利用双螺杆压缩机型线设计理论,研究了应用于双螺杆油气混输泵的3种不同齿数的双摆线-圆弧对称型线及其几何特性。通过全面解析螺杆转子的啮合特性,计算出相关型线的几何特征值,指出齿间容积的密封性能是评价转子型线优劣的重要标准;对型线密封性能有重要影响的几何特性参数有接触线、泄漏三角形和齿间容积等。研究结果表明,随着齿数的增多,泄漏三角形面积呈减小趋势,但幅度很小,而其与基元容积的比值呈上升趋势;齿高系数增大时,泄漏三角形的面积减小,而接触线的长度却大幅延长,多齿型线泄漏三角形的减小速度明显优于单齿型线;顶圆直径增大时,虽然面积利用系数得到提升,但转子密封性能却迅速下降,这种趋势随着齿数增加更为明显;不同的泄漏通道对泄漏量的贡献大小也不同,泄漏三角形占此类型线的主要泄漏部分。
The theory for designing the profile line of twin-screw compressor was applied to study the double cycloid-arc symmetry profile lines of three different tooth numbers which are applied to twin-screw oil and gas multi- phase pump as well as their geometric characteristics. The geometric characteristic values of relevant profile lines were calculated through a comprehensive analysis of the meshing property of screw rotor. It was pointed out that the sealability of inter-tooth volume is the important criterion for evaluating the quality of rotor lines. The geometric characteristic parameters which can have an important effect on the sealability of profile line include contact line, leakage triangle, inter-tooth volume, and so on. The research findings show that with the increase of tooth numbers the area of leakage triangle tends to decrease but in a very small degree. When the tooth height coefficient increa- ses, the area of leakage triangle decreases and the contact line increases remarkably. The decrease speed of leakage triangle area of multi-tooth profile is obviously better than that of single-tooth profile. When the diameter of adden- dum circle increases, the rotor sealability decreases fast, even though the area improves through the use of coeffi- cient. This tendency becomes more remarkable with the increase of tooth numbers. Different leakage channels make different contributions to leakage, and leakage triangle constitutes the main leakage part of such profile lines.