Abstract: When forming a toothed portion on the outer section of a blank by contacting a tooth profile-forming portion of a forming die with a curved portion of the blank, the first projection of the blank is accommodated in a first depression, and a load is applied axially to a center section of the blank so a material of the blank flows radially outward. The material of the blank at the first projection flows in the axial direction to inside the first depression, and the material of the blank at an intermediate section between the center and the outer section flows in axially to inside a second depression to form a second projection. When the load is maximized, a space is provided between a toothed portion and the tooth profile-forming portion, between the first projection and the forming die, and between the second projection and the forming die.

Abstract: When forming a toothed portion on the outer section of a blank by contacting a tooth profile-forming portion of a forming die with a curved portion of the blank, the first projection of the blank is accommodated in a first depression, and a load is applied axially to a center section of the blank so a material of the blank flows radially outward. The material of the blank at the first projection flows in the axial direction to inside the first depression, and the material of the blank at an intermediate section between the center and the outer section flows in axially to inside a second depression to form a second projection. When the load is maximized, a space is provided between a toothed portion and the tooth profile-forming portion, between the first projection and the forming die, and between the second projection and the forming die.

Abstract: A spline member manufacturing apparatus includes a shaving punch, a shaving die, a spline punch, and a stripper. The stripper supports a first surface of a base plate portion and an outer circumferential surface of a boss portion. The shaving punch is advanced relatively, while a material and the stripper are being pressed so that cutout portions are formed in an outer circumference portion of the base plate portion by the shaving punch and the shaving die. The shaving punch is further advanced relatively while the outer circumferential surface of the base plate portion is held by the shaving die, so that a spline portion is formed by inserting the spline punch along the inner circumferential surface of the boss portion.

Abstract: A method and apparatus for manufacturing a legged annular member. In one aspect, a work member is formed from a ring-like raw material, and has an annular part and an outer wall part, which is formed from a leg part and a connecting part. The connecting part is removed from the work member to form an intermediate legged annular member having an annular part and a leg part. An inner diameter of the leg part of the intermediate legged annular member is expanded while a burr is removed to form a carrier, which serves as a legged annular member. Therefore, the number of manufacturing processes until completion of the carrier can be reduced, compared to performing separate processes to expand the diameter of the leg part and remove the burr. Thus, it is possible to shorten the period of time needed for completion of the carrier.

Abstract: A method of forming a chamfered through hole having a chamfered portion at each end thereof by: forming a prepared hole in a plate-like portion; forming a first chamfered portion by driving a first punch; forming a second chamfered portion by driving a second punch, which has a second tapered surface and a generally columnar central pressing portion protruding from the center of the second tapered surface and having an annular corner at a tip thereof, and thereby forming the second chamfered portion and a central recess recessed axially inward; and punching out an unnecessary portion protruding radially inward of the prepared hole by using a finishing punch having an outer diameter equal to or smaller than that of the corner of the central pressing portion. The punching out the unnecessary portion is performed by punching from the first chamfered portion toward the second chamfered portion using the finishing punch.

Abstract: A method of forming a chamfered through hole having a chamfered portion at each end thereof by: forming a prepared hole in a plate-like portion; forming a first chamfered portion by driving a first punch; forming a second chamfered portion by driving a second punch, which has a second tapered surface and a generally columnar central pressing portion protruding from the center of the second tapered surface and having an annular corner at a tip thereof, and thereby forming the second chamfered portion and a central recess recessed axially inward; and punching out an unnecessary portion protruding radially inward of the prepared hole by using a finishing punch having an outer diameter equal to or smaller than that of the corner of the central pressing portion. The punching out the unnecessary portion is performed by punching from the first chamfered portion toward the second chamfered portion using the finishing punch.

Abstract: A spline member manufacturing apparatus includes a shaving punch, a shaving die, a spline punch, and a stripper. The stripper supports a first surface of a base plate portion and an outer circumferential surface of a boss portion. The shaving punch is advanced relatively, while a material and the stripper are being pressed so that cutout portions are formed in an outer circumference portion of the base plate portion by the shaving punch and the shaving die. The shaving punch is further advanced relatively while the outer circumferential surface of the base plate portion is held by the shaving die, so that a spline portion is formed by inserting the spline punch along the inner circumferential surface of the boss portion.

Abstract: A method and apparatus for manufacturing a legged annular member. In one aspect, a work member is formed from a ring-like raw material, and has an annular part and an outer wall part, which is formed from a leg part and a connecting part. The connecting part is removed from the work member to form an intermediate legged annular member having an annular part and a leg part. An inner diameter of the leg part of the intermediate legged annular member is expanded while a burr is removed to form a carrier, which serves as a legged annular member. Therefore, the number of manufacturing processes until completion of the carrier can be reduced, compared to performing separate processes to expand the diameter of the leg part and remove the burr. Thus, it is possible to shorten the period of time needed for completion of the carrier.

Abstract: A workpiece 20b is formed that includes a circular bottom portion 22b having a hole 23b and an inner wall portion 24b around the hole 23b, and a skirt-shaped outer wall portion 25b that includes prong portions 26b on the outer circumference of the bottom portion 22b and linking portions 27b that link these prong portions 26b, and by cutting off the linking portions 27b and the portion that includes the inner wall portion 24b from the formed workpiece, a pronged annular member that includes the circular bottom portion 22b that has a hole 23b and the prong portions 26b on the outer circumference of the bottom portion 22b.

Abstract: An interior splined member is a hollow cylinder with an interior cylindrical surface defining a through hole. A major portion of the axial length of the interior cylindrical surface is splined to provide alternating axially extending ribs and troughs disposed between the ribs. A ring-shaped residual portion is an unsplined portion, i.e., a minor portion of the axial length of the interior cylindrical surface and is substantially circular with a diameter that is equal to or smaller than that of a circle on which the distal ends (tips) of the ribs lie. The trough portions are open at one end of the cylindrical member, while closed by the ring-shaped residual portion at the other end of the cylindrical member.