Effect of percolation on hydrodynamic lubrication of rough bilayer porous bearing with circular contact

2019 ◽  
Vol 72 (1) ◽  
pp. 109-115
Author(s):  
Guotao Zhang ◽  
Baohong Tong ◽  
Shubao Yang ◽  
Liping Shi ◽  
Yanguo Yin
Keyword(s):  
Hydrodynamic Lubrication ◽  
Structural Parameters ◽  
Single Layer ◽  
Polar Coordinates ◽  
Root Mean Square Roughness ◽  
High Porosity ◽  
Content Type ◽  
Porous Bearing ◽  
Lubrication Performance ◽  
Filtering Technique

Purpose The purpose of this paper was to study the hydrodynamic lubrication of rough bilayer porous bearing to reveal the effect of percolation. Design/methodology/approach The seepage lubrication model of the circular bilayer porous bearing was established in polar coordinates. The digital filtering technique and Darcy’s law were used to simulate the rough surface and the percolation characteristic of the oil bearing, respectively. The influence of the structural parameters on the lubrication performance was analyzed. Findings Compared with the ordinary monolayer oil bearing with high porosity, the bilayer bearing can reduce the whole porosity, prevent oil infiltrating into the porous medium and have better lubrication performance. The lubrication performance of bilayer oil bearing is better than that of the single-layer oil bearing which has a higher porosity. With increasing root-mean-square roughness or decreasing surface porosity, the lubrication performance of the bilayer bearing improves. The lower the porosity of the surface layer, the better the lubrication performance. Originality/value This research provides a theoretical basis for clarifying the lubrication mechanism and influence the mechanism of the bilayer oil bearing.

Optimization of hydrodynamic lubrication performance based on a heterogeneous slip/no-slip surface

2019 ◽  
Vol 71 (6) ◽  
pp. 772-778
Author(s):  
Zhenpeng Wu ◽  
Xianzhong Ding ◽  
Liangcai Zeng ◽  
Xiaolan Chen ◽  
Kuisheng Chen
Keyword(s):  
Friction Coefficient ◽  
Liquid Film ◽  
Bearing Capacity ◽  
Slip Surface ◽  
Hydrodynamic Lubrication ◽  
Slip Zone ◽  
Content Type ◽  
Starting Point ◽  
Lubrication Performance ◽  
Residual Space

Purpose This paper aims to use the method of curve splicing to combine the slip zone and the no-slip zone to further improve the lubrication performance of the liquid film. The combination of the slip zone and the no-slip zone of an existing heterogeneous surface is still a single line stitching method so that a very large residual space at the surface of the friction pairs remains present, necessitating further improvement of the joining scheme between the slip zone and the no-slip zone in heterogeneous surfaces. Design/methodology/approach A set of discrete sinusoids is used as the splicing track for both the slip zone and the no-slip zone, the starting point and amplitude of the curve are introduced as the simulation variables and the effects of these variables on the bearing capacity and friction coefficient of the liquid film are comprehensively analyzed. Findings The results show that the method of selecting the sinusoidal curve as the slip zone and the no-slip zone trajectory, which is based on the existing method of linear stitching, can further enhance the bearing capacity and reduce the friction coefficient of the liquid film. Originality/value This method can further enhance the bearing capacity and reduce the friction coefficient of the liquid film.

Effect of groove shape on the hydrodynamic lubrication of journal bearing considering cavitation

2019 ◽  
Vol 37 (5) ◽  
pp. 1557-1576 ◽  
Author(s):  
Yu Chen ◽  
Jun Feng ◽  
Y. Sun ◽  
Xu Peng ◽  
Qiao Dai ◽  
...  
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Hydrodynamic Characteristics ◽  
Operation Condition ◽  
Content Type ◽  
Hydrodynamic Simulations ◽  
Groove Shape ◽  
Operation Conditions ◽  
Lubrication Performance ◽  
Shape Selection

Purpose The purpose of this study is to investigate the influence of groove shape on the hydrodynamic characteristics of a journal bearing. Design/methodology/approach The computational fluid dynamics model also takes into account the cavitation phenomena and thermal effect, which can illustrate the lubrication performance of a journal bearing. Findings The hydrodynamic simulations of the journal bearing with the different groove shapes are conducted under different operation conditions. Originality/value Based on the numerical analysis, the suggestions are presented for groove shape selection and can be used to the design of a journal bearing under the extreme operation condition.

Hydrodynamic lubrication of partial textured sliding journal bearing based on three-dimensional CFD

2016 ◽  
Vol 68 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Xingxin Liang ◽  
Zhenglin Liu ◽  
Huanjie Wang ◽  
Xuhui Zhou ◽  
Xincong Zhou
Keyword(s):  
Negative Pressure ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Great Influence ◽  
Lower Half ◽  
Maximum Pressure ◽  
Content Type ◽  
Oil Film ◽  
Lubrication Performance ◽  
Divergent Region

Purpose – The purpose of this study is to investigate the effects of partial texture location and dimple depth on load carrying capacity (LCC), friction coefficient and circumferential flow of journal bearing. Design/methodology/approach – Based on the Navier-Stokes equation, the methodology used computational fluid dynamics (CFD). A phase change boundary condition was applied on fluid domain, and the negative pressure at divergent region of oil film was considered. Findings – It has been found that texture located at lubricant inlet area can improve the performance of the bearing, and the effect of shallow dimples is superior to the deep ones. However, the bearing performance will be reduced due to the texture located at the maximum pressure area. When texture is located at the lubricant outlet area, there will be two different situations: the part of the texture located within the oil film divergent area can improve the LCC, while the part that is beyond the divergent region will make the LCC decrease. Originality/value – The lower-half oil film model was established only in this study to analyze the hydrodynamic lubrication performance of partial textured journal bearing, and the lower-half oil film was divided into three parts. A new cavitation algorithm was introduced to deal with the negative pressure. The formula for calculating the friction of liquid film is refined, including the consideration of vapor phase. The simulation results show that the location of partial texture have a great influence on the bearing performance.

Effects of surface roughness and porous structure on the hydrodynamic lubrication of multi-layer oil bearing

2017 ◽  
Vol 69 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Lu Xue ◽  
Guoqian Zhu ◽  
Ming Tian
Keyword(s):  
Surface Roughness ◽  
Porous Structure ◽  
Pressure Distribution ◽  
Combined Effects ◽  
Roughness Parameters ◽  
Film Rupture ◽  
Content Type ◽  
Porous Bearing ◽  
Lubrication Performance ◽  
Internal Pore

Purpose The purpose of this paper is to discuss the combined effects of the deterministic surface roughness and porous structure on the lubrication property of the multi-layer bearing. Design/methodology/approach Digital filtering technique and Kozeny-Carman equation are used to simulate the random Gauss surface and the internal pore structure of the porous bearing, respectively. Effects of surface morphology, structure and pores on the lubrication property are discussed by using the finite difference method. Findings Results show that the lubrication performance of the multi-layer bearing increased with the increase of the surface roughness. Also, the transverse surface is better than that of the longitudinal surface. Moreover, lubricating property is getting worse with the increase of the height of each layer and the porosity. The lower permeability surface is beneficial to improve the lubrication performance when the total porosity is certain. Originality/value The effect of the Gauss roughness parameters on the detail of lubrication performance are analysed, such as the migration of the oil film rupture point position, the expansion of the pressure distribution region and the fluctuation of the pressure distribution curve with the roughness parameters. The combined effects of surface roughness, multi-layer structure and the internal pore parameters on the hydrodynamic behaviours of multi-layer porous bearing are analysed. This work is beneficial for the analysis of the tribological property and the structural design of multi-layer bearing.

Evaluation of hydrodynamic lubrication performance of textured surface from the perspective of skewness and kurtosis

2018 ◽  
Vol 70 (5) ◽  
pp. 829-837 ◽  
Author(s):  
Xia He ◽  
Wenling Liao ◽  
Guorong Wang ◽  
Lin Zhong ◽  
Mengyuan Li
Keyword(s):  
Cross Section ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Numerical Approach ◽  
Textured Surface ◽  
Content Type ◽  
Lubrication Performance ◽  
Texture Type ◽  
Negative Skewness ◽  
Skewness And Kurtosis

Purpose The purpose of this study is to investigate the influence of texture on hydrodynamic lubrication performance of slide surface from the perspective of skewness and kurtosis. Design/methodology/approach Hydrodynamic lubrication theoretical model of textured surface was established based on two-dimensional Reynolds equation, and finite difference algorithm was used as the numerical approach in the paper. Skewness and kurtosis of surface were obtained by discrete calculation. Findings Numerical analysis results show that the influence law of texture types on skewness, kurtosis and hydrodynamic lubrication was the more negative skewness and higher kurtosis, the better hydrodynamic lubrication performance when texture cross section contour and geometric parameters were the same. Similarly, the same influence law of skewness, kurtosis and hydrodynamic lubrication performance by texture cross-section contour was observed. However, it was unable to evaluate the effect of texture angle on hydrodynamic lubrication performance of textured surface from the perspective of skewness and kurtosis. Originality/value This paper confirms the feasibility of evaluating influence of texture types and texture cross-section contour on hydrodynamic lubrication performance from the perspective of skewness and kurtosis and provides a way to optimize texture type and texture cross section.

Effectiveness of multi-shape laser surface texturing in the reduction of friction under lubrication regime

2016 ◽  
Vol 68 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Content Type ◽  
Laser Ablation Process ◽  
Specific Formula ◽  
Steel Surfaces ◽  
Lubrication Conditions

Purpose – The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance. Design/methodology/approach – The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface. Findings – The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions. Originality/value – This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.

Effect of recess depth on lubrication performance of annular recess hydrostatic thrust bearing by constant rate flow

2018 ◽  
Vol 70 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jun-peng Shao ◽  
Guang-dong Liu ◽  
Xiao-dong Yu ◽  
Yan-qin Zhang ◽  
Xiu-li Meng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Simulation Method ◽  
Content Type ◽  
Oil Film ◽  
Constant Rate ◽  
Lubrication Performance ◽  
Optimal Value ◽  
Improved Performance ◽  
Lubrication Characteristics ◽  
Volume Method

Purpose The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow. Design/methodology/approach The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method. Findings The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing. Originality/value The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

Effect of laser-textured micro dimples on inhibition of stick-slip phenomenon of sliding guideway

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yonghong Fu ◽  
Jie Yang ◽  
Hao Wang ◽  
Yuyang He
Keyword(s):  
Hydrodynamic Lubrication ◽  
Textured Surface ◽  
Stick Slip ◽  
Content Type ◽  
Speed Range ◽  
Lubrication Condition ◽  
Micro Dimples ◽  
Pin On Disk ◽  
Micro Dimple ◽  
Slip Phenomenon

Purpose This study aims to investigate the efficacy of micro dimple in inhibiting stick-slip phenomenon on the sliding guideway. Design/methodology/approach In this study, micro-dimples were fabricated by laser on surfaces of steel disk and guideway. The disks and guideways were respectively performed pin-on-disk tribological tests and working condition experiments to study differences in lubrication condition and friction stability between textured and untextured surfaces. Findings Micro-dimples help reduce critical sliding speed that allows contact surfaces to enter in hydrodynamic lubrication regime. This increases hydrodynamic lubrication range and narrows speed range where stick-slip phenomenon can occur, enhancing sliding guideway’s adaptability for broader working conditions. Furthermore, friction stability on the textured surface improved, lowering the occurrence possibility of stick-slip phenomenon. Finally, difference between static and kinetic frictions on the textured surface is lower relative to the untextured surface, which decreases the critical velocity when the stick-slip phenomenon occurs. Originality/value The results indicate that laser-textured micro-dimples are significantly conducive to inhibit stick-slip phenomenon, thus providing smoother movement for the guideway and eventually increasing precision of the machine.

Analysis of lubrication and sealing performance on textured piston pair with multi-factor coupling

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Song Quan ◽  
Yong Guo ◽  
Xuedong Liu ◽  
Zhewu Chen ◽  
Yudi Liu
Keyword(s):  
Energy Consumption ◽  
Optimization Design ◽  
Great Influence ◽  
Diameter Ratio ◽  
Content Type ◽  
Hydraulic Impact ◽  
Sealing Performance ◽  
Lubrication Performance ◽  
Low Energy Consumption ◽  
Piston Pair

Purpose This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further carries out the optimization design of low energy consumption hydraulic impact piston pair. Design/methodology/approach Based on the characteristics of the ring gap seal piston pair, the flow field analysis model of the whole film gap is established for its periodic treatment. The friction power loss of the piston pair is defined as the evaluation index of the lubrication performance and the leakage power loss as the evaluation index of the sealing performance. The orthogonal test design and CFD software were used to analyze the lubrication and sealing performance of the textured piston pair. Findings The cross action of shape and structure factors has a great influence of the lubrication and sealing performance on the textured piston pair. Clearance and shape parameters have great influence on it, while seal length and depth diameter ratio have little influence. The sealing performance of conical textured piston pair is good, while the lubrication performance of square textured piston pair is good. The primary and secondary order of influence of shape and structure on energy consumption on piston pair is B (seal clearance) > C (texture shape) > D (area ratio) > A (seal length) > E (depth diameter ratio). Originality/value Breaking the defect of local optimization design on traditional piston pair structure, then find the matching relationship of structural parameters on textured piston pair. Further improve the lubrication and sealing performance of the piston pair, and provide reference for the global optimization design of the low energy consumption hydraulic impact piston pair.

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