Abstract: One aspect of the present invention relates to a spindle motor manufacturing method for forming an oil repellent film which prevents a lubricating oil from flowing out, on a predetermined area adjacent to a hydrodynamic bearing, the predetermined area being located on at least one of a stationary member and a rotating member. The spindle motor manufacturing method mentioned above comprises a step of supplying an oil repellent solution by a supplying portion onto a part of the predetermined area for forming the oil repellent film, a step of applying an air current to the part of the predetermined area on which the oil repellent solution is supplied so as to peel off an excess part of the oil repellent solution supplied onto the part of the predetermined area, and a step of making a relative movement of the predetermined area in which the oil repellent film is formed, the relative movement being made with respect to the supplying portion by which the oil repellent solution is supplied.

Abstract: Various inexpensive rolling elements for use under high interface pressure such as induction hardened gears are provided, which have improved seizure resistance at tooth flanks and a temper hardness of HRC 50 or more at 300° C. To this end, a rolling element is made from a steel material which contains at least 0.5 to 1.5 wt % carbon and 0.2 to 2.0 wt % one or more alloy elements selected from V, Ti, Zr, Nb, Ta and Hf; and in which 0.4 to 4.0% by volume one or more compounds selected from the carbides, nitrides and carbonitrides of the above alloy elements and having an average particle diameter of 0.2 to 5 ?m are dispersed. In such a rolling element, the soluble carbon concentration of a martensite parent phase of a rolling contact surface layer is adjusted to 0.3 to 0.8 wt %, the martensite parent phase having been subjected to induction hardening and low temperature tempering, and one or more of the above carbides, nitrides and carbonitrides are dispersed in an amount of 0.4 to 4.

Abstract: This guide member in the form of a ring (1) for mounting a pin (2) with friction and articulation and/or sliding capacity, the member being suitable for mounting in the bore of a support, is characterized in that: the ring and/or the pin is subjected, at least at its friction surface, to a surface hardening treatment by diffusion or by structural transformation, followed by finishing surface treatment for reducing the tendency to jamming and to reduce the friction coefficient; the friction surface of the ring (1), consisting of its bore (1a), has arrangements suitable for acting as a lubricant reserve; the outer periphery of the ring is joined to an element made from a deformable flexible material (3) suitable for being engaged in the bore of a support.

Abstract: To provide an improved rolling bearing assembly having an improved resistance to electric corrosion, which can provide a proper performance and can be assembled at a reduced cost, the rolling bearing assembly includes an inner race (1), an outer race (2) and a circumferential of rolling elements (3) rollingly interposed between the inner and outer races (1) and (2). An electrically insulating layer (4) is formed on a surface of one of the inner and outer races (1) and (2), which is held in contact with a housing or a shaft when the rolling bearing assembly is mounted. This electrically insulating layer (4) is made of a gray alumina containing Al2O3 mixed with TiO2 in a quantity chosen to be equal to or smaller than 1 wt % relative to the total weight of the gray alumina.

Abstract: The present invention is a bearing or seal structure 1 or 10 having a movable member and a stationary member. In the bearing or seal structure, at least one of the movable member 2 or 13 and the stationary member 4 or 14 is made of a material with a coefficient of thermal expansion of 8×106/° C. or less. Polycrystalline diamond is coated on a surface of the member made of the material which lies opposite the other member.

Abstract: A submersible pump motor having an electroless nickel-boron coating applied to the sleeve and/or bearing.

Abstract: There is provided a rolling slide member coming in contact with a mating member in a rolling or sliding manner, wherein a plurality of grooves having an inclination of 0 to 30 degree and a groove depth of 0.5 to 15 ?m are formed in a circumferential direction at the time of grinding a contact surface with the mating member. In the contact surface, the axial surface waviness is set to 0.1 or more in the filtered centerline waviness (WCA) and the axial surface roughness is set to 0.7 or more in the ten-point height of roughness profile (Rz) by the grooves 26.

Abstract: A ball bearing (1) has an inner race (2) and an outer race (3). In order to prevent the rotating parts from being damaged when the bearing assembly fails, the bearing has emergency bearing surfaces (14, 15) which are concentric to the rotational axis (6) and of which one is a part of the rotating bearing race and the other is a part of the fixed bearing race. During normal operation, the emergency bearing surfaces (14, 15) are situated opposite one another with a relatively narrow gap (24) therebetween. But, in the event of failure, the surfaces (14, 15) engage and function as emergency bearing surfaces.

Abstract: Methods for producing a heavy-duty coating for metals uses a material composition in the Sn/Cu system for heavy-duty metal coating of metal bases by laser welding. The material is composed essentially of the basic elements Sn, Sb, Cu, particularly of the basic elements Sn, Sb and Cu, optionally with 0-1 wt. % of Ni, 0-1 wt. % of As, 0-0.2 wt. % of Ag, 0-1.2 wt. % of Cd, 0-0.1 wt. % of Se, 0-0.2 wt. % of Cr, 0-2 wt. % Bi, 0-5 wt. % of In, and 0.1-1 wt. % of Zn; also optionally with hard materials, solid lubricants, auxiliary welding agents and auxiliary processing agents, such as free-flowing agents and pressing agents.

Abstract: A rolling element including a base metal, and a nickel coat formed on a surface of the base metal and cooperating with the base metal to constitute a rolling contact surface satisfying condition that a mean value of ratios of L1 to L2 as measured in at least three optional observation areas is in a range of from 1.2 to 2.4, where each observation area is disposed in a cross section taken in a vertical direction relative to the surface of the base metal and is defined by two parallel vertical lines; lengths L1 and L2 respectively represent a length of an interface between the base metal and the nickel coat, and a length of a reference line segment extending perpendicular to the vertical direction, in same observation area.

Abstract: A sliding part comprises a first sliding member made of a steel, a second sliding member made of a steel, a first carbide film comprising a carbide and formed on the surface of the first sliding member, and a second carbide film comprising a carbide and formed on the surface of the second sliding member. The first sliding member and the second sliding member slide relative to each other while applying loads on each other. The carbide of the first carbide film and the carbide of the second carbide film differ from each other, and the hardness ratio of the first carbide film and the second carbide film is not more than 1.4.

Abstract: A roughness of an outer ring raceway surface 14 formed on an inner peripheral surface of an outer ring 13 is made larger than a roughness of inner ring raceway surfaces 12a, 12b of an inner ring 11. Also, an average roughness Ra of the outer ring raceway surface 14 is set within 0.1 ?m?Ra?0.5 ?m in an axial direction and a circumferential direction in ranges of b1/(B/2)?0.9, b2/ (B/2)?0.9 and in a measured length of 0.1 mm to 1.0 mm where B is a width of the outer ring 13 and b1, b2 are a distance from both end surfaces of the outer ring 13 in the axial direction respectively. A roughness parameter S of the outer ring raceway surface is set within 0<S?20 ?m.

Abstract: An inner ring 2 and an outer ring 3 of a rolling bearing 1 are made from steel that contains carbon in the range of 0.65 to 1.25% by mass, silicon in the range of 0.7 to 2.5% by mass, manganese in the range of 0.1 to 1.5% by mass, chromium in the range of 0.5 to 3.0% by mass, 1.5% by mass or less of molybdenum, 9 ppm or less of oxygen, 30 ppm or less of titanium, and 80 ppm or less of sulfur, and whose rating number of the Thin type A series inclusion is 1.5 or less and that of the Heavy type A series inclusion is 1.0 or less when the rating numbers are measured by a method stipulated in ASTM E45.

Abstract: The invention provides a motorcycle having a frame, an engine coupled to the frame, and a crankshaft assembly. The crankshaft assembly includes a first flywheel half having an aperture, a crank pin including a first end portion, a second end portion opposite the first end portion, and a bearing surface between the first and second end portions. The first end portion is press-fit into the aperture of the first flywheel half. The first end portion, the second end portion, and the bearing surface are coated with a friction enhancer. A bearing is positioned at least partially onto the bearing surface, and a connecting rod has an aperture that at least partially receives the bearing.

Abstract: A formed film is formed on the surface of a metal substrate made of an iron-based metal. Thereafter, the surface of the formed film is subjected to treatment for lessening surface roughness such as rolling. In this arrangement, a member which exhibits a sufficient seizing resistance even after being freed of formed film can be obtained.

Abstract: There is provided a cam follower in which a surface roughness of an outer surface of a roller of a cam follower which is in rolling contact with a cam of an engine is obtained individually in an axial direction and a circumferential direction, a skewness Rsk of a profile is formed to be negative, a core roughness depth Rk is made to be 0.3 or less, a reduced valley depth Rvk is made to be 0.3 or less, and a ratio Rk/Rt of the Rk to a maximum height Rt of the profile is made to be 0.19 or more.

Abstract: The invention relates to an alloy consisting of at least three components A, B, C, which form at least a first matrix and a soft phase dispersed therein, with a first surface (5) and a second surface (9) lying opposite it, the proportions of components A, B, C in the alloy being different from one another in the regions of the first (5) and the second surface (8). At least one of the components forms a hard phase and at least one of the other components forms another matrix different from the first matrix, the first matrix being disposed at least in the region of the first surface (5) and the other matrix being disposed at least in the region of the second surface (8), whilst the hard phase is dispersed through both the first and the other matrix.

Abstract: A tapered roller bearing 1 comprises an inner ring 2, an outer ring 3, a plurality of tapered rollers 4 rollably disposed between the inner and outer rings, and a cage 5 for holding the tapered rollers at predetermined circumferential intervals. In this tapered roller bearing, the roller coefficient {y=(the number of rollers ×mean roller diameter)/(?×PCD)} is greater than 0.94. At least one of the members, i.e., the outer ring, inner ring, and rolling elements, has a nitrogen rich layer. The grain size number of austenite crystal grains in the nitrogen rich layer exceeds number 10.

Abstract: A rolling element bearing comprises an inner ring and an outer ring which are each provided with a raceway, and a series of rolling elements which are in contact with the raceways of each ring. A lubricant film is provided in the contacts between the rolling elements and the raceways, which film forms a lubricant meniscus at the inlet side of each contact. In the bearing starved lubrication conditions prevail. The surface of each rolling element has minute recesses filled with a lubricant quantity, said recesses being flattened in the contact area defined by the contact between the rolling elements and the rings and thereby releasing lubricant at the inlet side of each contact resulting in a displacement of the meniscus further away from said contact. This meniscus displacement results in an increased lubricant film thickness in each contact area, thus improving the lubricating conditions in the bearing.

Abstract: A composition for cleaning bearings in rotating equipment and industrial machinery that contains powdered limestone having a high calcium content dispersed in a calcium sulfonate grease, together with a colorant that readily enables a user to differentiate between contaminated grease, cleaning composition and fresh grease. A method is also disclosed that enables a user to clean and re-lubricate bearings without the need for removing the bearings from service or for shutting down the associated equipment or machinery.

Abstract: An electrical submersible pump runner having a core layer and a wear layer affixed to the core layer. One embodiment of the invention provides an electrical submersible pump that includes a motor section and a centrifugal pump section. A seal section and rotary gas separator may also be included. The pump is powered by an electric cable that connects the pump, located in a bore hole, to a power source on the surface. A thrust runner coated with a wear layer (e.g., polymer) is provided in the motor and/or seal section to reduce bearing temperature, provide longer bearing life, reduce costs, and facilitate overhaul. The runner may also function as a rotating up-thrust bearing when the runner is coated with a wear layer on one side that is formed with a bearing geometry. In this case, the up-thrust bearing may be eliminated.

Abstract: A component of a crank mechanism is incorporated in the crank mechanism that converts reciprocating motion of a piston to rotary motion by means of a crank pin, a crank arm and a crank shaft via a connecting bar, and has a hydrogen content of no more than 0.5 ppm, austenite crystal grains of a grain size number exceeding 10, or a fracture stress value of no less than 2650 MPa. Thus, a support structure in and a component of a crank mechanism ensuring a long fatigue life, high anti-crack strength, and a reduced rate of secular dimensional change to improve dimensional stability, can be obtained.

Abstract: A rolling bearing intended for longer life by improving seizure resistance and wear resistance in the circumstance with slip contact or in the circumstance where lubricant tends to be exhausted, which is manufactured by applying carburization or carbonitridation to an Si-added material to disperse and precipitate carbides or carbonitrides containing Si or Si—X (X=one or more of Mn, Mo, and Cr) thereby improving the seizure resistance and the wear resistance by the self-lubrication effect thereof, the size of the carbides or carbonitrides being preferably 10 ?m or less for preventing flaking, and the area ratio for the carbides or carbonitrides being preferably 1.0–30% for obtaining sufficient self-lubrication effect.

Abstract: An object is to provide a cage and a thrust roller bearing with improved oil passage performance of a lubricating oil in the inside of a bearing while holding a needle roller in a stable manner so as to ensure excellent durability. The thrust roller bearing includes a needle roller and a cage holding the needle roller in pockets for accommodating the same. A length La of a roller holding portion provided in the pocket is set to be within a range of 30% to 80% of a length in a radial direction of the pocket.

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: An integral type thrust bearing is proposed which can be manufactured with fewer heat treatment steps. The retainer and the inner and outer rollers not hardened are assembled together with rollers into a bearing and thereafter the assembled bearing is carburized, hardened and tempered. This eliminates the need for individual heat treatment of the retainer and the inner and outer rings and decreases heat treatment steps for the production of thrust bearings.

Abstract: A rolling bearing for belt-type continuously variable transmission with a metal belt including pieces has an inner ring; an outer ring; and rolling elements, wherein at least one of the inner ring, the outer ring and the rolling element is made of an iron alloy having a chromium content of from 2.5 to 20.0% 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: A rolling bearing unit includes a shaft body, an inner ring mounted on the shaft body, an outer ring concentric with the inner ring, and a plurality of balls between the inner ring and the outer ring. A caulking portion to be caulked onto the outer end face of the inner ring is formed on the shaft body. A pre-load is applied to the balls to fix the inner ring to the shaft body. The retained austenite amount of an edge of the inner ring in the vicinity of the caulking portion is between 3% or more and 20% or less.

Abstract: A shaft and bearing assembly comprising a soft shaft having an outer contact surface having a hardness less than 30 HRC and a bearing assembly having a plurality of rollers. The bearing assembly is configured to be positioned about the shaft with the rollers in rolling contact with the shaft outer contact surface. The rollers have a roller contact surface having a hardness less than 45 HRC.

Abstract: A journal bearing has a lining of bearing metal applied to a steel backing. The surface of the lining is laser peen hardened to locally increase the hardness and the seizure resistance of the lining. The underlying core of the lining is unaffected and maintains good conformability of the lining. The overall lining thus possesses both good seizure resistance and conformability.

Abstract: A bearing material for the manufacture of wear-resistant slide bearings made of a Cu—Al-alloy, consisting of 0.01 to 20% Al, optionally further elements, the remainder copper and the common impurities. The slide bearing has for this purpose an outer, wear-reducing cover layer with a range of thickness D=10 nm to 10 ?m and consists exclusively of aluminum oxide.

Abstract: A rolling bearing 10 comprises races 11, 12 having a raceway 15, 16 and rolling elements 13 having a rolling contact surface, wherein at least the raceway 15, 16 of the races 11, 12 has a machined surface, and a surface layer 11a, 12a is formed on the machined surface by electrochemically or chemically dissolving the machined surface, whereby contamination is substantially reduced.

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: In a rolling bearing put under a working circumstance in which water tends to intrude into lubricants, it has been known such a phenomenon that hydrogen ions formed by decomposition of the lubricants are adsorbed to raceway surfaces and accumulated as hydrogen atoms in highly strained sites (in the vicinity of the position for maximum shearing stress), to cause stress corrosion cracking type peeling. The present invention provides a rolling bearing in which an oxide layer of an iron/chromium oxide series is formed at a thickness of from 1 to 1000 nm to at least one of raceway surfaces of bearing rings or rolling contact surfaces of rolling elements and a manufacturing method thereof.

Abstract: A cam follower with roller of the present invention includes a cam follower body having a roller supporting portion integrated therein, a roller supporting shaft having both ends fixed to the roller supporting portion and a roller rotatably supported on the roller supporting shaft with a plurality of needle rollers interposed. At least one of the supporting shaft and the needle roller has a nitride layer on the surface thereof, and has a surface hardness of at least HV 650 and an amount of retained austenite of at least 25% by volume and at most 50% by volume. Thus, a cam follower with roller having excellent durability and fatigue life can be obtained.

Abstract: Method for the production of a part of a rolling bearing, such as a ring for a ball bearing. The starting material used is a grade of steel containing 0.90 1.00% C; at most 0.15% Si; 0.25-0.45% Mn; at most 0.0015% P; at most 0.010% S; 1.30-1.50% Cr; at most 0.15% Ni; 0.20-0.23% Mo; at most 0.20-0.23% Cu; at most 20 ppm Ti; at most 8 ppm O. Before subjecting this grade of steel to a quenching and tempering treatment, the shaped item is subjected to plastic deformation in the hot or cold state. The mechanical properties and in particular the anticipated life under severe stress improve as a result.

Abstract: The present invention provides a cage in which a nitride layer is formed on the surface by using an iron and steel material with a carbon content of 0.25% by weight or less, fabricating it into a predetermined shape and conducting nitriding, which is more excellent in slidability and wear resistance than conventional one. For this purpose, a nitride layer having a hardness of Hv 650 or more at a thickness of 3 &mgr;m or more and 15 &mgr;m or less is formed on the surface of a cage.

Abstract: An inexpensive rolling bearing is proposed which can be used stably for a long time even for applications where the lubricating conditions are severe or bending stresses act. Inner and outer rings of rolling bearings mounted in a rocker arm of an automobile are made of high-carbon chrome bearing steel. They are subjected to heat treatment in which after carbonitriding, high-temperature tempering is carried out. Then they are induction hardened to impart resistance to material quality change and a compressive stress of not less than 200 MPa to the surface layer, thereby markedly improving the rolling contact fatigue life and the tension-compression fatigue strength while keeping the material cost as before. Thus, this bearing can be used stably for a long time even though it is a full compliment type, lubricating conditions tend to worsen and the outer ring is repeatedly subjected to bending stress from the cam.

Abstract: The toroidal-type continuously variable transmission comprises an input shaft rotatably supported, an input side disk, an output side disk, a plurality of trunnions, a plurality of power rollers, and a plurality of thrust rolling bearings 32, in which the mutually opposed inner surfaces of the input side and output side disks are respectively formed as concave surfaces each having an arc-shaped section, the peripheral surfaces of the power rollers are formed as spherical-shaped convex surfaces, and the peripheral surfaces of the power rollers are contacted with the inner surfaces of the input side and output side disks. In the thus structured toroidal-type continuously variable transmission, each of the thrust rolling bearings 32 is made of high carbon chromium bearing steel and is also carbonitrided.

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: To provide a rolling bearing for a man-made satellite which is free from the damages, e.g., formation of the band mark on the surfaces of the rolling elements, and the losing of the luster of the surfaces thereof. There is provided a rolling bearing, which is used mainly for a man-made satellite, includes an outer ring, an inner ring, and rolling elements. The parent material of those components is martensitic stainless steel. Of those components, at least the rolling elements are processed to have nitride surface layers formed over their surfaces. A hardness of the nitride surface layer is Hv1200 to 1500.

Abstract: A rolling bearing such as a rolling bearing for an alternator of an automobile, the life period of which is prevented from being shortened due to the temporal reduction of a radial internal clearance even in a high temperature environment. The rolling bearing includes a plurality of rolling elements rotatably arranged between an inner race and an outer race, and at least the inner race and the outer race are made of a steel material. An austenite residual rate of the inner race is smaller than an austenite residual rate of the outer race. The amount of dimensional expansion of the outer race due to the martensite transformation of residual austenite is larger than that of the inner race, so that the occurrence of clearance loss is suppressed even when dimensional expansion of the rolling elements occurs.

Abstract: There are provided a rolling bearing comprising an outer race, an inner race, and a plurality of rolling elements each interposed between the outer race and the inner race, at least one of the outer race, the inner race and the rolling elements being made of a steel consisting essentially, by mass, of 0.40 to 0.60% C, not more than 0.5% Si, not more than 0.5% Mn, not less than 8.0% but less than 10.0% Cr, and the balance Fe and incidental impurities, said steel having a hardness not less than 740 HV, carbides contained in said steel having a long size not more than 1.2 &mgr;m, and an amount of said carbides being not more than 3.5% in area %, and a method of producing the rolling bearing.

Abstract: A wheel bearing assembly is provided which can prevent lowering of the life of a bearing assembly due to entry of muddy water into the bearing assembly through a gap between fitting surfaces of a first inner member and a second inner member. These members are rotatably supported by mounting rolling elements between double-row raceways formed on an inner peripheral surface of an outer member and raceways formed on outer peripheral surfaces of the first and second inner members. A stem formed on the second inner member is inserted into a hole formed in the first inner member, and a tip of the stem is caulked to hold the first and second inner members in a coupled state. An annular groove is formed in an outer periphery of the stem. A seal ring is mounted in the annular groove.

Abstract: A formed film is formed on the surface of a metal substrate made of an iron-based metal. Thereafter, the surface of the formed film is subjected to treatment for lessening surface roughness such as rolling. In this arrangement, a member which exhibits a sufficient seizing resistance even after being freed of formed film can be obtained.

Abstract: A needle case or needle bush produced without cutting for a thin-walled needle bearing is produced without cutting from a cold-rolled strip, which is a heat-treated steel which has the disclosed chemical composition and the disclosed mechanical characteristic values. After a heat treatment, a surface hardness of 860 to 880 HV and a core hardness of 550 to 650 HV are achieved.

Abstract: A bearing apparatus includes a hollow shaft provided around an outer peripheral surface with a bearing fitting region, and a rolling bearing having an inner ring fitted around the bearing fitting region of the hollow shaft. A shaft end of the hollow shaft is bent outwardly in a diametrical direction, thereby being caulked on an outer end surface of the inner ring. The bearing fitting region has a hardened layer in a region from a first position corresponding to an inner end surface of the inner ring of the rolling bearing to a second position before a position corresponding to an outer end surface of the inner ring, and has a non-hardened layer in another region from the outer end surface corresponding position of the inner ring to the shaft end. The second position representative of a caulked side end portion of the hardened layer is defined based on a predetermined relational expression.

Abstract: A helical groove 1B is formed in the sliding surface 1A of a sliding bearing 1 over the entire axial region thereof. To establish the height of a peak 1a defined by the helical groove 1B, an imaginary reference line L extending parallel to the axis is formed which is determined such that the total cross-sectional area of all the peaks 1a is equal to the total cross-sectional area of all the valleys 1b when the helical groove 1B is considered in axial section. A height, as measured from the reference line L to the top 1a? of the peak 1a is chosen in the range of from 1 to 8 ?m. The space created by forming the valleys 1b allows the supply of lubricant oil to be increased, thereby simultaneously achieving a reduction in the frictional resistance and the occurrence of an impact sound.