A method of manufacturing a constituent member of a constant-velocity joint includes: performing plastic working; and performing hardening of a material. The plastic working is performed with a material of the constituent member heated to a predetermined working temperature range. The hardening of the material is performed by utilizing heat applied for heating to the working temperature range in performing the plastic working as heat for the hardening of the material and cooling the material after performing the plastic working.

The present disclosure relates a brake disc and a method of manufacturing the same, in which the depth of the coating layer containing a nitride is adjustable and corrosion resistance and wear resistance can be improved. A brake disc according to an embodiment of the present disclosure includes: a disc base material made of gray cast iron; and a coating layer formed on a surface of the disc base material and including a nitride produced as nitrogen is diffused into a ferrite matrix structure.

Provided is a tripod type constant velocity universal joint (1), including: an outer joint member (2) having track grooves (6) formed at trisected positions in a circumferential direction to extend in an axial direction; a tripod member (3) including leg shafts (9) radially projecting from trisected positions in the circumferential direction; and rollers (4) fitted in a freely rotatable manner about the leg shafts (9), respectively, and received in the track grooves (6), respectively, in which a radially outer surface (4a) of each of the rollers (4) is formed of a surface unsubjected to grinding or cutting work after heat treatment.

Systems and methods of making an enhanced brake rotor having enhanced wear resistance are provided. The systems and methods provide a vehicular rotor comprising a base comprising iron (Fe). The base comprises an outer surface having a laser-hardened portion thereon. The laser-hardened portion comprises martensite and having a thickness of between 10 and 100 microns of the outer surface to define the enhanced brake rotor with enhanced wear resistance.

A method includes providing a metal ring and pastelessly slide-grinding at least one surface of the metal ring with grinding bodies, preferably until a predefined surface topography of the metal ring is achieved, which surface topography preferably has an Rsk value that is greater than or equal to 0.25 and/or an Rk value between 0.3 and 1.35 and/or Rpk value between 0.05 and 0.4 and/or an Rvk value between 0.2 and 1.2 and/or an Ra value between 0.1 and 0.4.

A method for manufacturing a ferrous rotational member including the steps of turning a first portion of the friction surface at a sufficient feed rate to provide a first deformed layer on the first portion of the friction surface; fine turning a second portion of the friction surface at a sufficient feed rate to provide a second deformed layer on the second portion of the friction surface; burnishing the first and second portions of the friction surface to achieve a predetermined roughness; and nitrocarburizing the rotational member at a time and temperature sufficient for the diffusion of nitrogen atoms and carbon atoms through the deformed layer to form hardened casings having variable thickness. The ferrous rotational member may be that of a brake rotor having a hub surface and a friction surface, where the hub surface and friction surface have a variable thickness hardened casing.

Disclosed is a method for manufacturing a lightweight brake disc with maximized heat dissipation ability. The method includes a first step of mixing gray cast iron and FeCr ferroalloy with each other to produce a mixture, melting and solidifying the mixture to cast an alloy; a second step of heat-treating the alloy cast in the first step to pearlitize a microstructure of the alloy; and a third step of performing nitriding heat treatment of the alloy heat-treated in the second step.

A counter track joint comprises an outer joint part, an inner joint part, first pairs of tracks widening towards the opening side of the outer joint part when the counter track joint is aligned, and second pairs of tracks widening towards the connecting side of the outer joint part when the counter track joint is aligned; a ball in each of the first and second pairs of tracks; a ball cage having circumferentially distributed cage windows each receiving one of the balls, wherein one of the outer ball track group and the inner ball track group is hardened and hard machined, and the other of the outer ball track group and the inner ball track group is soft finished and subsequently hardened. A method of manufacturing a counter track joint is provided.

A first constant velocity joint is equipped with a cup part made of a light alloy. First ball grooves that receive a torque from torque transmitting members are formed on an inner wall of the cup part. A high hardness layer made of ceramic or cermet as a principal component thereof is formed on an inner surface of the cup part including at least inner surfaces of the first ball grooves.

Assembly for synchronization unit of gear-changing transmission includes a friction ring and synchronizer ring. Friction ring has a conical friction ring body with friction surface and an installation surface that respectively bound friction ring body in a radial peripheral direction extending perpendicular to an axial friction ring axis. Friction surface extends at a predefinable friction angle and installation surface extends at a predefinable installation angle, in each case conically. Synchronizer ring has a contact surface corresponding to installation surface of friction ring. Synchronizer ring and friction ring are adapted so that contact surface of synchronizer ring contacts installation surface of friction ring, and friction surface of friction ring is in rubbing contact with a gear wheel during a synchronization process where synchronizer ring is displaced in a direction of a gear wheel to be synchronized. Installation surface of friction ring and/or contact surface of synchronizer ring has/have adhesion-reducing surface structure.