Research Of CNC Gear-hobbing Technology On Three Order Ellipse Helical Gear

In mechanical transmission,gear transmission is one form of the most widest forms in practice.With the development of the mechanic industry,the variable ratio transmission will become one important form in the mechanical transmission.On the basis of continuous progress for NC machining technology at present,the gear kinematic composed of non-circular gear will play a representative role in this transmission.By so far,non-circular gear has been widely applied on diversified machines gradually.Three order ellipse gear is one kind of typical non-circular gear that plays a important role in application;Although there have been many methods on machining non-circular,not enough processing theory and methods applied in concrete non-circular gear;Based on the idea and on the basis of existed NC hobbing key technology,correlative theory and methods of NC hobbing non-circular gear will be combined into this article,aiming at the research of CNC gear-hobbing technology on three order ellipse gear.On the basis of the meshing theory of helical gears and tool rack-skew methods,the blue-print of five coordinate simultaneous-control machining is brought forward for three order ellipse helical gear,the CNC simultaneous-control model is built by correlative math deduction,the simultaneous-control hobbing structure for three order ellipse helical gear after math optimization and by making use of the "CNC system of bobbing gear".it is the core of this article and the theory foundation of hobbing three order ellipse helical gear.Because of complex pitch curve of three order ellipse gear,it is difficult for interpolation processing the gear and the precision can't be guaranteed.According to equal polar angle interpolation algorithm,this paper present a interpolation algorithm for three order ellipse with equal polar angle on the basis of deduction for formula of three order elliptic radian length.When the NC bobbing machine tool is under the condition of bobbing or modifying tooth form,the coordinatation computation of tool setting is relevant to the machining precision and the extent of programming.This article will study on coordinatation computation of tool setting for three order helical ellipse according to the correlative theory of cylindrical gear.The precisive figure of pitch curve for three order ellipse helical gear and the solid figure are designed and protract by making much use of Pro/Engineer which is a CAD and emulational software and the CAD flow of non-circular;The approximative profile ichnography of three order ellipse helical gear is gained by simulating hobbing according to the CAM flow of non-circular and taking account for the NC hobbing machine tool with its locomotion form.