Abstract: In a wheel support bearing assembly having rows of rolling elements interposed between an outer member and an inner member, spacers are interposed between vehicle body fitting holes in the outer member, which is a stationary member, and a knuckle. A sensor unit including a sensor mounting member and a strain sensor is fitted to the outer member. The sensor mounting member has at least two contact fixing portions fixed to the outer member and, also, has at least one recess between the neighboring contact fixing portions, the strain sensor being disposed in this recess.

Abstract: To provide a wheel rolling bearing apparatus which can reinforce a proximal end portion of a first flange portion of an outer race member effectively. A first flange portion 21 is provided on an upper portion side of an outer circumference of an outer race member 11. A first reinforcement portion 26 is provided which connects a proximal end portion 21b of the first flange portion 21 with the outer circumferential surface 11c of the outer race member 11. The first flange portion 21 is reinforced by the first reinforcement portion 26 by connecting the proximal end portion of the first flange portion 21 with the outer circumferential surface 11c by a convexly curved surface.

Abstract: The invention relates to an anti-friction bearing comprising a first bearing race, a second bearing race and a plurality of anti-friction bodies that are located between the first bearing race and the second bearing race. According to the invention, the anti-friction bearings are arranged in several rows, which are asymmetrical in the longitudinal direction of the anti-friction bearing in relation to any plane that runs perpendicularly to said longitudinal direction of the anti-friction bearing.

Abstract: The invention relates to a wheel bearing arrangement which enables a hub to be mounted in at least one non-rotating external ring such that it can rotate about the rotational axis of the hub. The wheel bearing arrangement comprises at least one sealing arrangement and one encoder and the sealing arrangement is secured to the hub side on the side of the wheel bearing arrangement whereon a radial flange extends in a radial manner from the hub. The encoder is actively connected to the sealing arrangement.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member with at least one inner ring, double row rolling elements, and a constant velocity universal joint torque transmittably inserted into a wheel hub and axially separably connected by a securing nut. A shoulder of an outer joint member of the constant velocity universal joint abuts against a larger end face of the inner ring. The larger end face of the inner ring is formed as a ground surface. An end face of the shoulder of the outer joint member abutted against the larger end face is formed as a ground surface or a lathe-turned surface. The surface roughness Ra of at least the larger end face of the inner ring is limited to a range within 0.1˜0.3.

Abstract: A seal arrangement for a tire pressure-regulating device for a motor vehicle, which provides a compressed-air supply to a tire of a vehicle through a hole in an inner ring of a rolling bearing of a wheel bearing, through a seal housing which is connected to a wheel hub in a rotationally fixed manner, and through the wheel hub itself. A flat seal is fixed on the inner ring of the rolling bearing and the radially outer end of the seal has a sealing lip which is directed towards the seal housing and bears against it.

Abstract: The invention relates to an anti-friction bearing comprising a first bearing race, a second bearing race and a plurality of anti-friction bodies that are located between the first bearing race and the second bearing race. According to the invention, the anti-friction bodies are arranged in several rows and the pitch diameters of at least two rows differ.

Abstract: The rolling bearing unit includes an outer ring, an inner shaft disposed radially inward of the outer ring and having an inner ring fitting part on the outer peripheral surface on the one axial direction side, an inner ring fitted on the inner ring fitting part and having the shaft end on the one axial direction side crimped on the end face of the one axial direction side thereof, the inner ring having a step portion on the one axial direction side of the shoulder portion, and the step portion having an inclined surface shape the diameter of which expands in the other axial direction.

Abstract: A bearing unit comprises a rolling element bearing with at least two rings which are each provided with at least one raceway and at least one set of rolling elements which are in contact with the raceways as well as at least one tubular sheet metal element connected to one of the rings. The sheet metal element at least partly has a mounting part with non-circular cross section, and the mounting part being mounted to a counter-part with a correspondingly non-circular cross-section of the ring or connected to the ring.

Abstract: A unit which has a carrier and a wheel bearing. The wheel bearing has at least one outer ring which is provided with at least one track for the rolling bodies. The wheel bearing is maintained on the carrier in a fixed manner in relation to the carrier in a first receiving element by a first connection projection, and in a second receiving element by a second connection projection, at least in both axial directions of the wheel bearing, respectively by an end which axially borders on each of the connection projections.

Abstract: A sensor for detecting a speed of rotation is an active sensor, a sensing portion 35 of the sensor directly faces the magnetic encoder 10 without interposition between it and the encoder 10, and a harness 34 (or connector) of the sensor 30 for detecting the speed of rotation is taken out of a gap between a knuckle N and a constant velocity universal joint 9.

Abstract: A vehicle wheel bearing apparatus has an outer member formed with a body mounting flange on its outer circumferential surface. The body mounting flange is to be mounted on a knuckle of the vehicle. The outer member inner circumference includes double row outer raceway surfaces. An inner member includes a wheel hub with a wheel mounting flange formed on one end. A cylindrical portion extends from the wheel mounting flange. At least one inner ring is press-fit onto the cylindrical portion of the wheel hub. The inner ring outer circumference is formed with an inner raceway surface arranged opposite to the double row outer raceway surfaces. Double row rolling elements are freely rollably contained between the outer raceway surfaces and inner raceway surfaces of the outer member and the inner members. Seals are mounted within annular openings formed between the outer member and the inner member. The inner ring is axially secured relative to the wheel hub by a caulked portion.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member, and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. A brake pilot portion extends from a base of a wheel hub mounting flange toward the outer side to guide an inner circumferential surface of a brake rotor. A wheel pilot portion extends from the brake pilot portion further toward the outer side to guide an inner circumferential surface of the wheel. The wheel pilot portion including a plurality of separated pilots separated along a circumferential direction. A chamfered portion is formed, by forging, on a forward end of each separated pilot in view of its lathe cutting direction. The chamfered portion has a predetermined inclined angle relative to an axial end surface of each separated pilot after lathe cutting.

Abstract: A wheel bearing apparatus has an outer member, an inner member, double row rolling elements, and seals. At least one seal has a slinger and an annular sealing plate. The sealing plate has a metal core, press fit into the outer member, and a sealing member, integrally vulcanized adhered to the metal core. The sealing member has first and second side lips, formed with an inclination extending radially outward, and a cylindrical inner end portion, surrounding the inner circumferential edge and a portion of the back surface of the metal core. Each tip of the first and second side lips is in sliding contact with the slinger, with a predetermined interference. The cylindrical inner end portion is arranged opposite to the slinger with a slight radial gap therebetween to form a labyrinth seal.

Abstract: A sensing part 35 of a sensor 30 for detecting speed of rotation is disposed to face a magnetic encoder 10 through a sensor holder 20, the sensor 30 for detecting the speed of rotation is disposed inward in the radial direction of a hub unit mounting hole NH of the knuckle N of a car body, a connecting portion 34a of a harness 34 is provided with deformation tolerance for allowing deformation of the shape when a load exceeding a predetermined level is applied thereon externally and a shape retaining capacity for retaining and maintaining the shape always as it is when the load is not higher than the predetermined level, and the connecting portion 34a of the harness 34 is, when the load is not higher than the predetermined level, positioned more on the outer diameter side than the outer diameter of a constant velocity universal joint 9 at least until the connecting portion 34a is located out of the hub unit mounting hole NH of the knuckle N.

Abstract: A unit, which has a wheel bearing and at least one vehicle-sided fixed support. The wheel bearing has at least one outer part which is rigidly fixed to at least one bearing seat which is embodied as an axial passage of a sheet metal molded part of the support, and at least one end section of the outer part is surrounded in a radial and supple manner, at least in the proximity of the passage such that the end section engages in an axial mariner behind the support.

Abstract: A wheel bearing apparatus for a driven wheel of a vehicle has an outer member, an inner member and rolling elements between the two. The outer member has a body mounting flange for mounting it to a knuckle of a suspension apparatus. The knuckle has a disc shaped bottom portion. The outer member is secured to the knuckle by fastening bolts. The body mounting flange abuts against the bottom portion of the knuckle. The inner side end of the inner member is closed by the knuckle. A plurality of pins is secured to the knuckle. Pin bores to receive the pins are formed on the body mounting flange. The pin bores radially positioning the outer member relative to the knuckle.

Abstract: A wheel bearing device, in which a swaged portion of a wheel hub abuts against a shoulder portion of a joint outer ring, is provided to positively prevent a stick slip noise from being generated at the time of the vehicle being pulled away from a parked position. The wheel bearing device includes an outer ring having double rows of race surfaces formed on its inner circumference; a wheel hub having one of the double rows of race surfaces formed on its outer circumference; an inner ring press-fitted over a reduced diameter step portion of the wheel hub and having the other of the race surfaces formed on its outer circumference; and double rows of rollers interposed on the respective race surfaces between the outer ring and the wheel hub and between the outer ring and the inner ring.

Abstract: Bearing wheel hub unit (1) is provided with a mounting flange (3) which is integral with an inner race (21) of the bearing (2) in order to mount a wheel, and with a centering collar (4) which extends from a frontal surface (31) of the flange (3) to permit the centering of the wheel in relation to the unit (1). The centering collar (4) produced, preferably of alloy, in such a way as to be independent of the mounting flange (3), and is assembled with the flange (3) by fixing onto the frontal surface (31).

Abstract: A vehicle wheel bearing apparatus with a back-to-back double row tapered roller bearing has an outer member integrally with a body mounting flange and double row outer raceway surfaces tapered open respectively axially inward and outward. An inner member include a wheel hub and an inner ring or an outer joint member of a constant velocity universal joint. The wheel hub has a wheel mounting flange and one inner raceway surface arranged oppositely to one of the double row outer raceway surfaces and a cylindrical portion. The inner ring or the outer joint member of a constant velocity universal joint are press fit onto the cylindrical portion and include the other inner raceway surface arranged opposite to the other raceway surface of the double row outer raceway surfaces. Double row tapered rollers are freely rollably held between the outer and inner raceway surfaces by cages. Seals are arranged in annular openings formed by the outer and inner members. The cages are formed of synthetic resin.

Abstract: A wheel support bearing assembly with a hub axle of enhanced strength and a durability under a rotational bending condition as well as weight reduction, and without changing a shape and a dimension of a wheel mounting flange nor deteriorating a surface runout, and a manufacturing method thereof. A surface hardness is set to 20 HRC or more and than 35 HRC or less by applying an air cooling or a thermal refinement after hot forging a raw material of the hub axle, and a shot peening treatment is applied to an inner diameter portion of the hub axle.

Abstract: A sealing device 12b of a hub unit bearing O has a first slinger 16 fixed to an inner ring 5, a second slinger 17 fixed to an outer ring 1, and a sealing portion 18 which is fixed to the first slinger 16 and is slide-contacted with the second slinger 17. A magnetic encoder 20 is fixed to the first slinger 16. The magnetic encoder 20 and the sealing portion 18 are bond-fixed to the first slinger 16 with the same adhesive agent.

Abstract: A wheel support bearing assembly including an outer member having an inner periphery formed with a plurality of raceway surfaces; an inner member having an outer periphery formed with raceway surfaces cooperable and aligned with the raceways in the outer member; rows of balls interposed between the raceway surfaces in the outer member and the raceway surfaces in the inner member, respectively; and a wheel fitting flange provided in the outer periphery of one of the outer and inner members. In the wheel support bearing assembly, the diameter of the pitch circle depicted by the balls of a row on an outboard side is greater than the pitch circle of the balls of the row on an inboard side, and the ratio of the diameter of the balls relative to the pitch circle diameter of the row of the balls on the inboard side is within the range of 0.14 to 0.25.

Abstract: A method of manufacturing a double row rolling bearing device includes: providing a collet chuck having radially expandable separated parts and a tapered cone for radially expanding the separated parts; inserting the radially contracted collet chuck into a through hole before the double row rolling bearing is caulked to the hub shaft; caulking the cylindrical end of the hub shaft, with the separated parts being in contact with the end by radially expanding the collet chuck to prevent radially inward plastic deformation of the end; and contracting the collet chuck and extracting the collet chuck out of the hub shaft after the caulking.

Abstract: A wheel bearing unit which has at least one outer part, at least one inner part and at least two rows of rolling bodies between the outer part and the inner part. One inner raceway is formed on the outer part and one outer raceway is formed on the inner part for the rolling bodies of each row. The wheel hub has internal toothing, which projects radially inwards in the direction of the rotational axis, for engaging external toothing on a drive pin. The internal toothing of the hub is rotationally fixedly coupled to the outer raceway. The ratio of the diameter dz of a tip circle of the internal toothing to the bearing width bL of the outer part is greater than 0.9.

Abstract: In order to simplify mounting of the inner ring (5) of one of the bearings (102) of a wheel hub on the associated spindle (1) and in order to perform keying together of this ring and the spindle by means of multiple-lobe—for example three-lobe-machining which can be performed using the same machine for turning the spindle and the ring, this same three-lobe machining operation is such as to involve all or only partly the shoulder (6) of the spindle and involve, in recessed form, the corresponding inner end of the ring (5) intended to rest against this shoulder, so that the said ring (5) may be mounted on the spindle (1) as though these two parts were two normal parts with a round cross-section and therefore without any need for prior relative angular alignment thereof.

Abstract: A wheel hub of a wheel bearing apparatus has an outer member and an inner member. The inner member includes a wheel hub and an inner ring. The wheel hub has a wheel mounting flange, a shaft portion, an inner raceway surface, a cylindrical portion, a shoulder portion, and a through bore. The inner ring is press-fit onto the cylindrical portion abutting against the shoulder portion. Double row rolling elements are contained between the inner and outer raceway surfaces of the inner member and the outer member. Fiber flow near the inner circumference of the material forming the wheel hub from the shoulder to the open end surface of the wheel hub is in a condition substantially parallel to the axis of the wheel hub.

Abstract: A method of manufacturing a rolling bearing device for a road-wheel that includes an outer ring, an inner ring member, rolling elements arranged between the outer ring and the inner ring member, and a shaft body having the inner ring member mounted to an outer periphery includes a caulking step of radially outwardly bending and deforming a cylindrical portion formed at one end side of the shaft body by using a predetermined caulking pressure acting from the one end side toward other end side of the shaft body, thereby forming a caulked portion caulked to an axial end face of the inner ring member. Identification information indicating an existence of the caulked portion so formed is die-stamped on a visually observable surface at the other end side of the shaft body by using the caulking pressure during the caulking step.

Abstract: A wheel support bearing assembly includes an inner member having a hub axle and an inner race mounted on the hub axle. This bearing assembly includes one of an engagement recess formed in a portion of an inner peripheral surface of the inner race corresponding to an inboard edge portion of the hub axle and an engagement projection is formed in the hub axle for engagement with the engagement recess, and an annular recess formed in the outer peripheral surface of the hub axle and is opposed to an inboard side face of the inner race by the radially outward deformation of an inboard edge portion of the hub axle.

Abstract: A sensor-incorporated wheel support bearing assembly, enabling a load sensor to be compactly installed on the vehicle and capable of detecting a load on a wheel with good sensitivity includes a ring member, affixed to a stationary member, which has at an intermediate portion thereof a first non-contact ring portion not in contact with the stationary member, at one end a first contact ring portion in contact with the stationary member, and at the other end the following (A) or (B): (A) a second non-contact ring portion having a wall thickness greater than that of the first non-contact ring portion; (B) a second contact ring portion in contact with the stationary member. A strain sensor is fitted to; in (A), the first non-contact ring portion, and in (B), the first non-contact ring portion or first contact ring portion, which has smaller wall thickness.

Abstract: A drive wheel support bearing assembly includes a hub axle, a constant velocity joint and a bearing unit which are unitized together, and an inner member made up of an outer coupling member of the CVT with the hub axle mounted on an outer periphery of a hollow stem portion of the outer coupling member. Inner peripheral side raceway surfaces are formed on the hub axle and the outer coupling member. Hardened indentations are formed in an inner periphery of the hub axle, and the hub axle and the outer coupling member are plastically coupled integrally with each other by radially outwardly expanding a mounting area, at which the hub axle is mounted on the hollow stem portion, to allow it to bite into the indentations to crimp. Sensors for detecting the displacement or deformation of the outer coupling member and the hub axle are provided in the outer member.

Abstract: A vehicle wheel bearing apparatus has an outer member (10), an inner member (1), an inner ring (3), and double row rolling elements (6, 6) are freely rollably retained between double row outer raceway surfaces (10a, 10a) and double row inner raceway surfaces (2a, 3a). An end face at the outboard side of the inner ring (3) is adapted to abut a stepped portion (11) formed on the wheel hub (2). The inner ring (3) is secured on the wheel hub (2) by being sandwiched between a caulked portion (2c) and the stepped portion (11). A ratio (?) of the thickness (e), of an end (3c) at the outboard side of the inner ring (3) to abut the stepped portion (11), relative to the inner diameter (d) of the inner ring (3) is limited at or smaller than a predetermined value.

Abstract: To provide a wheel support bearing assembly, in which the sufficient proof strength of an inner race during assemblage onto the vehicle body can be secured without its function being lowered, the wheel support bearing assembly includes an outer member, an inner member, and rows of rolling elements interposed therebetween. The inner member includes an hub axle having a flange and an inner race on an inner race mount, with raceways defined in the hub axle and the inner race. The inner race has a counterbore at its inboard end. The hub axle has a plastically deformed portion which engages an axially oriented surface of the counterbore when radially outwardly crimped and does not protrude outwardly beyond an inboard end face of the inner race. The difference P between the inner race mount and an outer peripheral face of the plastically deformed portion is 0.13 mm or more.

Abstract: A vehicle wheel bearing apparatus has an outer member (10), an inner member (1) and double row rolling elements (6, 6) freely rollably arranged between the outer and inner raceway surfaces (10a, 10a; 2a, 3a), respectively, of the outer and inner members (10 and 1), via cages (7). An annular projection (12) is formed on the outer circumferential surface at an inboard side end of the cylindrical portion (2b) of the wheel hub (2). An annular recess (13) is formed on the inner circumferential surface at the inboard side end of the inner ring (3). The annular recess (13) corresponds to the annular projection (12) and has a difference in height slightly larger than that of the annular projection (12). The inner ring (3) is press fit onto the cylindrical portion (2b) of the wheel hub (2) with the recess (13) engaged by the projection (12).

Abstract: A vehicle wheel bearing apparatus has an outer member formed, on its inner circumference, with double row outer raceway surfaces. An inner member is formed on its outer circumference surface, with double row inner raceway surfaces arranged opposite to the double row outer raceway surfaces. Double ball groups are freely rollably contained between the outer raceway surfaces and inner raceway surfaces, respectively, of the outer member and the inner member. It is formed as a double row angular contact ball bearing of back-to-back duplex type where a predetermined contacting angle is applied to each ball. A pitch circle diameter of the outer-side ball group is larger than a pitch circle diameter of the inner-side ball group. The outer-side groove diameter of curvature ratios are smaller than inner-side groove diameter of curvature ratios.

Abstract: A collar, made from plastically deformed material, of a hub. The collar holds at least one inner ring of a wheel bearing unit on the hub in an axially fixed manner. Also, end-side teeth, are formed in the collar for engaging in a mating toothing.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member, and at least one inner ring press fit onto a cylindrical portion of a wheel hub. Double row rolling elements are rollably contained between double row outer raceway surfaces and double row inner raceway surfaces. A constant velocity universal joint torque is inserted into the wheel hub. It is axially separably connected to the wheel hub by a securing nut. A shoulder of an outer joint member of the constant velocity universal joint abuts against the inner member. An abutting surface of the inner member that abuts the shoulder of an outer joint member is formed so that it does not include a segment of a mirror finished surface with an area exceeding 0.005 mm2.

Abstract: In a CV joint-bearing mounting structure, a steering unit, including a CV joint and a bearing, is engaged with a knuckle via tapered portions, a first nut is mounted to the outer end of the bearing, a disk is engaged with an engagement part of the CV joint via toothed portions, and a second nut is mounted to one end of the CV joint. The quality of the bearing is improved, the tolerance of the assembled components is reduced, and the types and number of the components are reduced, thereby improving the efficiency of assembly of the components.

Abstract: A wheel bearing arrangement which has at least two rows of rolling bodies for mounting a wheel hub which can be driven with the wheel bearing arrangement by a drive element. The wheel hub is connected to the drive element, and the wheel hub and the drive element engage positively into one another via a pair of mutually corresponding spur toothings. In the wheel bearing arrangement, a value of greater than three is obtained for a ratio of the diameter of a toothing reference circle of the spur toothing in the wheel bearing arrangement to the rolling body row spacing of the at least two rows of rolling bodies.

Abstract: A vehicle wheel bearing apparatus has an outer member and an inner member. The inner member has a wheel hub and at least one inner ring fit onto a cylindrical portion of the wheel hub or an outer raceway surface of a constant velocity universal joint. Double row rolling element groups are freely rollably contained between said inner and outer raceway surfaces of the inner member and the outer member. A pitch circle diameter of the ball element group near to the wheel mounting flange is larger than that of the double row ball group away from the wheel mounting flange. A maximum diameter of the outer raceway surface of the smaller diameter side of the double row outer raceway surfaces of the outer member is substantially the same as an inner diameter of a shoulder portion of the outer diameter side. The size of each rolling element of the group near to the wheel mounting flange is different from that of each rolling element of the group away from the wheel mounting flange.

Abstract: A vehicle wheel bearing apparatus has a pitch circle diameter of an outer side ball group that is larger than a pitch circle diameter of an inner side ball group. Each corner portion of the outer circumferential surfaces of the inner member is rounded as a smooth circular arc.

Abstract: A bearing apparatus for a wheel comprising a rolling bearing for rotatably supporting a wheel relative to a body of vehicle having double row rolling elements (20) arranged between an inner member 1 and an outer member (10); a wheel mounting flange (5) for fastening the wheel on a hub wheel (2); and an annular groove (7) formed on the wheel mounting flange (5) and having a predetermined width including hub bolts (6); characterized in that one side of the wheel mounting flange (5) at a region other than the annular groove (7) is formed as a cut-finished surface cut after the press fit of the hub bolts (6).

Abstract: An inner ring is fitted on one-end side of an inner shaft and fixed to the inner shaft by caulking. During the caulking, the inner shaft is supported by a caulking receiving jig. A receiving section to which the jig is in contact is provided at a position near the one-end side of the inner shaft, for example, at a position nearer to the inner ring than a raceway section formed on the outer periphery on the other side of the inner shaft. As a result, a caulking load acting from a caulking jig on the inner shaft plastically deforms only a desired portion.

Abstract: A hub unit includes a double-row outer ring having a first inner peripheral raceway and a second inner peripheral raceway, a hub having a wheel-mounting flange provided with a reference surface for mounting the wheel formed on a vehicle outer end-side thereof, a first outer peripheral raceway opposed to the first inner peripheral raceway of the outer ring, a shaft body and an inner ring element having a second outer peripheral raceway opposed to the second inner peripheral raceway of the outer ring, rolling members interposed between the double-row inner peripheral raceway of the outer ring and the double-row outer peripheral raceway of the hub and cages. A rust-preventive layer is provided at least on the wheel-mounting reference surface of the flange.

Abstract: A bearing device for a wheel enabling the easy control of quality since there is no possibility of cracking even if caulking is applied thereto. The bearing device comprises an outer ring having double rows of raceway surfaces on the inner periphery thereof, an inner member having raceway surfaces opposed to the raceway surfaces, and balls interposed between the double rows of raceway surfaces opposed to each other. The inner member further comprises a HUB ring and an inner ring. Caulking is applied to the HUB ring to join it to the inner ring. The grain size number of the austenite grains of a caulked section is at least 6.

Abstract: A bearing device for a drive wheel having a knuckle member surrounding a part of a cup part through a clearance. An annular first seal member is disposed between the knuckle member and an outer ring member. An opening part is formed between the peripheral edge part of the knuckle member and the large diameter end part of a joint boot. A recessed part formed in the first seal member is installed to be opened toward the joint boot.

Abstract: A wheel bearing arrangement which as at least two rows of rolling bodies which are used to bear a wheel hub which can be driven by a drive element and which includes a wheel bearing arrangement. The wheel hub is connected to the drive element. The wheel hub and the drive element engage together in a positive fit via a pair of face splines which correspond to each other.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member and double row rolling elements freely rollably contained between the outer raceway surfaces and inner raceway surfaces, respectively, of the outer member and the inner member. Either one of the outer member or inner member, on its outer side end, is integrally formed with a wheel mounting flange to mount a wheel. A plurality of bolt apertures is formed in the wheel mounting flange. The wheel is secured on the wheel mounting flange by a plurality of bolts. Cut-out portions are formed between the bolt apertures. The cut-out portions avoid the vicinity of each bolt aperture. Each cut-out portion is formed with a circular arc configuration so that its deepest portion is positioned closely to a pitch circle diameter of the bolt apertures.

Abstract: A wheel bearing device of the invention includes a flanged shaft member that includes a shaft portion to which a rolling bearing is assembled, a fitting shaft portion that is formed on one end side of the shaft portion and that is fitted to a center hole of a wheel, and a plurality of flange portions that extend radially outward on an outer peripheral surface located between the shaft portion and the fitting shaft portion and each of which has a through bolt hole in which a hub bolt for fastening the wheel is arranged. Each flange portion of the wheel bearing device is formed by side extrusion when a forged recess is formed at a center of an end surface of the fitting shaft portion by cold forging. An edge portion of a cross-sectional shape taken perpendicularly to a longitudinal direction of each flange portion is formed in an R-chamfered shape.

Abstract: A hub ring and/or an outer ring constituting a bearing device for a wheel, which is formed of a steel which contains 0.45 to 0.70 mass % of C and at least one of V, Nb and Ti in a total amount of 0.3 mass % or less, wherein a micro structure of a part being not surface-hardening-treated contains a ferrite in 15 to 30 area % and contains a particulate ferrite.