A method of forming a bearing ring having improved hardness is disclosed herein. The method generally includes a duplex hardening process in which the bearing ring is first subjected to a heat treatment. After the heat treatment process, the bearing ring undergoes a nitriding treatment in predetermined portions, including at least a raceway and a cage pilot surface.

A rolling bearing, a rolling device, and a method of manufacturing the rolling device are provided, by which a long life can readily be implemented by suppressing surface damage even on the use condition that the oil film formation performance of a rolling part is poor. A rolling device includes: a first rolling component made of SUJ2; and a second rolling component made of SUJ2 and configured to contact the first rolling component. A surface of a rolling part of the first rolling component is greater in arithmetic mean roughness than a surface of a rolling part of the second rolling component. The arithmetic mean roughness of the surface of the rolling part of the second rolling component is 0.07 μm or more and 0.20 μm or less.

A rolling bearing includes an inner ring, an outer ring, and a plurality of balls interposed between the inner ring and the outer ring. The inner ring and the outer ring are made of stainless steel. A raceway surface with which the ball is in rolling-contact in each of the inner ring and the outer ring and is a superfinished surface and a coating layer made of a solid lubricating film is formed on the superfinished surface.

A method for manufacturing a bearing ring of a rolling bearing includes a series of steps of cutting out an annular member from a material, forming a surface-hardened layer on the annular member, quenching and tempering the annular member, and polishing inner and outer diameter surfaces of the annular member. The method includes, after the quenching, rapidly cooling the ring member such that the ring member has a surface temperature of 50 C. or lower to form a bearing ring intermediate member, and after the tempering, polishing inner and outer diameter surfaces of the bearing ring intermediate member.

A rolling bearing, a rolling device, and a method of manufacturing the rolling device are provided, by which a long life can readily be implemented by suppressing surface damage even on the use condition that the oil film formation performance of a rolling part is poor. A rolling device includes: a first rolling component made of SUJ2; and a second rolling component made of SUJ2 and configured to contact the first rolling component. A surface of a rolling part of the first rolling component is greater in arithmetic mean roughness than a surface of a rolling part of the second rolling component. The arithmetic mean roughness of the surface of the rolling part of the second rolling component is 0.07 m or more and 0.20 m or less.

A radial bearing having a wear surface with improved wear characteristics comprises a steel support, to which is bonded a metal carbide composite wear surface made by first arranging, within a cavity defined between a steel mold and the steel support, tiles made of microwave sintered, cemented metal carbide, closely packing the voids between the tiles with metal carbide powder, and infiltrating the mold cavity with a metal brazing alloy by subjecting the filled mold to rapid heating. The brazing alloy fills voids between the metal carbide particles, the microwave sintered metal carbide tiles, and the metal support, thereby relatively rapidly consolidating the carbide into a wear layer bonded with the steel support without substantially damaging the properties of the microwave-sintered metal carbide tiles.

A radial bearing having a wear surface with improved wear characteristics comprises a steel support, to which is bonded a metal carbide composite wear surface made by first arranging, within a cavity defined between a steel mold and the steel support, tiles made of microwave sintered, cemented metal carbide, closely packing the voids between the tiles with metal carbide powder, and infiltrating the mold cavity with a metal brazing alloy by subjecting the filled mold to rapid heating. The brazing alloy fills voids between the metal carbide particles, the microwave sintered metal carbide tiles, and the metal support, thereby relatively rapidly consolidating the carbide into a wear layer bonded with the steel support without substantially damaging the properties of the microwave-sintered metal carbide tiles.

A ceramic ball material according to an embodiment including: a spherical portion; and a band-shaped portion formed over a circumference of a surface of the spherical portion. The ceramic ball material has a ratio Rtb/Rts of 1.0 or more, where Rtb denotes a maximum cross-sectional height of a roughness profile on an outer peripheral surface of the band-shaped portion; and Rts denotes a maximum cross-sectional height of roughness on an outer peripheral surface of the spherical portion.

At a position of a depth of the first predetermined value from the surface of the gear portion, a surface treatment that satisfies a range of a required hardness defined in advance of the gear portion is performed. A surface treatment is performed at a depth of a second predetermined value from a surface of a bearing portion, the surface treatment satisfying a required hardness in a range prescribed in advance for the bearing portion. Since the second predetermined value is deeper than the first predetermined value, the hardness distribution is made different between the gear portion and the bearing portion. The required hardness in the gear portion and the required hardness in the bearing portion are respectively satisfied.

A method of forming a bearing ring having improved hardness is disclosed herein. The method generally includes a duplex hardening process in which the bearing ring is first subjected to a heat treatment. After the heat treatment process, the bearing ring undergoes a nitriding treatment in predetermined portions, including at least a raceway and a cage pilot surface.