An axial section of a continuous portion where an outer peripheral surface of a spindle portion of a main spindle in which a punch is installed is continuous with an outer peripheral surface of a punch holder is formed of a first circular arc joined to the outer peripheral surface of the spindle portion and a second circular arc joined to the outer peripheral surface of the punch holder. The first circular arc and the second circular arc are in contact with each other. The second circular arc is smaller than the first circular arc in curvature radius.

Rotary forging for forming a hub-side face spline is started in a state in which a caulking section is made to come in contact with a flat surface section that is an inner end surface of an inner ring in an axial direction and a chamfer. In addition, a contact portion between an inner end surface of the caulking section in the axial direction and a processing surface of a roll at the beginning of the rotary forging overlaps a contact portion between the caulking section and the flat surface section and the chamfer of the inner ring in the axial direction.

A steering knuckle of a utility vehicle has a main body, a steering knuckle bearing for receiving in a rotating articulated manner a vehicle axle, a hub-type, cup-shaped receiving portion, open towards a rim of a vehicle wheel, in which portion an anti-friction bearing and a bearing journal can be received. The main body has an opening for receiving a drive shaft. The opening leads into the hub-type receiving portion. An axle assembly and a vehicle axle of a utility vehicle are also provided.

A wheel hub system is disclosed. The wheel hub system has a hub assembly, a joint component, and a threaded bolt. The hub assembly has a hub having a though-hole, a circumferential groove formed in the through-hole, and a first support surface having a first plurality of teeth. The hub assembly also has a bearing unit positioned on the hub. The joint component is secured to the hub assembly and has a projection positioned in the through-hole and having a threaded bore and a retainer positioned in the circumferential groove. The joint component also has a second support surface having a second plurality of teeth operatively engaging the first plurality of teeth. The retainer positions the hub assembly and the joint component relative to each other during assembly. The threaded bolt is positioned in the threaded bore and secures the hub assembly in the position.

A method for manufacturing a rolling bearing unit is provided to periodically reciprocate a stage (38) in a vertical direction by rotating and driving a servo motor (44) while rotating a roll about a central axis of a hub main body using a roll driving motor (43) in a state in which a processing surface of the roll is pressed against other end surface of a caulking section in an axial direction. A period of the reciprocation is restricted by a relation between a rotation position of the roll about the central axis of the hub main body and an engaged state between concave sections, which are sections between a plurality of processed teeth formed in the processing surface of the roll, and a face spline tooth formed by the concave section.

Construction is achieved that is capable of preventing the formation of radial streaks in the tip-end surfaces of teeth of hub-side face splines 21. When a swing center distance is taken to be L, a swing angle that is the inclination angle of the center axis of a roll 30 with respect to a main hub body 8 is taken to be , the pitch diameter of the hub-side face splines 21 is taken to be D.sub.h, the number of teeth of the hub-side face splines 21 is taken to be N.sub.h, and the number of teeth of a processing surface 31 of the roll 30 is taken to be N.sub.r, the position relationship of the main hub body 8 and the roll 30, or in other words, at least one of the swing center distance L, the swing angle , and the pitch circle diameter D.sub.h is regulated so that the relationship Nh/Nr=cos +(2L/D.sub.h).Math.sin is satisfied.

A driving ring is configured to be assembled to and rotatable with a hub assembly and defines an axial direction, the drive ring includes a first axial side and a first circumferential side around the axial direction, the first axial side includes first ratchet teeth arranged around the axial direction and first grooves extending radially, the first circumferential side includes first engaging teeth arranged around the axial direction and engaged with the hub assembly, and between neighboring two of the first ratchet teeth is one of the first grooves. A hub device including the driving ring is provided, wherein the hub device further includes a hub assembly, a driving assembly an elastic member, and a shaft disposed through the hub assembly, the driving assembly and the elastic member.

A freewheel system for a bicycle hub, comprising an inner ratchet fixed to a hub body and an outer ratchet fixed to a freehub. This system is particular in that an internal surface of the inner ratchet is coupled to an external surface of a connection shell joined to the body, where a diameter of the internal surface of the connection shell is larger than a diameter of a bearing connecting the hub body and the axle. Similarly, also the coupling between the outer ratchet and the freehub can be carried out by the interaction between the internal surface of the outer ratchet and the external surface of the freehub. An inner ratchet and an outer ratchet are also described.

A method and tool for obtaining face teeth having a plurality of radial teeth on an annular collar of an inner ring of a wheel hub; in which annular roughed-out face teeth are first formed on the collar coaxial with an axis of symmetry (A) of the collar and having a plurality of radial first teeth arranged in a crown and alternating at constant pitch with a plurality of radial first concavities; then a shaping tool comprising a pressing head provided with annular calibration face teeth is axially pressed onto the collar to engage with the annular roughed-out face teeth, second radial concavities of the annular calibration teeth each being delimited by a bottom wall having a rounded circumferential profile exactly reproducing in negative the rounded circumferential profile of the tips or ridges of the radial teeth of the required face teeth.

A wheel bearing apparatus has a double row rolling bearing detachably united with a constant velocity universal joint. The double row rolling bearing has an outer member, an inner member, and double row rolling elements rollably disposed between the double row raceway surfaces of the outer member and inner member. The constant velocity universal joint has an outer joint member, a shoulder portion, and a shaft portion. A female thread is formed on the shaft portion. End faces of the shoulder portion and the caulked portion are formed with face splines, respectively. The face spline of the caulked portion has a portion where a tooth height of a tooth space of a portion radially outside the pitch circle diameter is set lower than that of other portions of the tooth space.