【作者】 王彦斌；

【导师】 王兆伍；

【作者基本信息】 南京林业大学 ， 机械设计及理论， 2010， 硕士

【摘要】 三螺杆泵主要靠主从杆相互啮合形成密封腔将液体从吸入口输送到排出口。因此,正确设计螺杆型面是保证螺杆泵工作效率的主要因素。本文以三维CAD软件SolidWorks为基础,设计了<135>型三螺杆泵主、从杆及衬套的参数化设计系统,方便了工程技术人员设计不同参数下的主、从杆及衬套。因此,该参数化设计系统在工程中具有较强的实用价值。在研究SolidWorks软件中样条曲线实现技术的基础上,分别提取了主、从杆法截面和纵截面上型线数据,并与理论数据对比,得出了主、从杆法(纵)截面型线与提取法(纵)截面型线之间最大的极坐标误差。由于计算结果表明二者误差很小,即可直接通过主、从杆三维模型获取主从杆法、纵截面型线,并加工成样板进行检验。此方法同时也为一些表达式未知的复杂型面样板的获取提供了参考。螺杆泵工作时,相互啮合的主、从螺杆在衬套内以较高速度旋转。当衬套在介质压力作用下,变形量达到一定程度,衬套与螺杆之间的磨损会加快,致使螺杆型面遭到破坏,产生泄漏、降低容积率等问题,变形严重时甚至会出现螺杆“卡死”现象。为解决这一问题,本文利用有限元分析软件MSC.Nastran对衬套实际工况下的力学性能进行了研究,并在此基础上,对衬套设计提出了改进意见,并对改进后模型进行了有限元分析,结果表明改进后的衬套力学性能较改进前有了较大提高。最后,采用电测法对衬套外表面进行了应变测量,得出了衬套外表面测点的应力值分布规律。实验结果与有限元分析结果较为接近,验证了有限元分析结果的正确性。更多还原

【Abstract】 A screw pump is a special type of positive displacement pumps that has two or more intermeshing screws rotating axially to deliver fluids. So it is important to design the cutter profile accurately to obtain a high volumetric efficiency of the pump. With the customization of Solidworks, achieving the parametric design of <135>-type three-screw pump’s central rotor、idler rotor and Bush. Therefore, this system has a strong practical value.Research on the SolidWorks software spline implementation technology, based on which extracting the data of the central rotor and idler rotor’s law Section and longitudinal section Surface contour and compared with the standard data, then obtaining the largest error between the extracting data and theoretically correct value. As the error is small, through the central rotor and idler rotor’s three-dimensional model, we can directly obtain the central rotor and idler rotor’s law Section Surface contour and longitudinal section Surface contour. At the same time, this method can also provide a reference model for access complex surface’s checking template.When the three-screw pumps is working, the deformation of the central rotor、idler rotor and Bush will be made by liquid pressure. If the deformation reaches a certain level, the wear between the bush and the screw will speed up; there may be screw "stuck" phenomenon. In order to solve the problem, the actual condition of the mechanical properties of the bush was studied by MSC.Nastran. Based on the above, some advice of was presented.Then the improved model was analyzed, the results show the mechanical properties of the improved bush has great improvementFinally, electrometric method was used to measure the strain of the bush’s outer surface, in order to get the measuring point’s stress distribution. By comparing the experimental results and finite element analysis results showed that the error is small, which verify the correctness of the finite element analysis results更多还原