| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and lightweight steering device by shortening a distance between bearings for supporting an output shaft and by restricting a moment load to be applied to the bearing. SOLUTION: Diameter of the center of rolling of a needle roller of a thrust bearing 42 (a distance from the central axis of an output shaft 23 to the center of rolling of the needle roller) D1 works as a fulcrum for supporting a moment load to be applied to the output shaft 23, and with this structure, the distance D1 between the fulcrums supporting the load is extended to reduce a load to be applied to a radial ball bearing 41 and the thrust bearing 42, and rigidity of the bearing can be therefore reduced, and the weight can be reduced and the manufacturing cost can be reduced. Furthermore, since a bearing-to-bearing distance between the radial ball bearing 41 and the thrust bearing 42 (a distance between the bearings in a direction parallel with the center axis of the output shaft 23) is not required to be formed long, length in the center axial direction of an assist device 20 can be shortened. COPYRIGHT: (C)2008,JPO&INPIT |
