High-efficiency gear hobbing technics based on fuzzy adaptive control of spindle torque

In this paper, the problem of relatively low efficiency of the current gear hobbing process is addressed through fuzzy adaptive control of the cutting force. The paper studies the influencing factors of the cutting torque of gear hobbing, and the relationship between the feed rate and the cutting torque is established. Based on the relationship and the fuzzy adaptive control method, a high efficiency gear hobbing method is designed. A methodology using the static spindle torque rather than the dynamic one as the feedback signal of the fuzzy controller is also presented, which can deal with the severe cutting torque fluctuations during gear hobbing. The input and the output scaling factors of the fuzzy controller can also be tuned online to adapt to different types of gears or various cutting conditions. The key issue of determining the reference value of the spindle torque is also resolved through analysis of the spindle torque data in a trial cut. The proposed method is simulated and implemented on a numerical control gear hobbing machine, which cuts spur gears and helical gears. The simulation and experimental results are in a good consistency. The efficiency is improved considerably, which saves as high as 40% and 30% cutting time of the gear hobbing process in the first and second set of experiments, respectively.