Abstract: A case hardening bearing steel having an excellent rolling contact fatigue life in intermediate temperature, in addition, excellent toughness at room temperature is provided. Specific means for solving the problems are as follows. The composition contains, by mass percent, C of 0.15 to 0.30 mass percent, Si of 0.5 to 2.0 mass percent, Mn of 0.3 to 2.0 mass percent, Cr of 1.3 to 2.5 mass percent, Mo of 0.3 to 1.0 mass percent, and O of not more than 0.0012 mass percent in a range where (Si+Mo)?1.0 mass percent is satisfied, and contains iron and inevitable impurities as remnant; the maximum size of oxide nonmetallic inclusion is not more than 12.5 ?m when examined area is 320 mm2; number of the oxide nonmetallic inclusion having a diameter of equivalent circle of 3 ?m or more is not more than 250 when the examined area is 320 mm2; in addition, C density of an outer layer is adjusted to be in a range from 0.7 to 1.2 mass percent by carburization.

Abstract: An antifriction bearing comprises an inner race, an outer race having an outer peripheral surface to be brought into contact with other member for use as a roll, and a plurality of rolling elements arranged between the inner and outer races. The portion of the outer race from an outer peripheral surface thereof to a depth of 3 mm has a hardness of 58 to 62 in Rockwell C hardness (hereinafter referred to as “HRC”) and a hardness gradient of up to 1 HRC/1 mm from the outer peripheral surface inward, and contains 5 to 18 vol. % of retained austenite. The portion of the outer race from an inner peripheral surface thereof to a depth of 1 mm has a hardness of 61 to 64 in HRC and contains 5 to 15 vol. % of retained austenite. The center portion of the thickness of the outer race between the inner and outer peripheral surfaces thereof has a hardness of 35 to 42 in HRC. The outer race can be prevented from cracking or breaking and from undergoing plastic deformation due to use for a short period of time.

Abstract: A rolling bearing including a rolling element made of steel is provided. The rolling element has a hardness of 620 to 750 HV in its interior. The rolling element is so constructed that the hardest point may exist within a depth of 10% of its diameter from a rolling contact surface of the rolling element, and that the hardness at this point is made higher by 20 to 150 HV than the hardness in the interior.

Abstract: The moving trajectory that a robot hand 16 depicts when chamfering a glass sheet G is a trajectory A that a center of rotation 01 of the robot hand 16 vertically moves along a straight line Q connecting between the center of rotation 01 of the robot hand 16 and a rotation 02 of a grinding wheel 30.

Abstract: Bearing parts are formed of damping steel containing 0.2 to 0.6 wt. % C, 5.0 to 15.0 wt. % Cr, 0.2 to 1.3 wt. % Si, 0.05 to 0.20 wt. % N, and comprising Fe and inevitable impurities as the remaining. The damping steel may be hardened in an ordinary manner to have a surface hardness, in terms of Rockwell C hardness of at least 57.

Abstract: For extension of service lives of rollers and discs of a toroidal continuously variable transmission, input discs, output discs and rollers are formed of a heat-resisting bearing steel. At least a roller has its peripheral surface subjected to a shot peening for achieving a compressive residual stress of 0.6 to 1.2 GPa and a hardness of HRC 63 to 66 at the outermost surface.

Abstract: A distortion correcting device is accommodated at a concave portion of the neck of a stringed instrument, and comprises: a bar 10 including a bottom plate portion 11 and a pair of opposing side plate portions 12 erected at both sides of the bottom plate portion 11; and an adjusting rod 20 whose one end portion is secured to one end portion of the bar 10 and whose other end portion engages with an adjusting nut 30 which is rotatably supported by the other end portion of the bar 10, and in which the distance between the one end portion of the adjusting rod 20 and the adjusting nut 30 can be changed by turning the adjusting nut 30. A first support member 40 and a second support member 50 are secured to the side plate portions 12 at both end portions of the bar 10, and one end portion of the adjusting rod 20 is supported such that movement in an axial direction is blocked by the first support member 40, and the adjusting nut 30 is rotatably supported by the second support member 50.

Abstract: Peeling occurring in a short period of time is avoided in a roller member such as a roller cam follower of a cam apparatus in a valve system of a car engine. The roller member is produced by heating an already processed a roller member material in a carburizing atmosphere of carbon potential being 1.2% or more at 840 to 870° C. for 3 hours or longer, thereby to carry out a carburization treatment, followed by quenching, said roller member material being formed in a predetermined shape from a bearing steel. Thereby, all amount of carbon are rendered to be 1.0 to 1.6 wt % in a surface portion of a range from a surface of a rolling face until a depth where a maximum shearing stress acts on, an amount of solute carbon is is rendered to be 0-6 to 1.0 wt % in a matrix of said surface portion, and said surface portion is precipitated with carbides of 5 to 20% in an area rate and of particle size being 3&mgr; or less.

Abstract: Bearing steel containing 0.10 wt % to 0.35 wt % of C, less than 0.5 wt % of Si, 0.3 wt % to 1.5 wt % of Mn, 0.03 wt % or less of P, 0.03 wt % or less of S, 1.0 wt % to 3.5 wt % of Ni, 1.0 wt % to 5.0 wt % of Cr, 0.03 wt % to 2.5 wt % of Mo, 0.005 wt % to 0.050 wt % of Al, 0.003 wt % or less of Ti, 0.0015 wt % or less of O, 0.025 wt % or less of N, and a substantially residual part of Fe, wherein the bearing steel after carburizing or carbonitriding treatment exhibits a surface C concentration of not lower than 0.9%, contains 15% by area or less of carbide and contains 0.1% by area or less of rod-like carbide 10 having an aspect ratio of not lower than 3 in terms of the ratio of major diameter to minor diameter and having a minor diameter of not smaller than 2 &mgr;m.

Abstract: In a heat treatment wherein a blank (intermediate material) formed with a lubrication hole is heated and quenched, the quenching of the blank is terminated at the point of time that a temperature at a portion corresponding to a depth from a raceway surface (surface of a bearing part) of an outer ring (the bearing part), to which depth the maximum shear stress affects, is lowered to an MS point.

Abstract: A blank for disc is heat treated for adjusting a surface hardness thereof to not less than Hv700. The blank has a spline hole thereof heated by high frequency heating while cooling a race thereof. Subsequently, the spline hole is subjected to slow cooling. Thus is obtained a disc having a surface hardness of not less than Hv700 at the race, and a surface hardness of not more than Hv600 at the spline hole, the disc wherein at least a thin portion is varied in hardness between a hardened layer of a bottom of the spline hole and a hardened layer of the race by an amount of not less than Hv20 per 1-mm depth.

Abstract: A blank for disc is heat treated for adjusting a surface hardness thereof to not less than Hv700. The blank has a spline hole thereof heated by high frequency heating while cooling a race thereof. Subsequently, the spline hole is subjected to slow cooling. Thus is obtained a disc having a surface hardness of not less than Hv700 at the race, and a surface hardness of not more than Hv600 at the spline hole, the disc wherein at least a thin portion is varied in hardness between a hardened layer of a bottom of the spline hole and a hardened layer of the race by an amount of not less than Hv20 per 1-mm depth.

Abstract: In a material for bearing parts constructed from a steel hardened by a heat treatment, its surface layer is adjusted, before a shot peening treatment, for a mean particle size of carbide to less than 1 &mgr;m, an area percentage of carbide to 10-15%, an amount of residual austenite to 7-14% and a hardness thereof to HRC=61-65; and subsequently, the shot peening treatment is conducted. Thus is produced a material for bearing parts which can satisfy the life requirements for bearings without an excessive increase in a shot time during the shot peening treatment.

Abstract: A long-life bearing steel for general purpose use is provided at low cost with no use of specific secondary refining process. Specifically, a bearing material having a component composition in which C: 0.95 to 1.10 mass %, Si: 0.15 to 0.70 mass %, Mn: 1.15 mass % or less, Cr: 0.90 to 1.60 mass %, and P: 0.025 mass % or less are contained, S and O, that are elements forming nonmetallic inclusions, are contained at S: 0.025 mass % or less and O: 0.0012 mass % or less, and the rest is composed of Fe and incidental impurities, wherein the maximum diameter of the oxide-based nonmetallic inclusion is more than 10 &mgr;m, but 15 &mgr;m or less in an inspection area: 320 mm2, the number of oxide-based nonmetallic inclusions having an equivalent circle diameter of 3 &mgr;m or more is 250 or less in the inspection area: 320 mm2, while in the material, AlN is contained at 0.

Abstract: An antifriction bearing comprises an inner race, an outer race having an outer peripheral surface to be brought into contact with other member for use as a roll, and a plurality of rolling elements arranged between the inner and outer races. The portion of the outer race from an outer peripheral surface thereof to a depth of 3 mm has a hardness of 58 to 62 in Rockwell C hardness (hereinafter referred to as “HRC”) and a hardness gradient of up to 1 HRC/1 mm from the outer peripheral surface inward, and contains 5 to 18 vol. % of retained austenite. The portion of the outer race from an inner peripheral surface thereof to a depth of 1 mm has a hardness of 61 to 64 in HRC and contains 5 to 15 vol. % of retained austenite. The center portion of the thickness of the outer race between the inner and outer peripheral surfaces thereof has a hardness of 35 to 42 in HRC. The outer race can be prevented from cracking or breaking and from undergoing plastic deformation due to use for a short period of time.

Abstract: An antifriction bearing comprises bearing rings and rolling members which are made from a steel material containing 0.15 to 0.3 wt. % of carbon by being subjected to heat treatments including carburizing. The surface layer of raceway surface of each of the bearing rings and the surface layer of rolling surface of each of the rolling members are 1.0 to 1.5 wt. % in carbon content, 64 to 66 in Rockwell hardness C, 150 to 2000 MPa in compressive residual stress, up to 3 &mgr;m in maximum carbide particle size and 10 to 25% in carbide area ratio, at a depth of 0 to 50 &mgr;m as measured from the outermost surface of the surface layer. The surface layers are 0.75 to 1.3 wt. % in carbon content, 150 to 1000 MPa in compressive residual stress, 25 to 45% in residual austenite content, up to 1 &mgr;m in maximum carbide particle size and up to 15% in carbide area ratio, at a depth of 50 to 200 &mgr;m as similarly measured from the outermost surface.

Abstract: A rolling bearing including a rolling element made of steel is provided. The rolling element has a hardness of 620 to 750 HV in its interior. The rolling element is so constructed that the hardest point may exist within a depth of 10% of its diameter from a rolling contact surface of the rolling element, and that the hardness at this point is made higher by 20 to 150 HV than the hardness in the interior.

Abstract: For extension of service lives of rollers and discs of a toroidal continuously variable transmission, input discs, output discs and rollers are formed of a heat-resisting bearing steel. At least a roller has its peripheral surface subjected to a shot peening for achieving a compressive residual stress of 0.6 to 1.2 GPa and a hardness of HRC 63 to 66 at the outermost surface.

Abstract: A blank for disc is heat treated for adjusting a surface hardness thereof to not less than Hv700. The blank has a spline hole thereof heated by high frequency heating while cooling a race thereof. Subsequently, the spline hole is subjected to slow cooling. Thus is obtained a disc having a surface hardness of not less than Hv700 at the race, and a surface hardness of not more than Hv600 at the spline hole, the disc wherein at least a thin portion is varied in hardness between a hardened layer of a bottom of the spline hole and a hardened layer of the race by an amount of not less than Hv20 per 1-mm depth.

Abstract: A continuously variable transmission including discs made of heat-resisting bearing steel, and rollers made of ceramics. The heat-resisting bearing steel contains 0.8-1.5 wt % of C, 0.5-2.0 wt % of Si, 0.3-2.0 wt % of Mn, 1.3-1.98 wt % of Cr, and 0.3-1.0 wt % of Mo, (Si+Mo) being 1.0 wt % or more. Because the rollers are made of ceramics superior in heat resistance, the toroidal type continuously variable transmission, even if used under high load and high rotational speed, is free from occurrence of sticking between discs and rollers and damage of the raceway surfaces.