Development of design systems for FRP gears: fundamental study for bending fatigue strength of tooth root of FRP spur gears

摘要

Since FRP gears have acquired higher strength and stiffness than plastic gears, FRP gears have replaced metal gears in packing machines and engines of automobiles in order to reduce weight and noise. Although many researches have done about metal gears, there has been only few about FRP gears. In particular, no one has made an integrated research including material selection through the decision of the gear dimension. Therefore, the purpose of this study is to establish the way of constructing a design system of FRP gears. In this paper fundamental data of Cotton Fiber Reinforced Plastics Gears would be shown. Through the research and experimental techniques, several things were clarified as follows: 1) the property of woven cloth phenol resin and the paper phenol resin as gear material; 2) the superiority of cloth phenol resin over the paper phenol resin; 3) the effect of decreasing noise by using FRP gears comparing to using metal gears; and 4) the effect of the orientation angle of the fiber on the fracture shape in FRP gears.