高压三螺杆泵啮合泄漏机制分析

Analysis on the Mechanism of Mesh Leakage of High Pressure Three Screw Pump

针对三螺杆泵在高压化过程中出现泄漏增加、容积效率急剧下降的问题,详细分析一种新型高压三螺杆泵的啮合原理及泄漏机制。根据啮合形式以及泄漏部位的不同,对高压三螺杆泵的泄漏进行分类,并分别建立数学模型,得到不同位置的泄漏量与间隙、姿态、转速等因素的关系,得到定量的分析结果。基于理论分析的结果,为了使高压三螺杆泵的容积效率在高压情况下达到设计要求,对螺杆的加工精度、主从螺杆间的配合间隙以及与衬套间的配合间隙提出了要求。

With the expanding of three screw pump application, many occasions require the use of high pressure, at least up to 25MPa. Because of the pressure increasing, the problem of leakage cannot be ignored. The meshing principle of the three screw pump was elaborated. According to differences of meshing form, the total leakage was divided into three leakage parts. For each part, an independent mathematical model was established and the leakage was decided by different clearance, gesture and revolution speed. The final results show that most amount of leakage exists in the spiral region of active and driven screws, and there are relatively small leakage between the bush wall and cylindrical surface. To meet practical requirements of volume efficiency, there are demands for machining accuracy of screws and bush in theory.