The Face-hobbing Method For Manufacturing Straight Bevel Gears Based On The General 5-Axises Machining Center

Straight bevel gear is usually used for transmission between the cross-axis. It is widely used in the equipments of cars,tractors, engineering machinery, printing machinery, agricultural machinery and the other power machines. The demand of Straight bevel gear is becoming more and more great.In 2010, the German company Klingelnberg disclosed a new face-hobbing method for manufacturing straight bevel gears based on the six axis CNC milling gear machine under a hypocycloidal straight mechanism.Face hobbing method is a continuous indexing and double-flank cutting process that can support high productivity and precision than the traditional methods. But, The six axis milling gear machine is very expensive and the CNC system is not open. So, this article propose use Face hobbing method for machining straight bevel gear in general five axis machining center and open CNC system.The main contents as the following:1.According to the mathematical model of Oerlikon extended epicycloid bevel gear machined by six axis CNC milling gear machine and the mathematical theory of Internal cycloidal motion, when the radius of the rolling circle equals to half of the radius of the base circle yields straight line, Infers the mathematical model of processing straight bevel gear in general five axis machining center by face hobbing.2. Study the process and motion control requirements of straight bevel gear with the Face-hobbing method based on the machining center. Combined with mathematical model,a CNC machining system modules was developed which can generate NC program automaticly. Developed an electronic gear functions to meet the requirements of two-axis synchronization for the Face-hobbing method.3.Through the study of tooth pitch deviation and the tooth surface error of straight bevel gear, developt on-line measurement CNC system module,which can plan measure path, generate test program automaticly and generate gear quality report according to the method of error evaluation.The accuracy of the mathematical model and the feasibility of the CNC system, On-line measurement system be verified by simulation.