Abstract: A plunging type constant velocity universal joint 1 for a propeller shaft includes an outer joint member 2, an inner joint member 3, eight torque transmidetting balls 4, and a cage 5. A center of curvature O1 of a spherical outer surface 12 and a center of curvature O2 of a spherical inner surface 13 of the cage 5 each have an equal and axially opposite offset (f) with respect to a center O3 of pockets 5a. A ratio f/PCDBALL between the offset (f) of the cage 5 and a pitch circle diameter (PCDBALL) of the torque transmitting balls 4 is 0.07 or more and 0.09 or less.

Abstract: A plunging type constant velocity universal joint 1 for a propeller shaft includes an outer joint member 2, an inner joint member 3, eight torque transmitting balls 4, and a cage 5. A center of curvature O1 of a spherical outer surface 12 and a center of curvature O2 of a spherical inner surface 13 of the cage 5 each have an equal and axially opposite offset (f) with respect to a center O3 of pockets 5a. A ratio f/PCDBALL between the offset (f) of the cage 5 and a pitch circle diameter (PCDBALL) of the torque transmitting balls 4 is 0.07 or more and 0.09 or less.

Abstract: A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, eight balls, and a cage. The fixed type constant velocity universal joint has a ball retaining mechanism. A ratio of an axial length from a joint center to an opening-side end surface of the outer joint member to a diameter of each of the balls is within a range of 0.35 to 0.52. A ratio of a width of the cage to the diameter of each of the balls is within a range of 1.63 to 1.80. The ball retaining mechanism includes a cylindrical shaft portion at an end portion of a shaft and an angle restriction stopper surface of the outer joint member.

Abstract: A plunging type constant velocity universal joint includes an outer joint member, an inner joint member, eight balls, and a cage. A curvature center of a spherical portion of an outer peripheral surface of the cage and a curvature center of a spherical portion of an inner peripheral surface of the cage are offset to opposite sides in the axial direction with respect to a joint center by an equal distance. A ratio PCDBALL/DBALL of a pitch circle diameter PCDBALL of the balls to a diameter DBALL of each of the balls is set from 3.3 to 3.6. A ratio TI/DBALL of a radial thickness TI of the inner joint member to the diameter DBALL of each of the balls is set from 0.30 to 0.45.

Abstract: 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 (D31c) of the outer joint member (31) at an opening end of an inner peripheral surface (31c) is set larger than an outer diameter (D34b) 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.

Abstract: 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 (O31d) of track grooves (31d) of the outer joint member (31) and a curvature center (O32e) 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 (PCDBALL/DBALL) of a pitch circle diameter (PCDBALL) of the balls (33) to a diameter (DBALL) of each of the balls (33) is set from 3.70 to 3.87. A ratio (TC/DBALL) of a radial thickness (TC) of the cage (34) to the diameter (DBALL) of each of the balls (33) is set from 0.22 to 0.25.

Abstract: A rear-wheel drive shaft (1) includes a fixed type constant velocity universal joint (3), a plunging type constant velocity universal joint (2), and an intermediate shaft (4) coupling both the constant velocity universal joints to each other. A ratio (PCDBALL(f)/DBALL(f)) of a pitch circle diameter (PCDBALL(f)) of balls (33) of the fixed type constant velocity universal joint (3) to a diameter (DBALL(f)) of each of the balls (33) is set from 3.70 to 3.87. A ratio (PCDBALL(s)/DBALL(s)) of a pitch circle diameter (PCDBALL(s)) of balls (23) of the plunging type constant velocity universal joint (2) to a diameter (DBALL(s)) of each of the balls (23) is set from 3.3 to 3.6.

Abstract: A plunging type constant velocity universal joint 1 for a propeller shaft includes an outer joint member 2, an inner joint member 3, eight torque transmitting balls 4, and a cage 5. A center of curvature O1 of a spherical outer surface 12 and a center of curvature O2 of a spherical inner surface 13 of the cage 5 each have an equal and axially opposite offset (f) with respect to a center O3 of pockets 5a. A ratio f/PCDBALL between the offset (f) of the cage 5 and a pitch circle diameter (PCDBALL) of the torque transmitting balls 4 is 0.07 or more and 0.09 or less.

Abstract: A forging method for a shaft member includes preforming at least one of a plurality of enlarged diameter portions to obtain a semi-finished member, and forming a remainder of the enlarged diameter portions in the semi-finished member using a mold. The mold includes a punch, split dies, and a workpiece receiving member. The forming of the remainder of the enlarged diameter portions includes allowing the semi-finished member having the at least one of the enlarged diameter portions to be placed on the workpiece receiving member, cramping the semi-finished member in its radial direction by closing the split dies, and filling the semi-finished member into forming surfaces of the split dies by the pressure applied by the punch under the state in which the semi-finished member is cramped.

Abstract: An inspection device inspects a joint-type outer joint member of a constant velocity universal joint that includes a cup section having a bottomed cylindrical shape and track grooves in an inner periphery thereof for torque transmitting elements, and a shaft section extending from a bottom of the cup section. The inspection device inspects the outer joint member, which is obtained through melt-welding on a cup member forming the cup section and a shaft member forming the shaft section. The inspection device includes a surface inspection unit to inspect for a defect which appears on a surface of the outer joint member due to welding, an internal inspection unit to inspect for an internal defect of a welded portion, and a recording unit to record an inspection result of the inspection. The inspection device is configured to efficiently perform in-line total inspection for the melt-welded joint-type outer joint member.

Abstract: Provided is a plunging type constant velocity universal joint (2) comprising an outer joint member (21), an inner joint member (22), eight balls (23), and a cage (24). A curvature center (O24b) of a spherical portion (24b) of an outer peripheral surface of the cage (24) and a curvature center (O24d) of a spherical portion (24d) of an inner peripheral surface of the cage (24) are offset to opposite sides in the axial direction with respect to a joint center (O(s)) by an equal distance. A ratio PCDBALL/DBALL of a pitch circle diameter PCDBALL of the balls (23) to a diameter DBALL of each of the balls (23) is set from 3.3 to 3.6. A ratio TI/DBALL of a radial thickness TI of the inner joint member (22) to the diameter DBALL of each of the balls (23) is set from 0.30 to 0.45.

Abstract: A rear-wheel drive shaft (1) includes a fixed type constant velocity universal joint (3), a plunging type constant velocity universal joint (2), and an intermediate shaft (4) coupling both the constant velocity universal joints to each other. A ratio (PCDBALL (f)/DBALL (f)) of a pitch circle diameter (PCDBALL (f)) of balls (33) of the fixed type constant velocity universal joint (3) to a diameter (DBALL(f)) of each of the balls (33) is set from 3.70 to 3.87. A ratio (PCDBALL(s)/DBALL(s)) of a pitch circle diameter (PCDBALL(s)) of balls (23) of the plunging type constant velocity universal joint (2) to a diameter (DBALL(s)) of each of the balls (23) is set from 3.3 to 3.6.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion, and preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member. The method also includes bringing the joining end surfaces of the cup and shaft members into abutment against each other, and welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup members.

Abstract: 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 (O31d) of track grooves (31d) of the outer joint member (31) and a curvature center (O32e) 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 (PCDBALL/DBALL) of a pitch circle diameter (PCDBALL) of the balls (33) to a diameter (DBALL) of each of the balls (33) is set from 3.70 to 3.87. A ratio (TC/DBALL) of a radial thickness (TC) of the cage (34) to the diameter (DBALL) of each of the balls (33) is set from 0.22 to 0.25.

Abstract: 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 (D31c) of the outer joint member (31) at an opening end of an inner peripheral surface (31c) is set larger than an outer diameter (D34b) 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.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion after the forging, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

Abstract: For butt-welding, which includes bringing joining end surfaces of a cup member and a shaft member into abutment against each other and radiating a high energy intensity beam from a radially outer side, the shaft member has a recess on a radially inner side of the joining end surface to obtain a welded portion having a closed hollow cavity on a radially inner side after butt-welding. The joining end surface (protruding surface) of the cup member protrudes toward a radially inner side with respect to an inner diameter of the joining end surface of the shaft member. With this, a welded portion of an outer joint member of a constant velocity universal joint, which is manufactured by joining the cup member and the shaft member, can be improved in strength and quality.

Abstract: In an outer joint member of a constant velocity universal joint, a cup member and a shaft member are made of medium to high carbon steel and welded together. The cup member has a bottomed cylindrical shape that is opened at one end, and includes a cylindrical portion, a bottom portion, and a short shaft section of a solid shaft shape protruding from the bottom portion and having a joining end surface. The shaft member has a solid shaft shape and a joining end surface. The joining end surfaces of the cup and shaft members are brought into abutment against each other, and a high energy intensity beam is radiated from an outer side in a radial direction to form a welded portion. A structure of a molten metal at the welded portion is in a mixed phase of ferrite and granular cementite.

Abstract: A cup member has a cylindrical portion, a bottom portion, and a short shaft portion having a solid shaft shape and including a joining end surface at an end portion thereof. A shaft member has a solid shaft shape and includes a joining end surface at one end thereof. The joining end surfaces of the cup and shaft members are brought into abutment against each other and welded from a radially outer side to form a welded portion. At this time, center segregation is prevented from interfering with the welded portion. The cup member is formed by forging including upsetting a billet having a columnar shape successively in a plurality of stages, extruding the cylindrical portion and the short shaft portion, and ironing the cylindrical portion. In the course of the upsetting, a region of the billet corresponding to a bottom side of the cup member is narrowed.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members using medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed, and a joining end surface formed on an outer surface of the bottom portion, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion.