Ntn Corporation

Nok Corporation

Kenta Yamazaki

Minoru Ishijima

Hiroyasu Hirukawa

Hisaaki Kura

Kenji Terada

Junichi Izumino

Tatsuro Sugiyama

Tatsuhiro Goto

Kisao Yamazaki

Teruaki Fujio

Hiroyuki Satoh

Kazuhiko Yoshida

Tomoshige Kobayashi

Masafumi Osugi

Masato Chokyu

Rikuou Takagi

Provided is a cage () for a constant velocity universal joint, which is formed into a ring shape with a substantially uniform thickness, including a plurality of pockets () formed in a circumferential direction of the cage (), for receiving torque transmitting balls, respectively, the cage () being formed of carbon steel including 0.41 to 0.51 mass % of C, 0.10 to 0.35 mass % of Si, 0.60 to 0.90 mass % of Mn, 0.005 to 0.030 mass % of P, and 0.002 to 0.035 mass % of S, with the balance being Fe and an element inevitably remaining at the time of steelmaking and refining, the cage () being subjected to carburizing, quenching, and tempering as heat treatment, each of the plurality of pockets () having a side surface () finished after the heat treatment.

Cage for constant velocity universal joint, fixed type constant velocity universal joint incorporating same, and drive shaft incorporating said fixed type constant velocity universal joint

A fixed type constant velocity universal joint has an outer joint member including first track groove portions and second track groove portions. Each of the first track groove portions includes an arc part having a curvature center that is not offset in an axial direction with respect to a joint center. The first track groove portions are inclined in a peripheral direction of the outer joint member with respect to a joint axial line and adjacent to each other in the peripheral direction with inclination directions opposite to each other. Each of the second track groove portions has a different shape than the first track groove portions. Each of the first track groove portions and each of the second track groove portions are connected to each other at a position on an opening side with respect to the joint center.

Fixed type constant velocity universal joint

Track grooves of an outer joint member include first and second track groove portions. Each of the first track groove portions is formed into an arc shape having a curvature center at a position offset to an opening side with respect to a joint center. The first track groove portions are inclined in a peripheral direction of the outer joint member with respect to a joint axial line and adjacent to each other in the peripheral direction with their inclination directions opposite to each other. Each of the second track groove portions includes a linear part and is connected to the each of the first track groove portions at a position on the opening side with respect to the joint center. Track grooves of inner and outer joint members are formed to be mirror-image symmetrical with respect to a joint center plane at an operating angle of 0&#xb0;.

Fixed type constant-velocity universal joint

Provided is a fixed type constant velocity universal joint, in which: each of first track groove portions positioned on an interior side of an outer joint member includes an arc part having a curvature center that is positioned without being offset in an axial direction with respect to a joint center; the first track groove portions are inclined in a peripheral direction with respect to a joint axial line (N-N) and adjacent to each other in the peripheral direction with their inclination directions opposite to each other; each of second track groove portions positioned on an opening side is formed into a different shape from a shape of the each of the first track groove portions so as to increase an effective track length at a maximum operating angle; the each of the first track groove portions and the each of the second track groove portions are connected to each other at a position on the opening side with respect to the joint center; each of track grooves of an inner joint member is formed so as to be mirror-image symmetrical with corresponding one of paired track grooves of the outer joint member with respect to a plane including the joint center and being perpendicular to the joint axial line at an operating angle of 0&#xb0;; and an axial clearance between the inner joint member and a cage is set to be larger than an axial clearance corresponding to a clearance between each of balls and each of the track grooves.

In a fixed type constant velocity universal joint, track grooves of an outer joint member include first track groove portions positioned on an interior side and second track groove portions positioned on an opening side. The first track groove portions each have an arc-shaped ball raceway center line having a curvature center that is prevented from being offset in an axial direction of the outer joint member with respect to a joint center. Planes each including at least the ball raceway center line and the joint center are inclined with respect to a joint axial line with their inclination directions alternately opposite to each other in the first track groove portions that are adjacent to each other in a peripheral direction of the outer joint member.

In a fixed type constant velocity universal joint, track grooves of an outer joint member include first and second track groove portions positioned on interior and open sides, respectively. Each of the first track groove portions includes an arc-shaped ball raceway center line having a curvature center prevented from being offset in an axial direction of the outer joint member with respect to a joint center. Planes each including at least the ball raceway center line and the joint center are inclined with respect to a joint axial line with their inclination directions opposite to each other in the first track groove portions, which are adjacent to each other in a peripheral direction of the outer joint member. Each of the second track groove portions includes a ball raceway center line having a straight part when being projected onto corresponding one of the planes.

Track grooves of an outer joint member include first and second track groove portions positioned on interior and opening sides, respectively. Each first track groove portion has an arc shape with a curvature center at a position offset to the opening side with respect to a joint center. The first track groove portions are inclined in a peripheral direction of the outer joint member with respect to a joint axial line and adjacent to each other in the peripheral direction with their inclination directions opposite to each other. Each second track groove portion has a shape that is different than each of the first track groove portions so as to increase an effective track length at a maximum operating angle. The second track groove portions are connected to the first track groove portions at a position on the opening side with respect to the joint center.

An outer joint member has first and second track groove portions located respectively on depth and opening sides. The first track groove portions each have a circular-arc ball-raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The second track groove portions each have a ball-raceway center line including a straight part to increase an effective track length at a maximum operating angle. Track grooves of an inner joint member each have a ball-raceway center line that is mirror-image symmetrical with a ball-raceway center line of the paired track groove of the outer joint member with respect to a plane passing through the joint center at an operating angle of 0&#xb0;.

Fixed constant velocity universal joint

A fixed type constant velocity universal joint has track grooves of an outer joint member including first and second track groove portions located on depth and opening sides, respectively. The first track groove portions each have a circular-arc part having a curvature center that is not offset in an axial direction with respect to a joint center, are inclined in a circumferential direction with respect to a joint axial line, and are adjacent to each other in the circumferential direction with their inclination directions opposite to each other. The second track groove portions have a different shape than the first track groove portions to increase an effective track length with respect to a maximum operating angle. The first and second track groove portions are connected respectively to each other on the opening side with respect to the joint center.

An outer joint member () and an inner joint member () each have a shaft portion (and) having a male spline formed thereon, and shaft clamps () are press-fitted onto the respective shaft portions (and). Each of the shaft clamps () includes: a connection hole () that has a female spline formed therein, extends from a first axial end partway toward a second axial end, and has no quench-hardened layer; and a cylindrical portion () that has no female spline formed therein and extends from the second axial end partway toward the first axial end. The shaft portions (and) each have a quench-hardened layer on the outer circumference thereof. The inner diameter of the connection hole () at a portion having no female spline formed therein is less than the outer diameters of the shaft portions (and).

Steering joint

A fixed type constant velocity universal joint is capable of securing a ball groove depth larger than conventional products and enhancing performance without an increase in a 'force of pushing out balls in an axial direction', the force having an influence on joint efficiency. In the fixed type constant velocity universal joint, a center of each of a plurality of guide grooves of an outer joint member and a center of each of a plurality of guide grooves of an inner joint member are offset with respect to a spherical surface center of an inner surface and a spherical surface center of an outer surface. A ratio (F/PCR) of an offset amount F to a length of a segment (PCR) ranges from 0.045 to 0.065. A ratio (&#x3b1;t/&#x3b1;) when an angle &#x3b1; is the total of an angle &#x3b1;t and an angle &#x3b1;c ranges from 0.45 to 0.65.

Fixed-type, constant-velocity universal joint

An object of the present invention is to ensure the miniaturization, strength, durability, load-carrying capacity, and an operating angle of a constant velocity universal joint. Six ballsare disposed in the constant velocity universal joint. The ratio r1 (=PCD/D) between the pitch circle diameter PCD(PCD=2&#xd7;PCR) of the balland the diameter Dthereof is set in a range of 1.5&#x2266;r1&#x2266;4.0. The ratio r2 (=D/PCD) between the outside diameter Dof an outer memberand the pitch circle diameter PCDof serrations (or splines)of an inner joint memberis set in a range of 3.0&#x2266;r2&#x2266;5.0.

Constant velocity universal joint

To prevent inverting of a mountain portion of a bellows member when a rotating shaft is angularly displaced, the boot includes a bellows member with large and small diameter mounting members. A first mountain portion nearest the large diameter mounting member rises from the large diameter mounting member. A length (L) between a top of the first mountain portion and a bottom at the large diameter mounting member side is not more than a length (L) between the inner peripheral position of the bottom and an end portion of an outer ring at the rotating shaft side. A first valley portion adjacent to the first mountain portion is positioned at the rotating shaft side from the end part.

Boot for universal joint

To make a bellows section of a boot to be flexibly and repeatedly deformable without deterioration in durability, to thereby reduce rotational resistance when a joint angle is large, the boot has the bellows portion where three or more circumferentially extending crest portions and root portions therebetween are alternately formed. A large-diameter attaching portion is formed at one end of the bellows portion. A small-diameter attaching portion is formed at the other end. A rising wall closest to the large-diameter attaching portion and a rising wall closest to the small-diameter attaching portion have smaller wall thickness than other portions of the bellows section. A ratio (t/t) of the thickness (t) of the rising walls to the thickness (t) of the other portions of the bellows portion is set to 0.6&#x2266;t/t&#x3c;1.0.

A fixed type constant velocity joint has a plurality of torque transmitting ball tacks, the torsional angle at the input torque 0 Nm in a torque-torsional angle diagram be approximately 0. Further, the torsional rigidity in the vicinity of input torque 0 Nm in the torque-torsional angle diagram is placed in a range of 1.5 Nm/deg to 6 Nm/deg.

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Iwata, Japan

Kenta Yamazaki