In the process of cutting teeth, the material of straight bevel gear blank continues to be cut off, and the stiffness and internal stress distribution of straight bevel gear blank also change with the reduction of material. The change of the rigidity of the split gear blank in the process of gear cutting changes the ability of the straight bevel gear blank to resist deformation, and the change of its internal stress distribution can directly lead to the deformation of the straight bevel gear blank. These two change factors determine the deformation degree of the straight bevel gear blank.

In order to more accurately predict the deformation law of straight bevel gear blank in the process of tooth cutting, the change of straight bevel gear blank stiffness – residual stress evolution – blank deformation should be studied as a system. Therefore, it is necessary to explore the change of straight bevel gear blank stiffness in the process of straight bevel gear blank cutting, and analyze the evolution law of straight bevel gear blank stiffness with different machining processes, so as to lay a foundation for predicting the cutting deformation of straight bevel gear blank.

The straight bevel gear blank in the machining process is equivalent to an equal section beam with the same length. The equation for calculating the equivalent stiffness of straight bevel gear blank is established by using the method of bending strain energy equivalence. The equivalent stiffness of the straight bevel gear blank in the machining process is calculated by establishing the equation. According to the obtained equivalent stiffness change curves in different states, it can be seen that the stiffness of the straight bevel gear blank in the cutting process continues to decline, and the stiffness of the straight bevel gear blank in the machining process is also different due to different process sequences, but the stiffness tends to be the same at the end of the machining. This lays a foundation for the establishment of the mapping relationship model between stiffness change, residual stress evolution and wheel blank deformation.