Abstract: A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

Abstract: A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

Abstract: A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

Abstract: A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

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 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 for forming a wheel bearing apparatus where the end portion of the cylindrical portion is pre-formed as a cylinder prior to its plastic deformation to form the caulking portion. A caulking tool with a punch and a swing shaft abuts against the end portion of the cylinder at a predetermined inclined angle relative to the inner circumferential surface of the cylinder. Teeth on the punch form the face-spline by plastically deforming the end face of the caulking portion. The swing shaft central axis is inclined at an angle relative to a central axis of the wheel hub. The face-spline is formed simultaneously with the formation of the caulking portion by advancing the caulking tool toward the wheel hub. A main shaft is rotated to cause a swing motion of the caulking tool.

Abstract: A method for forming a wheel bearing apparatus where the end portion of the cylindrical portion is pre-formed as a cylinder prior to its plastic deformation to form the caulking portion. A caulking tool with a punch and a swing shaft abuts against the end portion of the cylinder at a predetermined inclined angle relative to the inner circumferential surface of the cylinder. Teeth on the punch form the face-spline by plastically deforming the end face of the caulking portion. The swing shaft central axis is inclined at an angle relative to a central axis of the wheel hub. The face-spline is formed simultaneously with the formation of the caulking portion by advancing the caulking tool toward the wheel hub. A main shaft is rotated to cause a swing motion of the caulking tool.

Abstract: To provide a wheel support bearing assembly, in which the sufficient proof strength of an inner race during assemblage onto the vehicle body can be secured without its function being lowered, the wheel support bearing assembly includes an outer member, an inner member, and rows of rolling elements interposed therebetween. The inner member includes an hub axle having a flange and an inner race on an inner race mount, with raceways defined in the hub axle and the inner race. The inner race has a counterbore at its inboard end. The hub axle has a plastically deformed portion which engages an axially oriented surface of the counterbore when radially outwardly crimped and does not protrude outwardly beyond an inboard end face of the inner race. The difference P between the inner race mount and an outer peripheral face of the plastically deformed portion is 0.13 mm or more.

Abstract: To provide a wheel support bearing assembly, in which the sufficient proof strength of an inner race during assemblage onto the vehicle body can be secured without its function being lowered, the wheel support bearing assembly includes an outer member, an inner member, and rows of rolling elements interposed therebetween. The inner member includes an hub axle having a flange and an inner race on an inner race mount, with raceways defined in the hub axle and the inner race. The inner race has a counterbore at its inboard end. The hub axle has a plastically deformed portion which engages an axially oriented surface of the counterbore when radially outwardly crimped and does not protrude outwardly beyond an inboard end face of the inner race. The difference P between the inner race mount and an outer peripheral face of the plastically deformed portion is 0.13 mm or more.