A power transmission shaft includes: a bearing including a cylindrical portion, an internal spline portion, and an internal spline side annular groove including a bottom surface, and a first side wall and a second side wall, the first side wall which includes a first inclination surface inclined with respect to the rotation axis of the shaft portion, and on which the circlip is abutted in a state where a radius of the circlip is decreased within the internal spline side annular groove, and the second side wall on which the circlip is abutted in the state where the radius of the circlip is decreased within the internal spline side annular groove.

A constant velocity universal joint includes outer and inner joint members configured to transmit torque therebetween through intermediation of balls while allowing angular displacement. A power transmission shaft is coupled to the inner joint member. 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 inserted externally on the power transmission shaft so as to extend from the inner joint member, a fixing member received in the tubular member, and an annular member arranged on an outer periphery of the tubular member. The fixing member is moved in the radial direction along with movement of the annular member in the axial direction so that the fixing member is mountable to and dismountable from the power transmission shaft.

A shaft assembly. The shaft assembly includes a joint assembly having a first joint member, a second joint member and one or more third joint members drivingly connecting said first and second joint members. At least a portion of a first shaft is drivingly connected to the second joint member. Circumferentially extending from at least a portion of an outer surface of a second end portion of the first shaft is a first and second increased diameter portion having a wall portion that connects the first increased diameter portion to the second increased diameter portion. Drivingly connected to the second increased diameter portion of the first shaft is a second shaft. During a crash condition, an amount of force is applied to the wall portion until it fractures and at least a portion of the first shaft and/or the joint assembly translates into a hollow portion of the second shaft.

A constant velocity universal joint has an outer joint member and an inner joint member that transmits torque while permitting angular displacement due to balls between the inner and outer joint members. An attaching and detaching mechanism for attaching and detaching a power transmission shaft to and from the inner joint member is provided between the inner joint member and the power transmission shaft such that torque can be transmitted between the two. The attaching and detaching mechanism has a cylindrical member that fits over the power transmission shaft, a retaining ring that is radially movable, and an annular member that is axially movable. By using a boot band to fixedly tighten, to the power transmission shaft, a small diameter end portion of a boot closing an opening portion of the outer joint member, the axial position of the annular member is restricted by the small diameter end portion.

A constant-speed universal joint includes: an outer ring; an inner ring; a plurality of balls that engages with the outer-ring ball grooves and the inner-ring ball grooves; and a holder that is interposed between an inner spherical surface of the outer ring and an outer spherical surface of the inner ring and in which a holding window for holding the plurality of balls is formed. A chamfered portion is formed in the inner ring. The chamfered portion includes a linear section portion that is formed in a linear shape in a section perpendicular to a moving locus of the center of the corresponding ball and an arc section portion that is formed in a protruding arc shape in the section perpendicular to the moving locus of the center of the corresponding ball.

A ball-type constant velocity joint may include: an outer race part installed on a shaft and having a plurality of first grooves formed axially in the inner surface thereof; a first inner race part including: a first inner race rotatably installed in the outer race part, having a plurality of second grooves formed on the outer surface thereof, and having a plurality of third grooves formed axially on the inner surface thereof; and a plurality of first balls installed between the first grooves and the second grooves; and a second inner race part including: a second inner race rotatably installed in the first inner race, and having a plurality of fourth grooves formed on the outer surface thereof and facing the third grooves; and a plurality of second balls installed between the third grooves and the fourth grooves.

A propeller shaft includes a shaft section connected between an input shaft and an output shaft via respective constant velocity joints, wherein the input shaft is connected to a drive source of a vehicle, and the output shaft is connected to driving wheels. The constant velocity joint includes a circlip-restricting surface to engage with a circlip provided in an outer peripheral surface of the input or output shaft, for restricting movement of the first or second shaft in an axial direction. The circlip-restricting surface is implemented by a first inclined surface and a second inclined surface, wherein the second inclined surface is closer to a rotational axis of the shaft section, and wherein the first inclined surface has an acute angle with respect to the axial direction, and the second inclined surface has a smaller angle with respect to the axial direction.

A constant velocity ball joint uses a star shaped sleeve with a splined connection to its shaft. The sleeve is longitudinally retained on its shaft using a retaining ring in an outwardly facing groove of the shaft. The star shaped sleeve has a 30° assembly assist chamfer angle on one side, as well as a 45° transition chamfer angle and a 65° ramp chamfer angle facing the opposite direction. These angles control the diameter of the retaining ring as it is compressed inward into the groove during assembly and disassembly. The star shaped sleeve can be used in a dynamic length CV joint, with the splines of a configuration that allows longitudinal sliding of the sleeve on the shaft, so the shell of the dynamic length CV joint still can be of the spherical race type.

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 rotational driving force transmission mechanism includes a cylindrical shaft made of fiber reinforced plastic, and a first constant velocity joint. The shaft is joined to the first constant velocity joint via a metallic intervening member which is attached to one end of the shaft in the axial direction. The intervening member includes a shaft portion and a main body portion. The shaft portion is inserted into the one end of the shaft from a distal end side thereof. The main body portion is of a bottomed tubular shape made up from a bottom part joined to a proximal end side of the shaft portion, and a tubular portion fitted over the one end of the shaft. The first constant velocity joint includes an inner ring fitted externally over the tubular portion of the intervening member.