杭州汽轮机厂生产汽轮机时,主轴油泵叶轮B752(见图1)铸造条件恶劣,叶片线型复杂(图1及图2),壁薄(2～3.5毫米),扭曲度大(165°),且叶轮须与油泵轴一起做动平衡试验,剩余不平衡重量不得大于30克·毫米。铸造叶轮困难很大,最主要的是叶片形状复杂,无法起模,按 The main pump impeller, B752 (see Figure 1), had poor casting conditions, complex blade shapes (Figure 1 and Figure 2), thin wall thickness (2 to 3.5 mm) and large twist (165 °) when producing steam turbines at Hangzhou Steam Turbine Works Impeller shall be used with the pump shaft balancing test, the remaining unbalanced weight of not more than 30 grams · mm. Casting impeller is very difficult, the most important is the blade shape is complex, can not play mold, press