计入深腔气穴及浮环质量的三维浮环轴承特性研究

【作者】 胡松峰；

【导师】 岑少起； 郭红；

【作者基本信息】 郑州大学 ， 机械设计， 2007， 硕士

【摘要】 动静压浮环轴承具有摩擦功耗低、精度高、寿命长、稳定性好、油膜刚度高等优点，在空分、钢铁、发电和高速旋转机械领域具有良好的应用前景。目前对动静压轴承的研究主要集中在单层油膜轴承，对于动静压浮环轴承—转子系统，特别是浮环轴承深腔中的气穴现象以及浮环质量等因素对轴承—转子系统的影响，还未进行深入研究。本文对具有深浅腔的径向—推力联合动静压浮环轴承在计入深腔气穴的情况下进行了理论分析，建立了两相流数学模型及公式，编制了计算机程序，求得了该轴承静、动态特性；并对圆锥浮环动静压轴承在计入浮环质量时研究了其稳定性，得出了一些有意义的结论，为进一步研究浮环轴承—转子系统稳定性和工程应用奠定了一定的理论依据。首先，导出了径向及推力动静压浮环轴承内、外层油膜圆柱坐标系、极坐标系下的无量纲广义Reynolds方程；在此基础上引入气油两相流物理模型，并推导出了含惯性项的变密度、变粘度的广义Reynolds方程；无量纲化后，利用八节点等参元法求解出了该种轴承内、外层油膜的压力场，并计算了该轴承得静、动态特性，讨论了不同工况下的变化规律，绘制了可作工程参考的特性曲线。其次，推导了计入浮环质量和运动状态的圆锥浮环动静压轴承—转子系统动力学方程和稳定性计算公式。在求解方程后，与不计浮环质量和其运动状态的稳定性结果进行比较，得到了一些重要结论。文中给出的数据及图表可供设计者参考。更多还原

【Abstract】 Externally pressurized multiprocessing hydrostatic/hybrid floating-ring bearings have become increasingly popular in many super high speed machines such as air separation and generator equipment due to their remarkable characteristics in respect of low friction, high accuracy, long life, smooth operation, high fluid film stiffness etc. At present many research about hydrostatic/hybrid bearing is focused on single fluid film, the floating-ring hydrostatic/hybrid bearing-rotator system especially the cavitations in the deep pockets and the floating-ring mass are not sufficiently studied.The paper includes two parts. The first part presents a theoretical study concerning the static and dynamical performance of externally pressurized multiprocessing hydrostatic/hybrid journal-thrust floating-ring bearing considering the cavitations in the deep pockets. The cylinder coordinates dimensionless generalized Reynolds equations governing the inner and outer film in the hybrid floating-ring bearing having radial and thrust structures are developed. On this basis, the physical model about the two-phase flow of bubbly oil is introduced, and derives generalized Reynolds equations of the variable density and viscosity with inertia term. The equations governing the flow of this journal-thrust floating-ring bearing together with the pressure boundary condition and the two-phase flow equation are solved by using the Finite Element Method. The static and dynamical characteristics coefficients of this bearing are obtained under different eccentricity and threshold rotational speed. The working characteristics under different condition was discussed and kinds of behavior curve were plotted.The second part studies the stability of conical floating ring hybrid bearing when the mass of floating ring is considered. The dynamical equations and stability equations of the conical floating ring hybrid bearing are derivatived and some useful conclusions are got. After these equations solved, results were compared with non-floating ring with the quality and stability of the state and gets some forms. These provided the theoretical references for the further research about the stability of the floated bearing-rotor system and its technical application.The data and charts in this paper can be referenced for designers.更多还原