等螺距螺杆转子车削工艺研究

Machining with Numerical Control Lathe and Clearance Design of Fixed Pitch Screw Rotor

螺杆转子是螺杆真空泵的核心部件。本文提出了一种采用普通数控车床加工等螺距螺杆转子的工艺及间隙设计方法。使用两把普通车刀对螺杆进行加工,根据进给量计算螺杆转子轴截面刀位点坐标值,通过二次车削分别加工螺杆螺旋槽凹、凸两面;采用ANSYS进行螺杆转子热变形有限元分析,得到最大变形量,据此分别进行齿顶圆轴向斜切、凹面切削以满足间隙要求;使用数控车宏程序进行编程,并以刀位点坐标作为变量以简化程序。本研究具有通用性,对不同的转子型线均可使用相同的设计及加工方案。

Herein,we addressed the clearance design and machining,with two regular NC lathe turning tools,of a fixed-pitch screw rotor,a core component of screw vacuum rotor pump.The original work was the two-step machining.First,the coordinates,of the cutter position point of the axial section of rotor shaft,were derived according to the feed-rate;second,the groove’s concave and convex sidewalls were machined,respectively;third,the thermal deformation distribution of the screw rotor were simulated with ANSYS software to determine the axial bevel and concave cutting clearances for satisfying the gap requirements;and finally,a dedicated program was developed by means of NC lathe micro-program,and the variables of cutter position point coordinate simplified the program.We suggest that the newly-developed machining scheme be of some technological interest in fabrication of other types of screw rotor.