Constant velocity universal joint

A constant velocity universal joint comprising:

• an outer joint member having an inner periphery provided with three axial track grooves, axial roller guideways being arranged on both sides of each of the track grooves;
• a tripod member having three radially-projecting trunnions;
• and
• a roller assembly mounted on each of the trunnions of the tripod member, the roller assembly being capable of tilting movement with respect to the trunnion and having a roller to be guided along the roller guideways in directions parallel to the axis of the outer joint member, wherein
• at least one component part of the joint is limited to a predetermined range in softening resistance characteristic value (R).

A constant velocity universal joint comprising:

• an outer joint member having an inner periphery provided with three axial track grooves, axial roller guideways being arranged on both sides of each of the track grooves;
• a tripod member having three radially-projecting trunnions;
• and
• a roller assembly mounted on each of the trunnions of the tripod member, the roller assembly being capable of tilting movement with respect to the trunnion and having a roller to be guided along the roller guideways in directions parallel to the axis of the outer joint member, wherein
• at least one component part of the joint has a surface layer having a residual austenite content γ(R) (vol %) in the range of 20≦γR≦40.

A constant velocity universal joint comprising:

• an outer joint member having an inner periphery provided with three axial track grooves, axial roller guideways being arranged on both sides of each of the track grooves;
• a tripod member having three radially-projecting trunnions;
• and
• a roller assembly mounted on each of the trunnions of the tripod member, the roller assembly being capable of tilting movement with respect to the trunnion and having a roller to be guided along the roller guideway in directions parallel to the axis of the outer joint member, wherein
• at least one component part of the joint has a surface layer containing a structure in which carbide is distributed into a martensite matrix.

A constant velocity universal joint comprising:

• an outer joint member having an inner periphery provided with three axial track grooves, axial roller guideways being arranged on both sides of each of the track grooves;
• a tripod member having three radially-projecting trunnions;
• and
• a roller assembly mounted on each of the trunnions of the tripod member, the roller assembly including
• a roller to be guided along the roller guideway in directions parallel to the axis of the outer joint member,
• a support ring for supporting the roller rotatably, and
• engaging means for retaining the roller and the support ring from both sides so as to prevent axial relative movement of the roller and the support member,
• the roller assembly being capable of tilting movements and axial displacements with respect to the trunnion, wherein the engaging means has an engaging ring attached to the roller or the support ring, the engaging ring having a width W in the range of 0.5 mm≦(W)≦1.2 mm and a surface hardness in the range of HRC 43 to HRC 52, wherein HRC represents a C scale in Rockwell hardness.