| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent magnitude of meshing resistance of a worm gear and a gear tooth part from being partially different in a peripheral direction of a worm wheel by enhancing the shaping accuracy of the worm wheel. <P>SOLUTION: The plurality of first thinned wall parts 44f are arranged in one side of the worm wheel 44 in an axial direction and near gear tooth parts 44a arranged along a radial direction along the peripheral direction of the worm wheel 44. The plurality of second thinned wall parts 44g are arranged in the other side of the worm wheel 44 in the axial direction and near the gear tooth parts 44a arranged along the radial direction, along the peripheral direction of the worm wheel 44. The first thinned wall parts 44f and the second thinned wall parts 44g are alternatively arranged so as to appear alternatively along the peripheral direction of the worm wheel 44. Thereby, the wall thickness in the vicinity of the gear tooth part 44 of the worm wheel 44 are well balancedly thickened to prevent sinks from being generated, and it is possible to enhance the shaping accuracy of the worm wheel 44. <P>COPYRIGHT: (C)2012,JPO&INPIT |
