【作者】 于振华；

【导师】 李志远；

【作者基本信息】 合肥工业大学 ， 机械电子工程， 2015， 博士

【摘要】 目前航天技术和新能源、新材料等高新领域需要大抽速的高真空的机械真空泵,这意味着对大抽速双级滑阀真空泵的研制迫在眉睫。然而同单级滑阀泵一样,大抽速双级滑阀泵同样面临振动大、噪声高等问题,而且泵抽速越大其振动和噪声越高,很大程度影响了泵的各项性能的稳定性以及对环境造成严重污染。因此,研究大抽速双级滑阀真空泵的振动和噪声对于提高双级滑阀泵各种性能指标、获得高真空、减小振动和噪声都具有十分重要的工程应用意义和理论研究价值。本文对2H-150型大抽速双级滑阀真空泵进行振动和噪声研究,分析中大抽速双级滑阀泵在工作过程中产生振动和噪声的原因,建立双级滑阀式真空泵机械运动系统的力学模型,精确计算滑阀泵机械运动系统的不平衡惯性力；并进行双级滑阀泵的运动系统的多刚体动力学动态激励仿真和振动响应分析；对双级滑阀泵的排气系统进行了气动声学噪声预测、噪声辐射分析等方面的研究。本文主要研究内容和完成成果如下：(1)分析引起大抽速双级滑阀泵振动和噪声的来源和产生机理：通过振动测量实验分析结果表明滑阀泵的转子运动系统是振动的主要来源,通过谐波分析指出滑阀泵运动系统是非线性振动系统,产生谐波振动。(2)基于机械系统运动学和动力学理论,建立滑阀泵机械系统运动学模型,分析了滑阀杆的运动规律,推导了滑阀杆的速度与加速度的方程,计算出滑阀杆不平衡惯性力,为后续计算双级滑阀泵动平衡提供准确数据。(3)基于最小二乘曲线拟合的方法,在分析双缸结构的空间力系双级滑阀泵的受力和力矩的基础上,提出多级平衡的概念,计算出各级平衡配重的关键参数,对双级滑阀真空泵的动平衡进行精确计算。(4)基于多体动力学理论建立双级滑阀泵转子运动系统的多刚体动力学理论模型,进行双级滑阀泵的动态激励仿真和振动响应分析。通过仿真分析各作用力对双级滑阀泵系统激励影响,得到双级滑阀泵系统的振动力和位移幅值,获得双级滑阀真空泵系统准确可靠振动响应。(5)基于声学理论和抗性消声器原理,针对滑阀真空泵排气腔结构特征建立排气腔系统的声学模型,推导出滑阀泵排气腔声学模型传递功率系数和传递损失的表达式,为滑阀泵排气系统的降噪设计提供理论依据。(6)利用计算流体力学大涡模拟和声学比拟理论方法对滑阀式真空泵变截面管道排气腔气动噪声进行数值分析及预测。对变截面管道排气空腔建立流场及声场模型,通过近场和远场数值模拟,得到双级滑阀泵的声场场点处声压值,并确定了排气腔气动噪声辐射指向性,为工程实验提供数据参考。(7)利用声压测量对双级滑阀泵的排气腔基准体进行声压和声功率级测试以及噪声源辐射指向性分析。通过对声压数据的处理与分析得出声压分布图、计算声功率级和辐射指向性分布图,分析和识别双级滑阀泵排气腔系统主要噪声频率成分。更多还原

【Abstract】 The crttent trend is that high-pumping-speed vaccum pumps are greatly needed in those fields, such as space technology,new material and new energy. It means that high-pumping-speed two-stage sliding valve vaccum pumps need to be studied at stake. However, high-pumping-speed two-stage sliding valve vaccum pumps also,like one-stage sliding valve pumps, have the problem of large vibration and high noise.The vibration and noise are higher further speed. That has a crippling effect on the stability of the performance of the pump and cause serious pollution to the environment. Therefore,it is extremely important to study vibration and noise of the high-pumping-peed two-stage sliding valve vaccum pumps.In this paper,vibration and noise of that 2H-150 high-pumping-peed two-stage sliding valve vaccum pumps is studied, The main causes of vibration and noise of sliding valve pumps are analyzed. The model of motor system of rotary piston pump is established to calculate accurately the dynamic force of piston pumps, The research of dynamic incentive simulation of multibody dynamics of motor system of rotary piston pump, dynamic response analysis, noise radiation analysis of acoustic boundary element,sound intensity testing and noise source identification of exhaust chamber of rotary piston pump are described. The main research contents in this paper are as follows:(1) The noise and vibration generating mechanisms of high-pumping-peed two-stage sliding valve vaccum pumps is analyzed. The experiments show that the motion of the rotor system is the primary source of vibration, and the motion system of sliding valve pump is a non-linear system of vibration which produces wave-vibration.(2) Based on the theory of kinematics and dynamics of mechanical system, kinematics model of mechanical system of sliding valve pumpis established, the equations of the velocity and acceleration of the slide valve rod are analyzed to calculate its inertia force for the subsequent accurate calculation of two-stage rotary piston pump.(3) Based on the least square method, space force and torque of two-cylinder pump are analyzed to obtain the key parameters of balance weight at all levels, the author puts forward the concept of multistage balance. The two-stage dynamic balance of rotary piston vacuum pump is accurately calculated.(4) Based on computational dynamics of multibody systems to establish multi-rigid-body dynamics model of the two-stage sliding valve pump, the simulation and vibration response are analyzed. Through the simulation the forces of the two-stage rotary piston pump system are analyzed to get the displacement and amplitude of vibration, which means the accurate and reliable response of vibration have been gotten.(5) Based on the acoustic theory and resistant muffler, the acoustic model of exhaust cavity structure is established. The expression of the transferring power coefficient and transmission loss of the acoustic mode 1 of are deduced, for providing the theory basis for the noise reduction of two-stage rotary piston pump.(6) The method of large eddy simulation and acoustic analogy is used to predict and calculate noise of evacuation system of two-stage rotary piston vacuum pump. The model of flow field and acoustic field on variable cross-section exhaust pipe cavity is established to get the sound pressure and determine the radiation directivity of aerodynamic noise, which providing the reference data for engineering experiment.(7) As the reference body, the evacuation of the two-stage rotary piston pump is tested through testing the sound pressure, which help to ananlysis its sound pressure and sound intensity and the radiation directivity of aerodynamic noise. By means of processing the acoustic pressure data, the noise power spectrum and the radiation directivity distribution are analyzed to analyze and identify the main noise frequency components of evacuation system of two-stage rotary piston pump.更多还原