基于RPM的水轮机叶片复杂曲面制造技术

Manufacturing Technology of Free-Form Surface of Turbine Blade Based on RPM

针对传统的木模铸造方法在制造水轮机叶片时存在精度差、周期长、成本高等缺点,提出了基于RPM技术制造具有复杂曲面水轮机叶片的新方法。该方法首先应用非均匀有理B样条理论进行水轮机叶片的整体造型,实现了叶片的数字化表示,在此基础上利用自由曲面和解析曲面的求交方法对叶片数字模型进行切片分层,最终实现在成型机上层积制作原型。实例分析表明,该方法能够克服传统制造方法的不足,有明显的优越性。

As a traditional means,the woodmould founding turbine blade has such limitations as inaccuracy,long period and high cost.A new method based on Rapid Prototyping & Manufacturing is presented in this paper for producing the freeform surface blades. This method first shapes the whole structure of turbine blade by Nonuniform rational Bspline so as to achieve the blade's digitalized expression,on the basis of which the means of intersection for freeform and analytic surface successfully slices up the blade digital structure model. Finally,the prototype model is made on the RPmachine.The analysis of the practical examples indicates that this new method can overcome the limitations of traditional means and have obvious advantages.