Abstract: In a thrust needle roller bearing, even in an environment where an amount of lubricating oil is small, the amount of lubricating oil is held and seizure is prevented. The thrust needle roller bearing includes a plurality of needle rollers, a bearing ring (31) having an annular raceway surface (31a) on which the needle rollers roll, and a cage that rollably holds the needle rollers, in which an oil repellent film (41a) is formed by oil repellent treatment on a portion of the raceway surface (31a) other than a portion in contact with the needle rollers.

Abstract: An object is to provide an evaluation method for detecting the amount of hydrogen supposed to influence white structure flaking in a simple manner in a short period of time and evaluating possibility of white structure flaking from the detected hydrogen amount. The provided is a possibility evaluation method of white structure flaking that, by measuring an amount of hydrogen gas generated under a condition simulating a use condition of a rolling device used in industrial equipment and existing in an atmosphere, evaluates possibility of white structure flaking in the rolling device.

Abstract: Provided are a method for assessing hydrogen environment severity of a rolling device during operation and a method for predicting likelihood that white structure damage occurs to the rolling device as a result of operation. A hydrogen environment severity assessment method is a method for assessing, among operating conditions of a rolling device including two rolling members coming into rolling contact with each other and having at least one of the two rolling members being a steel rolling member, hydrogen environment severity, the hydrogen environment severity being an index representing magnitude of influence exerted by hydrogen.

Abstract: Provided is a friction design method capable of estimating sliding friction generated between mutual sliding surfaces of two sliding members lubricated with lubricant with high precision. The friction design method sets a friction coefficient ? in a sliding surface model corresponding to mutual sliding surfaces of two sliding members (2 and 3) lubricated with lubricant (step S1), and, based on a correlation between the friction coefficient ? and an oil film parameter (?(Rk) or ?(Rk+Rpk)) calculated using a core portion level difference (Rk) or a sum of the core portion level difference (Rk) and reduced peak height (Rpk) as a parameter representing surface roughness in the sliding surface model (step S2), sets a target value for surface roughness of the sliding surfaces required to be controlled as a product (steps S3 to S6).

Abstract: Provided is a friction design method capable of estimating sliding friction generated between mutual sliding surfaces of two sliding members lubricated with lubricant with high precision. The friction design method sets a friction coefficient ? in a sliding surface model corresponding to mutual sliding surfaces of two sliding members (2 and 3) lubricated with lubricant (step S1), and, based on a correlation between the friction coefficient ? and an oil film parameter (?(Rk) or ?(Rk+Rpk)) calculated using a core portion level difference (Rk) or a sum of the core portion level difference (Rk) and reduced peak height (Rpk) as a parameter representing surface roughness in the sliding surface model (step S2), sets a target value for surface roughness of the sliding surfaces required to be controlled as a product (steps S3 to S6).

Abstract: Provided are a method for assessing hydrogen environment severity of a rolling device during operation and a method for predicting likelihood that white structure damage occurs to the rolling device as a result of operation. A hydrogen environment severity assessment method is a method for assessing, among operating conditions of a rolling device including two rolling members coming into rolling contact with each other and having at least one of the two rolling members being a steel rolling member, hydrogen environment severity, the hydrogen environment severity being an index representing magnitude of influence exerted by hydrogen.

Abstract: A rolling bearing has an outer diameter surface of the outer ring which is a fitting surface with a housing and the inner diameter surface of the inner ring, which is a fitting surface with a shaft. The outer diameter surface of the outer ring or the inner diameter surface of the inner ring is coated with a bonded film containing an organic binder, a solid lubricant powder such as molybdenum disulfide powder, and a friction/wear modifier such as antimony oxide powder. According to the rolling bearing, a creep resistance is kept excellent without causing increase in cost and size and being deformed and softened.

Abstract: A rolling bearing has an outer diameter surface of the outer ring which is a fitting surface with a housing and the inner diameter surface of the inner ring, which is a fitting surface with a shaft. The outer diameter surface of the outer ring or the inner diameter surface of the inner ring is coated with a bonded film containing an organic binder, a solid lubricant powder such as molybdenum disulfide powder, and a friction/wear modifier such as antimony oxide powder. According to the rolling bearing, a creep resistance is kept excellent without causing increase in cost and size and being deformed and softened.

Abstract: A rolling bearing has an outer diameter surface of the outer ring which is a fitting surface with a housing and the inner diameter surface of the inner ring, which is a fitting surface with a shaft. The outer diameter surface of the outer ring or the inner diameter surface of the inner ring is coated with a bonded film containing an organic binder, a solid lubricant powder such as molybdenum disulfide powder, and a friction/wear modifier such as antimony oxide powder. According to the rolling bearing, a creep resistance is kept excellent without causing increase in cost and size and being deformed and softened.

Abstract: A rolling bearing has an outer diameter surface of the outer ring which is a fitting surface with a housing and the inner diameter surface of the inner ring, which is a fitting surface with a shaft. The outer diameter surface of the outer ring or the inner diameter surface of the inner ring is coated with a bonded film containing an organic binder, a solid lubricant powder such as molybdenum disulfide powder, and a friction/wear modifier such as antimony oxide powder. According to the rolling bearing, a creep resistance is kept excellent without causing increase in cost and size and being deformed and softened.

Abstract: On the contact surface of the rolling bearing part made of alloy steel containing appropriate amounts of Cr and Mo, the C+N content is 0.9 to 1.4 mass % and the area ratio of carbide is 10% or less. At the depth of 1% of the diameter of the rolling element from the contact surface, the hardness is 720 to 832 in Hv, the amount of retained austenite is 20 to 45 volume %, and the compressive residual stress is 50 to 300 Mpa. At the depth of 1 to 3% of the diameter of the rolling element from the contact surface, the average value of the prior austenite grain size is 20 ?m or less and the maximum value of the prior austenite grain size is 3 times or less the average value, and the hardness of the core portion is 400 to 550 in Hv.

Abstract: A ball screw (1) as a linear motion device according to the invention has retaining pieces (21) each having two concave surfaces (23) facing adjacent ones of rolling elements (9) respectively. Each of the retaining pieces (21) is disposed between adjacent ones of the rolling elements (9). A carbonitrided layer containing residual austenite of 15-40% by volume is provided in the surface layer of each of the rolling elements (9).

Abstract: In a wheel-support rolling bearing unit, in order to made a flange 6 thinner and thus lighten the bearing unit without impairing fatigue strength, machinability, and workability after forging, the composition of the alloy steel constituting the flange attached member (hub ring 2), the surface hardness of the root portion 14 on the axial outside surface side of the flange 6, and the surface roughness, are stipulated to thereby improve the durability ratio (fatigue limit strength/tensile strength) of the flange 6. In one aspect, the member is made from an alloy steel containing C: 0.5 to 0.65 weight %, Mn: 0.3 to 1.5 weight %, Si: 0.1 to 1.0 weight %, Cr: 0.01 to 0.5 weight %, S: 0.35 weight % or less, and any one type or more selected from 0.01 to 0.2 weight % of V, 0.01 to 0.15 weight % of Nb, and 0.01 to 0.15 weight % of Ti, with the rest being Fe and inevitable impurities, and the oxygen contents is 15 ppm or less.

Abstract: A rolling bearing has the radius of curvature of the raceway on an inner ring and an outer ring is from not smaller than 50.1% to not greater than 51.9% of the diameter of the balls, and at least one of the compositions of the bearing is obtained by forming an alloy steel having a carbon (C) content of from not smaller than 0.50% to not greater than 0.90%, a chromium (Cr) content of from not smaller than 3.0% to not greater than 15.0%, a manganese (Mn) content of from not smaller than 0.10% to not greater than 2.0%, a silicon (Si) content of from not smaller than 0.10% to not greater than 2.0%, a molybdenum (Mo) content of zero or not greater than 2.0% by weight, and a vanadium (V) content of zero or not greater than 2.0%, by weight.

Abstract: In a wheel-support rolling bearing unit, in order to made a flange 6 thinner and thus lighten the bearing unit without impairing fatigue strength, machinability, and workability after forging, the composition of the alloy steel constituting the flange attached member (hub ring 2), the surface hardness of the root portion 14 on the axial outside surface side of the flange 6, and the surface roughness, are stipulated to thereby improve the durability ratio (fatigue limit strength/tensile strength) of the flange 6. In one aspect, the member is made from an alloy steel containing C: 0.5 to 0.65 weight %, Mn: 0.3 to 1.5 weight %, Si: 0.1 to 1.0 weight %, Cr: 0.01 to 0.5 weight %, S: 0.35 weight % or less, and any one type or more selected from 0.01 to 0.2 weight % of V, 0.01 to 0.15 weight % of Nb, and 0.01 to 0.15 weight % of Ti, with the rest being Fe and inevitable impurities, and the oxygen contents is 15 ppm or less.

Abstract: The bearing rings 1 and 2 of a rolling bearing is formed of one kind of titanium alloys of &bgr; type titanium alloys, near &bgr; type titanium alloys and &agr;+&bgr; type titanium alloys. The titanium alloy has a surface hardness of Hv 400 or more and less than Hv 600 for increasing the corrosion resistance and wear resistance of the bearing ring. Spherical rolling elements 3 rolling on the raceway surfaces 1a and 2a of the bearing rings 1 and 2 are formed of ceramics such as silicon nitride. When &bgr; type titanium alloys or &agr;+&bgr; type titanium alloys after a solution treatment and applied with an oxidation treatment at a low temperature of 400 to 600° C. are used as the material for the bearing ring, a bearing ring made of titanium alloy suitable to use under a circumstance requiring corrosion resistance is obtained.

Abstract: A rolling bearing has the radius of curvature of the raceway on an inner ring and an outer ring is from not smaller than 50.1% to not greater than 51.9% of the diameter of the balls, and at least one of the compositions of the bearing is obtained by forming an alloy steel having a carbon (C) content of from not smaller than 0.50% to not greater than 0.90%, a chromium (Cr) content of from not smaller than 3.0% to not greater than 15.0%, a manganese (Mn) content of from not smaller than 0.10% to not greater than 2.0%, a silicon (Si) content of from not smaller than 0.10% to not greater than 2.0%, a molybdenum (Mo) content of zero or not greater than 2.0% by weight, and a vanadium (V) content of zero or not greater than 2.0%, by weight.

Abstract: A ball screw (1) as a linear motion device according to the invention has retaining pieces (21) each having two concave surfaces (23) facing adjacent ones of rolling elements (9) respectively. Each of the retaining pieces (21) is disposed between adjacent ones of the rolling elements (9). A carbonitrided layer containing residual austenite of 15-40% by volume is provided in the surface layer of each of the rolling elements (9).

Abstract: The bearing rings 1 and 2 of a rolling bearing is formed of one kind of titanium alloys of &bgr; type titanium alloys, near &bgr; type titanium alloys and &agr;+&bgr; type titanium alloys. The titanium alloy has a surface hardness of Hv 400 or more and less than Hv 600 for increasing the corrosion resistance and wear resistance of the bearing ring. Spherical rolling elements 3 rolling on the raceway surfaces 1a and 2a of the bearing rings 1 and 2 are formed of ceramics such as silicon nitride. When &bgr; type titanium alloys or &agr;+&bgr; type titanium alloys after a solution treatment and applied with an oxidation treatment at a low temperature of 400 to 600° C. are used as the material for the bearing ring, a bearing ring made of titanium alloy suitable to use under a circumstance requiring corrosion resistance is obtained.