Numerical investigation of gas journal foil bearing performance with thick top foil
-
摘要: 提出了一种具有厚顶箔特征的箔片动压轴承(TTF-GJFB),并对其进行了建模及分析。针对这种型轴承,采用Newton-Raphson迭代法求解静态气膜雷诺润滑方程和箔片受力方程;采用折合系数法和小扰动法,推导了厚顶箔轴承的动态刚度系数与动态阻尼系数。以此为基础,对厚顶箔轴承和传统箔片轴承进行了对比,并对初始轴承间隙、波箔宽度、顶箔质量对厚顶箔轴承动静态特性的影响进行了研究。结果表明:厚顶箔轴承比传统箔片轴承拥有较大的承载力及偏位角,承载力增幅至少为23%;厚顶箔轴承的动态特性与传统箔片轴承有较大差异;厚顶箔轴承的初始间隙会影响偏位角和承载力,小初始间隙在所有偏心率范围内可以提高承载力和减小偏位角;波箔宽度对轴承静态特性的影响较小,但对动态特性的影响较大,在中低激振比范围内,动态系数基本随着箔片宽度的变窄而变小;厚顶箔的质量会在高激振比下对轴承的动态特性产生影响,使得动态刚度系数上升,动态阻尼系数下降。Abstract: A type of gas journal foil bearing with thick top foil (TTF-GJFB) was presented, and its modeling and analysis were carried out. The Newton-Raphson iterative method was used to solve the Reynolds equation and the force equilibrium equation to predict this novel bearing static performance. The dynamic stiffness and damping coefficients of this bearing were derived and solved by using reduced coefficient method and small perturbation method. Based on those methods, the comparative study of TTF-GJFB and traditional foil bearing was carried out, and the effects of bearing initial clearance, bump foil width and top foil mass on the bearing performance of novel foil bearing were studied. Results showed that TTF-GJFB had higher bearing load capacity and deflection angle than traditional foil bearing. The capacity increase was at least 23%. The dynamic characteristics of TTF-GJFB differed from those of traditional foil bearing. The initial clearance of TTF-GJFB affected the attitude angle and bearing load capacity. The width of the bump foil had great effect on the dynamic characteristics. Within the range of medium and low excitation ratio, the dynamic coefficients decreased with the declining width of the bump foil. The mass of top foil of TTF-GJFB affected the dynamic characteristics of bearing at high excitation ratio, dynamic stiffness coefficient increased and dynamic damping coefficient decreased.
-
[1] CHRISTOPHER D.Oil-free shaft support system rotordynamics:past,present and future challenges and opportunities[J].Mechanical Systems and Signal Processing,2012,29(4):67-76. [2] 气体润滑理论与气体轴承设计[M].北京:机械工业出版社,1999:464. [3] 王元勋,陈尔昌,师汉民.气体润滑轴承的研究与发展[J].湖北工学院学报,1994,9(3):155-159. WANG Yuanxun,CHEN Erchang,SHI Hanmin.Research and development of gas-lubricated bearing[J].Journal of Hubei Polytechnic University,1994,9(3):155-159.(in Chinese) [4] JONES A M.Adjustable tension foil bearing:US4815864A[P].1989-03-28. [5] LICHT L.Resilient foil journal bearing:US4133585A[P].1979-01-09. [6] OH K P,ROHDE S M.A theoretical investigation of the multileaf journal bearing[J].Journal of Applied Mechanics,1976,43(2):237-242. [7] BARNETT M A,SILVER A.Application of air bearings to high-speed turbomachinery[R].Edinburgh,UK:European Conference on Integrated Optics and Optical Fiber Communications,1970. [8] WALOWIT J A,ANNO J N,HAMROCK B J.Modern developments in lubrication mechanic[J].Tribology International,1977,9(2):90. [9] HESHMAT H,WALOWIT J A,PINKUS O.Analysis of gas-lubricated foil journal bearings[J].Journal of Lubrication Technology,1983,105(4):647-655. [10] IORDANOFF I.Analysis of an aerodynamic compliant foil thrust bearing:method for a rapid design[J].Journal of Tribology,1999,121(4):816-822. [11] LEZ S L,ARGHIR M,FRENE J.A new bump-type foil bearing structure analytical model[J].Journal of Engineering for Gas Turbines and Power,2007,129(4):1047-1057. [12] LUND J W,ORCUTT F K.Calculations and experiments on the unbalance response of a flexible rotor[J].Journal of Engineering for Industry,1967,89(4):785-796. [13] PENG J P,CARPINO M.Calculation of stiffness and damping coefficients for elastically supported gas foil bearings[J].Journal of Tribology,1993,115(1):20-27. [14] 龚焕孙,张鸿兴.径向波箔轴承的设计计算和试验研究:Ⅰ理论分析[J].上海机械学院学报,1991,13(4):1-17. GONG Huansun,ZHANG Hongxing.The formulars for design and test of bump foil journal bearings:Ⅰtheoretical Analysis[J].Journal of University of Shanghai for Science and Technology,1991,13(4):1-17.(in Chinese) [15] 戚社苗,耿海鹏,郭海刚.弹性箔片动压气体推力轴承承载性能研究[J].润滑与密封,2006(5):6-9. QI Shemiao,GENG Haipeng,GUO Haigang.Theoretical research on the load performance of aerodynamic compliant foil thrust bearings[J].Lubrication Engineering,2006(5):6-9.(in Chinese) [16] LEE Y B,PARK D J,KIM C H,et al.Operating characteristics of the bump foil journal bearings with top foil bending phenomenon and correlation among bump foils[J].Tribology International,2008,41(4):221-233. [17] LEE D H,KIM Y C,KIM K W.The static performance analysis of foil journal bearings considering three-dimensional shape of the foil structure[J].Journal of Tribology,2008,130(3):538-544. [18] 虞烈,戚社苗,耿海鹏.可压缩气体润滑与弹性箔片气体轴承技术[M].北京:科学出版社,2011. [19] 刘万辉.柔性动压气体轴承及其转子系统的理论和实 验研究[D].长沙:湖南大学,2018. LIU Wanhui.Theoretical and experimental study on flexure hydrodynamic gas bearing-rotor system[D].Changsha:Hunan University,2018.(in Chinese) [20] ZYWICA G,BAGIN'SKI P,BREN'KACZ ,et al.Dynamic state assessment of the high-speed rotor based on a structural-flow model of a foil bearing[J].Diagnostyka,2017,18(1):95-102.
点击查看大图
计量
- 文章访问数: 232
- HTML浏览量: 2
- PDF量: 381
- 被引次数: 0