Rolling-element bearing and method of manufacturing thereof
AssigneeAktiebolaget Skf
InventorsJuergen Gegner, Wolfgang Nierlich, Armin Herbert Emil August Olschewski, Arno Stubenrauch
Life of this patent
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Abstract
A rolling-element bearing includes an inner ring made of steel and having an inner-ring raceway, an outer ring having an outer ring raceway, and ceramic rolling elements which roll on the inner-ring raceway and on the outer-ring raceway. The inner ring has been subjected to a heat treatment to harden it. The heat treatment is concluded with the performance of a final heat-treatment step at a predetermined temperature. In the inner ring, compressive residual stresses are formed in an outer layer by cold working in the region of the inner-ring raceway. The inner ring also has been subjected to a bluing treatment.
Claims20
A method for manufacturing a rolling-element bearing, which includes an inner ring made of steel and having an inner-ring raceway, an outer ring having an outer ring raceway, and rolling elements that roll on the inner-ring raceway and on the outer-ring raceway, the method comprising:
- subjecting the inner ring to a heat treatment to harden it, wherein the heat treatment is concluded with the performance of a final heat treatment step at a predetermined temperature,
- forming compressive residual stresses in an outer layer of the inner ring by subjecting the inner ring to cold working in the region of the inner-ring raceway,
- after the cold working, subjecting the inner ring to a bluing treatment and
- disposing rolling elements manufactured from a ceramic material between the inner-ring raceway and the outer-ring raceway.
A rolling-element bearing, comprising:
- an inner ring made of steel and having an inner-ring raceway,
- an outer ring having an outer-ring raceway and
- rolling elements made of a ceramic material, the rolling elements being rollable on the inner-ring raceway and on the outer-ring raceway,
- wherein:
- the inner ring has been hardened by a heat treatment,
- the inner ring exhibits compressive residual stresses formed by cold working, which compressive residual stresses are in an outer layer in the region of the inner-ring raceway, the outer layer extending at least up to a minimum depth below the surface of the inner-ring raceway, and
- the surface of the inner-ring raceway is formed by a blued layer.
Dependencies are inferred from the claim text.