Method for manufacturing ring-shaped member

Patent metadata

Field	Value
Publication number	US-10272485-B2
Application number	US-201515115698-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 14, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

There is provided a method for manufacturing ring-shaped members at a good yield and high production efficiency. To achieve this object, the following is performed. A single (a sequence of) forging produces a joined body formed by radially coupling four cylindrical portions with different inner diameter sizes. A cylindrical member that has the largest inner diameter size and a cylindrical member that has the third largest inner diameter size after the forging are employed as ring-shaped members without change. A rolling process is performed on respective cylindrical member that has the smallest inner diameter size and cylindrical member that has the second largest inner diameter size to obtain ring-shaped members. Thus, two sets of ring-shaped members are obtained as two sets of inner rings and outer rings.

First claim

The invention claimed is:

1. A method for manufacturing a ring-shaped member, comprising:
a forging step of forming a joined body from a round bar material, the joined body comprising a plurality of circular-shaped cylindrical portions coupled with each other;
a cutting and separating step of cutting and separating the joined body to obtain a plurality of cylindrical members; and
a rolling step of expanding an inner diameter size of a part of the plurality of cylindrical members to obtain a ring-shaped member,
wherein the joined body comprising a first cylindrical portion, a third cylindrical portion, a second cylindrical portion, and a fourth cylindrical portion, by radially coupling each other, the third cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the first cylindrical portion, the second cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the third cylindrical portion, the fourth cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the second cylindrical portion,
the rolling step comprises expanding an inner diameter size of a third cylindrical member such that the third cylindrical member has an inner diameter size identical to an inner diameter size of a first cylindrical member to obtain a third ring-shaped member, and expanding an inner diameter size of a fourth cylindrical member such that the fourth cylindrical member has an inner diameter size identical to an inner diameter size of a second cylindrical member to obtain a fourth ring-shaped member, and
wherein the forging step comprises forming the joined body by radially coupling of a bottom end of an inner surface of the first cylindrical portion and an upper end of an outer surface of the third cylindrical portion, an upper end of an inner surface of the third cylindrical portion and a bottom end of an outer surface of the second cylindrical portion, and a bottom end of an inner surface of the second cylindrical portion and an upper end of an outer surface of the fourth cylindrical portion.

2. The method for manufacturing the ring-shaped member according to claim 1 ,
wherein the rolling step includes expanding an inner diameter size of at least one of the third cylindrical member or the fourth cylindrical member while reducing a height of one of the third cylindrical member and/or fourth cylindrical member in an axial direction.

3. The method for manufacturing the ring-shaped member according to claim 1 ,
wherein during the cutting and separating step or after the cutting and separating step, at least one of the third cylindrical member and the fourth cylindrical member is upset.

4. The method for manufacturing the ring-shaped member according to claim 1 ,
wherein the rolling step includes a step of expanding an inner diameter size of the second cylindrical member.

5. The method for manufacturing the ring-shaped member according to claim 2 ,
wherein the rolling step includes a step of expanding an inner diameter size of the second cylindrical member.

6. The method for manufacturing the ring-shaped member according to claim 3 ,
wherein the rolling step includes a step of expanding an inner diameter size of the second cylindrical member.

7. A method for manufacturing a bearing, the method comprising:
a forging step of forming a joined body from a round bar material, the joined body comprising a plurality of circular-shaped cylindrical portions coupled with each other;
a cutting and separating step of cutting and separating the joined body to obtain a plurality of cylindrical members; and
a rolling step of expanding an inner diameter size of a part of the plurality of cylindrical members to obtain a ring-shaped member,
wherein the joined body comprising a first cylindrical portion, a third cylindrical portion, a second cylindrical portion, and a fourth cylindrical portion, by radially coupling each other, the third cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the first cylindrical portion, the second cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the third cylindrical portion, the fourth cylindrical portion having an outer diameter size configured to be identical to an inner diameter size of the second cylindrical portion,
the rolling step comprises expanding an inner diameter size of a third cylindrical member such that the third cylindrical member has an inner diameter size identical to an inner diameter size of a first cylindrical member to obtain a third ring-shaped member, and expanding an inner diameter size of a fourth cylindrical member such that the fourth cylindrical member has an inner diameter size identical to an inner diameter size of a second cylindrical member to obtain a fourth ring-shaped member, and
wherein the forging step comprises forming the joined body by radially coupling of a bottom end of an inner surface of the first cylindrical portion and an upper end of an outer surface of the third cylindrical portion, an upper end of an inner surface of the third cylindrical portion and a bottom end of an outer surface of the second cylindrical portion, and a bottom end of an inner surface of the second cylindrical portion and an upper end of an outer surface of the fourth cylindrical portion.

Assignees

• Nsk Ltd

Inventors

• Kobayashi Kazuto
• Yasuda Yuu

Classifications

• B21H1/12 Primary

  rings for ball or roller bearings · CPC title

• B21K1/04

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

• F16C33/64

  Special methods of manufacture · CPC title

• F16C19/06

  with a single row or balls · CPC title