Free-form Surface Based Design Of The Slice Cutter For Cylindrical Gear

Gear slicing is a new technology for cylindrical gear appearing in21century,which can separate tooth profile from blank directly. It has many advantagesespecially for the gears with special structure such as non-interpenetrated internalhelical gears, which cannot be machined by existing gear machining methods.Although a certain progress is gained in gear slicing principle, slicing cutter designand CNC gear slicing machine tool, there is great disparity compared to practice. Slicecutter, which is the key part in gear slicing, cannot satisfy production requirement. Anew design method of general slice cutter is proposed in this paper based on free-formsurface.Firstly, According to the design principle and the manufacturability, sphere ischosen to be as initial rake face and its free-form mathematical model is established.From the Theory of Conjugation, the model of the plane conjugating to the surface tobe processed is built. Taking the error-free machining as the goal, the major edge isdesigned to be the intersection between the rake face and the conjugate surface and itsmathematical model is established. The mathematical model of free-form major flankwhich consists of a series of major edges is built. Then the mathematical model of topedge and top flank face are established based on the same theory to major flank face.Thus, the topological structure of slice cutter can be obtained based on the abovemathematical models. Then according to cutting principle, the mathematical modelsof cutting angles are established and the factors which affect rake and relief angles areanalyzed. Then the optimal parameters including initial center distance, variablequantity of center distance, shaft angle, variable quantity of radius of rake face,variable quantity of vertical coordinate of data points on rake face and variablequantity of data points on cutting edge are chosen. The final structure is obtained byadjusting the above parameters. Then, calculation software is developed based onMATLAB GUI. Lastly, an example is given to verify the feasibility of the designmethod of cutting angles.The method mentioned in this paper breaks limitation of traditional method andthe cutter designed by this plan can be applied for straight and helical gears as well asin internal and external gears. The method in this paper lays the foundation of furtherstudy on design principle of slice cutter and gear slicing.