Design and optimization of textures on the surface of crankpin bearing to improve lubrication efficiency and friction power loss of engine

2020 ◽  
pp. 135065012094200
Author(s):  
Zhenpeng Wu ◽  
Vanliem Nguyen ◽  
Vanquynh Le ◽  
Xuanlong Le ◽  
Vancuong Bui
Keyword(s):  
Power Loss ◽  
Asperity Contact ◽  
Bearing Surface ◽  
Film Pressure ◽  
Oil Film ◽  
Design And Optimization ◽  
Friction Power ◽  
Study Results ◽  
The Impact ◽  
Oil Film Pressure

The study proposes a design and optimization of textures on the surface of crankpin bearing to improve the lubrication efficiency and friction power loss (LE-FPL). A hydrodynamic lubrication model of crankpin bearing considering the impact of the external dynamic load and micro asperity contact is established. Based on the established model, the lubrication textures designed on the bearing surface are then simulated and optimized through the algorithms developed in Matlab environment and multi-objective optimization method. Increasing the oil film pressure and reducing the contact force ( Wac) in the asperity contact region, friction force ( Ff), and friction coefficient ( µ) of crankpin bearing are the objective functions to evaluate the LE-FPL. The study results indicate that the lubrication textures designed on the bearing surface have an obvious effect on improving the LE-FPL. Especially, with the optimized textures, the maximum oil film pressure is greatly increased by 44.8% while the maximum values of Wac and Ff are significantly reduced by 22% and 25%. Consequently, the lubrication textures added on the surface of crankpin bearing can greatly improve the LE-FPL.

scholarly journals Coupled simulation of elastohydrodynamics and multi-flexible body dynamics in piston-lubrication system

2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989585 ◽  
Author(s):  
Seongsu Kim ◽  
Juhwan Choi ◽  
Jin-Gyun Kim ◽  
Ryo Hatakeyama ◽  
Hiroshi Kuribara ◽  
...  
Keyword(s):  
Cylinder Block ◽  
Flexible Body ◽  
Asperity Contact ◽  
Lubrication System ◽  
Film Pressure ◽  
Oil Film ◽  
Piston Skirt ◽  
Body Dynamics ◽  
Flexible Body Dynamics ◽  
Oil Film Pressure

In this work, we propose a robust modeling and analysis technique of the piston-lubrication system considering fluid–structure interaction. The proposed schemes are based on combining the elastohydrodynamic analysis and multi-flexible body dynamics. In particular, multi-flexible body dynamics analysis can offer highly precise numerical results regarding nonlinear deformation of the piston skirt and cylinder bore, which can lead to more accurate results of film thickness for gaps filled with lubricant and of relative velocity of facing surfaces between the piston skirt and the cylinder block. These dynamic analysis results are also used in the elastohydrodynamic analysis to compute the oil film pressure and asperity contact pressure that are used as external forces to evaluate the dynamic motions of the flexible bodies. A series of processes are repeated to accurately predict the lubrication characteristics such as the clearance and oil film pressure. In addition, the Craig–Bampton modal reduction, which is a standard type of component mode synthesis, is employed to accelerate the computational speed. The performance of the proposed modeling schemes implemented in the RecurDyn™ multi-flexible body dynamics environment is demonstrated using a well-established numerical example, and the proposed simulation methods are also verified with the experimental results in a motor cycle engine (gasoline) which has a four cycle, single cylinder, overhead camshaft (OHC), air cooled.

Optimal design of micro-dimples on crankpin bearing surface for improving engine’s lubrication and friction

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Renqiang Jiao ◽  
Vanliem Nguyen ◽  
Vanquynh Le ◽  
Vancuong Bui
Keyword(s):  
Optimal Design ◽  
Slip Surface ◽  
Asperity Contact ◽  
Bearing Surface ◽  
Content Type ◽  
Multi Objective Genetic Algorithm ◽  
Lubrication Performance ◽  
Study Results ◽  
Micro Dimples ◽  
The Impact

Purpose The purpose of this paper is to investigate the optimal design of micro-dimples on the bearing surface of the crankpin bearing (CB) to ameliorate the engine’s lubrication and friction (ELF). Design/methodology/approach A hydrodynamic model of the CB considering the influence of the asperity contact is built under the impact of the dynamic loading of the slider-crank-mechanism. The micro-dimples on non-slip surface of the bearing are designed and optimized based on the lubrication model and multi-objective genetic algorithm. The performance of optimal micro-dimples on ameliorating the ELF is analyzed and compared with that of optimal CB dimensions via the reduction of the solid contact force, friction force and friction coefficient between the crankpin and bearing surfaces; and the increase of the oil film pressure. Findings The optimal design of micro-dimples on the bearing surface may not only greatly ameliorate the ELF but also make the rotation of the crankpin inside the bearing more stable in comparison with the optimization of CB dimensions. Originality/value This study results not only clearly ameliorates the ELF but also can be applied to the slip/non-slip surface pairs of other journal bearings to enhance their lubrication performance.

Full Shafting-Based Elastohydrodynamic Lubrication Simulation for Main Bearings of Marine Diesel Engine

2012 ◽  
Vol 479-481 ◽  
pp. 1119-1123 ◽  
Author(s):  
Hui Xing ◽  
Hui Zhang ◽  
Qili Wu ◽  
Shu Lin Duan
Keyword(s):  
Diesel Engine ◽  
Marine Diesel Engine ◽  
Main Bearing ◽  
Film Pressure ◽  
Oil Film ◽  
Marine Diesel ◽  
Simulation Results ◽  
Lubrication Characteristics ◽  
The Impact ◽  
Oil Film Pressure

To predict and analyze accurately the lubrication characteristics and its influencing factors of main bearing for large low-speed two-stroke marine diesel engine, based on EHD lubrication model of dynamically loaded bearing, coupling simulation between EHD and MBD for main bearing of marine diesel engine was carried out. Systemic models were established separately considering the independent crankshaft of diesel engine and the full shafting of propulsion power plant. Main bearing load, peak oil film pressure, oil film pressure distribution, MOFT and orbital path in one working cycle under rated working conditions were investigated, and simulation results were compared based on both models. The results show that, if the impact of full shafting was considered, the lubrication characteristics of No.8 main bearing changed significantly, the lubrication characteristics of other main bearings were similar as the simulation results of the independent crankshaft model.

Mixed Lubrication and Friction Power Loss of Piston Ring Pack

2014 ◽  
Vol 668-669 ◽  
pp. 205-208
Author(s):  
Xiao Ri Liu ◽  
Guo Xiang Li ◽  
Shu Zhan Bai ◽  
Yu Ping Hu
Keyword(s):  
Diesel Engine ◽  
Film Thickness ◽  
Power Loss ◽  
Piston Ring ◽  
Asperity Contact ◽  
Simultaneous Solution ◽  
Oil Film ◽  
Friction Power ◽  
Piston Ring Pack ◽  
Ring Pack

With consideration of asperity contact, the minimum oil film thickness and friction power loss are calculated by simultaneous solution of the dynamics, blow-by and lubrication of piston ring pack. Take the piston ring pack in the first cylinder from the free end of a six-cylinder diesel engine for example, results show that the asperity contact takes place at all of the compression rings and oil ring; the minimum oil film thickness is 1.04μm at the top ring; the total friction loss power is 0.94kW, the top ring accounts for 37.2%, the second ring accounts for 33.0%, the oil ring accounts for 29.8%.

Impact of a Lubricated Surface by a Sphere

1975 ◽  
Vol 97 (4) ◽  
pp. 613-615 ◽  
Author(s):  
H. D. Conway ◽  
H. C. Lee
Keyword(s):  
Flat Surface ◽  
Oil Viscosity ◽  
Film Pressure ◽  
Oil Film ◽  
Pressure Distributions ◽  
The Impact ◽  
Oil Film Pressure

This paper presents an analysis of the impact between a sphere and a flat surface covered by an oil film. Pressure distributions are found as functions of time for oils whose viscosities are either constant or pressure-dependent. It is believed that the increase of oil viscosity with pressure is a main cause of the deep conical dents observed experimentally.

Influence of Surface Waviness on the Thermal Elastohydrodynamic Lubrication of an Eccentric-Tappet Pair

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
J. Wang ◽  
C. H. Venner ◽  
A. A. Lubrecht
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Surface Waviness ◽  
Film Pressure ◽  
Oil Film ◽  
Working Cycle ◽  
Temperature Oscillations ◽  
Minimum Film Thickness ◽  
Traction Coefficient ◽  
Oil Film Pressure

The effect of single-sided and double-sided harmonic surface waviness on the film thickness, pressure, and temperature oscillations in an elastohydrodynamically lubricated eccentric-tappet pair has been investigated in relation to the eccentricity and the waviness wavelength. The results show that, during one working cycle, the waviness causes significant fluctuations of the oil film, pressure, and temperature, as well as a reduction in minimum film thickness. Smaller wavelength causes more dramatic variations in oil film. The fluctuations of the pressure, film thickness, temperature, and traction coefficient caused by double-sided waviness are nearly the same compared with the single-sided waviness, but the variations are less intense.

Simulation studies on static thermal behaviour of true elliptical and orthogonally displaced non-circular journal bearing

2016 ◽  
Vol 68 (3) ◽  
pp. 349-360 ◽  
Author(s):  
Amit Singla ◽  
Amit Chauhan
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Current Trend ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Film Pressure ◽  
Content Type ◽  
Oil Film ◽  
Ellipticity Ratio ◽  
Oil Film Pressure

Purpose The current trend of modern industry is to use machineries which rotate at high speed along with the capability of carrying heavy rotor loads. This paper aims at static thermal analysis of two different profiles of non-circular journal bearings – a true elliptical bearing and orthogonal bearing. Design/methodology/approach The Reynolds equation has been solved through finite difference method to compute the oil film pressure. Parabolic temperature profile approximation technique has been used to solve the energy equation and thus used for computation of various bearing performance characteristics such as thermo-hydrodynamic oil film pressure, temperature, load capacity, Sommerfeld number and power loss characteristics across the bearing. The effect of ellipticity ratio on the bearing performance characteristics has also been obtained for both the elliptical and vertical offset bearing using three different commercially available grades of oil (Hydrol 32, 68 and 100). Findings It has been observed that the thermo-hydrodynamic pressure and temperature rise of the oil film is less in orthogonal bearing as compared to the true elliptical bearing for same operating conditions. The effect of ellipticity ratio of non-circularity on bearing performance parameters have been observed to be less in case of elliptical bearing as compared to orthogonal bearing. It has been concluded that though the rise in oil film temperature is high for true elliptical bearing, but still it should be preferred over orthogonal profile under study, as it has comparably good load-carrying capacity. Originality/value The performance parametric analysis will help the designers to select such kind of non-circular journal bearing for various applications.

scholarly journals Fuzzy Logic based Model to Predict Maximum Oil-Film Pressure in Journal Bearing

2013 ◽  
Vol 6 (20) ◽  
pp. 3871-3878 ◽  
Author(s):  
Diyar I. Ahmed ◽  
S. Kasolang ◽  
Basim A. Khidhir ◽  
B.F. Yousif
Keyword(s):  
Fuzzy Logic ◽  
Journal Bearing ◽  
Film Pressure ◽  
Oil Film ◽  
Oil Film Pressure
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