螺杆型干式真空泵转子

干式真空泵也称无油真空泵，是为了满足工业生产对真空环境越来越严格的要求而发展起来的新型的真空获得设备。螺杆型干式真空泵以其优良的抽气性能得到迅速发展。由于国内螺杆干泵的研究起步较晚，目前还没有规模化的产品，同类产品全部依靠进口，价格十分昂贵。干式真空泵中最重要的部件就是阴、阳螺杆转子，转子型线及其热力学性能决定了泵的抽气性能。转子型线决定了泵的抽速和工作压力范围，而型线和转子热力学性能综合作用决定了泵的极限真空和工作介质。此外，进行泵的结构设计和产品开发，转子特性也是必须要首先解决的瓶颈问题。 本文正是以螺杆型干式真空泵转子为研究对象，通过对其型线、变形、运行状态监测和故障诊断的研究，深入了解转子的特性，为优化泵的结构设计、提高泵的整体性能，早日实现国产化做出贡献。 对几种典型的螺杆转子型线进行理论与实验研究，包括多齿型线和单齿型线，其中单齿型线又分为变螺距和等螺距。通过对各型线齿面方程、型线几何参数、齿面干涉问题的逐一讨论，得出面积利用系数、几何抽速等型线要素。在此基础上，对面积利用系数和几何抽速计算公式中的重要变量进行比较分析，并且考虑了加工、制造的可行性，得出最优的变量范围。 对单齿等螺距凹齿面转子型线进行了实验研究，通过斜齿面导程角测量和计算值的比较，几何抽速和实际抽速的对比，验证了推导理论和方法的正确性。 对单齿等螺距凹齿面型线转子的变形进行了有限元计算，以此为依据确定阴、阳转子之间，转子与泵腔内壁之间各间隙的大小。有限元计算采用与实验所用转子尺寸一致的三维几何模型，综合考虑热膨胀、气体压力、旋转惯性力对转子变形的影响，借助于商业有限元计算软件ANSYS进行力-热耦合的变形分析。 对转子不同位置的表面温度和各密封间隙进行了测量，实验对象为Busch生产的AC0400F型泵的转子。实验结果验证了有限元计算方法的可行性和结果的合理性。 转子运行状态的监测诊断包括：温度、压力及流量、N2冷却和清洗系统、振动。对监测方法和常见故障进行了讨论，指出振动是最主要的监测诊断方法。结合2个工程实例，利用振动分析所得的时域波形和频谱图，结合温度监测，对常见的运行故障进行诊断。在诊断结果的基础上，采取相应的解决故障的方法。
电加热器
To satisfy the more and more strict requirement of clear vacuum environment of industry, a new type of vacuum acquiring equipment named dry (oil-free) pump was developed. Especially dry vacuum screw pump has a wide application because of its good pumping performance. There is no internal scale product of dry screw pump owing to the late research starting, so like products are all depend on importing and the price is very expensive. The driving and driven screw rotors are the most important components. The rotor profile and thermodynamic performance determine the pumping performance of pump. The rotor profile determines the pumping speed and working pressure range of pump. The rotor profile and thermodynamic performance determine the ultimate pressure and the working medium of pump. Furthermore, the rotor characters are the first key problem to be studied when you want to design the structure and develop the product.In this paper, Taking screw pump rotors as subject investigated, the rotor characters were discussed deeply including its profile, deforming, running monitoring and fault diagnosis. We hope to do some contribution in order to optimize the pump structure, increase the pump performance and realize the goal that we will make our own pump.Several typical screw rotor profiles were studied by theory investigation and experiment, which were the multithread and single thread profiles. The single thread profile includes variable thread pitch and fixed pitch. The calculation formulas of coefficient of used area and the geometric pumping speed were deduced by the equation of tooth flank and the study of flank interference. Then, the variables of calculation formulas of coefficient of used area and the geometric pumping were analyzed comparably and Taking into account the feasibility of machining and manufacture, the optimal variable range was got.The experiment of single thread and fixed pitch concave tooth flank rotor profile was done and it proofed that the deduction theory and method of rotor profile was valid by the comparison between measuring and calculation value of pitch angle of inclined tooth flank and geometric pumping speed and real pumping speed.