螺杆转子的旋风式法曲率包络铣削技术

Normal Curvature Enveloping Method for Whirlwind Milling Technique on PDM's Rotors

针对石油工业用大型螺杆钻具转子螺旋曲面的数控铣削加工 ,提出了一种新的旋风式法曲率包络铣削技术。该技术的核心是在每一走刀行程中 ,实时调整刀具的轴心线绕接触点工件理论曲面外法线向量转动的角度 ,使铣刀刀尖圆与理论曲面的切触线具有相同的曲率 ,对理论曲面形成等法曲率的逼近包络。该铣削技术的表面成形精度高 ,且铣刀切削刃在曲面上的扫描面积大 ,能显著提高切削效率。在保持加工精度不变的条件下 ,可大幅度地减少刀具切削的行程数。

Normal Curvature Enveloping Method for whirlwind milling technique is a new milling technique which is proposed in this paper for machining the helical surfaces of PDM's rotors based on 5-axis CNC horizontal special rotary-type milling machine. The important machining strategy of this scheme is to strive to control the on-line cutter orientation of whirlwind milling tool so as to create a close approaching envelopment to the surface being machined with the rotational surface of the tool. Such a full approach can maximize the material removal rate on the machined surface at point of contact and improve the machining quality. If the tool path is developed with the same surface finish, a less number of passes will be needed.