SLIDING-TYPE CONSTANT VELOCITY UNIVERSAL JOINT

摘要

To provide a lightweight and compact DOJ-type constant velocity universal joint enabling the maximum operating angle of 30° or larger by properly setting the contact angle, contact rate, and cage offset amount of balls on ball grooves. The constant velocity universal joint comprises an outer ring (12) in which six linear ball grooves (12b) are axially formed in a cylindrical inner peripheral surface (12a); an inner ring (13) in which six linear ball grooves (13b) are axially formed in a spherical outer peripheral surface (13a) and a connection hole for connecting a shaft is formed at its center part; the torque transmission balls (14) disposed in ball tracks formed by the pair of ball grooves (12b) of the outer ring (12) and the ball grooves (13b) of the inner ring (13); and a cage (15) having pockets (15c) for storing the torque transmission balls (14), a convex outer peripheral surface (15a) guided in contact with the inner peripheral surface (12a) of the outer ring (12), and a concave inner peripheral surface (15b) guided in contact with the outer peripheral surface (13a) of the inner ring (13) and having a spherical center (Oco) on the outer peripheral surface (15a) and a spherical center (Oci) on the inner peripheral surface (15b) offset opposite to each other in the axial direction relative to the center (O) of the joint. The constant velocity universal joint is characterized in that the ratio of a ball diameter to an outer ring diameter is 0.21 - 0.25, the ratio of a ball pitch circle diameter to an outer ring outer diameter is 0.64 - 0.68, the contact angle of the ball grooves is 30 - 35°, the contact rate of the ball grooves is 1.02 - 1.08, and the ratio of a cage offset amount to the ball pitch circle diameter is 0.07 to 0.09.