一种单螺旋转子型线及其热变形研究

Profile and Thermal Deformation of Single Screw Rotor

微型化和集成化是当前干式真空泵发展的重要趋势,高真空干泵正是具有代表性的一种新型干泵。本文对高真空干泵的螺旋级转子进行了研究,对组成螺旋级转子的外螺线、内螺线、母线的型线方程分别进行了方程推导和几何建模,利用有限元分析的方法,对转子受热所产生的温度场,结构场进行了耦合计算,研究了转子热变形结果对型线设计和间隙设置的影响,得到影响高真空干泵性能的参数调节机制,为高真空干泵的设计提供了理论依据和指导。

A novel single screw rotor was designed to enhance the pumping speed and reduce the size of high vacuum dry pump（ HVDP）. Based on Yield-Density model,the original work involved the nonlinear generatrix with its outer / inner spirals being on the cylindrical / conical surfaces,respectively. The profile equation of the rotor‘sendface was derived. The impact of the rotor＇schamfering on the thermal deformation,equivalent stress and displacement of the rotor in the screw stage was mathematically modeled,schematically visualized with CAD software,and numerically simulated in finite element method with software WRKBENCH. The simulated results show that the chamfering significantly reduces the thermal deformation and stress. For example,the rotor＇s chamfering results in a thermal deformation of 0. 108 mm and a maximum equivalent stress of 633. 02 MPa,17. 6% and 9. 74% lower than those（ 0. 131 mm and 701. 34 MPa） of the screw rotor without chamfering. We suggest that the simulated results be of some technological interest in design of HVDP.