Abstract: 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.

Abstract: A constant-velocity universal joint including a generally cup-shaped outer joint member and an inner joint member that 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 of the outer joint member. A pinch angle by which the ball is pinched in the second groove is open toward a bottom of the outer joint member. An absolute value of the pinch angle in a larger-pinch-angle groove portion that is one of the first and second groove portions, is larger than an absolute value of the pinch angle in a smaller-pinch-angle groove portion that is the other of the first and second groove portions in a reference state. A radial clearance in the smaller-pinch-angle groove portion is larger than a radial clearance in the larger-pinch-angle groove portion when torque is not transmitted in the reference state.

Abstract: 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.

Abstract: In a constant velocity joint, a center locus of a first ball rolling on a first outer central portion is inclined such that a distance from a central axis of an outer joint member decreases toward a bottom side of the outer joint member. A center locus of a second ball rolling on a second outer central portion is formed in a linear shape and inclined such that a distance from the central axis of the outer joint member increases toward the bottom side of the outer joint member. A center locus of the second ball rolling on the second outer bottom side portion is formed in an arc shape and disposed in the outer joint member at a position radially inwardly from a tangent at a connecting position between the second outer central portion and the second outer bottom side portion.

Abstract: 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.

Abstract: A constant-velocity universal joint including a generally cup-shaped outer joint member and an inner joint member that 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 of the outer joint member. A pinch angle by which the ball is pinched in the second groove is open toward a bottom of the outer joint member. An absolute value of the pinch angle in a larger-pinch-angle groove portion that is one of the first and second groove portions, is larger than an absolute value of the pinch angle in a smaller-pinch-angle groove portion that is the other of the first and second groove portions in a reference state. A radial clearance in the smaller-pinch-angle groove portion is larger than a radial clearance in the larger-pinch-angle groove portion when torque is not transmitted in the reference state.

Abstract: 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.

Abstract: In a constant velocity joint, a center locus of a first ball rolling on a first outer central portion is inclined such that a distance from a central axis of an outer joint member decreases toward a bottom side of the outer joint member. A center locus of a second ball rolling on a second outer central portion is formed in a linear shape and inclined such that a distance from the central axis of the outer joint member increases toward the bottom side of the outer joint member. A center locus of the second ball rolling on the second outer bottom side portion is formed in an arc shape and disposed in the outer joint member at a position radially inwardly from a tangent at a connecting position between the second outer central portion and the second outer bottom side portion.

Abstract: 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.

Abstract: In a constant-velocity joint, a center locus of a ball rolling on a first outer large-diameter portion has an arc shape having an arc center, and a center locus of the ball rolling on a second outer large-diameter portion has an arc shape having an arc center. Center loci of the ball rolling on an outer extension portion are positioned, throughout their lengths, in a region inducing a tangent line to an opening-side end portion of the center locus of the ball rolling on the second outer large-diameter portion, the region being positioned outward of the tangent line in a radial direction of the outer joint member. An opening-side end portion of the center locus of the ball rolling on the outer extension portion is positioned outward of the tangent line in the radial direction of the outer joint member.

Abstract: In a constant-velocity joint, a center locus of a ball rolling on a first outer large-diameter portion has an arc shape having an arc center, and a center locus of the ball rolling on a second outer large-diameter portion has an arc shape having an arc center. Center loci of the ball rolling on an outer extension portion are positioned; throughout their lengths, in a region inducing a tangent line to an opening-side end portion of the center locus of the ball rolling on the second outer large-diameter portion, the region being positioned outward of the tangent line in a radial direction of the outer joint member. An opening-side end portion of the center locus of the ball rolling on the outer extension portion is positioned outward of the tangent line in the radial direction of the outer joint member.

Abstract: A constant-velocity joint includes: an outer joint member; an inner joint member that is placed in the outer joint member and that can be angled with respect to the outer joint member; and balls that roll between the outer joint member and the inner joint member to transmit torque. First outer larger diameter portions and second outer larger diameter portions are formed alternately in the circumferential direction in the inner peripheral surface of the outer joint member. The center of an arc radius of a track of the center of the ball rolling on the first outer larger diameter portion and the center of an arc radius of a track of the center of the ball rolling on the second outer larger diameter portion are located on different sides with respect to the joint center in the axial direction of the outer joint member.