Gear modification has great influence on the vibration and noise of gear and the load distribution on the tooth surface. The tooth profile modification can optimize the partial load on the gear, make the load concentrated in the middle of the tooth surface, and strengthen the load bearing capacity of the gear. The tooth profile modification can make up for the impact phenomenon in the process of gear movement, and optimize the dynamic performance of the gear. Combined with the tooth profile modification and the tooth direction modification, the modification parameters of the gear are firstly designed by orthogonal experiment to determine the modification variable range, and then the parameters are optimized by genetic algorithm.
Orthogonal experimental design is a design method based on multiple factors, which can select the representative from all the combination schemes for research. Through the research on the selected experimental combination, the correlation degree between different factors and analysis results can be obtained, so as to get the optimal design. The orthogonal experimental design can provide the initial range of modification parameters for genetic algorithm and effectively speed up the optimization process.
Considering the influence on gear modification, four modification parameters are selected as the research object, which are tooth drum, tooth inclination, involute drum and involute inclination. Multiple analysis levels are set for each modification parameter, and orthogonal test is carried out for different levels of each factor, so as to analyze the transmission error of gear under different conditions, in which the maximum modification amount of gear can be calculated In order to get the optimal design level through the formula. After the optimal design level is obtained, an appropriate range is selected near each parameter as the initial optimization range of each parameter of genetic algorithm, as shown in the table, which is the variable range of each modification parameter of gear.