Initial Shape Optimization of Gears Using Response Phase Method

The miniaturization of automotive components requires higher precision in mechanical elements such as gears. Machining is necessary to achieve high precision, but there are issues such as increased costs and removal of surface modification layers. From this point of view, it is necessary to design the initial shape to achieve the target dimensions after heat treatment, taking thermal strain into consideration. Our group is working on the optimization of the initial shape using the response phase method as a method for this purpose. In our previous research, we have been able to obtain a shape close to the target size after heat treatment of flat plates by optimizing the initial shape. In this study, we applied this method to gear geometry and optimized the initial geometry. To create the response phase, 220 models were created based on the D optimization plan. Finite element analyses were performed on these models. The finite element model is a three-coupled model that considers heat transfer, microstructural change, and stress. The response phase was created from the obtained results, and the initial shape was selected to minimize the strain after heat treatment as the objective function. It was confirmed that the initial shape optimization considering the heat treatment strain reduced the strain after heat treatment compared to the case without considering the heat treatment strain. These results indicate that the response phase method is effective in designing the initial shape to achieve the target dimensions after heat treatment.