Abstract: Provided is a method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by welding a cup member and a shaft member, the method including: forming the cup member and the shaft member of medium carbon steel; preparing; preparing; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; welding the cup member and the shaft member; and performing, after the welding, ultrasonic flaw detection-inspection from any one of a surface side of the cup member and a surface side of the shaft member, which has the another one of the joining end surface of the cup member and the joining end surface of the shaft member.

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: A screw can be fastened to a bone at a desired angle. A bone plate includes: an upper surface on a side opposite to a bone; a lower surface on a side closer to the bone; and at least one first hole connecting the upper surface and the lower surface and being configured to allow insertion of a screw. The first hole has an upper inner peripheral surface on an upper surface side and a lower inner peripheral surface on a lower surface side. The upper inner peripheral surface has an inner diameter decreasing toward the lower surface. The lower inner peripheral surface has an inner diameter increasing toward the lower surface. The lower inner peripheral surface includes at least one first region inclined at a first angle with respect to a center axis of the first hole, and at least one second region inclined at a second angle with respect to the center axis of the first hole.

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: 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.

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: 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: 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: A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members of medium carbon steel, forging the cup member to have integrally formed cylindrical and bottom portions, and machining a joining end surface on an outer surface of the bottom portion after the forging. The method also includes preparing the shaft member to have a joining end surface to be joined to the bottom portion of the cup member, which is formed by machining, bringing the joining end surfaces of the cup and shaft members into abutment against each other and welding the cup and shaft members by radiating a beam 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: Provided is a method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by welding a cup member and a shaft member, the method including: forming the cup member and the shaft member of medium carbon steel; preparing; preparing; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; welding the cup member and the shaft member; and performing, after the welding, ultrasonic flaw detection-inspection from any one of a surface side of the cup member and a surface side of the shaft member, which has the another one of the joining end surface of the cup member and the joining end surface of the shaft member.

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, forging the cup member to have integrally formed cylindrical and bottom portions, and machining a joining end surface on an outer surface of the bottom portion after the forging. The method also includes preparing the shaft member to have a joining end surface to be joined to the bottom portion of the cup member, which is formed by machining, bringing the joining end surfaces of the cup and shaft members into abutment against each other and welding the cup and shaft members by radiating a beam 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: An outer joint member for a fixed type constant velocity universal joint contributes to the reduction of the number of man-hours through the reduction of the number of processes after a forging process, to an increase in yield, and to the reduction of manufacturing cost. The outer joint member is made of machine-structural carbon steel. The portions of the outer joint member that are finished by cold forging are track grooves, radially inner spherical-surface portions, a cup-inlet chamfer, track chamfers, track-inlet chamfers, a part except for a boot fixing portion on a radially outer surface of the cup section, and a center hole at an end surface of the shaft section.

Abstract: A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, a plurality of balls interposed between the outer and inner joint members, and a cage to hold the plurality of balls. At least one of the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member is formed by cold-forging finishing. The outer joint member, the inner joint member, the balls, and the cage are assembled to each other based on matching in which the plurality of balls and the cage each having a rank corresponding to a measured value of a pitch circle diameter of the outer joint member and to a measured value of a pitch circle diameter of the inner joint member, which have been arbitrarily selected, are selected with respect to the arbitrarily selected outer and inner joint members.

Abstract: A fixed type constant velocity universal joint includes an outer joint member including an inner surface in which a plurality of track grooves are formed, an inner joint member including an outer surface in which a plurality of track grooves are formed, a plurality of balls between the track grooves of the outer joint member and the inner joint member so as to transmit torque, and a cage having pockets for housing the balls, and being between the outer joint member and the inner joint member. At a maximum operating angle, the balls roll up to track-groove-opening-end portions of the outer joint member. Each of the track grooves of the outer joint member includes a hardened layer formed so as to extend from a track-groove deep side to the track-groove-opening-end portion, the hardened layer being thinner at the track-groove-opening-end portion compared with the other portions.

Abstract: A constant velocity universal joint includes an outer joint member having an inner surface with a plurality of track grooves, an inner joint member having an outer surface with a plurality of track grooves which are paired with the track grooves of the outer joint member, and an inner surface having a shaft hole with a spline, a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member so as to transmit torque, and a cage interposed between the inner surface of the outer joint member and the outer surface of the inner joint member so as to retain the balls, in which the inner joint member includes an axial step portion between an inlet-side end surface thereof and a spline end portion of the shaft hole so as to form a recessed end surface.

Abstract: A fixed type constant velocity universal joint has cutout round portions (32) provided at two portions of a ball-contact-point corresponding part on a track inlet end (22a) of each of the track grooves (22) of the outer joint member for reduce biting of balls. The fixed type constant velocity universal joint is capable of achieving reduction of stress generated when balls and edge portions interfere with each other, suppression of chipping of the edge portions, and prolongation of a service life of the joint as a whole. These advantages are achieved even at a time of an unexpected high-angle operation, and in particular even when an angle expected during use of the constant velocity universal joint is exceeded.

Abstract: A fixed type constant velocity universal joint secures smooth rotation and reduces a load on a cage even at a large operating angle and when bearing large torque. The universal joint includes an outer joint member having an inner spherical surface in which track grooves are circumferentially formed in an axial direction and an inner joint member having an outer spherical surface in which track grooves paired with the track grooves of the outer joint member are circumferentially formed in the axial direction and multiple outer spherical surface portions circumferentially arranged. Balls are interposed between the track grooves of the outer and inner joint members for transmitting torque. A cage is interposed between the inner spherical surface and the outer spherical surface for retaining the balls. A spherical surface angle of the outer spherical surface on a joint opening side is set to 12.5° or more.

Abstract: Provided are a power transmission shaft (shaft) which can achieve cost reduction by reducing a raw material diameter, and thus reducing a material cost and a lathing cost, and an assembly unit using the power transmission shaft. The power transmission shaft includes: a male spline (31) provided at an end portion of the power transmission shaft; an engagement large diameter portion (37) for preventing the power transmission shaft from being pushed in an axial direction of the power transmission shaft under a state in which the male spline (31) is fitted to a female spline (45) of another member; and a boot groove (33) for mounting a boot. When an outer dimension of the engagement large diameter portion (37) is denoted by D2, a maximum outer dimension of the male spline (45) is denoted by D1, and an outer dimension of a boot mount portion (32) provided with the boot groove (33) is denoted by D4, relationships D2<D1 and D2=D4 are established.