Ntn Corporation

Yoshihiro Sagisaka

Michio Iihara

Yasushi Takahara

Masazumi Kobayashi

Kikuo Maeda

Akio Sakaguchi

Takeshi Shinkai

Ryuma Mano

To make a peripheral lip region to be formed with chamfered portions by the use of a plastic working technique, to enable the use of a cup forming punch of a simplified shape so that a mold used therewith can be easily assembled and the punch when worn down can easily be repaired, a method of making an outer race of a constant velocity universal joint of a tripod type includes an upsetting step during which not only are outer peripheral shapes of a small diameter portion (W) and a large diameter portion (W) defined, but a recess (Wb) having a tapered peripheral wall face (Wba), which eventually defines general shapes of the chamfered portions () of the outer race (), is formed in an end face of the large diameter portion (W). During a cup forming step, the tapered peripheral wall face (Wba) defined during the upsetting step is rearwardly pushed while its shape is maintained. Thereafter, a cup drawing step is carried out to finish the tapered peripheral wall face (Wba) to represent the final design shapes of the chamfered portions ().

Method of manufacturing outer races for tripod-type constant velocity universal joints

A constant velocity universal joint for use with a propeller shaft which reduces its weight and size as well as facilitates assembling a stub shaft, thereby reducing the number of parts used and improving rotational balance. The universal joint, comprising: an outer ring with a cup-shaped enlarged diameter portion having track grooves formed on an inner peripheral surface and with a hollow reduced diameter portion integrated with the enlarged diameter portion; an inner ring having track grooves formed on an outer peripheral surface; balls, interposed between the track grooves of the inner and outer rings, for transmitting torque; a cage, accommodated in an annular space between the inner and outer rings, for holding the balls. The universal joint makes possible to form a unit provided with a stub shaft, having a shaft portion inserted from an open end portion of the enlarged diameter portion of the outer ring to mate with the inner ring to enable torque transmission and having an enlarged diameter portion on an end portion extending from the shaft portion, and provided with a boot, attached to the open end portion of the enlarged diameter portion of the outer ring and the shaft portion of the stub shaft, for sealing the joint.

Constant velocity universal joint for propeller shaft

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 having a shaft portion and a cylindrical portion is prepared as a blank. Then with a punch set fitted with an initial clearance in the radial direction into the inner periphery of the cylindrical portion the cylindrical portion is pressure-inserted into the die from the opening side thereof to form the ball rolling grooves on the inner periphery of the cylindrical portion 1 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 intact, thereby forming a margin recess for a grinding wheel at the base of the ball rolling groove

Universal joint outer race and method for manufacturing the same

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.

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Iwata, Japan

Yoshihiro Sagisaka