A fixed type constant velocity universal joint (3) includes an outer joint member (31), an inner joint member (32), eight balls (33), and a cage (34). A curvature center (O.sub.31d) of track grooves (31d) of the outer joint member (31) and a curvature center (O.sub.32e) of track grooves (32e) of the inner joint member (32) are offset to opposite sides in an axial direction of the joint with respect to a joint center (O(f)) by an equal distance. A ratio (PCD.sub.BALL/D.sub.BALL) of a pitch circle diameter (PCD.sub.BALL) of the balls (33) to a diameter (D.sub.BALL) of each of the balls (33) is set from 3.70 to 3.87. A ratio (T.sub.C/D.sub.BALL) of a radial thickness (T.sub.C) of the cage (34) to the diameter (D.sub.BALL) of each of the balls (33) is set from 0.22 to 0.25.

A fixed type constant velocity universal joint (3) includes an outer joint member (31), an inner joint member (32), eight balls (33), and a cage (34). A curvature center (O.sub.31d) of track grooves (31d) of the outer joint member (31) and a curvature center (O.sub.32e) of track grooves (32e) of the inner joint member (32) are offset to opposite sides in an axial direction of the joint with respect to a joint center (O(f)) by an equal distance. A ratio (PCD.sub.BALL/D.sub.BALL) of a pitch circle diameter (PCD.sub.BALL) of the balls (33) to a diameter (D.sub.BALL) of each of the balls (33) is set from 3.70 to 3.87. A ratio (T.sub.C/D.sub.BALL) of a radial thickness (T.sub.C) of the cage (34) to the diameter (D.sub.BALL) of each of the balls (33) is set from 0.22 to 0.25.

A fixed type constant velocity universal joint (3) includes an outer joint member (31), an inner joint member (32), eight balls (33), and a cage (34). A diameter (D.sub.31c) of the outer joint member (31) at an opening end of an inner peripheral surface (31c) is set larger than an outer diameter (D.sub.34b) of the cage (34) at a center portion in a circumferential direction of pockets (34a) when the cage (34) is seen from an axial direction of the joint. A bottom surface (31f) of a mouth section (31a) of the outer joint member (31) is arranged so as to interfere with an imaginary spherical surface (Q) being an extension of the inner peripheral surface (31c) of the outer joint member (31) toward a deep-side.

A fixed type constant velocity universal joint (3) includes an outer joint member (31), an inner joint member (32), eight balls (33), and a cage (34). A diameter (D.sub.31c) of the outer joint member (31) at an opening end of an inner peripheral surface (31c) is set larger than an outer diameter (D.sub.34b) of the cage (34) at a center portion in a circumferential direction of pockets (34a) when the cage (34) is seen from an axial direction of the joint. A bottom surface (31f) of a mouth section (31a) of the outer joint member (31) is arranged so as to interfere with an imaginary spherical surface (Q) being an extension of the inner peripheral surface (31c) of the outer joint member (31) toward a deep-side.

A center bearing assembly for a multi-piece propeller shaft includes a stud yoke extending along an axis A between first and second stud yoke ends to define a central stub shaft rotatable about the axis A. A rotatable weld collar is operably connected to the second stud yoke end of the central stub shaft for simultaneous rotation therewith. The rotatable weld collar includes a body extending from a first collar end disposed adjacent the central stub shaft to a second collar end to define an exterior surface. A tuned damper extends radially outwardly from the exterior surface of the rotatable weld collar for reducing noise, vibration, and/or harshness (NVH) generated during operation of the multi-piece propeller shaft. A first shaft segment is operably connected to the rotatable weld collar and a second shaft segment is operably connected to the stud yoke for transferring a rotational force therebetween.

Apparatus, such as a propeller shaft, includes an outer circumferential portion or outer race to rotate as a unit with an internal shaft (serving as the propeller shaft), an inner circumferential member or inner race to rotate as a unit with an external shaft and a plurality of balls disposed between the outer race and inner race, for transmitting rotation therebetween. A sleeve rotating as a unit with the inner race includes an inside cavity for receiving the external shaft. The sleeve is coated with a coating formed on an inside circumferential surface.

Apparatus, such as a propeller shaft, includes an outer circumferential portion or outer race to rotate as a unit with an internal shaft (serving as the propeller shaft), an inner circumferential member or inner race to rotate as a unit with an external shaft and a plurality of balls disposed between the outer race and inner race, for transmitting rotation therebetween. A sleeve rotating as a unit with the inner race includes an inside cavity for receiving the external shaft. The sleeve is coated with a coating formed on an inside circumferential surface.

A fixed type constant velocity universal joint has an operation mode in which, when a maximum operating angle is taken, in a column portion that is one of column portions on both sides of a pocket of a cage receiving a torque transmission ball at a phase angle and is located on a side corresponding to a phase angle larger than the phase angle, a projection end portion obtained by projecting an end portion of a spherical inner peripheral surface of the outer joint member on the opening side in a perpendicular direction toward the spherical outer peripheral surface of the cage and a projection end portion obtained by projecting an end portion of the spherical outer peripheral surface of the inner joint member on the back side in the perpendicular direction toward the spherical inner peripheral surface of the cage overlap in the axial direction of the cage.

A fixed type constant velocity universal joint has an operation mode in which, when a maximum operating angle is taken, in a column portion that is one of column portions on both sides of a pocket of a cage receiving a torque transmission ball at a phase angle and is located on a side corresponding to a phase angle larger than the phase angle, a projection end portion obtained by projecting an end portion of a spherical inner peripheral surface of the outer joint member on the opening side in a perpendicular direction toward the spherical outer peripheral surface of the cage and a projection end portion obtained by projecting an end portion of the spherical outer peripheral surface of the inner joint member on the back side in the perpendicular direction toward the spherical inner peripheral surface of the cage overlap in the axial direction of the cage.

An inner joint member has, on an opening portion side of an outer joint member, a holding portion that has a bottomed concave shape into which a sleeve for supporting a boot covering the opening portion is press-fitted, and a relief portion that is provided on part of a convex outer spherical surface at the opening portion side, and that has a smaller diameter than an outer diameter of the convex outer spherical surface corresponding to a press-fitting range of the holding portion into which the sleeve is press-fitted.