并行多微通道气体静压止推轴承承载特性研究

发布时间：2018-01-24 16:00

本文关键词： 气体静压止推轴承并行多微通道复合节流高刚度稳定性　出处：《东北林业大学》2013年博士论文　论文类型：学位论文

【摘要】：由于气体静压轴承具有运动精度高,经久耐用,对环境没有污染等特点,所以得到了广泛应用。但随着精密、超精密技术的发展,对气体静压轴承的刚度和稳定性有着更高的要求,而气体静压轴承的刚度与稳定性是一对矛盾,目前的技术水平还难以将二者兼顾,那么在保证气体静压轴承稳定的条件下,气膜刚度最大化是研究气体静压轴承的重点和难点。本文首先对国内外气体静压技术发展水平以及轴承采用的节流技术发展状况给予分析,针对刚度低、承载力不足设计了并行多微通道气体静压止推轴承,目的是提高气体静压止推轴承的静态刚度、承载力,以及轴承稳定性,采取了理论分析、仿真计算和实验验证三位一体的研究方法对并行多微通道气体静压止推轴承稳定性和静动态特性加以研究,为气体静压止推轴承的优化设计以及在大型机床和超精密工作平台的实际应用奠定理论基础。建立了并行多微通道气体静压止推轴承的静态特性及动态特性数学模型。在静态数学模型基础上,推导了气体静压止推轴承的静特性参数,建立了节流系统的气阻数学模型,利用气阻势流等效网络分析法对并行多微通道气体静压止推轴承节流系统气阻进行分析,确定了节流系统气阻以及气膜气阻对气体静压止推轴承静特性产生的影响因素。在动态数学模型基础上,利用小参数摄动理论推导了并行多微通道气体静压止推轴承的动态刚度和动态阻尼表达式,给出了气体静压轴承气膜动刚度、动阻尼的计算方法,对气膜压力系统进行合理的线性化和方程组的简化,分析了并行多微通道气体静压止推轴承动刚度和动阻尼的变化规律和影响因素。利用FLUENT软件对并行多微通道气体静压止推轴承静特性和动特性仿真计算。静特性仿真计算可直观看到气体在并行多微通道气体静压止推轴承的节流通道中流动特点和气膜流场内的压力分布,以及作用在轴承上的压力变化趋势,并绘制了静态特性曲线,得到了气膜入口区域的流场特性和压力回升区域流场特性,当小气膜间隙时的气流速度特性,压力陡降后的压力回升的具体因素；当大气膜间隙时压力陡降后的压力回升具体因素,压力回升过程中是否有激波产生并分析其原因,仿真计算结果表明,高压区使气体静压轴承具有高负载能力,供气压力增加,载荷和气体流速增加。分析影响并行多微通道气体静压止推轴承刚度提高的因素,为开发高压气浮止推轴承奠定理论基础。研究并行多微通道气体静压止推轴承动态特性时,仿真计算了不同供气压力下轴承的干扰频率对气膜系统的动刚度和动阻尼的影响,得到了供气压力和扰动频率对气体轴承动态特性的影响,并对并行多微通道气体静压止推轴承的稳定性进行了分析。设计了并行多微通道气体静压止推轴承实验台,该实验台能够满足S型力传感器、电感测微测头、微型压力传感器和直线位移传感器同时工作,该实验台的加载机构采用了弹簧加载原理,实现了加载的连续性和稳定性,设计了并行多微通道气体静压止推轴承静态性能的实验测量方案,同时根据测量系统的要求编写了测量气膜厚度和刚度的软件,该软件实现了同步采集串口传输的电感传感器测量值和数据采集卡采集的载荷值以及实测点数值与计算的气膜刚度值,使得测量数据可储存,图像实时可视化,实现了这些数据直观的显示并且可以输出打印出来。最后通过实验得到实测值,并将静态实验、理论分析以及仿真计算进行对比分析,表明了研究中所设计的物理模型以及在此基础上所取得的研究成果的可信性。本文研究所取得的成果丰富和发展了气体润滑理论,在实际应用上,为气体静压止推轴承在设计方面拓宽了设计思路,提供了一套较为完善合理有效的方法。
[Abstract]:With the development of precision and ultra - precision technology , the rigidity and stability of the gas hydrostatic bearing are more demanding , and the rigidity and stability of the gas hydrostatic bearing are contradictory . In this paper , a parallel multi - channel gas hydrostatic thrust bearing is designed to improve the static stiffness , bearing capacity and bearing stability of the gas hydrostatic thrust bearing . The aim is to improve the static stiffness , the bearing capacity and the stability of the bearing . On the basis of the static mathematical model , the dynamic stiffness and dynamic damping expression of the gas static thrust bearing of the gas static pressure thrust bearing are deduced . The dynamic stiffness and dynamic damping expression of the gas film dynamic stiffness and dynamic damping of the gas film are deduced by using the theory of the equivalent network analysis of the gas barrier potential flow . The reasonable linearization and the simplified equations of the gas film pressure system are given . The changing law and the influencing factors of the dynamic stiffness and dynamic damping of the parallel multi - microchannel gas static thrust bearing are analyzed . In this paper , the influence of gas pressure on dynamic stiffness and dynamic damping of gas film system is analyzed by using FLUENT software to simulate the static and dynamic characteristics of multi - channel gas hydrostatic thrust bearing . The invention designs a parallel multi - micro - channel gas static pressure thrust bearing experiment table which can meet the simultaneous operation of an S - type force sensor , an inductive micro - measuring head , a micro - pressure sensor and a linear displacement sensor , the loading mechanism of the experiment table adopts a spring loading principle , realizes the continuity and stability of loading , and designs a software for measuring the static performance of the parallel multi - micro - channel gas static pressure thrust bearing . Finally , the experimental results are obtained , and the static experiment , the theoretical analysis and the simulation calculation are compared and analyzed . The results show that the physical model designed in the study and the credibility of the research results are obtained . The results obtained in this paper enrich and develop the theory of gas lubrication . In practice , the design idea of the gas static thrust bearing is widened , and a perfect and effective method is provided .

【学位授予单位】：东北林业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH133.3

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