In a fixed type constant velocity universal joint, an axial offset amount of a curvature center of each of track grooves of outer and inner joint members is set to 0. The track grooves of the outer and inner joint members are each inclined with respect to an axis line. The track grooves adjacent to each other in a circumferential direction are inclined in opposite directions. The track grooves of the outer and inner joint members that are opposed to each other are inclined with respect to the axis line in opposite directions. A chamfered portion is formed on a track inlet end of each of the track grooves of the outer joint member. When the cage and the inner joint member are inclined with respect to the outer joint member, balls are incorporated into two cage windows at the same time through the chamfered portions.

A boot for a constant velocity universal joint includes large- and small-diameter mounting portions to be mounted to an outer joint member and a shaft, respectively, with boot clamps, a bellows portion integrally coupling the large- and small-diameter mounting portions to each other, and a cylindrical shoulder portion formed at a bellows portion-side end of the large-diameter-side mounting portion, and connected to the bellows portion through two auxiliary crest portions and one auxiliary trough portion between the auxiliary crest portions. A radial distance between each of the auxiliary crest portions and the auxiliary trough portion is shorter than a radial distance between a crest portion and a trough portion. A diameter passing through a center of the radial distance between each of the auxiliary crest portions and the auxiliary trough portion is larger than a diameter of the cylindrical shoulder portion.

A constant velocity joint comprises an outer joint part with outer ball tracks, an inner joint part with inner ball tracks, wherein respectively an outer ball track and an inner ball track form a pair of tracks with each other; a torque-transmitting ball in each pair of tracks; a ball cage in which the torque-transmitting balls are received; wherein a first articulation angle range is defined comprising articulation angles of less than twenty degrees, and a second articulation angle range comprising articulation angles greater than twenty degrees; wherein an opening angle within the first articulation angle range increases as the articulation angle (β) increases, and wherein a first mean opening angle increase of the first articulation angle range is greater than a second mean opening angle increase of the second articulation angle range.

A constant velocity joint comprises an outer joint part with outer ball tracks, an inner joint part with inner ball tracks, wherein respectively an outer ball track and an inner ball track form a pair of tracks with each other; a torque-transmitting ball in each pair of tracks; a ball cage in which the torque-transmitting balls are received; wherein a first articulation angle range is defined comprising articulation angles of less than twenty degrees, and a second articulation angle range comprising articulation angles greater than twenty degrees; wherein an opening angle within the first articulation angle range increases as the articulation angle (β) increases, and wherein a first mean opening angle increase of the first articulation angle range is greater than a second mean opening angle increase of the second articulation angle range.

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.

A transfer device is provided, which includes an input shaft configured to receive a driving force generated by a drive source, an output shaft configured to output a portion of the driving force to part-time drive wheels of a vehicle, a transfer case accommodating the input and output shafts, at least two output bearings rotatably supporting the output shaft, and a constant-velocity (CV) joint connected to the output shaft and provided on a first side of the part-time drive wheels with respect to the output shaft. The output shaft is formed with a recessed opening portion opening toward the first side and receiving at least a part of the CV joint therein. The transfer case has an annular intruding part extending from the first side of the output shaft into the recessed opening portion. A first output bearing is located inside the recessed opening portion.

A transfer device is provided, which includes an input shaft configured to receive a driving force generated by a drive source, an output shaft configured to output a portion of the driving force to part-time drive wheels of a vehicle, a transfer case accommodating the input and output shafts, at least two output bearings rotatably supporting the output shaft, and a constant-velocity (CV) joint connected to the output shaft and provided on a first side of the part-time drive wheels with respect to the output shaft. The output shaft is formed with a recessed opening portion opening toward the first side and receiving at least a part of the CV joint therein. The transfer case has an annular intruding part extending from the first side of the output shaft into the recessed opening portion. A first output bearing is located inside the recessed opening portion.

An undercut free (UF) joint assembly for a vehicle driveline system is provided and includes an axle bar, an inner race, a stem, an outer race, and a cage. Also included are a plurality of balls retained within the cage, the axle bar able to articulate relative to the outer race, an opening chamfer of the outer race parallel to an outer surface of the axle bar oriented at the required joint angle.

An undercut free (UF) joint assembly for a vehicle driveline system is provided and includes an axle bar, an inner race, a stem, an outer race, and a cage. Also included are a plurality of balls retained within the cage, the axle bar able to articulate relative to the outer race, an opening chamfer of the outer race parallel to an outer surface of the axle bar oriented at the required joint angle.