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摘要: 在内燃机曲轴系统的径向滑动轴承表面设计了球形凹坑织构, 以改善润滑性能; 为了获得最大的轴承承载力和最小的摩擦因数, 提出了基于序列二次规划算法和遗传算法的混合进化优化方法, 构建了径向滑动轴承球形凹坑织构的优化模型, 对凹坑织构的分布位置和结构参数进行了全局寻优, 得到了给定工况下最优的织构角度和最大深度; 为了求解径向滑动轴承的承载力和摩擦因数, 考虑曲轴和轴承表面粗糙度对油膜流动的影响, 采用质量守恒的JFO空穴算法处理油膜的破裂和再形成行为, 基于平均Reynolds方程和Greenwood-Tripp微凸体接触方程构建了球形凹坑织构径向滑动轴承的混合润滑模型, 分析了球形凹坑织构的分布位置和结构参数(数量、面积率和最大深度) 对径向滑动轴承承载力和摩擦因数的影响。分析结果表明: 径向滑动轴承的承载力和摩擦因数是凹坑面积率的单调函数; 存在最优的凹坑织构角度和最大深度使得径向滑动轴承的承载力最大与摩擦因数最小; 当偏心率由0.3增加到0.7时, 轴承承载力的提升量由13.38%下降到0.62%, 摩擦因数的降低量由0.73%逐渐下降至负数, 因此, 当偏心率较小时, 球形凹坑织构能够有效降低径向滑动轴承的摩擦因数, 增大承载力, 当偏心率较大时, 球形凹坑织构无益于轴承摩擦因数的降低。Abstract: The spherical dimple texture was designed on the surface of journal bearing to improve the lubrication performance of crankshaft system in diesel engine. In order to maximize the loadcarrying capacity and minimize the friction factor of the bearing, a hybrid evolutionary optimization method based on the sequential quadratic programming and the genetic algorithm was proposed, and an optimization model was developed for the journal bearing with spherical dimple texture. The distribution location and geometry parameters of dimple texture wereglobally optimized to obtain the optimal angle and maximum depth of texture under given working condition. In order to solve the load-carrying capacity and friction factor of journal bearing, the influence of surface roughness on oil flow was considered, a mass-conservation JFO (Jakobsson, Floberg, Olsson) cavitation algorithm was used to address the rupture and reformulation of oil film, and a mixed lubrication model was developed based on average Reynolds equation and Greenwood-Tripp asperity contact equation. The influence of spherical dimple textures with various distribution locations and geometry parameters (number, area density, and maximum depth) on the load-carrying capacity and friction factor of journal bearing was investigated. Analysis result shows that the load-carrying capacity and friction factor are the monotonic functions of dimple area density. There exists optimal angle and maximum depth of dimple that can maximize the load-carrying capacity and minimize the friction factor. When the eccentricity rises from 0.3 to 0.7, the increment of load-carrying capacity changes from 13.38% to 0.62%, and the decrement of friction factor changes from 0.73% to negative value. Therefore, when the eccentricity is smaller, the spherical dimple texture can increase the load-carrying capacity and decrease the friction factor effectively, and when the eccentricity is larger, the spherical dimple texture is unbeneficial to decrease the friction factor of the bearing.
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表 1 承载力最大时的凹坑织构角度和最大深度
Table 1. Texture angles and maximum depths of dimple when load-carrying capacity is maximum
表 2 摩擦因数最小时的凹坑织构角度和最大深度
Table 2. Texture angles and maximum depths of dimple when friction factor is minimum
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[1] LIU Jun, MOCHIMARU Y. The effects of trapezoidal groove on a self-acting fluid-lubricated herringbone grooves journal bearing[J]. ISRN Tribology, 2013, 2013: 1-7. [2] MUZAKKIR S M, HIRANI H, THAKRE G D. Lubricant for heavily loaded slow-speed journal bearing[J]. Tribology Transactions, 2013, 56 (6): 1060-1068. doi: 10.1080/10402004.2013.823530 [3] GROPPER D, WANG Ling, HARVEY T J. Hydrodynamic lubrication of textured surfaces: a review of modeling techniques and key findings[J]. Tribology International, 2016, 94: 509-529. doi: 10.1016/j.triboint.2015.10.009 [4] RAO T V V L N, RANI A M A, NAGARAJAN T, et al. Analysis of micropolar and power law fluid-lubricated slider and journal bearing with partial slip-partial slip texture configuration[J]. Tribology Transactions, 2016, 59 (5): 896-910. doi: 10.1080/10402004.2015.1121310 [5] YU Ru-fei, LI Pei, CHEN Wei. Study of grease lubricated journal bearing with partial surface texture[J]. Industrial Lubrication and Tribology, 2016, 68 (2): 149-157. doi: 10.1108/ILT-03-2015-0028 [6] ZHANG Jin-yu, MENG Yong-gang. A study of surface texturing of carbon steel by photochemical machining[J]. Journal of Materials Processing Technology, 2012, 212 (10): 2133-2140. doi: 10.1016/j.jmatprotec.2012.05.018 [7] MENG F M, ZHANG L, LONG T. Effect of groove textures on the performances of gaseous bubble in the lubricant of journal bearing[J]. Journal of Tribology, 2017, 139 (3): 1-11. [8] JI Jing-hu, FU Yong-hong, BI Qin-sheng. Influence of geometric shapes on the hydrodynamic lubrication of a partially textured slider with micro-grooves[J]. Journal of Tribology, 2014, 136 (4): 1-8. [9] KANGO S, SINGH D, SHARMA R K. Numerical investigation on the influence of surface texture on the performance of hydrodynamic journal bearing[J]. Meccanica, 2012, 47 (2): 469-482. doi: 10.1007/s11012-011-9460-y [10] DADOUCHE A, CONLON M J. Operational performance of textured journal bearings lubricated with a contaminated fluid[J]. Tribology International, 2016, 93: 377-389. doi: 10.1016/j.triboint.2015.09.022 [11] MUZAKKIR S M, HIRANI H, THAKRE G D. Experimental investigations on effectiveness of axial and circumferential grooves in minimizing wear of journal bearing operating in mixed lubrication regime[J]. International Journal of Current Engineering and Technology, 2015, 5 (1): 486-489. [12] ADATEPE H, BIYIKLIOGLU A, SOFUOGLU H. An investigation of tribological behaviors of dynamically loaded non-grooved and micro-grooved journal bearings[J]. Tribology International, 2013, 58: 12-19. doi: 10.1016/j.triboint.2012.09.009 [13] ASHIHARA K, HASHIMOTO H. Theoretical modeling for microgrooved journal bearings under mixed lubrication[J]. Journal of Tribology, 2010, 132 (4): 1-16. [14] LIU Fu-xi, LU Yan-jun, ZHANG Qi-meng, et al. Load performance analysis of three-pad fixing pad aerodynamic journal bearings with parabolic grooves[J]. Lubrication Science, 2016, 28 (4): 207-220. doi: 10.1002/ls.1326 [15] KHATRI C B, SHARMA S C. Influence of textured surface on the performance of non-recessed hybrid journal bearing operating with non-Newtonian lubricant[J]. Tribology International, 2016, 95: 221-235. doi: 10.1016/j.triboint.2015.11.017 [16] WANG G R, ZHONG L, HE X, et al. Experimental study of tribological properties of surface texture on rock bit sliding bearings[J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2014, 228 (12): 1392-1402. doi: 10.1177/1350650114539937 [17] BRIZMER V, KLIGERMAN Y. A laser surface textured journal bearing[J]. Journal of Tribology, 2012, 134 (3): 1-9. [18] TALA-IGHIL N, FILLON M. A numerical investigation of both thermal and texturing surface effects on the journal bearings static characteristics[J]. Tribology International, 2015, 90: 228-239. doi: 10.1016/j.triboint.2015.02.032 [19] CUPILLARD S, GLAVATSKIH S, CERVANTES M J. Computational fluid dynamics analysis of a journal bearing with surface texturing[J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2008, 222 (2): 97-107. doi: 10.1243/13506501JET319 [20] ZHANG Hui, DONG Guang-neng, HUA Meng, et al. Parametric design of surface textures on journal bearing[J]. Industrial Lubrication and Tribology, 2015, 67 (4): 359-369. doi: 10.1108/ILT-08-2013-0089 [21] 刘成, 吕延军, 李莎, 等. 表面织构对曲轴轴承润滑性能的影响[J]. 交通运输工程学报, 2017, 17 (3): 65-74. doi: 10.3969/j.issn.1671-1637.2017.03.007LIU Cheng, LU Yan-jun, LI Sha, et al. Effects of surface texture on tribological performance of crankshaft bearing[J]. Journal of Traffic and Transportation Engineering, 2017, 17 (3): 65-74. (in Chinese). doi: 10.3969/j.issn.1671-1637.2017.03.007 [22] KANGO S, SHARMA R K, PANDEY R K. Thermal analysis of microtextured journal bearing using non-Newtonian rheology of lubricant and JFO boundary conditions[J]. Tribology international, 2014, 69: 19-29. doi: 10.1016/j.triboint.2013.08.009 [23] PATIR N, CHENG H S. An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication[J]. Journal of Lubrication Technology, 1978, 100 (1): 12-17. doi: 10.1115/1.3453103 [24] WANG Y S, WANG Q J, LIN C, et al. Mixed lubrication of coupled journal-thrust-bearing systems including mass conserving cavitation[J]. Journal of Tribology, 2003, 125 (4): 747-755. doi: 10.1115/1.1574519 [25] HAJJAM M, BONNEAU D. A transient finite element cavitation algorithm with application to radial lip seals[J]. Tribology International, 2007, 40 (8): 1258-1269. doi: 10.1016/j.triboint.2007.01.018 [26] MORRIS N, RAHMANI R, RAHNEJAT H, et al. Tribology of piston compression ring conjunction under transient thermal mixed regime of lubrication[J]. Tribology International, 2013, 59: 248-258. doi: 10.1016/j.triboint.2012.09.002