Dynamic and tribological coupling analysis of journal bearing based on dynamic substructure
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摘要:
目的 分析主轴承的动力学与摩擦学特性以及其相互耦合关系。 方法 首先,利用子结构法建立轴承磨损试验台耦合摩擦特性的动力学模型;然后,通过该动力学模型计算得到轴承摩擦耗功和轴心轨迹并与实测结果进行比较,验证模型的正确性;最后,在该模型的基础上进行主轴承摩擦学和动力学的耦合分析。 结果 结果显示,试验台的4个支撑轴承均处于液动润滑状态,被测轴承在上止点处于混合润滑状态;随着轴承间隙的增大,轴承试验台被测轴承最小油膜厚度先增大后减小,当间隙在20 μm左右时可以得到最佳润滑状态;相比非线性弹簧的油膜模型,采用EHD模型可得到精度更高的轴承载荷和摩擦功耗。 结论 研究结果可为轴承副的润滑性能设计和高精度建模提供理论指导。 Abstract:Objectives This paper studies the dynamic and tribological characteristics of the main journal bearing, and the coupling relationship between them. Methods First, a dynamic model of the coupling tribological properties of a bearing wear test bed is established using the substructure method. The friction power consumption and orbital paths of the bearing are then calculated and compared with the measured results to verify the accuracy of the model. Finally, based on the model, the dynamic and tribological coupling analyses of the bearing are carried out. Results The results show that the four support bearings of the test bed are in a state of hydrodynamic lubrication, while the tested bearing is in a state of mixed lubrication at the top dead center. With the increase in radial clearance, the minimum oil film thickness of the tested bearing increases first and then decreases, and the most optimal lubrication state can be obtained when the tested bearing clearance is about 20 μm. Compared with the oil film model of a nonlinear spring, the elastohydrodynamic model can provide bearing load and friction power consumption results with higher accuracy. Conclusions The results of this study can provide theoretical guidance for the lubrication performance design and high-precision modeling of bearing pairs. -
Key words:
- journal bearing /
- dynamic property /
- substructure /
- tribology /
- coupling
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表 1 轴承磨损试验台主要参数
Table 1. Main parameters of bearing wear test bed
参数 数值 参数 数值 轴承宽度b/mm 29 油孔位置/(°) 45 轴颈直径/mm 52.68 油孔直径/mm 4 径向(半径)间隙c/μm 250 进油温度/℃ 55 支撑轴瓦1(半径)间隙c1/μm 50 进油压力/bar 9 支撑轴瓦2(半径)间隙c2/μm 50 轴颈表面粗糙度/μm 0.4 润滑油牌号 10W-30 轴瓦表面粗糙度/μm 0.5 表 2 主要零部件有限元模型与缩减模型
Table 2. Finite element model and condensed model of main parts
零部件 有限元模型 缩减模型 偏心轴 支撑轴承座 连杆 表 3 偏心轴有限元模型与缩减模型模态对比
Table 3. Comparison of modal frequency between finite element models and condensed model of eccentric shaft
阶数 频率/Hz 误差/% 振型 有限元模型 缩减模型 1 1 708.5 1 710.5 0.117 YZ 面内弯曲模态 2 1 718.7 1 721.7 0.175 XZ 面内弯曲模态 3 4 021.6 4 020.4 −0.030 扭转模态 4 4 332.6 4 344.5 0.275 YZ 面内弯曲模态 5 4 360.8 4 362.9 0.048 XZ 面内弯曲模态 表 4 连杆有限元模型与缩减模型模态对比
Table 4. Comparison of modal frequency between finite element model and condensed model of connecting rod
阶数 频率/Hz 误差/% 振型 有限元模型 缩减模型 1 963.5 963.23 −0.03 XZ 面内弯曲模态 2 1 213.6 1 212.4 −0.10 扭转模态 3 1 558.6 1 554.6 −0.26 YZ 面内弯曲模态 4 1 816.4 1 814.4 −0.11 小端局部模态 5 2 644.1 2 645.1 0.038 扭转模态 表 5 轴承磨损试验台主要测试参数
Table 5. Main test parameters of bearing wear test bed
传感器 信号类型 被测对象 位移传感器 位移 轴心轨迹 扭矩仪 扭矩 摩擦功耗 温度传感器 温度 瓦背温度 压力传感器 压力 供油压力 表 6 各轴承EHD润滑计算结果
Table 6. EHD calculation results of diffrent bearings of the test bed
轴承号 性能参数 pmax /MPa hmin /μm λ γ/% Wm /W 1 2.87 20.87 32.61 0 241.74 2 16.51 8.07 12.61 0 318.92 3 106.78 1.38 2.03 1.42 486.89 4 16.49 8.07 12.61 0 319.03 5 2.68 20.89 32.64 0 248.67 -
[1] 李正民, 何琳, 徐伟, 等. 轴承润滑特性对船舶推进轴系校中的影响[J]. 中国舰船研究, 2016, 11(6): 104–111. doi: 10.3969/j.issn.1673-3185.2016.06.016LI Z M, HE L, XU W, et al. The influence of bearing lubrication characteristics on marine propulsion shaft alignment[J]. Chinese Journal of Ship Research, 2016, 11(6): 104–111 (in Chinese). doi: 10.3969/j.issn.1673-3185.2016.06.016 [2] 孙谦, 刘文玺, 周其斗. 推力轴承基座结构形式对潜艇振动噪声的影响[J]. 中国舰船研究, 2018, 13(5): 39–45. doi: 10.19693/j.issn.1673-3185.01099SUN Q, LIU W X, ZHOU Q D. Influence of thrust bearing seating on acoustic radiation of submarine[J]. Chinese Journal of Ship Research, 2018, 13(5): 39–45 (in Chinese). doi: 10.19693/j.issn.1673-3185.01099 [3] WANG D E, KEITH T G, YANG Q M, et al. Lubrication analysis of a connecting-rod bearing in a high-speed engine. Part II: lubrication performance evaluation for non-circular bearings[J]. Tribology Transactions, 2004, 47(2): 290–298. doi: 10.1080/05698190490439436 [4] WANG D E, KEITH T G, YANG Q M, et al. Lubrication analysis of a connecting-rod bearing in a high-speed engine. Part I: rod and bearing deformation[J]. Tribology Transactions, 2004, 47(2): 280–289. doi: 10.1080/05698190490439346 [5] CRAIG JR R R, BAMPTON M C C. Coupling of substructures for dynamic analyses[J]. AIAA Journal, 1968, 6(7): 1313–1319. doi: 10.2514/3.4741 [6] CRAIG JR R R, CHANG C J. Free-interface methods of substructure coupling for dynamic analysis[J]. American Institute of Aeronautics and Astronautics, 1976, 14(11): 1633–1635. doi: 10.2514/3.7264 [7] 杜大华, 贺尔铭, 李锋. 基于多重动态子结构法的大型复杂结构动力分析技术[J]. 推进技术, 2018, 39(8): 1849–1855.DU D H, HE E M, LI F. Dynamics analysis technology of large-scale complex structures based on multilevel dynamic substructure method[J]. Journal of Propulsion Technology, 2018, 39(8): 1849–1855 (in Chinese). [8] 李红. 碰摩转子系统动力学特性及其故障分析研究[D]. 北京: 华北电力大学, 2016.LI H. Research on dynamic characteristics and fault analysis of rubbing rotor system[D]. Beijing: North China Electric Power University, 2016 (in Chinese). [9] GREENWOOD J A, TRIPP J H. The contact of two nominally flat rough surfaces[J]. Proceedings of the Institution of Mechanical Engineers, 1970, 185(1): 625–633. doi: 10.1243/PIME_PROC_1970_185_069_02 [10] PATIR N, CHENG H S. Application of average flow model to lubrication between rough sliding surfaces[J]. Journal of Lubrication Technology, 1979, 101(2): 220–229. doi: 10.1115/1.3453329 [11] BUKOVNIK S, DÖRR N, ČAIKA V, et al. Analysis of diverse simulation models for combustion engine journal bearings and the influence of oil condition[J]. Tribology International, 2006, 39(8): 820–826. doi: 10.1016/j.triboint.2005.07.023 [12] 卢伯聪, 向建华, 庄林毅. 基于动态子结构的主轴承热弹性流体润滑研究[J]. 润滑与密封, 2012, 37(1): 22–28. doi: 10.3969/j.issn.0254-0150.2012.01.006LU B C, XIANG J H, ZHUANG L Y. Thermo-elastohydrodynamic lubrication research on engine main bearings based on the dynamic substructure theory[J]. Lubrication Engineering, 2012, 37(1): 22–28 (in Chinese). doi: 10.3969/j.issn.0254-0150.2012.01.006 [13] ALLMAIER H, PRIESTNER C, REICH F M, et al. Predicting friction reliably and accurately in journal bearings–the importance of extensive oil-models[J]. Tribology International, 2012, 48: 93–101. doi: 10.1016/j.triboint.2011.11.009 -