Numerical Simulation And Cutter Back-off Analysis Of Efficient Gear Shaping Via Variational Circular Feed Rate

Gear shaping is a widely applied cutting process of spur gears, which are a kind of the common mechanical transmission. In conventional gear shaping the pinion cutter and the gear blank rotate uniformly with a given gear ratio, which results in the cutting area per stroke varies greatly in cutting tooth spaces. This makes the cutting force less than the rated capacity of the gear shaper in most cutting strokes, and thus reduces process efficiency. To overcome such a shortage, a new gear shaping method for involute spur gears is proposed, in which the cutting area per stroke is homogenized to a target value through optimizing the circular feed rate. This makes it possible to keep the cutting force approximately at the rated capacity of the gear shaper and thus to enhance the process efficiency. In this thesis, a further research was developed on numerical control(NC) simulation and cutter back-off analysis of the efficient gear shaping through variational circular feed rate. The contents and contribution of the thesis are as follows.The theoretical models of the gear generation were built based on the gear meshing theory and the gear shaping theory; the simulation models of the NC gear shaping were constructed by UG and VERICUT software. The conventional gear shaping was calculated on the base of the theoretical models and simulated on VERICUT software. The results showed that the theoretically calculated cutting area fit well to that via VERICUT simulation. This validated the correctness of the theoretical modeling.The modeling for planning variational circular feed rate was established based on the theoretical models. The efficient gear shaping was simulated on VERICUT software via variational circular feed rate of cutter and gear blank, which were calculated through the rate planning modeling. Made a comparison between the theoretically calculated and simulated cutting area of efficient gear shaping, and compared the teeth profiles generated by conventional gear shaping with that generated by efficient gear shaping. The results showed that the cutting area and the teeth profiles fit well separately. This validated the correctness of the rate planning modeling.According to the condition of the interference between cutter and gear blank, analysis was developed on the cutter back-off of conventional and efficient gear shaping based on the gear generation theory. The velocity and the amount of the cutter back-off were calculated on conventional and efficient gear shaping.The programming system was designed for the efficient gear shaping using Visual C++ software. It has the function of planning the variational circular feed rate and the cutter back-off. This laid a foundation of the efficient gear shaping via variational circular feed rate.