Key Technologies Research Of NC Machining Equal Base Circle Bevel Gear Based On Disc Cutter

Due to the good mesh characteristics, spiral bevel gears are widely applied in variouskinds of mechanical transmission systems, and they are always processed by theexclusive disc milling-cutter mounted in the exclusive machine-tool. There are manyobvious weak points for large size spiral bevel gear machining, such as low processingefficiency, poor tooth surfaces quality, long production cycle，high processing cost, etc..The equal base circle bevel gear is a new kind of curve bevel gear. The gear is machinedusing finger milling cutter which based on forming principle. Its characteristic is thebigger gear machining with a small machine tools, and the price of the finger millingcutter is low, which greatly reduces the machining cost of large size curve bevel gear.However, its machining efficiency is low using finger milling cutter, the tooth surfacequality is not good, and it is not easy to achieve to machining a equal base circle bevelgear which tooth face is hard.In this paper, combined with the development demands of equal base circle bevelgear, aimed to improve the processing quality and production efficiency, integratedlyused the existing multidisciplinary research results of equal base circle bevel gear theory,the gear meshing theory, numerical control technology. The technical route of “study therelevant theories, break through the key technologies and solve the practical problems”are applied, to systematically explore and research the key technical problems of NCmachining the equal base circle bevel gear, The specific content are as follows:The theory study of machining equal base circle bevel gear using a disc cutter.Demonstrates the possibility of using a disc cutter machining equal base circle bevelgear, by means of the gear meshing theory and differential geometry. Established themathematical model of the disc cutter, based on the principle and processing method ofequal base circle bevel gear. Through the analysis and planning of the space motion ofthe cutting tool, processing coordinate system is established for the first time. Based onthis, by solving the tangential vector and normal vector of tool surface respectively,solving the speed of tool surface points and the tooth surface points, deduced andestablished the tooth surface equation machining with the disc cutter. The aboveresearch provide a theoretical basis for subsequent study of machining method.The study of disc cutter’s space position and posture and NC machining method ofequal base circle bevel gear. In order to improve the consistency of the theoretical toothsurface and the disc cutter machining tooth surface, Deduced the formula of parameterswhich affect the position and posture of cutter, such as cutter turning angle, the tool tiltangle, tool-position correction. By solving the tool center coordinates and cutter axisvector, got the tool position calculation formula in the wheel block coordinate system,furthermore, according to post processing theory of NC machining, converted the tool-position to machine tool moving coordinates and rotary coordinates in general NCmachine tool coordinate system, and its explicit expression is presented. The resultsshow that using a disc cutter can processing equal base circle bevel gear.The study of Intervention and it’s detection method in the process of machining equalbase circle bevel gear using disc cutter. According to the NC machining principle andmethod of processing equal base circle bevel gear, analysed the generating mechanismof excessive cutting interference in machining movement. For the concave tooth surfacemachining, put forward two kinds of methods for excessive cutting interferenceinspection: cross section curve method and rotating comparison method, based on thesurface equation of disc cutter and the tooth surface equation, combined with theinstantaneous position relationship of the two. For the convex tooth surface machining,through the study and analysis on collision interference between tool front end face andconcave tooth surface., came up with a collision interference inspection method. Theabove intervention study, provide the basis for the reasonable design of disc cutter andinterference prejudge.Based on the above research,carried on the NC machining equal base circle bevelgear experiment using disc cutter,and gear rolling test. Experiments proved thatprocessing principle, processing method and the interference testing method are allcorrect and feasible which have been put forward in this paper.