Sintered bearing

Patent metadata

Field	Value
Publication number	US-9939015-B2
Application number	US-201615236913-A
Country	US
Kind code	B2
Filing date	Aug 15, 2016
Priority date	Mar 7, 2012
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Provided is a sintered bearing ( 1 ) including an inner layer ( 2 ) and an outer layer ( 3 ) formed by integral molding, the sintered bearing ( 1 ) having a bearing surface (A) formed on an inner peripheral surface ( 2 a ) of an inner layer ( 2 ). The inner layer ( 2 ) is made of sintered metal containing Fe and a hardness increasing element (such as Ni or Mo). The outer layer ( 3 ) is made of sintered metal containing Fe and no hardness increasing element. A concentration gradient of the hardness increasing element is present at an interface between the inner layer ( 2 ) and the outer layer ( 3 ).

First claim

The invention claimed is:

1. A manufacturing method for a sintered bearing, the manufacturing method comprising:
molding a green compact having a cylindrical shape, the green compact having an inner layer and an outer layer provided on a radially outer side of the inner layer; and
sintering the green compact to obtain a sintered compact having an inner layer and an outer layer provided on a radially outer side of the inner layer, a bearing surface being provided on an inner peripheral surface of the inner layer of the sintered compact,
wherein the inner layer of the green compact is made of Fe as a main component, C, and a quenching-property enhancing element, and the outer layer of the green compact is made of Fe and no quenching-property enhancing element.

2. The manufacturing method for the sintered bearing according to claim 1 , wherein the quenching-property enhancing element comprises at least one of Ni, Mo, Mn, and Cr.

3. The manufacturing method for the sintered bearing according to claim 1 , wherein the inner layer of the green compact is made of Fe, Cu, C, Ni, Mo, and inevitable impurities as the balance, and the outer layer of the green compact is made of Fe, Cu, C, and inevitable impurities as the balance.

4. The manufacturing method for the sintered bearing according to claim 3 ,
wherein the inner layer of the green compact is made of 15 to 20 wt % of Cu, 0.3 to 0.8 wt % of C, 1.5 to 3.5 wt % of Ni, 0.5 to 1.5 wt % of Mo, Fe, and the inevitable impurities as the balance, and
wherein the outer layer of the green compact is made of 2 to 5 wt % of Cu, 0.2 to 0.8 wt % of C, Fe, and the inevitable impurities as the balance.

5. The manufacturing method for the sintered bearing according to claim 1 , wherein at least one of the inner layer of the green compact and the outer layer of the green compact contains Cu.

6. The manufacturing method for the sintered bearing according to claim 5 , wherein a mixing ratio of Cu in the outer layer of the green compact is lower than a mixing ratio of Cu in the inner layer of the green compact.

7. A manufacturing method for a sintered bearing, the manufacturing method comprising:
molding a green compact having a cylindrical shape, the green compact having an inner layer and an outer layer provided on a radially outer side of the inner layer; and
sintering the green compact to obtain a sintered compact having an inner layer and an outer layer provided on a radially outer side of the inner layer, a bearing surface being provided on an outer peripheral surface of the outer layer of the sintered compact,
wherein the outer layer of the green compact is made of Fe as a main component, C, and a quenching-property enhancing element, and the inner layer of the green compact is made of Fe and no quenching-property enhancing element.

8. The manufacturing method for the sintered bearing according to claim 7 , wherein the quenching-property enhancing element comprises at least one of Ni, Mo, Mn, and Cr.

9. The manufacturing method for the sintered bearing according to claim 7 , wherein the outer layer of the green compact is made of Fe, Cu, C, Ni, Mo, and inevitable impurities as the balance, and the inner layer of the green compact is made of Fe, Cu, C, and inevitable impurities as the balance.

10. The manufacturing method for the sintered bearing according to claim 9 ,
wherein the outer layer of the green compact is made of 15 to 20 wt % of Cu, 0.3 to 0.8 wt % of C, 1.5 to 3.5 wt % of Ni, 0.5 to 1.5 wt % of Mo, Fe, and the inevitable impurities as the balance, and
wherein the inner layer of the green compact is made of 2 to 5 wt % of Cu, 0.2 to 0.8 wt % of C, Fe, and the inevitable impurities as the balance.

11. The manufacturing method for the sintered bearing according to claim 7 , wherein at least one of the inner layer of the green compact and the outer layer of the green compact contains Cu.

12. The manufacturing method for the sintered bearing according to claim 11 , wherein a mixing ratio of Cu in the inner layer of the green compact is lower than a mixing ratio of Cu in the outer layer of the green compact.

Assignees

• Mouri Toshihiko
• Yoshizuka Noriyoshi
• Sugai Yousuke
• Satoji Fuminori
• Ntn Toyo Bearing Co Ltd

Inventors

• Mouri Toshihiko
• Yoshizuka Noriyoshi
• Sugai Yousuke
• Satoji Fuminori

Classifications

• B22F5/106

  Tube or ring forms · CPC title

• C22C38/08

  containing nickel {(C22C38/105 takes precedence)} · CPC title

• F16C33/145

  of sintered porous bearings · CPC title

• C22C38/16

  containing copper · CPC title

• B22F7/06

  of composite workpieces or articles from parts, e.g. to form tipped tools {(B22F7/002 takes precedence)} · CPC title