| 摘要 |
PROBLEM TO BE SOLVED: To provide a joint cross type universal joint which is constructed to make it easy to compatibly securing its reliability and durability and reducing its size and weight by increasing its breaking strength when a great load is applied thereto.SOLUTION: The base end outer peripheral face of each of shaft parts 12 constituting a joint cross 9a and a step face 38 as the outer face of a joint base part 13 are continued via each of concave faces 28a shaped partially circular in cross section. At least a part of the outer face of each of the concave faces 28a exists near the center of the joint base part 13 with respect to the axial direction of each of the shaft parts 12, than a portion of the joint base part 13 around each of the concave faces 28a. In a portion of the step face 38 around the base end of each of the shaft parts 12, an annular recessed part 29 is formed. This construction increases the curvature radius of the cross-section shape of each of the concave faces 28a without increasing the length size of each of the shaft parts 12, to hardly cause damage such as crack in the base end of each of the shaft parts 12. |
