Patent ID: 9410581
Filing Date: 2016-08-09
CPC Classification: F16D

Claim Text:
1. A fixed type constant velocity universal joint, comprising: an outer joint member having a spherical inner peripheral surface in which a plurality of track grooves are formed so as to extend in an axial direction of the outer joint member, an inner joint member having a spherical outer peripheral surface in which a plurality of track grooves are formed so as to be paired with the plurality of track grooves of the outer joint member; a plurality of balls for transmitting torque, a cage for holding the plurality of balls, wherein the plurality of track grooves of the outer joint member comprise: wherein each of the first track groove portions comprises an arc-shaped ball raceway center line having a curvature center free from offset in the axial direction with respect to a joint center, wherein planes each including at least the arc-shaped ball raceway center line of one of the first track groove portions and the joint center are inclined with respect to a joint axial line, the planes of adjacent first track groove portions in a peripheral direction of the outer joint member having inclination directions opposite to each other, wherein each of the second track groove portions comprises a ball raceway center line having a straight part when being projected onto corresponding one of the planes, wherein the straight part is formed in an inclined manner to approach the joint axial line as a distance to the opening side becomes smaller, wherein the arc-shaped ball raceway center line of each of the first track groove portions comprises an end portion positioned on the opening side with respect to the joint center, wherein the ball raceway center line of each of the second track groove portions is connected to a respective one of the end portions, wherein each of the plurality of track grooves of the inner joint member comprises a ball raceway center line, which is formed so as to be mirror-image symmetrical with a ball raceway center line of a corresponding one of the plurality of track grooves of the outer joint member with respect to a plane including the joint center at an operating angle of 0°, and wherein the plurality of balls is at least eight balls.