1.Mechanical model

In the process of precision forging of bevel gear, the elastic deformation part of the material is far less than its plastic deformation part, so the elastic deformation of the deformed body is ignored, the workpiece is regarded as a rigid plastic body, and the die is regarded as a rigid body. The rigid viscoplastic finite element method is used to simulate the forging process of bevel gear. Considering the approximate symmetry of bevel gear parts, 1/4 of the workpiece is taken as the research object of finite element simulation.

2.Geometric modeling

The die cavity of precision forging bevel gear is curved surface modeling, and the shape is complex. In order to obtain high-quality curved surface shape quickly and accurately, a special CAD three-dimensional modeling software UG is selected to complete the geometric model design of the die and blank. Because the theoretical tooth profile curve of spur bevel gear is spherical involute, it can not be expanded into a plane, which brings great difficulties to the three-dimensional modeling of bevel gear.

Based on the back cone theory and UG modeling command, the real three-dimensional modeling of bevel gear is realized to the greatest extent. Figure 1 and Figure 2 respectively show the geometric models of planetary gear pre forging and final forging, and figure 3 and Figure 4 respectively show the geometric models of half shaft gear pre forging and final forging.