小型涡轮分子泵动叶片设计与制造技术研究

Design and manufacturing technology of the vane wheel for small turbo-molecular pump

本文从结构设计角度分析了叶片轴向高度h、节距a、叶片角α、叶片数z、叶片厚度δ等结构参数对压缩比的影响,并基于分析结论提出了薄叶片分子泵叶轮的设计思想;采用有限元计算分析涡轮分子泵运行时叶片的应力状态,获知叶片工作时产生的应力几乎与叶片厚度无关,从而为薄叶片的设计提供在强度理论方面的支持;最后,通过工艺优化,试制出薄叶片的小型涡轮分子泵,该试制件在测试中转速达到了60000 rpm,使用效果良好。

The pumping characteristics of turbo-molecular pump has an interlocking relationship with the geometrical design parameters of its vane wheels, including blade height, blade pitch, blade angle, blade number and blade thickness. In this paper, the effects of the geometrical design parameters on pumping characteristics were analyzed. According to the analysis results, the design of the vane wheel with thin blades w~,s presented. The stress within the blade for operation at a high speed was calculated by the finite element analysis （FEA） method. The results demonstrate that the stress within the blade is almost independent of the blade thickness, thus providing theoretical support for the design of thin blades from the viewpoint of strength. With process optimizations, the vane wheel with thin blades was trial-produced and then tested in a small turbo molecular pump at 60000ram with favorable performance.