箔片安装位置对气体轴承性能影响的仿真分析
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摘要
为研究弹性箔片气体轴承中箔片安装位置对轴承静、动态性能的影响,对具有不同箔片安装位置角的弹性箔片气体轴承进行了静、动态性能的计算。采用有限差分法耦合气体轴承压力控制方程及箔片柔度方程,获得了气膜压力、厚度分布及轴承承载力;基于小扰动法,计算了轴承的动力学系数。结果表明:弹性箔片气体轴承安装箔片时存在一个"敏感"位置区间,会对轴承静、动态性能构成显著影响;在这一区间内,气膜平均气压及承载力显著下降,主刚度系数下降,交叉刚度系数会在数值上接近主刚度系数,严重影响轴承稳定性,阻尼系数变化相对较小;这一"敏感"位置区间在数值上与轴承偏位角形成近似互补关系;在进行弹性箔片气体轴承实际安装操作时,可以先进行360°整周箔片轴承的偏位角计算,将安装狭槽布置在偏位角的对侧,即远离主要承载区位置。
To analyze the influence of installation position on static and dynamic performances of foil gas bearing, the performances of foil bearing with different foil mounting angles are evaluated. The coupled pressure equation and foil deflection equation are solved with finite difference method, the pressure distribution, film thickness distribution and load capacity of bearing are obtained, and the dynamic characteristics are revealed by perturbation method. The results indicate that there exists a sensitive area affecting the static and dynamic performances of foil bearing significantly, where direct stiffness coefficients are reduced and the cross-stiffness coefficients nearly approach the direct stiffness coefficients numerically, which affects bearing stability dramatically. The variation of damping coefficients is relatively small. The sensitive position interval is approximately complementary to the bearing attitude angle numerically. For actual installation operation of foil gas bearings, it is suggested that the attitude angle of 360° full-circumferential foil bearings be calculated firstly, then the installation slot is arranged on the opposite side of the attitude angle, far away from the loading area.
To analyze the influence of installation position on static and dynamic performances of foil gas bearing, the performances of foil bearing with different foil mounting angles are evaluated. The coupled pressure equation and foil deflection equation are solved with finite difference method, the pressure distribution, film thickness distribution and load capacity of bearing are obtained, and the dynamic characteristics are revealed by perturbation method. The results indicate that there exists a sensitive area affecting the static and dynamic performances of foil bearing significantly, where direct stiffness coefficients are reduced and the cross-stiffness coefficients nearly approach the direct stiffness coefficients numerically, which affects bearing stability dramatically. The variation of damping coefficients is relatively small. The sensitive position interval is approximately complementary to the bearing attitude angle numerically. For actual installation operation of foil gas bearings, it is suggested that the attitude angle of 360° full-circumferential foil bearings be calculated firstly, then the installation slot is arranged on the opposite side of the attitude angle, far away from the loading area.
引文
[1] 王元勋, 陈尔昌, 师汉民, 等. 气体润滑轴承的研究与发展 [J]. 湖北工业大学学报, 1994, 9(3): 155-159. WANG Yuanxun, CHEN Erchang, SHI, Hanmin, et al. Research and development of gas lubricated bearings [J]. Journal of Hubei University of Technology, 1994, 9(3): 155-159.
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[9] 王伟, 李晓疆, 曾强, 等. 高速透平机械全金属鼓泡箔片动压气体轴承稳定性研究 [J]. 西安交通大学学报, 2017, 51(8): 84-89. WANG Wei, LI Xiaojiang, ZENG Qiang, et al. Stability analysis for fully hydrodynamic gas-lubricated protuberant foil bearings in high speed turbomachinery [J]. Journal of Xi’an Jiaotong University, 2017, 51(8): 84-89.
[10] FENG K, LIU W, YU R, et al. Analysis and experimental study on a novel gas foil bearing with nested compression springs [J]. Tribology International, 2017, 107: 65-76.
[11] FENG K, ZHAO X, HUO C, et al. Analysis of novel hybrid bump-metal mesh foil bearings [J]. Tribology International, 2016, 103: 529-539.
[12] 杨琴, 刘宇陆, 张海军, 等. 气体稀薄效应对微机电系统(MEMS)气体轴承-转子系统不平衡响应的影响 [J]. 西安交通大学学报, 2015, 49(7): 134-139. YANG Qin, LIU Yulu, ZHANG Haijun, et al. Influence of gas rarefaction effect on unbalance response of micro-electro-mechanical (MEMS) gas bearing-rotor system [J]. Journal of Xi’an Jiaotong University, 2015, 49(7): 134-139.
[13] 王法义. 空气箔片轴承设计、制造及其静态和动态特性实验研究 [D]. 长沙: 湖南大学, 2014: 19-20.
[14] PATIL M B, KALITA K, KAKOTY S K. Performance analysis of gas foil bearing with different foil pivot configuration [J]. Advances in Mechanical Engineering, 2013, 5: 843419.
[15] ROYLANCE B J. Introduction to tribology of bearings [J]. Tribology International, 1987, 20(2): 107-107.
[16] HESHMAT H. Analysis of gas-lubricated foil journal bearings [J]. Journal of Lubrication Technology, 1983, 105(4): 647-655.
[17] PENG J P. Calculation of stiffness and damping coefficients for elastically supported gas foil bearings [J]. ASME Journal of Tribology, 1993, 115(1): 20-27.
[2] AGRAWAL G L. Foil air/gas bearing technology: an overview [C]//ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. New York, NY, USA: American Society of Mechanical Engineers, 1997: 1-6.
[3] BLOCK H. The foil bearings: a new departure in hydrodynamic lubrication [J]. Lubrication Engineering, 1953, 9(6): 316-320.
[4] 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.
[5] FENG K, ZHAO X, GUO Z. Design and structural performance measurements of a novel multi-cantilever foil bearing [J]. Proceedings of the Institution of Mechanical Engineers: Part C Journal of Mechanical Engineering Science, 2015, 229(10): 1830-1838.
[6] GRAY S, BHUSHAN B. Support element for compliant hydrodynamic journal bearings: 4274683 [P]. 1981-06-23.
[7] 赖天伟, 马斌, 郑越青, 等. 多层弹性支承箔片动压气体径向轴承稳定性的实验研究 [J]. 西安交通大学学报, 2014, 48(3): 79-83. LAI Tianwei, MA Bin, ZHENG Yueqing, et al. Experimental investigation on stability of multi-decked protuberant foil gas journal bearing [J]. Journal of Xi’an Jiaotong University, 2014, 48(3): 79-83.
[8] 马斌, 孙皖, 赖天伟, 等. 波箔箔片动压气体轴承的实验研究 [J]. 西安交通大学学报, 2014, 48(1): 118-122. MA Bin, SUN Wan, LAI Tianwei, et al. Experimental study on gas lubricated hydrodynamic bump type foil bearing [J]. Journal of Xi’an Jiaotong University, 2014, 48(1): 118-122.
[9] 王伟, 李晓疆, 曾强, 等. 高速透平机械全金属鼓泡箔片动压气体轴承稳定性研究 [J]. 西安交通大学学报, 2017, 51(8): 84-89. WANG Wei, LI Xiaojiang, ZENG Qiang, et al. Stability analysis for fully hydrodynamic gas-lubricated protuberant foil bearings in high speed turbomachinery [J]. Journal of Xi’an Jiaotong University, 2017, 51(8): 84-89.
[10] FENG K, LIU W, YU R, et al. Analysis and experimental study on a novel gas foil bearing with nested compression springs [J]. Tribology International, 2017, 107: 65-76.
[11] FENG K, ZHAO X, HUO C, et al. Analysis of novel hybrid bump-metal mesh foil bearings [J]. Tribology International, 2016, 103: 529-539.
[12] 杨琴, 刘宇陆, 张海军, 等. 气体稀薄效应对微机电系统(MEMS)气体轴承-转子系统不平衡响应的影响 [J]. 西安交通大学学报, 2015, 49(7): 134-139. YANG Qin, LIU Yulu, ZHANG Haijun, et al. Influence of gas rarefaction effect on unbalance response of micro-electro-mechanical (MEMS) gas bearing-rotor system [J]. Journal of Xi’an Jiaotong University, 2015, 49(7): 134-139.
[13] 王法义. 空气箔片轴承设计、制造及其静态和动态特性实验研究 [D]. 长沙: 湖南大学, 2014: 19-20.
[14] PATIL M B, KALITA K, KAKOTY S K. Performance analysis of gas foil bearing with different foil pivot configuration [J]. Advances in Mechanical Engineering, 2013, 5: 843419.
[15] ROYLANCE B J. Introduction to tribology of bearings [J]. Tribology International, 1987, 20(2): 107-107.
[16] HESHMAT H. Analysis of gas-lubricated foil journal bearings [J]. Journal of Lubrication Technology, 1983, 105(4): 647-655.
[17] PENG J P. Calculation of stiffness and damping coefficients for elastically supported gas foil bearings [J]. ASME Journal of Tribology, 1993, 115(1): 20-27.