Ntn Corporation

Tomoshige Kobayashi

Masazumi Kobayashi

Teruaki Fujio

Minoru Ishijima

Yuichi Asano

Hisaaki Kura

Shin Tomogami

Kisao Yamazaki

Takeshi Kohara

Tohru Nakagawa

Kenta Yamazaki

Tsugito Nakazeki

Aiko Ishikawa

Mika Kohara

Taku Itagaki

Masashi Funahashi

Takeyoshi Konomoto

Tomoaki Kaneko

Kouji Masuoka

Yoshinori Terasaka

Masamichi Nakamura

Tsubasa Nishikawa

A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, eight balls, and a cage. The fixed type constant velocity universal joint has a ball retaining mechanism. A ratio of an axial length from a joint center to an opening-side end surface of the outer joint member to a diameter of each of the balls is within a range of 0.35 to 0.52. A ratio of a width of the cage to the diameter of each of the balls is within a range of 1.63 to 1.80. The ball retaining mechanism includes a cylindrical shaft portion at an end portion of a shaft and an angle restriction stopper surface of the outer joint member.

Fixed-type constant velocity universal joint

A plunging type constant velocity universal jointfor a propeller shaft includes an outer joint member, an inner joint member, eight torque transmidetting balls, and a cage. A center of curvature Oof a spherical outer surfaceand a center of curvature Oof a spherical inner surfaceof the cageeach have an equal and axially opposite offset (f) with respect to a center Oof pockets. A ratio f/PCDbetween the offset (f) of the cageand a pitch circle diameter (PCD) of the torque transmitting ballsis 0.07 or more and 0.09 or less.

Plunging type constant velocity universal joint for propeller shaft

A plunging type constant velocity universal jointfor a propeller shaft includes an outer joint member, an inner joint member, eight torque transmitting balls, and a cage. A center of curvature Oof a spherical outer surfaceand a center of curvature Oof a spherical inner surfaceof the cageeach have an equal and axially opposite offset (f) with respect to a center Oof pockets. A ratio f/PCDbetween the offset (f) of the cageand a pitch circle diameter (PCD) of the torque transmitting ballsis 0.07 or more and 0.09 or less.

A constant velocity universal joint includes an inner ring and an outer ring. A cage is disposed between an outer spherical surface of the inner ring and an inner spherical surface of the outer ring, and has windows in which respective balls are received. The cage has ball contact surface areas with which the balls come into contact, and includes soft portions that are lower in hardness than the ball contact surface areas. The soft portions are formed by local heat treatment at portions of the windows that are kept out of contact with the balls or surface portions around the windows.

Constant velocity universal joint and cage thereof

A fixed type constant velocity universal joint () includes an outer joint member (), an inner joint member (), eight balls (), and a cage (). A diameter (D) of the outer joint member () at an opening end of an inner peripheral surface () is set larger than an outer diameter (D) of the cage () at a center portion in a circumferential direction of pockets () when the cage () is seen from an axial direction of the joint. A bottom surface () of a mouth section () of the outer joint member () is arranged so as to interfere with an imaginary spherical surface (Q) being an extension of the inner peripheral surface () of the outer joint member () toward a deep-side.

A plunging type constant velocity universal joint includes an outer joint member, an inner joint member, eight balls, and a cage. A curvature center of a spherical portion of an outer peripheral surface of the cage and a curvature center of a spherical portion of an inner peripheral surface of the cage are offset to opposite sides in the axial direction with respect to a joint center by an equal distance. A ratio PCD/Dof a pitch circle diameter PCDof the balls to a diameter Dof each of the balls is set from 3.3 to 3.6. A ratio T/Dof a radial thickness Tof the inner joint member to the diameter Dof each of the balls is set from 0.30 to 0.45.

Plunging type constant velocity universal joint for rear-wheel drive shaft

A fixed type constant velocity universal joint () includes an outer joint member (), an inner joint member (), eight balls (), and a cage (). A curvature center (O) of track grooves () of the outer joint member () and a curvature center (O) of track grooves () of the inner joint member () are offset to opposite sides in an axial direction of the joint with respect to a joint center (O(f)) by an equal distance. A ratio (PCD/D) of a pitch circle diameter (PCD) of the balls () to a diameter (D) of each of the balls () is set from 3.70 to 3.87. A ratio (T/D) of a radial thickness (T) of the cage () to the diameter (D) of each of the balls () is set from 0.22 to 0.25.

Fixed type constant velocity universal joint for rear-wheel drive shaft

A rear-wheel drive shaft () includes a fixed type constant velocity universal joint (), a plunging type constant velocity universal joint (), and an intermediate shaft () coupling both the constant velocity universal joints to each other. A ratio (PCD(f)/D(f)) of a pitch circle diameter (PCD(f)) of balls () of the fixed type constant velocity universal joint () to a diameter (D(f)) of each of the balls () is set from 3.70 to 3.87. A ratio (PCD(s)/D(s)) of a pitch circle diameter (PCD(s)) of balls () of the plunging type constant velocity universal joint () to a diameter (D(s)) of each of the balls () is set from 3.3 to 3.6.

Rear-wheel drive shaft

A fixed type constant velocity universal joint includes an outer joint member having a cup shape, an inner joint member, which is received in the outer joint member, and transmits torque between the outer and inner joint members through intermediation of balls while allowing angular displacement, and a shaft, which is coupled to the inner joint member so as to allow torque transmission. A recessed portion is formed in a bottom portion of the outer joint member, and an embedded stopper that enters the recessed portion of the outer joint member is mounted to a shaft end portion of the shaft opposed to the recessed portion. The embedded stopper is allowed to interfere with the recessed portion of the outer joint member at an angle that is smaller than an incorporating angle of the balls and larger than a maximum operating angle during use of the joint.

Fixed constant velocity universal joint

A fixed type constant velocity universal joint includes an outer joint member having a cup shape, an inner joint member, which is received in the outer joint member, and transmits torque between the inner and outer joint members through intermediation of balls while allowing angular displacement, and a hollow shaft, which is coupled to the inner joint member so as to allow torque transmission. A threaded hole is formed in a bottom portion of the outer joint member along an axial direction. A recessed hole is formed to be open in a shaft end portion of the hollow shaft opposed to the threaded hole. An embedded stopper that enters the threaded hole is press-fitted into the recessed hole. The embedded stopper is retractable into the hollow shaft in a press-fitting direction.

Fixed constant velocity universal joint, and bearing device for wheels

A corrugated portion is formed in one end edge portion of the metallic shaft main body (), and a triangular corrugated portion () is formed in an end edge portion of the shaft auxiliary body () on the metallic shaft main body side. The metallic shaft main body () and the shaft auxiliary body () are integrated by being linearly arranged by way of meshing that brings a side of the triangular corrugated portion () on the main body side and a side of the triangular corrugated portion () on the auxiliary body side into contact with each other. A fiber orientation angle (&#x3b8;) of the fiber reinforced plastic of the shaft auxiliary body () is set so as to be in the same direction as a direction of stress generated in a hypotenuse of each triangular portion under a torque load state.

Power transmission shaft

A fixed type constant velocity universal joint includes an outer joint member having eight curved track grooves, an inner joint member having eight curved track grooves, eight torque transmission balls, and a cage configured to hold the torque transmission balls in pockets. A curvature center of each of the track grooves of the outer joint member and a curvature center of each of the track grooves of the inner joint member are offset from a joint center by an equal distance to opposite sides in the axial direction. The joint has grease sealed therein. Initial pocket gaps between the pockets and the balls each have a positive value. The grease has an initial consistency equivalent to consistency number 1 or 2, and a mixture stability of from 390 to 440.

An outer joint member includes a cutout portion that is formed at least at each corner portion on an opening side of a cup section, which is defined between a radially inner opening end portion of each of track grooves and a radially inner spherical surface portion formed between the track grooves. The cutout portion is configured to prevent a cage from interfering with the outer joint member when the cage is incorporated into the outer joint member. The cutout portion and the track grooves of the outer joint member are finished by cold-forging ironing using a single ironing punch.

Fixed type constant velocity universal joint

A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, a plurality of balls for transmitting torque provided between track grooves of the outer joint member and track grooves of the inner joint member, and a cage for retaining the balls. Grease is enclosed in the fixed type constant velocity universal joint which includes a thickener and a lubricant component which is constituted by base oil. The grease contains 90% by mass or more of paraffinic mineral oil with respect to the total mass of the lubricant component of the grease, and 3 to 8% by mass of the thickener with respect to the total mass of the components of the grease.

A constant velocity universal joint has track shapes which facilitate quality control on a forging die set, securing higher durability through securement of a stable contact state of forging-molded tracks and finishing-processed tracks with respect to balls. At least one of each of track grooves of an outer joint member and each of track grooves of an inner joint member is formed by cold-forging finishing. A track groove bottom side of the at least one of each of the track grooves is formed into a Gothic arch shape in horizontal cross-section, and a track groove opening side of the at least one of each of the track grooves is are each formed into an elliptical shape in horizontal cross-section.

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Shizuoka, Japan

Tomoshige Kobayashi