A new multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth

Spiral bevel gears are critical transmission components, and are widely used in the aerospace field. This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears. Firstly, the multi-DOF envelope forming principle of spiral bevel gears is proposed. Secondly, the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships. Thirdly, the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear. Fourthly, a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference. Finally, experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment. The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.