Purely FEM-Based Tooth Profile Design of Circular Spline for Double-Circular-Arc Harmonic Drive

This paper presents a novel method for the tooth profile design of circular splines in double-circular-arc harmonic drives, utilizing solely the Finite Element Method (FEM). A double-circular-arc tooth profile with two profiled edges at the dedendum and addendum circle is parameterized. By considering material properties and eliminating unrealistic assumptions, the method allows for a more realistic reflection of the actual deformation. The design process is validated through four cases. Compared to the conventional envelope theory, this FEM-based technique reduces the constraints on tooth parameters, thereby expanding the design space. The study also reveals that the parameters of the wave generator significantly influent tooth profile design, necessitating consideration of both the flexible spline teeth and wave generator parameters in the design process. The findings demonstrate the potential of this method in providing a more flexible and realistic design approach for harmonic drive tooth profiles.