| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection-molded gear which is formed by injection molding of a polyacetal homopolymer as a non-fiber-reinforced resin and can retain excellent operation durability and quietness, compared with fiber-reinforced materials using polyamides etc.SOLUTION: The injection-molded gear includes a rim having a gear portion formed outside in the radial direction, a boss arranged concentrically inside the rim in the radial direction and a web connected with the inner periphery of the rim and the outer periphery of the bosses and arranged concentrically outside the boss in the radial direction. The ratio of the height of the rim to the thickness of the web is 3 or higher, and the height of the rim is 10-100 mm. It is injection-molded with the polyacetal homopolymer of a melt flow rate(MFR) of 1.5-8.0 g/10 min as a non-fiber-reinforced resin. |
