| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a worm wheel, which has a simple structure, is high in the connecting strength between metal and resin, and thus can suppress cracking. <P>SOLUTION: The worm wheel 1 includes an annular worm wheel body 2, and the worm wheel body 2 includes an annular resin portion 6 molded with a metal shaft 4 being inserted thereto. An outer circumference 4a of the metal shaft 4 includes a first main surface 7 that is a part of a cylindrical surface, and a protrusion 8 protruded outward in a radial direction X1 from the first main surface 7. The protrusion 8 has a first convex curved portion 21, a pair of second convex curved portions 22 disposed on both sides across the first convex curved portion 21 in a circumferential direction Y1 of the metal shaft 4, and a pair of linear cross-sectional portions 23 connecting each second convex curved portion 22 to the first main surface 7 and crossing the first main surface 7 at a predetermined crossing angleθ. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
