The secondary motion of piston is modeled by considering the inertia of connecting rod according to the balance of the forces and moments acting on the piston. The influence of the structural parameters of the piston skirt longitudinal molded lines, the horizontal molded lines, the offset of piston pin and the thermal deformation on tribological properties of the piston skirt is investigated by considering coupling of the mixed lubrication of the piston-cylinder liner system and the dynamic behaviors of the piston. The average Reynolds equation of skirt lubrication is solved with FDM, and then the secondary motion trajectory of the piston is calculated by Runge-Kutta method. The influence of the piston skirt longitudinal molded lines, the horizontal molded lines, the offset of piston pin and the thermal deformation on the displacements and velocities of secondary motion, and friction power consumption is investigated by taking the inertia of the connecting rod, the surface roughness of the piston skirt and cylinder liner into consideration. The numerical results show that the inertia force of the connecting rod has important influence on the tribological property of the piston skirt. When the parabolic longitudinal molded line is applied for the middle-convex and varying ellipse piston, the amplitude and velocity of the secondary motion can be reduced. When the top and bottom ellipticities of the middle-convex and varying ellipse piston are chosen as smaller and bigger values respectively, the top and bottom radial reductions are chosen as smaller and bigger values respectively, the amplitude and velocity of the secondary motion can be also reduced. When the offset of piston pin is put to the thrust side slightly, the amplitude and velocity of the secondary motion can be also reduced. Meanwhile, the oil film thickness is increased, and the friction power consumption of the piston-cylinder liner system is reduced. The proposed model and numerical results can provide a theoretical direction to the design of piston skirt molded lines and further improvement of tribological properties of the piston-cylinder liner system.
LÜ Yanjun, LI Meng, ZHANG Yongfang, LIU Wanwan, YAN Dong
. Effect of Piston Skirt Profile Parameter on Secondary Motion and Lubrication Performance of Piston[J]. Journal of Mechanical Engineering, 2018
, 54(15)
: 100
-116
.
DOI: 10.3901/JME.2018.15.100
[1] MANSOURI S H, WONG V W. Effects of piston design parameters on piston secondary motion and skirt-liner friction[J]. Proc. IMechE Part J:Journal of Engineering Tribology,2005,219(6):435-449.
[2] MENG F M,ZHANG Y Y,HU Y Z,et al. Thermo- elasto-hydrodynamic lubrication analysis of piston skirt[J]. Tribology International,2007,40(7):1089-1099.
[3] MCFADDEN P D,TURNBULL S R. Dynamic analysis of piston secondary motion in an internal combustion engine under non-lubricated and fully flooded lubricated conditions[J]. Proc. IMechE Part C:Journal of Mechanical Engineering Science,2011,225(11):2575- 2585.
[4] LIVANOS G A,KYRTATOS N P. Friction model of a marine diesel engine piston assembly[J]. Tribology International,2007,40(1):1441-1453.
[5] MURAKAMI H,NAKANISHI N,ONE N,et al. New three-dimensional piston secondary motion analysis method coupling structure analysis and multi dynamics analysis[J]. SAE International Journal of Engines,2011,5(1):42-50.
[6] MCFADDEN P D,TURNBILL S R. A study of the secondary piston motion arising from changes in the piston skirt profile using a simplified piston skirt model[J]. Proc. IMechE Part C:Journal of Mechanical Engineering Science,2013,227(1):38-47.
[7] LITTLEFAIR B,CRUZ M D,THEODOSSIADES S,et al. Transient tribo-dynamics of thermo-elastic compliant[J]. Tribology Letters,2014,53(1):51-70.
[8] 孙军,王先义,张亮,等. 计入润滑油输送状况的活塞裙部-缸套摩擦副润滑分析[J]. 机械工程学报,2014,50(9):84-90. SUN Jun,WANG Xianyi,ZHANG Liang,et al. Lubrication analysis of piston skirt-cylinder liner frictional pair considering transport status of lubricating oil[J]. Journal of Mechanical Engineering,2014,50(9):84-90.
[9] GUNELSU O,AKALIN O. The effects of piston skirt profiles on secondary motion and friction[J]. ASME Journal of Engineering for Gas Turbines and Power,2014,136(6):062503-1-8.
[10] HE Zhenpeng,XIE Weisong,ZHANG Guichang,et al. Piston dynamic characteristics analyses based on FEM method Part I:Effected by piston skirt parameters[J]. Advances in Engineering Software,2014,75(6):68-85.
[11] TAN Y C,RIPIN Z M. Technique to determine instantaneous piston skirt friction during piston slap[J]. Tribology International,2014,74:145-153.
[12] MENG F M,WANG X F,LI R R,et al. Influence of cylinder liner vibration on lateral motion and tribological behaviors for piston in internal combustion engine[J]. Proc. IMechE Part J:Journal of Engineering Tribology,2015,229(2):151-167.
[13] MENG Xianghui,XIE Youbai. A new numerical analysis for piston skirt-liner system lubrication considering the effects of connecting rod inertia[J]. Tribology International,2012,47:235-243.
[14] MENG Xianghui,NING Lipu,XIE Youbai,et al. Effects of the connecting-rod-related design parameters on the piston dynamics and the skirt-liner lubrication[J]. Proc. IMechE Part D:Journal of Automobile Engineering,2013,227(6):885-898.
[15] ZHAO Bo,DAI Xudong,ZHANG Zhinan,et al. A new numerical method for piston dynamics and lubrication analysis[J]. Tribology International,2016,94:395-408.
[16] PATIR N,CHENG H S. An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication[J]. ASME Journal of Lubrication Technology,1978,100(1):12-17.
[17] PATIR N,CHENG H S. Application of average flow model to lubrication between rough sliding surfaces[J]. ASME Journal of Lubrication Technology,1979,101(2):220-229.
[18] ZHU Dong,CHENG H S,ARAI T,et al. A numerical analysis for piston skirts in mixed lubrication-Part I:Basic modeling[J]. ASME Journal of Tribology,1992,114(3):553-562.
[19] YIN Bifeng,LI Xiaodong,FU Yonghong,et al. Effect of laser textured dimples on the lubrication performance of cylinder liner in diesel engine[J]. Lubrication Science,2012,24(7):293-312.
[20] GREENWOOD I,TRIPP J H. The contact of two nominally flat rough surfaces[J]. Proceedings of the Institution of Mechanical Engineers,1970,185:625-633.
