Influence of microdimple on lubrication performance of textured plunger pump

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hekun Jia ◽  
Zeyuan Zhou ◽  
Bifeng Yin ◽  
Huiqin Zhou ◽  
Bo Xu

Purpose The purpose of this study is to investigate the influence of dimple radius, depth and density on the lubrication performance of the plunger. Design/methodology/approach A lubrication model was adopted to consider eccentricity and deformation during the working process of the plunger, and a rig test was performed to confirm the simulation results. The texture was fabricated using laser surface texturing. Findings The simulation results suggested that when dimple radius or depth increases, oil film thickness of the plunger increases before decreasing, and asperity friction displays an opposite trend. Therefore, appropriate microdimple texture could facilitate lubrication performance improvement and reduce the wear. Microdimples were then lased on the plunger surface, and a basic tribological test was conducted to validate the simulation results. The experimental results suggested that the average friction coefficient decreased from 0.18 to 0.13, a reduction of 27.8%. Social implications The introduction of microdimple on a plunger couple to reduce friction and improve lubrication is expected to provide a new approach to developing high-performance plunger couple and improve the performance of the internal combustion engine. If applied, the surface texture could help reduce friction by around 27% and cap the cost relative to the plugger friction. Originality/value The microdimple texture was introduced into the plunger couple of a vehicle to reduce the friction and improve the performance. Findings suggested that surface texture could be used in the automotive industry to improve oil efficiency and lubrication performance. Peer review The peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-07-2020-0259.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junru Wang ◽  
Quandai Wang ◽  
Yueyan Li ◽  
Meiling Guo ◽  
Pengyang Li ◽  
...  

Purpose The purpose of this paper is to investigate the effects of surface texture with roughness orientation considered on tribological properties under a mixed lubrication state numerically and experimentally. Design/methodology/approach Based on the average Reynolds equation and asperity contact model, the impacts of surface texture parameters and roughness orientation on lubrication properties have been calculated using finite difference method. Tin–bronze samples with various prescribed surface texture geometric parameters and roughness orientation were fabricated by laser surface texturing technique, and the tribology performance of the textured surface was studied experimentally. Findings The effects of surface geometric parameters and roughness orientation parameters have been discerned. The experimental observations are in good agreement with the numerical prediction, which suggests that the numerical scheme adopted in this work is suitable in capturing the surface texture and roughness effect under mixed lubrication state. Originality/value By meticulously controlling the surface roughness and surface texture geometric characteristics based on the laser surface texturing process, samples with prescribed surface texture parameters and roughness orientation consistent with that in theoretical studies were fabricated and the theoretical model and results were verified experimentally.


2019 ◽  
Vol 71 (2) ◽  
pp. 232-241 ◽  
Author(s):  
Chao Chen ◽  
Xiaojing Wang ◽  
Yifan Shen ◽  
Zhaolun Li ◽  
Jian Dong

PurposeSurface texturing has emerged in the past two decades as a viable option of surface engineering, resulting in significant improvement in wear resistance and friction coefficient. The purpose of this study is to find the appropriate surface texture to reduce vibration and improve the stability of journal bearings.Design/methodology/approachMicro-dimples, evenly distributed in a square array, were selected as the texture pattern and formed on the lower surface of bush by the laser surface texturing technique. Experiments were carried out to evaluate the effects of micro-dimples under different depths, densities and distributions.FindingsThe results are summarized in the form of shaft center orbits, waterfall illustrations and Hilbert-Huang transforms. In the entire test, it was found that an optimum geometric and distributive range of micro-dimples exists, where vibration acceleration can be decreased at least 3dB and stability can be greatly improved.Originality/valueA majority of researchers devoted to studying on static characteristics, such as friction coefficient, load carrying capacity, pressure distribution and cavitation model. Besides, the influence of surface texture on stability of rotor-journal bearing system was rarely investigated and the recent examples can be found in Refs. (Ausas et al. 2007). However, a complete study of textured journal bearings has not been undertaken in the dynamic properties. Therefore, the purpose of this paper is to experimentally investigate the comprehensive effects of density, depth and distribution of micro-dimples on bearing vibration and stability.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junning Li ◽  
Ka Han ◽  
Wuge Chen ◽  
Xiaojie Tang ◽  
Qian Wang

Purpose The purpose of this study is to reveal the lubrication performance of textured roller bearings under various texture size, texture depth, texture types and slip. Design/methodology/approach In the present study, the improved thermal elastohydrodynamic lubrication method based on the surface texturing of the textured roller bearings is proposed, and then the effect of texture size, texture depth, texture types and slip on the contact pressure, film thickness and temperature distribution are analyzed systematically. Findings The results show that the pressure decreases and the film thickness increases on the contact area because of the surface texturing. The temperature increases first and then decreases as the texture size increases, and then the temperature increases as the texture depth and the slip increases. Compared to circle and square texture, cross texture can obviously decrease the temperature on the contact area. The effectiveness of the proposed method is verified. Originality/value This study can help to reduce friction and wear of textured roller bearings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0318/


2018 ◽  
Vol 70 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Shuwen Wang ◽  
Feiyan Yan ◽  
Ao Chen

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach Three different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication. Findings Test results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress. Originality/value The findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.


Author(s):  
Tiffany Davis ◽  
Jian Cao ◽  
Wei Chen ◽  
Q. Jane Wang ◽  
Cedric Xia ◽  
...  

Surface texturing has become a valuable technique for reducing friction and wear in contacting parts; laser surface texturing is one such method used to create micro-dimples on the interface surface. This work investigates the surface material property variation caused by laser surface texturing. The hardness and modulus of elasticity of a steel laser surface texture sample were evaluated near the dimples and away from the dimpled zone through nano-indentation. Resulting data shows that no significant difference exists between the material properties from the two positions. An alternate technique for surface texture generation was also explored, involving the use of micro-punches to create surface features in a metal sample. Computational simulations were performed using a second material underneath a thin copper sheet. The second material was present to serve as a support and to allow extensive deformation of the top material. The choice of the support material and ratio of material thicknesses was optimized to minimize pile up. Trials were conducted for three base supporting materials: PTFE, PMMA, and aluminum. Results show that PMMA performed better than the other materials. Positive deflection was minimized when the PMMA thickness was at least fifteen times that of the copper sheet. Physical experiments were completed with a thin copper sheet to verify the results. An array of micro-indentations was also created in a bulk steel sample. In order to assess the effect of dimpling via micro-forming, nano-indentation was performed near and far from the deformed material of the dimples. Similar to the laser textured sample, no significant differences were found between the two locations.


2016 ◽  
Vol 68 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang

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.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuying Zhang ◽  
Yuanhao Zhang

Purpose The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed. Design/methodology/approach Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness. Findings The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions. Originality/value The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/


2020 ◽  
Vol 72 (9) ◽  
pp. 1059-1073
Author(s):  
Gabriel Welfany Rodrigues ◽  
Marco Lucio Bittencourt

Purpose This paper aims to numerically investigate the surface texturing effects on the main bearings of a three-cylinder ethanol engine in terms of the power loss and friction coefficient for dynamic load conditions. Design/methodology/approach The mathematical formulation considers the Partir-Cheng modified Reynolds equation. The mass-conserving Elrod-Adams p-θ model with the JFO approach is used to deal with cavitation. A fluid-structure coupling procedure is considered for the elastohydrodynamic lubrication. Accordingly, a 3-D linear-elastic substructured finite element model obtained from Abaqus is applied Findings Simulations were carried out considering different dimple texture designs in terms of location, depth and radius. The results suggested that there are regions where texturing is more effective. In addition, distinct journal rotation speeds are studied and the surface texture was able to reduce friction and the power loss by 7%. Practical implications The surface texturing can be a useful technique to reduce the power loss on the crankshaft bearing increasing the overall engine efficiency. Originality/value The surface texturing performance in a three-cylinder engine using ethanol as fuel was investigated through numerical experimentation. The results are supported by previous findings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2019-0380/


2018 ◽  
Vol 70 (6) ◽  
pp. 977-983 ◽  
Author(s):  
Yunlong Jiao ◽  
Xiaojun Liu ◽  
Kun Liu

PurposeDynamic spreading and wetting on the rough surfaces is complicated, which directly affects the fluxion and phrase transition properties of the fluid. This paper aims to enhance our knowledge of the mechanism of micro-texture lubrication from interface wettability and provide some guidance for the practical manufacturing of the surfaces with special wettability and better lubrication characteristics.Design/methodology/approachThe effect of surface topography on the wetting behavior of both smooth and rough hydrophilic surfaces was investigated using a combination of experimental and simulation approaches. Four types of patterns with different topographies were designed and fabricated through laser surface texturing. The samples were measured with a non-contact three-Dimensional (3D) optical profiler and were parameterized based on ISO 25178. Quantitative research on the relevancy between the topography characteristic and wettability was conducted with several 3D topography parameters.FindingsResults show that for the surfaces with isotropic textures, topography with a small skewness (Ssk) and a large kurtosis (Sku) exhibits better wettability and spreading behavior. For the surfaces with anisotropic textures (smaller texture aspect ratio,Str), dominant textures (such as long groove, rectangle) play a significant guiding role in promoting spreading. In addition, the moving mechanism of the triple contact line and anisotropic spreading were also studied using a computational fluid dynamics simulation. The simulation results have a good adherence with the experimental results.Originality/valueMost of the surface characterization methods at present remain at a level that is related to geometric description, and the topography parameters are limited to 2D roughness parameters. So in present study, the relevancy between wettability and 3D surface topography parameters is explored. The authors believe that the current work provides a new viewpoint to the relevancy between surface topography and wettability.


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