Abstract: Based on the reliability of higher order moments theory， by integrating optimization design， sensitivity design and robust design， a reliability robust design model of cylindrical gear transmission modification parameters was built and a cylindrical gear modification optimization method which regards modification parameters as the design variables and modification parameter sensitivity and gear quality as the objective function was proposed so as to solve the problem of gear modification parameter determination from the perspective of reliability-based robust design. Apart from that， the effect of the change of tooth modification parameters on gear transmission reliability was studied， whose ideal numerical results were validated and obtained through computer programing. The numerical example showed that the proposed method is a convenient and practical method to improve the amount of gear tooth modification， which can provide a theoretical basis to determine the best gear tooth modification.

Key words: reliability of higher order moments theory, sensitivity design, robust design method, gear transmission, amount of gear tooth modification