Abstract Screw rotors or their cross-sectional profiles primarily determine the performance of twin-screw vacuum pumps. In order to develop new types of screw rotors with high comprehensive performance, a novel eccentric involute screw rotor (EIR) was constructed, and its geometric model was established. Its cross-sectional profile only consists of four curves, in which an eccentric involute is used to smoothly connect addendum and dedendum circular arcs. Moreover, effects of geometric parameters on the area-utilizing ratio and spatial contact curve of the proposed EIRs were analyzed. The proposed EIR was compared with the conventional screw rotor concerning the spatial contact curves. The results show that the proposed EIR has the continuous spatial contact curve during operations.

中文翻译：

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双螺杆真空泵新型偏心渐开线转子的研究及性能分析

摘要 螺杆转子或其截面轮廓主要决定双螺杆真空泵的性能。为开发综合性能高的新型螺杆转子，构建了新型偏心渐开线螺杆转子（EIR），并建立了其几何模型。其横截面轮廓仅由四条曲线组成，其中使用偏心渐开线将齿顶和齿顶圆弧平滑连接。此外，还分析了几何参数对所提出的 EIR 的面积利用率和空间接触曲线的影响。建议的 EIR 与传统螺杆转子的空间接触曲线进行了比较。结果表明，所提出的 EIR 在操作过程中具有连续的空间接触曲线。