Abstract: To improve the machining accuracy of complex thin-walled structural components during high speed milling process, a flexible force model suitable for both thin-wall tooth profile and rigid tooth profile of cycloid gear is proposed. The model is based on identifying key processing characteristics that influence deflection of low-rigidity process system. Based on the application of bending-torsional coupled theory, a new mathematical model suitable for static machining deflection prediction of thin-walled tooth profile is proposed due to bending deflection and shear deflection. Taking into account the deflections of workpiece and cutter the expressions are derived for process geometries parameters in peripheral milling where curvature varies continuously along the tool path. Then modified cutting teeth immersion angle and undeformed chip thickness are introduced due to the deflections and process geometries. In machining workpiece geometries, the milling force distribution for thin-wall tooth profile of cycloid gear is solved by the modified Newton-Raphson iterative algorithm. Researches indicate that the milling forces are influenced strongly by workpiece-cutter defection in the radial direction and vary periodically along the cutting profile. This is attributed to the periodic variation of gear profiles and feed per tooth along the gear tooth path. Finally, the force model is experimentally validated and the results show good consistency between predicted and measured deflection values.

Key words: Cycloid gear, Elastic deformation, Flexible milling force, High speed milling, Thin-walled structural component