Rolling bearing with coated element

Details Rolling bearing with coated element Rolling bearing with coated element

1999-11-18

2001-05-22

Footland, Lenard A. (Department: 3682)

Bearings

Rotary bearing

Antifriction bearing

C384S492000, C384S569000, C384S625000, C384S913000

Reexamination Certificate

active

06234679

ABSTRACT:

This application claims priority under 35 U.S.C. §§119 and/or 365 to Application No. 9803957-1 filed in Sweden on Nov. 18, 1998; the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to bearing components and bearings made of bearing steel. More particularly, the present invention relates to bearings including an inner race, outer race positioned coaxially about the inner race and a set of rolling bodies positioned in the space between and in rolling contact with the inner and said outer race.
The discussion that follows contains certain references to various structures and methods. However, nothing that follows should be construed as an admission of prior art.
Many bearing function under poor tribological conditions, which results in bearing wear. The primary method for meeting this problem is to provide proper lubrication. However, for many applications operating at high speeds, high load and elevated temperatures, the available lubricants will not give a satisfactory result.
Attempts have been made to provide rolling bearing components with hard surface coatings, e.g.—carbides and nitrides, such as TiN, TiC, CrN. Although nitrides and carbides have high hardness and a good resistance to abrasive wear, they also pose a problem. Because their friction coefficients are rather high, which in combination with the high hardness, leads to excessive abrasive wear on components in rolling or sliding contact with these coated elements.
Moreover, sufficient adhesion between coatings of this type and the substrate are not obtained unless the application temperature of the coating is high (over 400° C.). At these temperatures, the comparatively low alloyed bearing steels will be subjected to excessive softening and dimensional changes.
Therefore such coating materials do not give a satisfactorily result.
Coatings of diamond-like carbon (DLC) have been used to coat sliding bearing components. The adhesion of this material against the underlying bearing steel material is sufficient for sliding bearing applications, but as a result of the much higher contact stresses in rolling bearings, in combination with the fact that DLC is not thermally stable and have inferior elastic properties, it has proven itself to have insufficient adhesion for most rolling applications as the DLC coating will flake off.
Some have sought to apply DLC coatings to rolling bearings by providing specific interlayers. However, the limited elastic properties of the DLC coating have meant a limited usefulness in such applications.
One objective of the present invention is to provide a well functioning rolling bearing component made of bearing steel. The component may one or more of an inner race, an outer race positioned coaxially about the inner race and a set of rolling bodies positioned in the annular space between and in rolling contact with the inner and outer races, and which has an increased life also under severe operation conditions with poor lubrication.
SUMMARY OF THE INVENTION
These and other objects have been achieved by providing a rolling bearing having components made of bearing steel comprising an inner race, an outer race positioned coaxially about the inner race, and a set of rolling bodies positioned in the annular space between and in rolling contact with said inner race and said outer race. At least one of the inner race, the outer race and the set of rolling bodies is provided with a coated surface comprising an exterior carbon nitride layer and an intermediate layer interposed between the carbon nitride layer and the surface of the component(s), the intermediate layer comprising hexagonal boron carbon nitride.
The above objects, and others can also be achieved by providing a steel bearing component comprising a surface coated with a carbon nitride layer and an intermediate layer interposed between the carbon nitride layer and the component surface, the intermediate layer comprising hexagonal boron carbon nitride.


REFERENCES:
patent: 4731302 (1988-03-01), Weissmantel et al.
patent: 5249554 (1993-10-01), Tamor et al.
patent: 5593234 (1997-01-01), Liston
patent: 43 27 440 A1 (1995-02-01), None
patent: 195 00 576 A1 (1995-09-01), None
patent: 197 02 852 A1 (1997-07-01), None
patent: 718513 (1993-09-01), None

Affiliated with

Also associated with

Rating

Rolling bearing with coated element does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Rolling bearing with coated element, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rolling bearing with coated element will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2543085