| 摘要 |
PROBLEM TO BE SOLVED: To increase a bond strength between a cored bar and a rim portion of a worm wheel in which the outer peripheral portion of the metal-made core bar is covered with the synthetic resin-made rim portion than that of the conventional one.SOLUTION: A cored bar 1A of a worm wheel has one end surface in the axial direction in which a first annular recess 12 is formed, the other end surface in the axial direction in which a second annular recess 13 is formed, and a third annular recess 14 which is formed on an outer region in the radial direction of the first annular recess 12. A rim portion 2A has a first inner peripheral portion 22 which is fixed to the first annular recess 12, a second inner peripheral portion 23 which is fixed to the second annular recess 13, and a projection 24 which is fitted into the third annular recess 14. A depth A of the first annular recess 12 is deeper than a depth B of the second annular recess 13. According to a method for manufacturing the worm wheel, the rim portion 2A is formed integrally with the cored bar 1A by injection molding of a synthetic resin.SELECTED DRAWING: Figure 8 |
