Method for manufacturing ring member for bearing, and mold for inversion working

Patent metadata

Field	Value
Publication number	US-12409487-B2
Application number	US-202218712251-A
Country	US
Kind code	B2
Filing date	Nov 16, 2022
Priority date	Nov 24, 2021
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A method for manufacturing a bearing ring member includes an inversion step of deforming a workpiece having an annular shape by sandwiching the workpiece between a punch disposed on a first side in a predetermined direction and a die disposed on a second side. The punch has a first R surface formed in a circular arc shape. The die has a second R surface formed in a circular arc shape, and a tapered surface inclined with respect to the predetermined direction. The inversion step includes a first step of deforming the workpiece using the punch and the die in a state where the first R surface and the second R surface are in contact with the workpiece, and a second step of deforming the workpiece using the punch and the die in a state where the first R surface and the tapered surface are in contact with the workpiece.

First claim

The invention claimed is:

1. A method for manufacturing a bearing ring member having a cylindrical shape, the method comprising:
an inversion step of deforming a workpiece having an annular shape by sandwiching the workpiece between a punch disposed on a first side of the workpiece and a die disposed on a second side of the workpiece opposite to the first side in a predetermined direction in which the punch and die are configured to move relative to each other,
wherein the punch includes a first R surface formed in a circular arc shape in a cross section parallel to the predetermined direction,
the die includes a second R surface formed in a circular arc shape in a cross section parallel to the predetermined direction, and a tapered surface formed on the second side of the second R surface and inclined with respect to the predetermined direction, and
the inversion step includes a first step of deforming the workpiece using the punch and the die in a state where the first R surface and the second R surface are in contact with the workpiece, and a second step of deforming the workpiece using the punch and the die in a state where the first R surface and the tapered surface are in contact with the workpiece, after the first step.

2. The method for manufacturing a bearing ring member according to claim 1 ,
wherein in the first step, no sliding occurs between the workpiece and the second R surface, and
in the second step, sliding occurs between the workpiece and the tapered surface.

3. The method for manufacturing a bearing ring member according to claim 1 ,
wherein 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 calculated using Formula (1),

M
=

W
W

×

t
2

4

⁢
Y

(
1
)

in Formula (1), W W is a width of the workpiece, t is a thickness of the workpiece, and Y is a yield stress of the workpiece.

4. The method for manufacturing a bearing ring member according to claim 1 ,
wherein an inclination angle of the tapered surface with respect to the predetermined direction is smaller than 30 degrees, and
Formula (2) is satisfied at a time that an inclination angle θ of the workpiece with respect to the predetermined direction is 30 degrees,

Z
d

<

W
W

×
A

(
2
)

in Formula (2), Z d is a distance between a radially inner edge of an end portion on the second side of the workpiece and a contact point between the workpiece and the first R surface, W W is a width of the workpiece, and A is a constant of 0.2 or more and 0.6 or less.

5. The method for manufacturing a bearing ring member according to claim 1 ,
wherein the punch includes a main body portion having a columnar shape on which the first R surface is formed,
an inclination angle of the tapered surface with respect to the predetermined direction is smaller than 30 degrees, and
Formula (3) is satisfied at a time that an inclination angle θ of the workpiece with respect to the predetermined direction is 30 degrees,

{

(

D
p

/
2

-

r
p

)

-

d
bi

/
2

}

+

2
⁢
π
⁢

r
p

⁢

90
⁢
°

-
θ

360
⁢
°

<

D

b
⁢
o

-

d

b
⁢
i

2

×
A

(
3
)

in Formula (3), D p is a diameter of the main body portion, r p is a radius of first R surface, d bi is an inner diameter of the workpiece, D bo is an outer diameter of the workpiece, and A is ⅖.

6. The method for manufacturing a bearing ring member according to claim 1 ,

Assignees

• Nsk Ltd

Inventors

• Tezuka Kenji
• Hagiwara Nobuyuki

Classifications

• B23P15/003

  bearings (see also F16C33/00) · CPC title

• B21K1/04

  ball-races {or sliding bearing races} · CPC title

• B21D53/12

  cages for bearings · CPC title

• B21D22/28

  of cylindrical articles using consecutive dies · CPC title

• B21D22/26

  for making peculiarly, e.g. irregularly, shaped articles · CPC title