| 摘要 |
PURPOSE:To enable the discrepancy between engaging angles of spoke and hub or the like to be absorbed by forming the surface of spoke engaging hub or the like and the surface of hub or the like for receiving spoke into spherical surfaces having respectively specified curvatures and centers of curvature. CONSTITUTION:A spoke 10 is formed on one end with a large diameter portion 10a, while a spherical engaging surface 12 having the center O1 of curvature and radius R1 of curvature is formed on the axis L1 of the spoke 10 at the straight portion 10b side of the large diameter portion 10a. On the other hand, a hub 11 is formed with a through hole 14 through which a spoke 10 extends, while one opening end of the through hole 14 is formed with a spherical receiving surface 15 having approximately same radius R2 as that of said engaging surface 12. And the center O2 of curvature of the receiving surface 15 is adapted to generally coincide with the center O1 of curvature of the engaging surface 12 when the spoke 10 engages the hub, i.e. when the engaging surface 12 contacts the receiving surface 15. Thus, the discrepancy between the engaging angles of the spoke 10 and hub 11 can be absorbed to prevent the occurrence of stress. |
