Electro-chemical hardening of bearing raceways

Patent metadata

Field	Value
Publication number	US-10746226-B2
Application number	US-201916598855-A
Country	US
Kind code	B2
Filing date	Oct 10, 2019
Priority date	Jun 6, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A method of making bearings includes treating a metallic surface of a bearing raceway with a pulsed electrochemical processing nozzle to transform the amorphous oxide into a crystalline structure on the metallic surface electro-chemically and convert the metallic surface into a ceramic like hardness surface. Treating the metallic surface can include forming a gradient in material composition transitioning from a purely metallic material at a cross-sectional position within the bearing raceway to a purely crystalline structure material at the ceramic like hardness surface of the bearing raceway.

First claim

What is claimed is:

1. A bearing comprising:
a bearing raceway including a raceway with a ceramic like hardness crystalline structure surface over a metallic material; and
ceramic rolling elements disposed at the ceramic like hardness crystalline structure surface.

2. The bearing as recited in claim 1 , wherein the bearing raceway includes a gradient in material composition transitioning from the metallic material at a cross-sectional position within the bearing raceway to a ceramic like hardness crystalline structure material at the surface of the bearing raceway.

3. The bearing as recited in claim 2 , wherein a gradient depth is defined from the cross-sectional position where the gradient in material composition is the metallic material, to the ceramic like hardness crystalline structure surface, wherein the gradient depth is within a range up to 300 microns.

4. The bearing as recited in claim 1 , wherein the ceramic like hardness crystalline structure material is on a radially outward facing surface of an inner raceway, with a radially inward facing metallic surface of the inner raceway being metallic.

5. The bearing as recited in claim 1 , wherein the ceramic like hardness crystalline structure material is on a radially inward facing metallic surface of an outer raceway, with a radially outward facing metallic surface of the outer raceway being metallic.

6. The bearing as recited in claim 1 , wherein the bearing raceway is an inner bearing raceway, wherein the ceramic like hardness crystalline structure material is on a radially outward facing metallic surface of the inner raceway, with a radially inward facing metallic surface of the inner raceway being metallic, and further comprising:
an outer bearing raceway with a ceramic like hardness structure material on the radially inward facing surface of the outer bearing raceway, with a radially outward facing surface of the outer raceway being metallic; and
wherein the inner and outer bearing raceways are assembled together with the ceramic rolling elements therebetween.

7. The bearing as recited in claim 6 , wherein the ceramic rolling elements only contact the inner and outer bearing races on the ceramic like hardness crystalline structure surfaces thereof.

8. The bearing as recited in claim 1 , wherein the ceramic like hardness surface has a hardness greater than or equal to a hardness of 80 on the Rockwell hardness scale.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Hansen Bruce D
• Fallon Jr William P

Classifications

• C25D11/026

  Anodisation with spark discharge · CPC title

• F16C33/64

  Special methods of manufacture · CPC title

• F16C33/62 Primary

  Selection of substances · CPC title

• F16C2206/40

  Ceramics, e.g. carbides, nitrides, oxides, borides of a metal · CPC title

• F16C33/303

  of hybrid bearings, e.g. rolling bearings with steel races and ceramic rolling elements · CPC title