| 摘要 |
PURPOSE:To obtain a gear having high mechanical strength, high inter-layer bonding strength of base material, and a small number of voids by impregnating base fabric of woven cloth with phenol resin, forming dried pre-preg into an annular body, forming the annular body into an annular element by means of a cold die, forming molding material for web and boss of gear, bush, and the annular element into a precursor of gear by heat and pressure molding, and forming gear teeth by machining. CONSTITUTION:Pre-preg prepared by impregnating base fabric of woven cloth with phenol resins and drying them is wound up into a cylinder shape, whereby both ends thereof are connected to form an annular body. Two annular bodies 2 in a hot state are superposed and thrown into a cold die 10, where they are compressed by applying pressure thereto so that both of them are formed into an integral annular element 11. The annular element 11 is left as it is at a room temperature for predetermined days, and thereafter it is thrown into a molding die 3 to be molded by application of heat and pressure. Molding material for a web 8 and boss 9 is prepared by impregnating cotton fabric and glass-cotton fabric with phenol resin and drying them to form pre-preg and then cutting said pre-preg into small pieces and mixing them with each other. Gear teeth are formed by cutting a part of the precursor 6 which is formed into the annular body 2 to form a gear. |
