Abstract: A bearing device includes an inner ring and an outer ring. At least one of the radially inner surface of the inner ring and the radially outer surface of the outer ring is covered with a coating layer. The coating layer is a coating layer composite composed of a plurality of layers. Of the plurality of layers, the surface layer is composed of an anti-creep film having lubricity, and at least one layer other than the surface layer is composed of an insulating film having insulating properties.

Abstract: A rolling bearing having concentric bearing rings supported on one another rotatably with respect to each other by means of at least one row of rolling elements and have bearing races for the rolling elements of the at least one row of rolling elements. The invention further relates to a material transfer- or construction machine, such as a crane or cable excavator, having such a rolling bearing. Providing different bearing race corrections in different angular sectors of the bearing rings and/or providing the bearing race correction only in a fraction of the circumference of the bearing rings is advantageous over the conventional use of a bearing race correction that is constant over the circumference. A bearing race correction that is limited to one sector or that is different from sector to sector, or that is not constant over the circumference, enables the bearing rings to adapt to expected loads.

Abstract: A raceway element for a rolling-element bearing, the rolling-element bearing having an inner ring, an outer ring, and a plurality of rolling elements that are disposed between the inner ring and the outer ring. The raceway element is configured as an inner ring or as an outer ring, or is configured to be attachable to an inner ring or outer ring of the bearing, wherein at least one surface of the raceway element is configured as a raceway for the rolling elements. The raceway element is formed from a sheet metal panel having at least one recess formed in the surface configured as the raceway.

Abstract: Features for a prosthetic digit actuator. The various systems and methods allow for smaller volume actuators, which in turn allows for smaller digits and/or more space for other features of the digit. The actuator includes a motor that causes rotation of a worm gear along a fixed worm wheel. The worm gear is unibody with the output shaft. The worm gear climbs along the worm wheel to cause rotation of a digit or digit segment. The arrangement of the actuator parts allows for transmitting axial forces in first and second directions corresponding respectively to performing opening and closing rotations of the digits.

Abstract: Provided is construction which is able to downsize an orbital forging device comprising a spherical seat with shaft that swings and rotates with a molding die. The end section on the other side in the axial direction of the swinging shaft 13 is supported with respect to the driving mechanism 17 in a state where the movement toward one side in the axial direction (lower side) is prevented, and a member for preventing the swinging shaft 13 from moving toward the one side in the axial direction with respect to the frame 10 is not assembled in a section which is located between the convex spherical seat 14 and the driving mechanism 17 in the axial direction of the swinging shaft 13.

Abstract: A pulley assembly for belt tensioners having a bearing unit provided with a rotating outer ring and made of metal, an outer wheel body overmoulded onto the outer ring to rotate with the outer ring and interact with a belt, a gripping surface at the interface between the outer wheel body and the outer ring to prevent circumferential slipping between the outer wheel body and the outer ring; and an axial retainer integral with the outer ring and having two lateral edge members located axially on opposite sides of the gripping surface to engage the outer wheel body and prevent axial movement of the outer wheel body relative to the outer ring.

Abstract: The invention relates to a cage-free rolling bearing (1) having a plurality of rolling elements (4) which are arranged so as to be distributed in the circumferential direction between an inner ring (2) and an outer ring (3) that is arranged concentrically to the inner ring (2); and a pressing element (6) which is arranged in the manner of a ring segment along the circumferential direction, at least temporarily contacts at least two of the rolling elements (4) simultaneously, and applies a force oriented in an axial direction to each of the contacted rolling elements (4).

Abstract: Wheel hubs for a motor-vehicle wheel hub assemblies provided with a bearing unit in turn which include at least one row of rolling bodies, the wheel hub being provided with at least two sheet-metal elements which are rigidly joined together, wherein a first sheet-metal element forms a raceway for the at least one row of rolling bodies.

Abstract: A planetary gear set having a planet shaft that extends from a planet gear carrier into a hole in a planet gear. At least one set of bearing rollers may be received inside the hole and may rotatably support the planet gear on the planet shaft. A first shaft thrust washer may extend between the planet gear carrier and a set of bearing rollers.

Abstract: A boot needle roller bearing is designed to reduce friction between a flexible boot non-rotatably attached to a differential housing and a rotatable half-shaft. A plurality of rollers is retained axially between a first lip formed in the outer ring and a set of protrusions that are formed after installation of the rollers by bending prongs inwardly. The inner ring is retained axially between the protrusions and a second lip formed into the outer ring after installation of the inner ring.

Abstract: A bearing housing for connecting a bearing to a supporting structure of a gas turbine engine is discussed. The bearing housing has an inner wall and an outer wall radially spaced apart from the inner wall between which an annular space is defined. A device extends from the inner wall toward the outer wall and includes at least a first and a second member in series between the inner and outer walls, the second member having a radial stiffness greater than a radial stiffness of the first member. The device may operate in multiple operating stages, where in a first stage the first member of the device deforms to absorb at least partially a vibration load over a given range of vibration amplitude when the bearing housing deflects, and where in a subsequent second stage the second member of the device increases a total radial stiffness of the assembly of the bearing housing and device over the bearing housing alone.

Abstract: A roller assembly includes an outer ring having an interior having an inner surface extending an overall axial length between first and a second axial ends. The inner surface has a radially inward facing bearing surface extending between first and second radially inwardly extending flanges. The roller assembly includes a one piece inner member extending into the interior and having a groove formed therein between third and a fourth axial ends. A retaining ring is positioned in the groove. A first row of first rollers is positioned in the interior and between the retaining ring and the first radially extending flange. A second row of second rollers is positioned in the interior between the retaining ring and the second radially extending flange. An annular seal engages the inner member and has an overall axial width no more than 6% of the length of the outer ring.

Abstract: A rolling element bearing includes inner and outer rings having raceways and rolling elements between the raceways. The raceways of the inner and outer rings are coated with a first coating, such as a phosphate coating, and the rolling elements are coated with a second, different, coating such as a black oxide coating.

Abstract: A taper roller bearing includes: an inner ring, an outer ring, a plurality of taper rollers, and an annular cage. The cage includes a small-diameter annular portion on one side in a axial direction, a large-diameter annular portion which is positioned on the other side in the axial direction and on a radial outer side of a large flange of the inner ring, and a plurality of column portions which link the small-diameter annular portion and the large-diameter annular portion. The taper roller bearing has a labyrinth structure which suppresses a flow of lubricating oil to the outside of the bearing from the inside of the bearing between the large flange and the large-diameter annular portion.

Abstract: A taper roller bearing includes: an inner ring, an outer ring, a plurality of taper rollers, and an annular cage. The cage includes a small-diameter annular portion on one side in a axial direction, a large-diameter annular portion which is positioned on the other side in the axial direction and on a radial outer side of a large flange of the inner ring, and a plurality of column portions which link the small-diameter annular portion and the large-diameter annular portion. The taper roller bearing has a labyrinth structure which suppresses a flow of lubricating oil to the outside of the bearing from the inside of the bearing between the large flange and the large-diameter annular portion.

Abstract: A roller bearing system comprising a rolling element having a cylindrical outer raceway; said rolling element is housed inside an outer ring to the bearing system; said outer ring having an inner and an outer diameter surface, is connected to a rotatable shaft from one end, said inner diameter surface of the outer ring having a non-symmetric convex shaped profiling facing the rolling element to facilitate maximum contact area during any operational condition.

Abstract: A bearing for a wind turbine is provided. The bearing includes an inner ring and an outer ring concentrically arranged about an axis of rotation. Furthermore, the bearing includes rollers interposed between the inner ring and the outer ring. At least one of the inner ring and the outer ring has a layer that functions as a raceway for the rollers. A main body of a corresponding one of the inner ring or the outer ring has a first metal composition having a first chromium content. The layer includes a second metal composition having a second chromium content higher than the first chromium content. A method of manufacturing such a bearing is also provided.

Abstract: A bearing position for rotatably mounting a shaft or an axle in a housing. The bearing position comprises a rolling bearing, which is designed as a roller bearing, with a bearing ring, which is assigned to the housing, where said bearing ring forms an outer rolling raceway, which faces radially inwards and on which rolling elements are guided, said rolling elements mutually interacting with a shaft, which forms an inner rolling raceway, or with an inner bearing ring. A polygonal bearing is provided as the roller bearing; and said polygonal bearing encloses a bearing ring with at least one elastic section, which forms a transversely convex raceway curvature. This arrangement guarantees that at least one rolling element is supported and guided in a radially prestressed manner without radial clearance on the rolling raceway.

Abstract: A bearing position for a torque converter, wherein a pump impeller is connected to a converter neck, and the pump impeller is rotatably mounted on the bearing position by at least one roller bearing in a housing, wherein the roller bearing comprises an outer rolling raceway, assigned to the converter neck and facing radially outwards, and an inner rolling raceway, assigned to the housing and facing radially inwards, and rollers disposed radially between the rolling raceways, wherein the bearing position comprises at least one radially elastically designed section of a sleeve of the roller bearing, where the sleeve is provided with the inner rolling raceway, wherein the section, enclosing an elastic convex raceway curvature, is resiliently prestressed in the radial direction against at least a first roller of the rollers, the first roller supported on the outer rolling raceway, and supported in the opposite radial direction on the housing.

Abstract: A rolling-element bearing includes an inner ring made of steel and having an inner-ring raceway, an outer ring having an outer ring raceway, and ceramic rolling elements which roll on the inner-ring raceway and on the outer-ring raceway. The inner ring has been subjected to a heat treatment to harden it. The heat treatment is concluded with the performance of a final heat-treatment step at a predetermined temperature. In the inner ring, compressive residual stresses are formed in an outer layer by cold working in the region of the inner-ring raceway. The inner ring also has been subjected to a bluing treatment.

Abstract: The present invention is directed to a shaft bearing support assembly for waterborne equipment, including: at least one bearing; at least one tapered forcing ring; a housing; and at least one adjusting device. The outer circumference of each of the at least one bearing is surrounded by one tapered forcing ring which is arranged inside the housing. The at least one adjusting device communicates with each of the at least one tapered forcing ring. A force generated by the at least one adjusting device is transmitted to the at least one tapered forcing ring to longitudinally move the at least one tapered forcing ring, causing the at least one bearing to constrict radially and to adapt to a desired clearance over a diameter of a shaft.

Abstract: A part-bearing-ring of a rolling-element bearing includes first and second assembly bores on its end surface, and the second assembly bore has a larger diameter than the first assembly bore so that it can accommodate a securing sleeve. The second assembly bore may include an internal thread for attaching the securing sleeve. Also a bearing ring formed of two part-bearing-rings and a securing sleeve and a method of installing a bearing ring.

Abstract: A method for manufacturing a bearing ring is provided. The method includes punching out a blank from sheet metal. A radially extending groove is formed in the blank. The blank is stamped in a cup-shaped die which creates an axially extending side wall and a bottom wall, with a first undercut being formed by the radially extending groove located at a juncture between the side wall and the bottom wall at a first axial end portion of the bearing ring. A second axial end portion of the side wall is thinned. The second axial end portion is then bent creating a flange with a second undercut located at a juncture between the flange and the side wall.

Abstract: A bearing ring for a radial rolling bearing, in particular for a cylindrical roller bearing or needle bearing which has, on one of the radial surface areas thereof, a track for a set of cylindrical rolling bodies which are cageless or are guided by a cage and one or two guide flanges axially bounding the track of the rolling bodies is/are fastened to the axial end surfaces of said bearing by adhesive bonding. Each guide flange has a rectangular profile cross section with a horizontal fastening limb and a vertical flange limb and, by way of the horizontal fastening limb thereof, is adhesively bonded in an encircling axial groove in an axial end surface of the bearing ring.

Abstract: A roller bearing capable of effectively improving the service life of the roller bearing is provided by performing surface treatment with coating. A cylindrical roller bearing includes: an outer ring having an outer ring raceway surface; an inner ring having an inner ring raceway surface that faces the outer ring raceway surface; and a plurality of cylindrical rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface. The inner ring raceway surface of the inner ring is provided with a black oxidation coating, and a rolling contact surface of each cylindrical roller is provided with a diamond-like carbon coating.

Abstract: A flanged bearing ring has a tubular core of steel and an outer flange of a light metal in which there are formed axial through bores for accommodating bolts for mounting a wheel to the ring; fixed in each bore is a steel insert which forms a threaded inner cylindrical cavity extending between two opposite faces of the flange, and one or two transverse shoulders which are in contact with the material of the flange so as to oppose relative axial movements of the steel insert with respect to the flange.

Abstract: A rolling bearing assembly having a rotatable element that rotates with respect to a non-rotatable element around a central rotation axis is provided. The assembly includes rolling systems disposed between the rotatable and non-rotatable elements, the rolling systems having at least one rolling system providing rolling elements arranged along radial axes with respect to the rotation axis. The assembly has at least one elastic ring forming a raceway track mounted on the non-rotatable element so that the rolling elements cooperate with the elastic ring, the elastic ring in contact with the rolling elements by resilient elements mounted in holes distributed around the circumference of the non-rotatable element. The assembly has at least one blocking member mounted in the non rotatable element that protrudes in a hole of the elastic ring, the blocking member blocks the elastic ring from rotating around the central rotation axis with respect to the non-rotatable element.

Abstract: In a method for producing an extruded bearing journal, the bearing journal is extruded in an extrusion tool by means of at least one extrusion punch and, after the extrusion of the bearing journal, reworking of the bearing journal is performed in order to improve the cylindricity of the bearing journal at least over a section of the longitudinal extent of the bearing journal. During the reworking, the bearing journal is arranged, at least over a section of its longitudinal extent adjoining its free end, in a cavity that is delimited in a radial direction of the bearing journal by a wall surface surrounding the lateral surface of the bearing journal, and a reworking punch which is movable in the longitudinal direction of the bearing journal is moved toward the free end of the bearing journal and is pressed against the face surface of the bearing journal and, in this way, a plastic deformation of the bearing journal, with a flow of material of the bearing journal, is effected.

Abstract: A bearing position for a torque converter, wherein a pump impeller is connected to a converter neck, and the pump impeller is rotatably mounted on the bearing position by at least one roller bearing in a housing, wherein the roller bearing comprises an outer rolling raceway, assigned to the converter neck and facing radially outwards, and an inner rolling raceway, assigned to the housing and facing radially inwards, and rollers disposed radially between the rolling raceways, wherein the bearing position comprises at least one radially elastically designed section of a sleeve of the roller bearing, where the sleeve is provided with the inner rolling raceway, wherein the section, enclosing an elastic convex raceway curvature, is resiliently prestressed in the radial direction against at least a first roller of the rollers, the first roller supported on the outer rolling raceway, and supported in the opposite radial direction on the housing.

Abstract: A bearing assembly, including a housing with a first circumferentially disposed groove; a bearing including an outer race with a second circumferentially disposed groove; and a retaining ring disposed within the first and second circumferentially disposed grooves. A method of retaining a bearing, including: locating a first portion of a ring within a groove in an outer race; installing a housing radially about the race to contact the race; locating a second portion of the ring within a groove in the housing; bringing temperature of the housing and the race to a first level; fixing, with contact between the race and the housing, the race with respect to the housing; increasing the temperature of the housing and race to a second higher level; creating a radial gap between the housing and the outer race; and fixing, with the retaining ring, a position of the race with respect to the housing.

Abstract: A speed-reduction transmission bearing includes a first outer race and a second outer race, each having a different number of inner teeth and outer teeth and being attached to each other, rolling elements set between the first and second outer races to prevent separation between the first and second outer races in axial or radial direction, an inner race rotatably mounted within the first and second outer races, and a wave generator rotatable to push the inner race, forcing the outer teeth of the inner race to partially mesh with the inner teeth of the first and second outer race. Thus, by means of rotation of a tooth number difference, the invention achieves high reduction ratio transmission.

Abstract: A bearing configuration for the purpose of mounting a shaft or axle in a housing in a manner allowing rotation. The bearing configuration has a rolling bearing designed as a roller bearing with at least one bearing ring which is functionally assigned to the housing, said bearing ring forming an outer race facing inward radially, wherein rolling elements are guided on said outer race, working together on the opposite side with a shaft which forms an inner race. The roller bearing of the bearing configuration is a combination of at least two joined polygonal bearings, wherein each polygonal bearing on the bearing ring includes at least one elastic segment which forms a convex, transversely rounded race curvature. This configuration ensures that at least one rolling element is radially pretensioned and supported on the outer race of the shaft, and the shaft is guided in the housing with no radial play.

Abstract: A method for manufacturing a steel component having a flash butt weld joint, which comprises the step of flash butt welding the joint. The method comprises the step of heating at least part of the component to a temperature above the martensite start temperature before and/or during said flash butt welding step.

Abstract: A bearing position for rotatably mounting a shaft or an axle in a housing. The bearing position comprises a rolling bearing, which is designed as a roller bearing, with a bearing ring, which is assigned to the housing, where said bearing ring forms an outer rolling raceway, which faces radially inwards and on which rolling elements are guided, said rolling elements mutually interacting with a shaft, which forms an inner rolling raceway, or with an inner bearing ring. A polygonal bearing is provided as the roller bearing; and said polygonal bearing encloses a bearing ring with at least one elastic section, which forms a transversely convex raceway curvature. This arrangement guarantees that at least one rolling element is supported and guided in a radially prestressed manner without radial clearance on the rolling raceway.

Abstract: A method for manufacturing a raceway element of a bearing assembly includes hardening a raceway element having a raceway surface by at least partially heating the raceway element, deep rolling the raceway surface using a first rolling element, and then deep rolling the raceway surface using a second rolling element. The first rolling element has at least one different dimension than the second rolling element. In the resulting raceway element, compressive residual stresses of at least 400 MPa are present at a depth from the raceway surface of 200 ?m or less, and between the raceway surface and a depth of 100 ?mm from the raceway surface, the amount of the compressive residual stresses changes by 500 MPa or less.

Abstract: In an embodiment, a roller bearing apparatus may include a rotor having first superhard raceway elements distributed circumferentially about an axis. Each first superhard raceway element includes a raceway surface positioned/configured to form a first portion of a raceway. The apparatus includes a stator including second superhard raceway elements generally opposed to the first superhard raceway elements. Each second superhard raceway element includes a raceway surface positioned/configured to form a second portion of the raceway. The apparatus includes rolling elements interposed between the rotor and stator and positioned and configured to roll on the raceway. One or more of the rolling elements may be configured to elastically deform on the raceway during use. At least a portion of the raceway exhibits a first modulus of elasticity greater than a second modulus of elasticity of at least a portion of the one or more of the rolling elements.

Abstract: Anti-friction bearing, comprising a metallic outer ring and a metallic inner ring with respective rolling-body raceways, and a plurality of metallic rolling bodies which roll on said rolling-body raceways, wherein an electric insulation layer (11) is provided on the outer ring (2) and/or on the inner ring (3) on the raceway side and/or on the rolling bodies (4).

Abstract: A rolling bearing for a steering column having an inner ring, an outer ring and at least one row of rolling elements disposed between the rings is provided. The bearing includes a housing and at least one wire disposed in the housing to form a rolling raceway of the ring, the wire being wound about a circumferential winding axis and having a radial gap. The rolling raceway of the wire includes a circular main track and at least one end track which extends the main track in the circumferential direction and which is adjacent to the gap. The end track is offset radially towards the winding axis of the wire in relation to the main track.

Abstract: A mass balancing unit having a hollow balancing shaft, at least one balancing weight which is provided on the balancing shaft and at least one roller bearing which has an outer bearing ring and a plurality of roller members. A longitudinal portion of the balancing shaft forms an inner bearing ring, the roller members being received between the outer bearing ring and the longitudinal portion of the balancing shaft. Adjacent to the longitudinal portion, the balancing shaft has at least one recess in order to reduce the rigidity of the longitudinal portion of the balancing shaft in a radial direction.

Abstract: A bearing with antiskid design used in combination with a circular spline to form a harmonic drive, and the circular spline is provided with an inner toothed portion, the bearing includes: an elliptical gear plug, a flexible ball bearing, and a flexible spline. Between the flexible ball bearing and the flexible spline are disposed a first and second antiskid members, and the arrangement of the first and second antiskid members prevents the axial slippage between the flexible ball bearing and the flexible spline, thus improving stability and transmission accuracy of the harmonic drive.

Abstract: A roller bearing assembly (10) having an annular outer race (22) with a raceway (24), a pair of opposed flanges (30), and a pair of shoulders (32), each shoulder (32) being disposed between a corresponding flange (30) and a corresponding edge of the raceway (24), a roller retainer (12) defining a plurality of roller pockets (16), and a plurality of rollers (14), each roller (14) being disposed in a corresponding roller pocket (16). Each shoulder (32) forms an annular ridge (32a) with the corresponding edge of the raceway (24).

Abstract: A bicycle assembly can include a main frame having a bottom bracket shell to receive a bottom bracket. The bottom bracket shell can be made of carbon fiber with one or more metal rings to serve as bearing surfaces within the bottom bracket shell. The metal rings may also be split metal rings with a gap between two spaced apart ends.

Abstract: A roller bearing, includes an outer race and an inner race coupled together and rotatable relative to each other, the inner and outer race each defining therein a respective rolling channel, each rolling channel defining two raceway faces abutted at right angles, and rollers accommodated in the rolling channels of the inner and outer races and rotatably kept in contact with the raceway faces of the inner and outer races. The roller bearing is characterized in that the inner and outer races each define a groove between the respective two raceway faces thereof; the ratio between the width of each raceway face and the diameter of each roller is ?0.45 and ?0.62, thus, the friction resistance between the rollers and the raceway faces is minimized, and therefore, the roller bearing does not wear easily when rotated at a high speed.

Abstract: A roller bearing includes an outer ring having a substantially cylindrical internal bearing surface and an outside surface defining a plurality of protuberances. A protective coating is applied to the outside surface of the outer ring. An inner ring is coaxially disposed at least partially in the outer ring and has a substantially cylindrical external bearing surface. The external bearing surface and the internal bearing surface define an annular cavity in which a plurality of rolling elements is disposed. The rolling elements are in rolling engagement with the external bearing surface and the internal bearing surface. The outside surface of the outer ring can be case hardened, for example the outer ring can be carburized. The outside surface of the outer ring can be knurled. A method of manufacturing such a bearing is also disclosed.

Abstract: A ball bearing includes: an outer ring; an inner ring having a ring-shaped member fitted portion that has a step portion that extends generally along a radial direction of the outer ring and an outer peripheral face portion; balls disposed between an inner periphery raceway groove of the outer ring and an outer periphery raceway groove of the inner ring; and a ring-shaped lubricant supply member that is fixed to the ring-shaped member fitted portion while being in contact with the step portion.

Abstract: An inner ring for a bearing, including: a first portion having a first hardness; and a second portion including an axial end of the inner ring with an axial circumferential edge, a slot for receiving a mounting or fastening device, or a hole for receiving a mounting fastener, an inner portion axially between the first portion and the slot or hole, and an outer portion axially between the slot or hole and the axial circumferential edge. At least one of the inner or outer portions has a second hardness less than the first hardness.

Abstract: An installation for calibration of a stress gauge for an external bearing block of a turbomachine roller bearing, the bearing block including a radially internal roller bearing race. The installation includes a support table on which the bearing block is attached; an internal roller bearing ring mounted coaxial with the bearing block; a drive shaft driving the ring. The installation also includes a device for applying an axial stress to the bearing block including a support drum on which the internal ring is removably fixed and a connection with the device for applying the axial stress.

Abstract: A high load capacity bearing that includes a cylindrical outer sleeve that fits around a separable cylindrical outer race assembly. The outer race assembly includes a set of non-helical grooves formed on its inside surface that mesh and engage teeth formed on the outside surface of a plurality of rotating rollers that are longitudinally and axially aligned inside the outer race assembly. The rollers are longitudinally aligned and evenly space apart and rotated as a unit inside the outer race assembly. Located in side the rollers is an inner race with non-helical grooves formed on its outside surface that mesh and engage the teeth on the rollers. The inner race includes a smooth inside bore that fits around the support surface on a shaft.

Abstract: A superfinishing machine and a superfinishing method which can perform axially uniform finishing on a logarithmically crowned surface formed on an inner peripheral surface of an annular member in a short time, and an outer ring of a bearing having a raceway surface superfinished by the superfinishing method, are provided. A superfinishing machine 1 includes a linearly reciprocating mechanism 40 configured to linearly reciprocate a grinding stone 3 held by a pressing section 30, along a plane B touching a generatrix of the logarithmically crowned surface, and in a direction C inclined by a given angle ? with respect to a center axis O of an outer ring 10.

Abstract: A tapered roller wheel bearing assembly may include: a hub provided with a hub flange for mounting a wheel formed radial outwardly at an end portion thereof and a hub raceway formed at a side portion close to the hub flange; an outer ring enclosing the hub and provided with an outer raceway corresponding to the hub raceway on an interior circumference thereof; and a tapered roller disposed between the hub raceway and the outer raceway and allowing a relative rotation of the hub and the outer ring, wherein a flange base is formed between the hub flange and the hub raceway and a first undercut for grinding the hub raceway is formed at the flange base, and wherein a second undercut for dispersing stress concentrated on the first undercut is further formed at the flange base.