| 摘要 |
In a fixed type constant velocity universal joint (1), track grooves (7) of an outer joint member (2) comprise first track groove portions (7a) each located on a depth side and second track groove portions (7b) each located on an opening side. The first track groove portions (7a) each comprise a circular-arc ball-raceway center line (Xa) having a curvature center that is not offset in an axial direction with respect to a joint center (O). Planes (M) defined in the first track groove portions (7a) that are adjacent to each other in a circumferential direction, the planes (M) each comprising at least the ball-raceway center line (Xa) and the joint center (O), are inclined with respect to a joint axial line (N-N) with their inclination directions opposite to each other. The second track groove portions (7b) each comprise a ball-raceway center line (Xb) comprising a straight part so as to increase an effective track length at a maximum operating angle. The ball-raceway center line (Xa) of each of the first track groove portions (7a) comprises an end portion (A) located on the opening side with respect to the joint center (O) in the axial direction. The ball-raceway center line (Xb) of each of the second track groove portions (7b) is connected to the end portion (A). Track grooves (9) of an inner joint member (3) each comprise a ball-raceway center line (Y) formed to be mirror-image symmetrical with a ball-raceway center line (X) of the paired track groove (7) of the outer joint member (2) with respect to a plane (P) comprising the joint center (O) at an operating angle of 0°. |
