变螺距螺杆真空泵抽气机理研究及转子结构优化

发布时间：2018-03-15 22:09

本文选题：螺杆真空泵　切入点：抽气机理　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：论文主要以变螺距螺杆真空泵为研究对象,建立了变螺距螺杆真空泵气体输运模型,分析研究了变螺距螺杆真空泵的抽气过程,探究了变螺距螺杆真空泵多种性能参数的变化规律,优化设计了变螺距转子结构,有效地降低了压缩功耗。全文主要研究内容及相关成果如下:(1)分析总结了常见的变螺距转子结构,基于光滑连接条件,运用多项式拟合构建了变螺距转子螺旋展开线的多项式方程,建立了变螺距转子结构的数学模型,为变螺距转子的结构设计提供了理论依据。(2)根据渐开线型转子螺杆真空泵构成特点对泵腔内不同级间泄漏通道进行了合理简化,建立了不同泄漏通道在不同流态下的流量计算模型。在忽略泵腔内温度变化的前提条件下,考虑了整个抽气过程中通过级间泄漏通道气体流动状态的改变,并根据质量守恒定律和理想气体状态方程建立了变螺距螺杆真空泵气体输运模型,为变螺距螺杆真空泵设计阶段的性能预测提供理论依据。(3)分析研究了变螺距螺杆真空泵多种性能参数的变化规律,研究结果表明:在排气端减小转子齿顶与泵腔内壁间间隙,而在吸气端减小转子齿间间隙,有利于提升泵的抽气性能。分析比较了等螺距螺杆真空泵与变螺距螺杆真空泵抽气性能上的差异,研究结果表明,等螺距螺杆真空泵在极限压强上具有优势,而变螺距螺杆真空泵在功率消耗方面具有较大优势。(4)比对分析了四种不同转子结构变螺距螺杆真空泵的抽气性能,优化了变螺距转子结构,有效地降低了压缩功耗,提升了变螺距螺杆真空泵抽气性能。
[Abstract]:Taking the variable pitch screw vacuum pump as the research object, the gas transport model of the variable pitch screw vacuum pump is established, and the extraction process of the variable pitch screw vacuum pump is analyzed. The variation law of various performance parameters of variable pitch screw vacuum pump is studied, and the structure of variable pitch rotor is optimized. The main research contents and related results are as follows: 1) the common variable pitch rotor structure is analyzed and summarized based on smooth connection condition. The polynomial equation of spiral expansion line of variable pitch rotor is constructed by polynomial fitting, and the mathematical model of variable pitch rotor structure is established. This paper provides a theoretical basis for the structural design of variable pitch rotor. According to the structural characteristics of involute rotor screw vacuum pump, the leakage passage between different stages in the pump cavity is reasonably simplified. The flow calculation model of different leakage channels under different flow states is established. The change of gas flow state through the inter-stage leakage channel is considered in the whole process of pumping under the precondition of ignoring the temperature change in the pump cavity. According to the law of mass conservation and the equation of state of ideal gas, the gas transport model of variable pitch screw vacuum pump is established. This paper provides a theoretical basis for predicting the performance of the variable pitch screw vacuum pump in the design stage. The variation law of various performance parameters of the variable pitch screw vacuum pump is analyzed and studied. The results show that the gap between the rotor tooth top and the inner wall of the pump cavity is reduced at the exhaust end. Reducing the clearance between the rotor teeth at the suction end is beneficial to the pumping performance of the pump. The difference of the pumping performance between the constant pitch screw vacuum pump and the variable pitch screw vacuum pump is analyzed and compared. The equal pitch screw vacuum pump has the advantage in limiting pressure, while the variable pitch screw vacuum pump has a great advantage in power consumption. The variable pitch rotor structure is optimized, the compression power consumption is reduced effectively, and the pumping performance of the variable pitch screw vacuum pump is improved.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB752

【参考文献】