A joint-center-fixed constant velocity joint configured to be provided in a vehicle includes an outer joint member, an inner joint member, a first ball, a second ball, and a cage. While a center of the first ball is moving to a position of the maximum use angle on an opening side from a joint center, a first open angle faces the opening side. While a center of the second ball is moving to a position of the maximum use angle on a bottom side from the joint center, a second open angle is not reversed from a state where the second open angle faces the bottom side to a state where the second open angle faces the opening side.

An axle assembly for a driving wheel of a vehicle allows a wheel-side joint and a shaft to be rotated separately from a boot while driving so as to prevent generation of friction noise of the boot. The axle assembly includes the shaft rotated by receiving driving force from a powertrain; an axle housing disposed to pass through a center of a steering knuckle connected to a steering apparatus; a wheel bearing mounted between the steering knuckle and the axle housing; a joint bearing mounted on an outer part of the shaft; and a boot unit configured to have a first end coupled to an outer race of the joint bearing and a second end coupled to an outer race of the wheel bearing so as to form a space filled with a lubricant outside the shaft.

A universal joint or other vehicle driveline assembly includes an inner race, an outer race, and bearings positioned between the races. In some embodiments, the components of the universal joint that are in contact with the bearings are selectively processed to be harder than the other non-contact surfaces of the component.

A double-offset plunging type constant velocity universal joint includes inner and outer joint members each having six linear track grooves extending along an axial direction. The inner joint member has a coupling hole at a center portion thereof for coupling a shaft. Six torque transmission balls retained by a cage are incorporated between the linear track grooves of the inner and outer joint members. A ratio T.sub.CAGE/D.sub.BALL of a minimum thickness (T.sub.CAGE) of the cage to a diameter of the torque transmission ball (D.sub.BALL) is from 0.225 to 0.245, wherein a ratio D.sub.BALL/D.sub.S of a diameter (D.sub.BALL) of the torque transmission ball to a spline large diameter (D.sub.S) of the coupling hole of the inner joint member is from 0.79 to 0.85, and wherein a ball contact ratio (ψ) of the torque transmission ball is from 1.08 to 1.12.

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 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 constant velocity joint includes an outer joint portion with a first longitudinal axis, a first attaching end, an aperture end and outer ball tracks on an inner circumferential surface, an inner joint portion with a second longitudinal axis, a second attaching end, an inner face facing towards the outer joint portion and inner ball tracks on its outer circumferential surface, balls for torque transmission between the outer and inner joint portions, an annular ball cage between the outer and inner joint portions with several cage windows in which the balls are guided. The inner and outer joint portions are arranged so that one outer ball track and one inner ball track are in each case arranged opposite to each other to form three different types of track pairs to receive one respective balls. The balls have different controlling behaviors due to different track geometries.

The present disclosure relates to a constant-velocity joint for torque-transmission, in which a first type of track pairs of ball tracks is configured in such a manner that the centers of curvature of the center lines of the ball tracks are situated in the joint center plane when the joint is straight. A second type of track pairs of ball tracks is configured in such a manner that their center lines have at least two portions. The respective center line of the outer ball tracks of the second type of track pairs has at least one inner portion and one outer portion, wherein the inner portion is situated on the connection side of the outer joint portion, while the outer portion is situated on the opening side of the outer joint portion, and the inner portion is curved.

A joint assembly (200) comprising a first joint member (232) that is drivingly connected to a second joint member (272) by one or more torque transfer elements (290). Drivingly connected to at least a portion of the second joint member (312) is a stub shaft (292). An end of the stub shaft, opposite the second joint member, is drivingly connected to at least a portion of a second shaft. At least a portion of a second end portion of a first shaft (202) is drivingly connected to at least a portion of a first end portion of the first joint member (232) and at least a portion of a first end portion of the first shaft has a gear member (210) with a plurality of gear teeth thereon.

A propeller shaft including a first shaft, a first constant velocity joint drivingly connected with the first shaft, a second shaft, a second constant velocity joint drivingly connected with the second shaft, a connecting shaft drivingly connecting the first constant velocity joint and the second constant velocity joint and a grease cover disposed about an axial end of the second constant velocity joint. The second constant velocity joint is provided with a spring mechanism including a spring, wherein a spring seat of the spring mechanism is positioned on one axial end of the spring and mates with the second shaft, and wherein another axial end of the spring mates with an additional spring seat that is formed in the grease cover of the second constant velocity joint. The second constant velocity joint further comprises a spacer positioned between the spring and the grease cover and attached to the grease cover, wherein the spring has an axial end portion and a reduced diameter portion, and wherein an outer diameter of the reduced diameter portion is less than an outer diameter of the axial end portion.