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 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.

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.

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 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 constant velocity joint comprises an outer joint part with outer ball tracks and an inner joint part with inner ball tracks. An outer ball track and an inner ball track respectively form a pair of tracks with one another; in each, a torque-transmitting ball is guided. The torque-transmitting balls are accommodated in a ball cage with circumferentially distributed cage windows. In any angular position of the constant velocity joint an opening angle is formed between an outer tangent to the outer ball track and an inner tangent to the inner ball track. At an articulation angle of zero degrees the opening angle is greater than zero degrees. A central articulation angle range is defined with articulation angles less than fifteen degrees. The opening angle increases by at least two degrees within the central articulation angle range, and is less than twelve degrees for all articulation angles within the central articulation angle range.

A constant velocity joint comprises an outer joint part with outer ball tracks and an inner joint part with inner ball tracks. An outer ball track and an inner ball track respectively form a pair of tracks with one another; in each, a torque-transmitting ball is guided. The torque-transmitting balls are accommodated in a ball cage with circumferentially distributed cage windows. In any angular position of the constant velocity joint an opening angle is formed between an outer tangent to the outer ball track and an inner tangent to the inner ball track. At an articulation angle of zero degrees the opening angle is greater than zero degrees. A central articulation angle range is defined with articulation angles less than fifteen degrees. The opening angle increases by at least two degrees within the central articulation angle range, and is less than twelve degrees for all articulation angles within the central articulation angle range.

A constant-velocity universal joint including a generally cup-shaped outer joint member and an inner joint member that cooperate with each other to define first and second groove portions. A pinch angle by which a ball is pinched in the first groove portion is open toward an opening end of the outer joint member. A pinch angle by which the ball is pinched in the second groove is open toward a bottom wall of the outer joint member. An absolute value of the pinch angle in the first groove portion is larger than an absolute value of the pinch angle in the second groove portion in a reference state in which centerlines of the outer joint member and the inner joint member lie in a straight line.