Coating method for bearing ring

Patent metadata

Field	Value
Publication number	US-2018128317-A1
Application number	US-201715798543-A
Country	US
Kind code	A1
Filing date	Oct 31, 2017
Priority date	Nov 7, 2016
Publication date	May 10, 2018
Grant date	—

Abstract

A method of producing a bearing ring of a rolling element bearing. External surfaces of the bearing ring are provided with an electrically insulating coating. The method providing the steps of (i) providing a prefinished bearing ring made of bearing steel. The bearing ring has a hardened and machined raceway surface for accommodating at least one row of rolling elements; (ii) providing a first coating on all surfaces of the bearing ring; (iii) removing the first coating from the external surfaces of the bearing ring; and (iv) providing the electrically insulating coating on the external surfaces.

First claim

What is claimed is:

1 . A method of producing a bearing ring of a rolling element bearing, external surfaces of the bearing ring are provided with an electrically insulating coating, the method comprising steps of:
(i) providing a prefinished bearing ring made of bearing steel, wherein the bearing ring has a hardened and machined raceway surface for accommodating at least one row of rolling elements; (ii) providing a first coating on all surfaces of the bearing ring; (iii) removing the first coating from the external surfaces of the bearing ring; and (iv) providing the electrically insulating coating on the external surfaces of the bearing ring.

2 . The method as claimed in claim 1 , wherein the step (iii) of removal is a mechanical removal procedure that roughens the external surfaces of the bearing ring to form a prepared substrate for the electrically insulating coating provided in step (iv).

3 . The method as claimed in claim 1 , wherein the first coating is one of a conversion coating, a physical vapour deposition coating, a chemical vapour deposition coating or a galvanic coating.

4 . The method as claimed in claim 3 , wherein the first coating is a black oxide surface layer with a thickness of less than 2 μm, formed on the surfaces of the bearing ring by immersion in a bath of alkaline solution at elevated temperature.

5 . The method as claimed in claim 1 , wherein the first coating is a diamond-like carbon coating.

6 . The method as claimed in claim 1 , wherein the electrically insulating coating is an organic coating, such as a polymer coating, or is an inorganic coating, such as a thermal spray coating.

7 . The method as claimed in claim 6 , wherein the electrically insulating coating is an oxide ceramic coating with a thickness of 2-3000 μm, the oxide ceramic coating comprising one or more materials selected from Al 2 O 3 , TiO 2 Cr 2 O 3 and ZrO 2 .

8 . The method as claimed in claim 7 , further comprising steps of:
(v) providing a layer of organic sealant on top of the oxide ceramic coating; and (vi) machining the external surfaces of the bearing ring to achieve required dimensions.

9 . A bearing ring comprising:
a first coating on a raceway surface of the bearing ring, and an electrically insulating coating on external surfaces of the bearing ring.

10 . A rolling element bearing comprising a bearing ring as claimed in claim 9 .

11 . The rolling element bearing as claimed in claim 10 , further comprising a second bearing ring, wherein a raceway surface of the second bearing ring is provided with the first coating.

12 . The rolling element bearing as claimed in claim 10 , further comprising at least one row of rolling elements, wherein an outer surface of the rolling elements is provided with the first coating, or with a second coating different from the first coating.

13 . The rolling element bearing as claimed in claim 10 , wherein the first coating is a black oxide surface layer with a thickness of less than 2 μm.

Assignees

• Skf Ab

Inventors

• Horchheimer Ralph
• Schnabl Gregor

Classifications

• F16C2223/70

  by electroplating or electrolytic coating, e.g. anodising, galvanising · CPC title

• F16C33/64 Primary

  Special methods of manufacture · CPC title

• F16C2223/60

  by vapour deposition, e.g. PVD, CVD · CPC title

• F16C2240/60

  Thickness, e.g. thickness of coatings · CPC title

• F16C33/62 Primary

  Selection of substances · CPC title