Ntn Corporation

Masashi Funahashi

Teruaki Fujio

Shin Tomogami

Tomoshige Kobayashi

Tsubasa Nishikawa

A fixed type constant velocity universal joint has outer joint member track grooves each with a raceway center line that includes an arc-shaped portion having a curvature center that has no offset with respect to a joint center in an axial direction. The track grooves are formed such that adjacent track grooves are inclined in opposite directions. The joint also has inner joint member track grooves that are each mirror-symmetric with a corresponding one of the outer joint member track grooves. When at a maximum operating angle, a torque transmission ball that moves toward an opening side of the outer joint member track groove loses contact with an opening-side end portion of that track groove, and when at an operating angle of 0°, an end portion of a cage projects from the opening-side end portion of the outer joint member in the axial direction.

Fixed type constant velocity universal joint

A fixed type constant velocity universal joint has outer joint member track grooves each with a raceway center line that includes an arc-shaped portion having a curvature center that has no offset with respect to a joint center in an axial direction. The track grooves are formed such that adjacent track grooves are inclined in opposite directions. The joint also has inner joint member track grooves that are each formed to be mirror-symmetric with a corresponding one of the outer joint member track grooves with a plane including the joint center and being orthogonal to the axis of the joint at an operating angle of 0°. When at a large operating angle, an operating angle at which a torque transmission ball loses contact with the inner joint member track groove is larger than that at which the torque transmission ball loses contact with the outer joint member track groove.

A fixed type constant velocity universal joint has an operation mode in which, when a maximum operating angle is taken, in a column portion that is one of column portions on both sides of a pocket of a cage receiving a torque transmission ball at a phase angle and is located on a side corresponding to a phase angle larger than the phase angle, a projection end portion obtained by projecting an end portion of a spherical inner peripheral surface of the outer joint member on the opening side in a perpendicular direction toward the spherical outer peripheral surface of the cage and a projection end portion obtained by projecting an end portion of the spherical outer peripheral surface of the inner joint member on the back side in the perpendicular direction toward the spherical inner peripheral surface of the cage overlap in the axial direction of the cage.

A constant velocity universal joint includes outer and inner joint members that transmit torque while allowing angular displacement via balls, a power transmission shaft connected to the inner joint member in a torque transmittable manner, and a detachable mechanism between the inner joint member and the power transmission shaft to detach the power transmission shaft from the inner joint member. The detachable mechanism includes a cylindrical member externally fit onto the power transmission shaft, spheres movable in a radial direction in the cylindrical member, and an annular member movable in an axial direction on an outer periphery of the cylindrical member. Locking claws are provided at an end of an inner joint member side of the annular member, and a locking groove is provided at an end of an annular member side of the inner joint member. The locking claws are fitted into the locking groove.

Constant velocity universal joint

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 constant velocity universal joint has an outer joint member and an inner joint member that transmits torque while permitting angular displacement due to balls between the inner and outer joint members. An attaching and detaching mechanism for attaching and detaching a power transmission shaft to and from the inner joint member is provided between the inner joint member and the power transmission shaft such that torque can be transmitted between the two. The attaching and detaching mechanism has a cylindrical member that fits over the power transmission shaft, a retaining ring that is radially movable, and an annular member that is axially movable. By using a boot band to fixedly tighten, to the power transmission shaft, a small diameter end portion of a boot closing an opening portion of the outer joint member, the axial position of the annular member is restricted by the small diameter end portion.

Track grooves of an outer joint member include first and second track groove portions. An end portion of the ball raceway center line of each of the first track groove portions is located on the opening side with respect to a joint center and a ball raceway center line of each of the second track groove portions is connected to the end portion. A ball raceway center line of each of the track grooves of the inner joint member is formed to be mirror-image symmetrical with a ball raceway center line of a corresponding one of the paired track grooves of the outer joint member with respect to a plane that includes the joint center at an operating angle of 0&#xb0; and is orthogonal to a joint axial line.

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Shizuoka, Japan

Masashi Funahashi