The ball socket assembly includes a housing that is made as a monolithic piece and has an inner bore. The ball socket assembly also includes a ball stud that has a semi-spherically curved portion, a cylindrical portion, and a shank portion. The ball socket assembly further includes a backing bearing and an exit bearing. A third bearing is received on the cylindrical portion of the ball stud. The third bearing has a curved outer surface which cooperates with the curved inner surface of at least one of the exit and backing bearings for allowing the ball stud and the bearing to articulate and rotate relative to the housing. The third bearing is also in slidable contact with the cylindrical portion of the ball stud for allowing the ball stud to more freely rotate relative to the housing about the central axis.

Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, N: 0.0200% or less, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2):
0.58C+Si/8+Mn/5+Cu/10+Cr/4+V0.67(1)
Si+0.9Cr0.50(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.

Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, N: 0.0200% or less, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2):
0.58C+Si/8+Mn/5+Cu/10+Cr/4+V0.67(1)
Si+0.9Cr0.50(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.

A wheel retainer that retains a wheel on a wheel mount and prevents the wheel from being fully separated from the wheel mount in the event of a failure of a wheel bearing. In some embodiments, a wheel retainer includes a sleeve, and a retaining member coupled to the sleeve. The retaining member has a retaining diameter sized such that when a wheel bearing fails, a wheel mounted on the wheel bearing is retained at least partially on the sleeve by the retaining member.

A wheel retainer that retains a wheel on a wheel mount and prevents the wheel from being fully separated from the wheel mount in the event of a failure of a wheel bearing. In some embodiments, a wheel retainer includes a sleeve, and a retaining member coupled to the sleeve. The retaining member has a retaining diameter sized such that when a wheel bearing fails, a wheel mounted on the wheel bearing is retained at least partially on the sleeve by the retaining member.

A roller assembly including a shaft, a first support body to which one end of the shaft is coupleable, a second support body to which another end of the shaft is coupleable, and a roller coupleable between the first support body and the second support body, having a cylindrical shape in which the shaft is insertable, and rotatably supported by the shaft. The first support body and the second support body respectively include a protrusion that protrudes toward side surfaces of the roller, the protrusion of the first support body and the second support body respectively protrude from the first support body and the second support body and are respectively insertable into spaces inside an outer circumference of the roller, and the roller includes accommodation grooves on both side surfaces of the roller and accommodate the protrusion of the first support body and the second support body with certain gaps, respectively.

A roller assembly including a shaft, a first support body to which one end of the shaft is coupleable, a second support body to which another end of the shaft is coupleable, and a roller coupleable between the first support body and the second support body, having a cylindrical shape in which the shaft is insertable, and rotatably supported by the shaft. The first support body and the second support body respectively include a protrusion that protrudes toward side surfaces of the roller, the protrusion of the first support body and the second support body respectively protrude from the first support body and the second support body and are respectively insertable into spaces inside an outer circumference of the roller, and the roller includes accommodation grooves on both side surfaces of the roller and accommodate the protrusion of the first support body and the second support body with certain gaps, respectively.

An axle system includes an axle stub, a first connecting section and a second connecting section, wherein the axle stub is embodied on its outer side so as to be essentially rotationally symmetrical about a stub axis and has two ducts which extend parallel to the stub axis in certain regions, wherein the connecting sections lie in a connecting plane which is oriented orthogonally with respect to the stub axis, wherein the axle stub has an attachment region for securing a brake carrier which extends parallel to the connecting plane.

An axle system includes an axle stub, a first connecting section and a second connecting section, wherein the axle stub is embodied on its outer side so as to be essentially rotationally symmetrical about a stub axis and has two ducts which extend parallel to the stub axis in certain regions, wherein the connecting sections lie in a connecting plane which is oriented orthogonally with respect to the stub axis, wherein the axle stub has an attachment region for securing a brake carrier which extends parallel to the connecting plane.

An axle of railway wheel sets and a corresponding method for the ultrasound inspection are described. A blind hole, coaxial to the axle and sized to accommodate an ultrasonic probe, is obtained in each end of the axle. Main holes are intended to accommodate the probe holder containing a plurality of ultrasonic transducers for the inspection of the axle from the inside of the hole. The main advantage is to facilitate the propagation of the ultrasounds without being subjected to the interference caused by the geometric discontinuities normally present at the ends of the axles thereby minimizing false positives in the readings of the echoes.