An Efficient Gear Shaping Process For Large Gear Shaper By Constant Area Cutting Through Changing Rotary Feed

Large gear is a kind of key components of heavy machineries. Gear shaping isthe important process for large gear manufacturing. The large gear shapers, as themachine tools of shaping the large gears, are precious manufacturing equipments.Since the great inertia of its reciprocating spindle, it is not suitable to improve thecutting efficiency of the large gear shaper. It has been a challenge of the gearmachining technology for increasing the efficiency. In conventional gear shaping, thepinion-shaped cutter and the gear workpiece rotate in constant rotator speed via agiven speed ratio, but the cutting area is is varied with different cutting positions onthe slot. The cutting force has also large changed with cyclical fluctuations. Thesecause the shaper machine working in low efficiency. In this thesis, a novel gearshaping processnamed “Constant cutting area based efficient shaping method for largegear shaper” was present. This gear shaping process can keep the cutting area almostconstant at its maximum allowable value, and thus improve cutting efficiencyeffectively. The example of YKW51250NC gear shaper was used to investigate thekinematic model of the gear shaping process. The contents and contributions of thethesis are as follows:1. The mathematical models of the pinion-shaped cutter and the gear shapingprocess were established with the method of coordinate transformation and meshingtheory.2. A numerical algorithm for simulating the gear shaping process and calculatingthe cutting area exactly was developed based on redevelopment of CAD and matrixcalculation of MATLAB. This algorithm can also calculate the cutting position andthe cutting area at anytime in the gear shaping process.3. The principle the optimal specification, which is established by taking theconstant cutting area as the constraint, the principle of constant cutting area wasproposed, which was applied to the analyzing of both the inner spur gear and theexternal spur gear at two different depths of cut in the shaping process. Thevariational law of rotatory feed was calculated and developed the kinematic model ofthe efficient gear shaping process.4. The influences of additional inertia moment in spindle and rotator work-tableon the driving components in changing rotary feed were analysis. The variation law of changing rotary feed was modified via the dynamic method.The novel gear shaping process proposed in this thesis could improve the abilityof machining, and this method will also available to the other smaller gear shaping.