Ntn Corporation

Akira Sera

Eiji Tajima

Syougo Suzuki

Hisashi Ohtsuki

Akira Torii

Mitsuru Umekida

Shigeaki Fukushima

Hiroyuki Ogura

Jiahua Miao

Shunsuke Makino

Michio Iihara

Jun Numamoto

Osamu Shimizu

Nobuo Suzuki

Tatsuro Sugiyama

Masazumi Kobayashi

Junichi Izumino

Hiroshi Matsunaga

Takuya Fujita

Hiroshi Murakami

Kenichi Nakano

Kenji Konaka

Miao Jiahua

Katsuhiko Nishio

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.

Constant velocity universal joint outer joint member and manufacturing method for same

After molding a preliminarily molded product as a material, the preliminarily molded product is put into a full-enclosed forging die so that a product is molded with the full-enclosed forging die. A shear-drop suppressing portion for suppressing thickness reduction on a boss-portion side of an outer peripheral portion of a leading end surface of each of shaft portions of the product is formed on the preliminary leading-end surface configuring a leading end surface of each of the shaft portions of the product in the preliminarily molded product. When the preliminarily molded product is put into the full-enclosed forging die and the product is to be molded, a relief portion is formed between the leading end surface of each of the shaft portions to be molded and a cavity of the full-enclosed forging die.

Forging method, molding device for forgings, and tripod uniform motion universal joint

After molding a product-to-be-preliminarily-molded to form a preliminarily molded product as a material, the preliminarily molded product is put into a full-enclosed forging die so that a product is molded with the full-enclosed forging die. On a preliminary leading-end surface to be formed as a leading end surface of a shaft portion of the product formed of the preliminarily molded product, there is formed a shear-drop suppressing portion for suppressing thickness reduction on a boss-portion side of an outer peripheral portion of the leading end surface of the shaft portion of the product. At a time of putting the preliminarily molded product into the full-enclosed forging die so as to mold the product, a relief portion is formed between the leading end surface of the shaft portion to be formed and a cavity of the full-enclosed forging die.

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.

Method for forming a wheel bearing apparatus

A manufacturing method for a tripod type constant velocity universal joint includes, when forging a raw-shaped material corresponding to each of three journals into a journal shape using a molding surface of a die and in a state where a relief portion is provided on a raw-shaped-material-leading-end-side of the die, molding an outer peripheral surface of the raw-shaped material into a projected round shape. The molding occurring with a tapered surface formed on the molding surface with which the outer peripheral surface of the raw-shaped material is held in contact and a recessed round surface formed between the molding surface and the tapered surface.

Tripod type constant-velocity universal joint and method for producing the same

A forging method and a full-enclosed forging die contribute to the alleviation of an enclosing force applied to dies and in which a relatively small enclosing apparatus can be used even with respect to larger-sized products. A tripod type constant velocity universal joint is formed with a tripod member molded with the full-enclosed forging die. The full-enclosed forging die includes openable/closable dies and punches for pressing a material between the dies. From the forging die, the tripod member including a boss portion and shaft portions protruded radially from the boss portion is molded.

Forging method, closed forging mold and tripod uniform motion universal joint

A wheel bearing device includes a hub ring, a double-row bearing and a constant velocity universal joint which are unitized together. At least one of double-row inner raceways of the bearing and a wheel mounting flange are formed on a hub ring. The hub ring and a stem portion of a joint outer ring of the constant velocity universal joint are fitted through a torque transmission assembly, wherein a pilot member as a separate element having a wheel guide portion and a brake guide portion is fitted to a side-end portion of the wheel mounting flange of the hub ring, and the hub ring and the pilot member are fixed to the joint outer ring by swaging.

Wheel bearing device

A closed forging die and a forging method with which sagging can be reduced, a constant velocity joint and a universal joint can be made compact and lightweight, removal of a shaft tip thereof by machining prior to heat treatment is not required, and material costs and machining costs can be reduced by using a closed forging die includes openable dies, and punches that move in an opening/closing direction of the dies to pressurize a material in the dies. By using the die, a product having shaft portions formed radially is manufactured. A clearance is provided to each of the formed shaft portions between a tip surface, and abutting portions are provided to the dies side abutting against at least a tip side of an outer circumferential surface of the shaft portions.

Closed forging die and forging method

A wheel bearing device having a unitized hub ring, double-row bearing and constant velocity universal joint with one of double-row inner raceways formed on the joint outer ring. An end portion of the joint outer ring is fitted to an outside periphery of the hub ring through serrated portions. The hub ring is plastically deformed and expanded from an inside diameter side toward an outside diameter side by pushing a steel ball into a through hole of the hub ring preventing play in the serrated portions by the diameter expansion. A surface-hardened layer is formed at least on a base portion of the wheel mounting flange.

A wheel bearing device having an outer ring with an attachment flange and two rows of raceway surfaces in the inner periphery, a hub ring having a wheel-attaching flange and one raceway surface in the outer periphery, an inner ring fitted on a stepped portion of the hub ring and having the other raceway surface in the outer periphery, and two rows of rolling elements. The end of the hub ring is crimped for integration, wherein the pre-crimping end on the hub ring is a hollow cylindrical portion with wall-thickness gradually increases toward the front end. Crimping imparts preload to the rolling elements and is effected by measuring the before-crimping axial dimension and controlling the lower dead point of a crimping punch according to the axial dimension so that the worked head height of the crimp portion is made constant.

Wheel bearing device and method of crimping the same

A cold forged pulsar ring (1) which comprises a ring body (1a) having inner and outer peripheral surfaces. A plurality of circumferentially spaced gear teeth (2) are integrally formed by the use of a cold forging process with one of the inner and outer peripheral surfaces of the ring body (1a) so as to protrude radially of the ring body (1a). Each of the gear teeth (2) is so profiled as to have a substantially trapezoidal shape having a tooth angle (.theta.) not smaller than 5.degree., but not greater than 15.degree.. With this design, not only can a cold forging process be employed to manufacture the pulsar ring (1), but also a required output voltage can be secured from a sensor of the rotation detecting device in which the pulsar ring (1) is operatively employed.

Cold forged toothed ring for producing rotational speed signals

A cold forming method for plastic deformation process of toothed ring-shaped products (W0) have a tooth profile portion (T) in at least one of the outer peripheral surface and inner peripheral surface thereof. When processing a ring-shaped product (W0) having a tooth profile portion (T) in the outer peripheral surface, a die (1) is utilized. The die (1) has a tooth forming part (4) having a shape corresponding to the shape of the tooth profile portion (T) of the ring-shaped product (W0) in its inner peripheral surface, and, if necessary, a tip shaping part (5) positioned in the groove of the tooth forming part (4). A ring-shaped material (W) is pressed and passed into the die (1) by a punch (2) in a round shaft shape in the axial direction, and processed. When processing a ring-shaped product (W1) having a tooth profile portion (T) in an inner peripheral surface, the tooth forming part (4) and tip shaping part (5) are provided on the outer circumference of a lower punch ( 11), and the ring material (W) is pressed and passed into the lover punch (11) by an upper punch (12), and processed.

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Iwata, Japan

Akira Sera