| 摘要 |
<p>A worm wheel (24) of a worm drive (21) includes an annular synthetic resin member (56) having tooth portions (56a) meshing with a worm shaft (23) and a core (55) having an outside diameter portion (61) joined to an inside diameter portion (58) of the synthetic resin member (56). The outside diameter portion (61) of the core (55) has first joining tooth portions (64) that protrude outward in a radial direction (R1) and are joined to the inside diameter portion (58) of the synthetic resin member (56). Each of the first joining tooth portions (64) includes a widening portion (64b) whose width in a circumferential direction (C1) increases toward the outside in the radial direction (R1).</p> |
