The optimal fatigue design of gear profile for transmission mechanism on ratchet wrench

• Main Authors: Shih-Chan Chien, 簡世展
• Other Authors: 張嘉隆
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/54119845473360702003

碩士 === 國立雲林科技大學 === 機械工程系 === 102 === In this thesis , the optimal fatigue design of gear profile for the ratchet wrench is studied. During the operation of wrench , the reversed torsional loading on gears causes the fatigue failure of gears. The contact stress on the involute gear is simulated by the finite element software ANSYS. The simulated result is compared with the calculated resulting by the equation from AGMA to verify the accuracy of the simulated model. Then Taguchi method is used to modify the gear profile for better fatigue performance. The design considers both three and four contact teeth for gears. The design factors are tooth angle , tooth fillet , and number of teeth on gear. The optimal design of gear profile is based on the minimum range of contact stress on the tooth during the reversed loading. The fatigue life is predicted by Basquin equation. The result shows that the fatigue life for the optimal design can be improved about fifty six percent.