セルロースナノファイバ（CNF）を添加したポリアセタール樹脂歯車の寿命

抄録

Plastic gears have many advantages including their low weight, low cost, negligible lubrication requirements, vibration absorption and quiet transmission relative to their metal counterparts. Polyacetal (POM) is used for approximately 80% of all injection-molded plastic gears used in Japan. However, mechanical properties of polymer are temperature-dependent, and the strength and fatigue life of plastic gears are affected by the frictional heat during operation. Therefore, polymer gears are often improved by adding some reinforcing materials that will improve their resistance to heat and wear. In recent years, cellulosenanofibril (CNF) have been attracting attention as reinforcing filler for engineering plastics. The purpose of this study is to evaluate the effect of adding CNF on fatigue life of polymer composite gear. The test gears are fabricated from the composite materials of POM combined with CNF. The endurance tests are conducted without lubricant. The test gears were operated at a constant transmitting torque and a rotational speed until broken. The bulk temperature and meshing noise are measured during operation. The results showed that the adding CNF increased the fatigue life, and the least amount of tooth wear. These results suggest that CNF can be useful as a reinforcing material for POM.