S111042 籾殻焼成粉体を配合した射出成形プラスチック歯車の寿命([S11104]伝動装置の基礎と応用(4))

Abstract

The lifetime of injection molded plastic gear is greatly affected by the plastic material and temperature. Because the plastic physical properties are greatly different in each plastic material, and the stiffness varies depending on temperature. Therefore, the plastic gears are filled with the reinforcing materials for keeping strength even in high temperature. On the other hand, natural materials are used to focus on the ecological recycling. The authors focused on using the Rice-Hull-Silica-Carbon (RHSC) as a reinforcing material in plastic. The rice hull is a residual product of rice and its amount is about 2.6 million tons per year in Japan. In this study, two kinds, polyacetal (POM) and POM filled with RHSC, were used for the materials of test gears. The lifetimes of test gears were investigated under fixed rotational speed and some torque. So, the effects of RHSC on the lifetime of plastic gear were studied experimentally. From the discussions, it seems reasonable to conclude: (1) The RHSC decrease the friction of tooth surfaces, and the process of tooth wears differs in existence of RHSC. The RHSC improved tribological property, and this effect is shown at the smaller median grain diameters of RHSC. (2)It is better to use that combining the gear of POM and POM filled with RHSC, since the spur gear pair of the POM is greatly influenced of misalignment for the lifetime.