Lubrication efficiency of crankpin bearing using square-cylindrical textures of partial textures optimized by genetic algorithm

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shaoyong Xu ◽  
Vanliem Nguyen ◽  
Xiaoyan Guo ◽  
Huan Yuan

Purpose This paper aims to propose an optimal design of the partial textures in the mixed lubrication regime of the crankpin bearing (CB) to maximize the CB's lubrication efficiency. Design/methodology/approach Based on a hybrid model between the slider-crank-mechanism dynamic and CB lubrication, the square-cylindrical textures (SCT) of partial textures designed on the CB’s mixed lubrication regime are researched. The effect of the density distributions of partial textures on CB’s lubrication efficiency is then evaluated via two indices of increasing the oil film pressure (p) and decreasing the frictional force (Ff) of the CB. The SCT’s geometrical dimensions are then optimized by the genetic algorithm to further improve the CB’s lubrication efficiency. Findings The results show that the SCT of partial textures optimized by the genetic algorithm has an obvious effect on enhancing CB’s lubrication efficiency. Especially, with the CB using the optimal SCT of partial textures (4 × 6), the maximum p is significantly increased by 3.7% and 8.2%, concurrently, the maximum Ff is evidently reduced by 9.5% and 21.6% in comparison with the SCT of partial textures (4 × 6) without optimization and the SCT of full textures (12 × 6) designed throughout the CB’s bearing surface, respectively. Originality/value The application of the optimal SCT of partial textures on the bearing surface not only is simple for the design-manufacturing process and maximizes CB’s lubrication efficiency but also can reduce the machining time, save cost and ensure the durability of the bearing compared to use the full textures designed throughout the CB’s bearing surface.

2016 ◽  
Vol 68 (4) ◽  
pp. 458-465 ◽  
Author(s):  
Lijesh K.P. ◽  
Muzakkir S.M. ◽  
Harish Hirani ◽  
Gananath Doulat Thakre

Purpose The journal bearings subjected to heavy load and slow speed operate in mixed lubrication regime causing contact between the interacting surfaces and resulting in wear. Complexity of wear behavior and lack of unifying theory/model make wear-control very challenging. Design/methodology/approach In the present research work, theoretical and experimental investigations have been conducted to explore the effect of grooving arrangements on the wear behavior of journal bearing operating in mixed lubrication regime. The theoretical model of Hirani (2005) that uses mass conserving cavitation algorithm has been used to determine the bearing eccentricity for different groove arrangements (with varying groove location and extent) for identifying a groove arrangement that minimizes the wear. The wear tests on the grooved bearings were conducted after suitable running-in of the new bearings on a fully automated journal bearing test set-up. A load and speed combination required to operate the bearing in mixed lubrication was used. The performance of different arrangement of bearing was evaluated by measuring their weight loss after the test. Findings Wear was significantly reduced with the use of proper groove arrangement for a bearing operating in mixed lubrication regime. Originality/value The improvement in bearing performance by providing grooves has been the subject matter of several studies in the past, but these studies were confined to the hydrodynamic operative regime of the bearing. In the present work, seven different combinations of axial and radial groove arrangement were tried, which has not been reported in any other work.


Author(s):  
Xiaohan Zhang ◽  
Yang Xu ◽  
Robert L Jackson

Fractal descriptions of rough surfaces are widely used in tribology. The fractal dimension, D, is an important parameter which has been regarded as instrument and scale independent, although recent findings bring this into question. A thrust bearing is analyzed in the mixed lubrication regime while considering the fractal nature. Surface data obtained from a thrust bearing surface are characterized and used to calculate the fractal dimension value by the roughness-length method. Then these parameters are used to generate different rough surfaces via a filtering algorithm. By comparing the predicted performance between the measured surface and generated fractal surfaces, it is found that the fractal dimension must be used carefully when characterizing the tribological performance of rough surfaces, and other parameters need to be found.


2019 ◽  
Vol 132 ◽  
pp. 265-274 ◽  
Author(s):  
Abdullah Azam ◽  
Ali Ghanbarzadeh ◽  
Anne Neville ◽  
Ardian Morina ◽  
Mark C.T. Wilson

1972 ◽  
Vol 186 (1) ◽  
pp. 421-430 ◽  
Author(s):  
H. Christensen

The phenomena observed when a lubricated contact or bearing is operating under mixed lubrication conditions are assumed to arise from an interaction of the surface asperities or roughness as well as from hydro-dynamic action of the sliding surfaces. It is shown how one of the previously published stochastic models of hydrodynamic lubrication can be extended or generalized to deal with mixed lubricating conditions. As an illustration of the application of the theory to a concrete example the influence on the operating characteristics of a plane pad, no side-leakage bearing is analysed. It is found that in the mixed lubrication regime friction is mainly controlled by the boundary lubrication properties of the liquid–solid interface. Load, on the other hand, is almost entirely controlled by the hydro-dynamic properties of the bearing. It is demonstrated how transition to mixed lubrication conditions will cause a rapid rise in friction thereby producing a minimum point in the Stribeck type diagram.


2019 ◽  
Vol 71 (9) ◽  
pp. 1099-1107
Author(s):  
Guo Xiang Guo Xiang ◽  
Yanfeng Han ◽  
Renxiang Chen ◽  
Jiaxu Wang Jiaxu Wang ◽  
Ni Xiaokang

Purpose This paper aims to present a numerical model to investigate the mixed lubrication performances of journal-thrust coupled bearings (or coupled bearings). Design/methodology/approach The coupled hydrodynamic effect (or coupled effect) between the journal and the thrust bearing is considered by ensuring the continuity of the hydrodynamic pressure and the flow field at the common boundary. The mixed lubrication performances of the coupled bearing are comparatively studied for the cases of considering and not considering coupled effect. Findings The simulated results show that the hydrodynamic pressure distributions for both the journal and thrust bearing are modified due to the coupled effect. The decreased load capacity of the journal bearing and the increased load capacity of the thrust bearing can be observed when the coupled effect is considered. And the coupled effect can facilitate in reducing the asperity contact load for both the journal and thrust bearing. Additionally, the interaction between the mixed lubrication behaviors, especially for the friction coefficient, of the journal and the thrust bearing is significant in the elastohydrodynamic lubrication regime, while it becomes weak in the mixed lubrication regime. Originality/value The developed model can reveal the mutual effects of the mixed lubrication behavior between the journal and the thrust bearing.


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