Rolling bearing
AssigneeNsk Ltd.
InventorsNobuaki Mitamura, Kazuo Sekino, Yasuo Murakami
Life of this patent
Estimating the term…
Abstract
At least any one of a bearing member (inner race, outer race and rolling element) is formed with a steel material containing 0.2 to 1.2 wt % of C, 0.7 to 1.5 wt % of Si, 0.5 to 1.5 wt % of Mo, 0.5 to 2.0 wt % of Cr, and 12 ppm or less of O. The bearing member is treated with carbonitriding, and thereafter, quenching and tempering so as to provide carbon concentration in the steel surface being 0.8 to 1.3 wt % and nitrogen concentration on the same being 0.2 to 0.8 wt %.
Claims11
A rolling bearing comprising an inner race, an outer race and plural rolling elements, in which at least one of said inner race, said outer race and said rolling elements comprises an alloy steel containing:
- 0.2 to 1.2 wt % of C;
- 0.7 to 1.5 wt % of Si;
- 0.5 to 1.5 wt % of Mo;
- 0.5 to 2.0 wt % of Cr;
- 0.1 to 0.3 wt % of Ti and 12 ppm or less of O;
- wherein said at least one of said inner race, said outer race and said rolling elements has been solution heat-treated, and thereafter, quenched and tempered so that TiC having a size of 0.1 μm or less is precipitated on a rolling surface of said at least one of said inner race, said outer race and said rolling elements.
A rolling bearing comprising an inner race, an outer race and plural rolling elements, in which at least one of said inner race, said outer race and said rolling elements comprises an alloy steel containing:
- 0.2 to 1.2 wt % of C;
- 0.7 to 1.5 wt % of Si;
- 0.5 to 1.5 wt % of Mo;
- 0.5 to 2.0 wt % of Cr;
- 0.1 to 0.3 wt % of Ti and 12 ppm or less of O;
- wherein at least one of said inner race, said outer race and said rolling elements has been solution heat-treated, carbonitrided, quenched and tempered, so that TiC having a size of 0.1 μm or less is precipitated on a rolling surface of said at least one of said inner race, said outer race and said rolling elements, carbon concentration on a surface of at least one of said inner race, said outer race and said rolling elements is in the range of 0.8 to 1.3 wt % and nitrogen concentration on the surface of at least one of said inner race, said outer race and said rolling elements is in the range of 0.2 to 0.8 wt %.
A rolling bearing comprising an inner race, an outer race and plural rolling elements, in which at least one of said inner race, said outer race and said rolling elements comprises an alloy steel containing:
- 0.2 to 1.2 wt % of C;
- 0.7 to 1.5 wt % of Si;
- 0.5 to 1.5 wt % of Mo;
- 0.5 to 2.0 wt % of Cr;
- 0.1 to 0.3 wt % of Ti and 12 ppm or less of O;
- wherein said at least one of said inner race, said outer race and said rolling elements has been solution heat-treated at a temperature of at least 1150° C. for at least 1 hour, and thereafter, quenched and tempered so that TiC having a size of 0.1 μm or less is precipitated on a rolling surface of said at least one of said inner race, said outer race and said rolling elements.
Dependencies are inferred from the claim text.