Loading capacity of multi-layer foil gas thrust bearing
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摘要:
为揭示叠层式箔片结构对动压气体推力轴承承载性能的强化机制,建立了该结构静力学有限元仿真模型及弹流润滑分析方法,研究了叠层式箔片结构刚度随载荷的变化及楔形气膜间隙特征参数的演化规律。结果表明:随着载荷升高,叠层式结构刚度增幅呈先小后大的非线性特征,且周向局部刚度大小交替变化。这导致轴承楔形气膜间隙特征参数随承载力增大而明显变化,承载力从15 N增大到75 N,楔形高度可从45 μm降低至16.8 μm,节距比则先增大后减小。与承载力相同条件下的波箔型轴承相比,叠层式箔片动压气体推力轴承气膜压力分布会出现承载力强化的双峰值,且最小气膜厚度可增大35%至50%,可有效降低转静子间的碰磨概率。
Abstract:In order to reveal the mechanism of strengthening the loading performance of multi-layer gas foil thrust bearing, the finite element method considering elastohydrodynamic lubrication in multi-layer gas foil thrust bearing was established. The variation of stiffness with different loads and the evolution of wedge-shaped film’s characteristic parameters were studied. Results showed that the stiffness of the multi-layer foil presented a nonlinear trend of increment with the increase of load capacity, also the variation amplitude of stiffness of the laminated foil kept in a low level at small load capacity, then it became large as the increase of the load capacity, and the stiffness of the circumferential direction changed alternately. It resulted in variation of the characteristic parameters of wedge-shaped clearance with the increase of the capacity. The wedge height attenuated from 45 μm to 16.8 μm and the pitch ratio first increased and then decreased correspondingly when the bearing capacity varied from 15 N to 75 N. Based on the characteristic change of wedge-shape clearance under different loads, the gas film pressure distribution induced a double peak, which enhanced load compared with the wave foil bearing under the same bearing capacity, and the minimum gas film thickness can be increased about 35% to 50%, which significantly reduced the collision and wear probability between rotor and stator.
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表 1 叠层式箔片动压气体推力轴承几何参数
Table 1. Geometric parameters of multi-layer foil gas thrust bearing
参数 数值 轴承箔片公称内径R1/mm 12 轴承顶箔公称外径R2/mm 21.5 顶箔厚度ht/mm 0.1 背板厚度hb/mm 0.12 中箔厚度hm/mm 0.3 中箔凸台高度hs/mm 0.2 底箔厚度hg/mm 0.2 轴承扇形箔片个数 n 8 顶箔张角β/(°) 45 -
[1] BENSOUILAH H,LAHMAR M. Elasto-aerodynamic lubrication analysis of a self-acting air foil journal bearing[J]. Lubrication Science,2012,24(3): 95-128. doi: 10.1002/ls.171 [2] DELLACORTE C. Oil-free shaft support system rotordynamics: past, present and future challenges and opportunities[J]. Mechanical Systems and Signal Processing,2012,29: 67-76. doi: 10.1016/j.ymssp.2011.07.024 [3] 张镜洋,赵晓荣,常海萍,等. 边界滑移对波箔型动压气体轴承静特性的影响[J]. 推进技术,2018,39(2): 388-395. doi: 10.13675/j.cnki.tjjs.2018.02.018ZHANG Jingyang,ZHAO Xiaorong,CHANG Haiping,et al. Effects of sliding boundary on static characteristics of aerodynamic compliant foil bearing[J]. Journal of Propulsion Technology,2018,39(2): 388-395. (in Chinese) doi: 10.13675/j.cnki.tjjs.2018.02.018 [4] ANDRES L,KIM T H. Analysis of gas foil bearings integrating FE top foil models[J]. Tribology International,2009,42(1): 111-120. doi: 10.1016/j.triboint.2008.05.003 [5] LEHN A,MAHNER M,SCHWEIZER B. Elasto-gasdynamic modeling of air foil thrust bearings with a two dimensional shell model for top and bump foil[J]. Tribology International,2016,100: 48-59. doi: 10.1016/j.triboint.2015.11.011 [6] IORDANOFF I. Analysis of an aerodynamic compliant foil thrust bearing: method for a rapid design[J]. Journal of Tribology,1999,121(4): 816-822. doi: 10.1115/1.2834140 [7] DYKAS B. Factors influencing the performance offoil gas thrust bearings for oil-free turbomachinery applications[D]. Cleveland, US: Case Western Reserve University, 2006. [8] 侯安平,林蓬成,王锐,等. 气体动压推力轴承性能及实验[J]. 航空动力学报,2018,33(6): 1510-1518.HOU Anping,LIN Pengcheng,WANG Rui,et al. Performance of air-dynamic lubrication thrust bearing and experiment[J]. Journal of Aerospace power,2018,33(6): 1510-1518. (in Chinese) [9] 徐方程,张广辉,孙毅,等. 平箔片楔形高度对气体推力箔片轴承特性影响[J]. 航空动力学报,2016,31(12): 3064-3072.XU Fangcheng,ZHANG Guanghui,SUN Yi,et al. Effect of flat foil wedge height on characteristics of gas thrust foil bearing[J]. Journal of Aerospace Power,2016,31(12): 3064-3072. (in Chinese) [10] 徐方程,侯留凯,吴斌,等. 楔形入口高度对气体推力箔片轴承性能仿真和试验研究[J]. 机械工程学报,2021,57(9): 51-60. doi: 10.3901/JME.2021.09.051XU Fangcheng,HOU Liukai,WU Bin,et al. Performance analysis of air foil thrust bearings with different top foil taper heights[J]. Journal of Mechanical Engineering,2021,57(9): 51-60. (in Chinese) doi: 10.3901/JME.2021.09.051 [11] LEHN A,MAHNER M,SCHWEIZER B. Characterization of static air foil thrust bearing performance: an elasto-gasdynamic analysis for aligned, distorted and misaligned operating conditions[J]. Archive of Applied Mechanics,2018,88(5): 705-728. doi: 10.1007/s00419-017-1337-7 [12] 胡小强,吕鹏,冯凯,等. 叠片式箔片气体动压推力轴承的静动态特性[J]. 航空动力学报,2018,33(1): 3022-3031. doi: 10.13224/j.cnki.jasp.2018.12.024HU Xiaoqiang,LÜ Peng,FENG Kai,et al. Static and dynamic characteristics of laminated gas foil thrust bearing[J]. Journal of Aerospace Power,2018,33(1): 3022-3031. (in Chinese) doi: 10.13224/j.cnki.jasp.2018.12.024 [13] 卢攀,周权,陈汝刚. 鼓泡型箔片动压止推轴承结构变形的数值研究[J]. 润滑与密封,2017,42(7): 91-96. doi: 10.3969/j.issn.0254-0150.2017.01.015LU Pan,ZHOU Quan,CHEN Rugang,et al. Numerical study of structural deformation of foil hydrodynamicthrust gas bearing with hemispherical convex dots[J]. Lubrication Engineering,2017,42(7): 91-96. (in Chinese) doi: 10.3969/j.issn.0254-0150.2017.01.015 [14] LAI T, GUO Y, WANG W, et al. Experimental study on multi-decked protuberant foil thrust bearing with different number of thrust pads[J]. Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2016, 10(9): 0106.1- 0106.9. [15] GAD A M,KANEKO S. A new structural stiffness model for bump-type foil bearings: application to generation Ⅱ gas lubricated foil thrust bearing[J]. Journal of Tribology,2014,136(4): 216-223. [16] HU H,FENG M,REN T. Study on the performance of gas foil thrust bearings with stacked bump foils[J]. Industrial Lubrication and Tribology,2020,72(6): 761-769. doi: 10.1108/ILT-10-2019-0449 [17] LI C,DU J,YAO Y. Modeling of a multi-layer foil gas thrust bearing and its load carrying mechanism study[J]. Tribology International,2017,114: 172-185. [18] ZHENG Y Q,LAI T W,CHENG S T,et al. Static characteristics of six pads multilayer protuberant foil thrust bearings[J]. Journal of Engineering Tribology,2017,231(2): 158-164. [19] 卢攀,周权,赖天伟,等. 推力轴承中多层鼓泡箔片支承结构弹性变形的数值研究[J]. 润滑与密封,2018,43(7): 67-71. doi: 10.3969/j.issn.0254-0150.2018.07.012LU Pan,ZHOU Quan,LAI Tianwei,et al. Numerical study on elastic deformation of multilayer Protuberant foil support structure in thrust bearings[J]. Lubrication Engineering,2018,43(7): 67-71. (in Chinese) doi: 10.3969/j.issn.0254-0150.2018.07.012 [20] ZHANG C B, AO H R, LIANG H R. Static and dynamic bearing performances of hybrid gas dynamic bearings[J]. Tribology International, 2021,160: 107036.1-107036.14. [21] 刘欢. 基于接触力学的箔片气体动压推力轴承承载特性的研究[D]: 哈尔滨: 哈尔滨工业大学, 2017.LIU Huan. Research on loading carrying characteristics of foil gas thrust bearing based on contact mechanics[D]. Harbin: Harbin Institute of Technology, 2017. (in Chinese) [22] KIM D,LATRAY N. Design of novel gas foil thrust bearings and test validation in a high-speed test rig[J]. Journal of Tribology,2020,142(7): 071803.1-071803.10. [23] KIM T H,PARK M,LEE T W. Design optimization of gas foil thrust bearings for maximum load capacity[J]. Journal of Tribology,2017,139(3): 031705.1-031705.11. [24] LEE Y B,KIM T Y,KIM C H,et al. Thrust bump air foil bearings with variable axial load: theoretical predictions and experiments[J]. Tribology Transactions,2011,54(6): 902-910. doi: 10.1080/10402004.2011.606957 [25] 罗轶欣. 箔片型动压气体推力轴承静特性及气动热研究[D]. 南京: 南京航空航天大学, 2018.LUO Yixin. Research on static characteristics and aerothermal of foil gas thrust bearings [D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2018. (in Chinese)