Abstract: There are provided an outer race of a constant velocity joint which has better operability and lower cost, and a method for manufacturing the same. First, an outer race 1 having a shaft portion 1a and a cylindrical portion 1b is prepared as a blank. Then with a punch set 4 fitted with an initial clearance in the radial direction into the inner periphery of the cylindrical portion 1b, the cylindrical portion 1b is pressure-inserted into the die 6 from the opening side thereof to form the ball rolling grooves 2 on the inner periphery of the cylindrical portion 1b, with the ironing operation being stopped when the ball rolling grooves of a predetermined length is formed while leaving an inner-most portion of cylindrical portion 1b intact, thereby forming a margin recess 7 for a grinding wheel at the base of the ball rolling groove 1.

Abstract: A constant velocity joint includes an outer race (1) having a spherical inner surface (2) with track grooves (3) each extending in an axial direction thereof, an inner race having a spherical outer surface (5) formed with track grooves (6) equal in number to the number of the track grooves (3) in the outer race (1), a plurality of torque transmitting balls (7) sandwiched between the inner race (4) and the outer race (1) and accommodated in part in the track grooves (6) in the inner race (4) and in part in the track grooves (3) in the outer race (1), and a cage (8) for retaining the torque transmitting balls (7) while being guided by and between the spherical inner surface (2) of the outer race (1) and the spherical outer surface (5) of the inner race (4). This constant velocity joint of the structure described above is featured in that at least the track grooves (3) in the outer race (1) and an entry chamfer (11) of the outer race (1) are formed by a plastic working process.

Abstract: A method for and an apparatus of producing an outer member of a universal joint having cross-grooves are provided in order to increase replenishability of the inner peripheral portion of the outer member. The outer member 1 is provided in a preformed material including a shaft 1a and a cylindrical portion 1b. A punch set 5 is fitted within the cylindrical portion 1b. The punch set is expandable and constrictable in the radial direction and includes a plurality of protrusions 3 having a configuration complementary to that of the cross-grooves. The cylindrical portion 1b is pressed into a die bore 8, starting with its opening portion 9, for performing an ironing operation.