螺杆被广泛用于石油、化工、橡塑机械等行业中的原料加压、输送及混合工序中。随着对所加工的原料特性及加工工艺认识的深入，螺杆的形式变得多种多样。近代的塑料、橡胶挤出机中，出现了具有如下特征的异形螺杆：（１）变螺距螺杆（图１ａ），包括线性变化螺距和非线性变... Screw is widely used in petroleum, chemical, rubber machinery and other industries in the raw material pressure, transportation and mixing processes. With the deepening of understanding of the characteristics of raw materials and processing technology, the form of the screw becomes diversified. Modern plastic, rubber extruder, there have been shaped with the following characteristics of the screw: (1) variable pitch screw (Figure 1a), including the linear change of pitch and nonlinear ...