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 rear-wheel drive shaft (1) includes a fixed type constant velocity universal joint (3), a plunging type constant velocity universal joint (2), and an intermediate shaft (4) coupling both the constant velocity universal joints to each other. A ratio (PCD.sub.BALL(f)/D.sub.BALL(f)) of a pitch circle diameter (PCD.sub.BALL(f)) of balls (33) of the fixed type constant velocity universal joint (3) to a diameter (D.sub.BALL(f)) of each of the balls (33) is set from 3.70 to 3.87. A ratio (PCD.sub.BALL(s)/D.sub.BALL(s)) of a pitch circle diameter (PCD.sub.BALL(s)) of balls (23) of the plunging type constant velocity universal joint (2) to a diameter (D.sub.BALL(s)) of each of the balls (23) is set from 3.3 to 3.6.

A rear-wheel drive shaft (1) includes a fixed type constant velocity universal joint (3), a plunging type constant velocity universal joint (2), and an intermediate shaft (4) coupling both the constant velocity universal joints to each other. A ratio (PCD.sub.BALL(f)/D.sub.BALL(f)) of a pitch circle diameter (PCD.sub.BALL(f)) of balls (33) of the fixed type constant velocity universal joint (3) to a diameter (D.sub.BALL(f)) of each of the balls (33) is set from 3.70 to 3.87. A ratio (PCD.sub.BALL(s)/D.sub.BALL(s)) of a pitch circle diameter (PCD.sub.BALL(s)) of balls (23) of the plunging type constant velocity universal joint (2) to a diameter (D.sub.BALL(s)) of each of the balls (23) is set from 3.3 to 3.6.

A propeller shaft includes a rotational shaft and a constant-velocity joint. The constant-velocity joint includes an inner race member connected to the rotational shaft, a rolling member disposed on an outer periphery of the inner race member in a radial direction relative to a direction of a rotational axis of the rotational shaft, and a tubular outer race member provided on an outer periphery of the rolling member in the radial direction and configured so that a rotational force of the rotational shaft is transmitted thereto via the rolling member. The outer race member has first and second end portions of the outer race member in the direction of the rotational axis. The outer race member includes a centering portion provided at the first end portion and formed so as to be smaller than a maximum diameter of the outer race member in the radial direction.

A fixed type constant velocity universal joint has outer joint member track grooves each with a raceway center line that includes an arc-shaped portion having a curvature center that has no offset with respect to a joint center in an axial direction. The track grooves are formed such that adjacent track grooves are inclined in opposite directions. The joint also has inner joint member track grooves that are each mirror-symmetric with a corresponding one of the outer joint member track grooves. When at a maximum operating angle, a torque transmission ball that moves toward an opening side of the outer joint member track groove loses contact with an opening-side end portion of that track groove, and when at an operating angle of 0°, an end portion of a cage projects from the opening-side end portion of the outer joint member in the axial direction.

A constant velocity joint for a multi-piece propeller shaft includes an outer race extending from a first outer race end to a second outer race end to define an exterior surface. A tuned damper extends radially outwardly from the exterior surface of the of the outer race for reducing noise, vibration, and/or harshness (NVH) generated during operation of the multi-piece propeller shaft.

A constant velocity universal joint includes an outer joint member and an inner joint member between which torque is transferred through intermediation of balls while allowing angular displacement. A power transmission shaft is coupled to the inner joint member to allow torque transmission therebetween. A mounting and dismounting mechanism configured to mount and dismount the power transmission shaft to and from the inner joint member is provided between the inner joint member and the power transmission shaft. The mounting and dismounting mechanism includes a tubular member, a snap ring mounted inside the tubular member, a pushing member arranged on a radially outer side of the snap ring to be movable in a radial direction, and an annular member arranged on an outer peripheral surface of the tubular member to be movable in an axial direction.

A constant velocity universal joint includes an outer joint member and an inner joint member between which torque is transferred through intermediation of balls while allowing angular displacement. A power transmission shaft is coupled to the inner joint member to allow torque transmission therebetween. A mounting and dismounting mechanism configured to mount and dismount the power transmission shaft to and from the inner joint member is provided between the inner joint member and the power transmission shaft. The mounting and dismounting mechanism includes a tubular member, a snap ring mounted inside the tubular member, a pushing member arranged on a radially outer side of the snap ring to be movable in a radial direction, and an annular member arranged on an outer peripheral surface of the tubular member to be movable in an axial direction.

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.