# Optimization design method of gear pair optimization model of automobile transmission

In the shift process of the manual transmission, the performance required by the shift gears of different gears is not exactly the same, so it is necessary to analyze the performance of different gears separately, which increases the workload of gear design. Now it is possible to realize the three-dimensional modeling design of gear on computer. However, only completing the three-dimensional model of gear can not meet the current requirements of gear design. Only when the three-dimensional modeling design of gear is integrated with its performance analysis, can the design analysis design process of gear be truly completed on computer. In the third chapter of this paper, the process of gear CAD design and CAE analysis has been discussed preliminarily. On the basis of this process, the design analysis design of gear can be studied to realize the CAD design of gear driven by CAE. The finite element method can be used to solve the complex problems, make the analysis of the gear all “digital”, and get a gear with the best performance. Now the improvement of the gear processing technology can also process the continuous parameter gear, and can process the gear with CAE analysis, so the CAE analysis has practical engineering application value. In this paper, based on the parametric modeling of involute helical gear and the contact analysis of gear pair, the orthogonal test method and genetic algorithm will be used to solve the extreme value of a certain performance of gear pair.

The general process of product design is product design performance test product design. When designing gears, when analyzing a certain performance of gear pair, how to get the given performance index accurately, so that the designed gears can meet the use requirements, which needs to clarify the relationship between design parameters and product performance. There are many methods for product design. In view of the parametric modeling and contact analysis of gears that have been completed in this paper, this process realizes “digital” and can analyze different problems by modifying the corresponding parameters. In this case, the relationship between the design parameters of the gear pair and its performance can be established. According to certain principles, the extreme value of a certain performance of the gear pair can be obtained. In this paper, ANSYS has been used to complete the modeling and analysis of gear, so in ANSYS software, the optimization method can be used to complete the design of gear pair.

Optimization design is an engineering design method that applies optimization principle and computer technology in product design. Optimization design method has been widely used in the design of mechanical products, and achieved good design results. The mechanical optimization design includes establishing the mathematical model of the optimization problem, selecting the appropriate optimization method, programming the optimization method, and calculating in the computer. When modeling practical problems, considering the complexity of practical problems, the mathematical model is not necessarily analytical, but also can be used to build the mathematical model of mechanical optimization design problems through experimental data and empirical formula. Although mathematical models have different forms, they can express the relationship between design variables and performance indicators. In this paper, the finite element contact model of gear pair can be established in ANSYS, and the contact problems of different gear pairs can be analyzed, so the design of high-performance gear pair can be realized by mechanical optimization design method. The mathematical model of optimization design includes three parts: design variable, constraint condition and objective function. Design variable is the design scheme. Under the constraint condition, the parameters obtained by solving the extreme value through the objective function are obtained. The design variables, constraints and objective functions in gear pair optimization are analyzed in the following. 