. 2021-189961 (JP), filed on Nov. 24, 2021; and application No. 2022-015064 (JP), filed on Feb. 2, 2022.
Prior Publication US 2025/0010356 A1, Jan. 9, 2025
Int. Cl. B21D 53/10 (2006.01)
CPC B21D 53/10 (2013.01) 20 Claims
OG exemplary drawing
 
1. A method for manufacturing a bearing ring member, the method comprising:
an inversion step of sandwiching a workpiece including a workpiece body portion having an annular shape between one or more punches disposed on a first side in an axial direction and a plurality of dies disposed on a second side opposite to the first side, and deforming the workpiece using the one or more punches and the plurality of dies such that the workpiece body portion has a cylindrical shape,
wherein the inversion step includes, in the following order, a first step of deforming the workpiece using a first die of the plurality of dies in a state where no sliding occurs between the workpiece and the first die, and a second step of deforming the workpiece using a second die of the plurality of dies in a state where a sliding occurs between the workpiece and the second die, and
a bending moment acting on the workpiece in the first step is smaller than a predicted value M of a limiting bending moment of the workpiece body portion calculated by Formula (1),

OG Complex Work Unit Math
where WW is a width of the workpiece body portion, t is a thickness of the workpiece body portion, and Y is a yield stress of the workpiece body portion.