Optimized double helical gearing designs can help to save weight, assembly space and costs of turbo gear units, increase efficiency and ensure low-noise operation. Double helical gears are becoming increasingly relevant, especially in the fields of turbomachinery, aerospace and electro mobility. The reasons for this are the elimination of axial forces, which means that bearings can be dimensioned smaller. Small gap widths between the gear halves are desirable in order to optimize the power density. Interaction effects between the two halves of the gear are thus becoming increasingly important. The apex point is an important parameter for tolerancing in these applications. It describes the intersection of the extension of the tooth flanks of the left and right half to an axial reference plane. In the current state of the art design processes the interactions between the individual gear meshes of the left and right half are neglected. Thus, no specific design of the apex point position is possible.

This paper, therefore, presents a method for considering the quasi-static stiffness behavior of coupled gear meshes e.g. double helical gears for gear design. An FE-based approach is used to derive design and tolerance recommendations for coupled gear meshes. The developed method is validated by means of experimental studies. The focus is on the investigations of the apex point and the influence of manufacturing deviations on the excitation and contact behavior. The validated method allows to derive design and tolerance recommendations for double helical gears in order to optimize the excitation behavior.