Effect of snake-biomimetic surface texture on finger sealing performance under hydrodynamic lubrication

2021 ◽  
Vol 9 (3) ◽  
pp. 035040
Author(s):  
Lingping Chen ◽  
Yanchao Zhang ◽  
Yahui Cui ◽  
Jie Wang ◽  
Mingfeng Wang
Keyword(s):  
Surface Texture ◽  
Hydrodynamic Lubrication ◽  
Biomimetic Surface ◽  
Sealing Performance

Research on sealing performance of oil seals with micro-dimple texture on lips

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuying Zhang ◽  
Yuanhao Zhang
Keyword(s):  
Peer Review ◽  
Surface Texture ◽  
Elastohydrodynamic Lubrication ◽  
Friction Torque ◽  
Pumping Rate ◽  
Content Type ◽  
Rotation Direction ◽  
Sealing Performance ◽  
Pumping Efficiency ◽  
Shaft Seals

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/

The Hydrodynamic Lubrication of Rough Surfaces Based on a New Perturbation Approach

1984 ◽  
Vol 106 (4) ◽  
pp. 440-447 ◽  
Author(s):  
Kristian To̸nder
Keyword(s):  
Boundary Conditions ◽  
Surface Texture ◽  
Hydrodynamic Lubrication ◽  
Rough Surfaces ◽  
Perturbation Parameter ◽  
New Method ◽  
Perturbation Approach ◽  
Approximate Theory ◽  
Large Roughness ◽  
New Perturbation

A new method for treating roughness problems in hydrodynamic lubrication is presented. The approach consists of an expansion of the pressure by means of the perturbation parameter ε which is the ratio of the characteristic wavelengths across and along the direction of motion, respectively. This parameter may also be interpreted as the inverse of the Peklenik number of the surface texture. It is found that the zeroth components are those of To̸nder’s approximate theory. The terms are modified so as to remain finite at infinite ε. It is demonstrated that the corrections thus obtained are very accurate for configurations which are not disconnected pockets, even for very large roughness amplitudes. Such pockets are well treated, however, for moderate roughnesses. The method is applicable to statistically symmetric cases and may be easily extended to two-sided roughness. The application of the approach is quite straightforward numerically and does not require the boundary conditions of sample roughnesses to be known.

Numerical Analysis of Laser-Textured Piston-Rings in the Hydrodynamic Lubrication Regime

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Gonzalo Brito Gadeschi ◽  
Katja Backhaus ◽  
Gunther Knoll
Keyword(s):  
Numerical Analysis ◽  
Friction Coefficient ◽  
Distribution Pattern ◽  
Surface Texture ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Piston Rings ◽  
Variable Curvature ◽  
Lubrication Regime ◽  
Optimal Surface

In this work, the performance of barrel-shaped laser-textured piston rings is numerically investigated. The surface texture, parameterized by the dimple density, dimple depth, and dimple distribution pattern, is optimized to minimize the friction coefficient for piston rings of variable curvature. We consider fully textured as well as partially textured piston rings with two different dimple distributions patterns: a central dimple distribution, and a distribution along the piston ring edges. Finally, the sensitivity of the optimal surface parameters to the piston ring curvature is assessed.

Effect of Pad Surface Texture and Slurry Abrasive Concentration on Tribological and Kinetic Attributes of ILD CMP

2003 ◽  
Vol 767 ◽  
Author(s):  
Ara Philipossian ◽  
Scott Olsen
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texture ◽  
Material Removal ◽  
Hydrodynamic Lubrication ◽  
Removal Rate ◽  
Two Phase ◽  
Lubrication Regimes ◽  
Time Coefficient ◽  
Wide Range ◽  
Average Coefficient

AbstractReal-time coefficient of friction (COF) analysis is used to determine the extent of normal and shear forces during CMP and identify the lubrication regimes associated with the process. Pads with different surface textures and slurries with varying abrasive concentrations are used to polish ILD films over a wide range of operating parameters. Results show that by varying abrasive concentration and pad surface texture, one can cause the process tribology to change from ‘boundary lubrication’ to ‘partial lubrication’, to ‘hydrodynamic lubrication’. A two-phase model relating average coefficient of friction and Preston's constant is presented. At abrasive concentrations up to 9 percent, material removal is proportional to the extent of contact between the abrasives and the wafer. At abrasive concentrations between 9 to 25 percent, removal rate is directly influenced by average COF. A new parameter termed the ‘tribological mechanism indicator’ is defined and extracted from the data, which coupled with the information on COF and ILD removal rate, results in a series of ‘universal’ correlations. A qualitative model based on pad storage modulus is used to explain the trends.

Influence of different rhombic surface textures on the tribological performance of water-lubricated bearings

2020 ◽  
Vol 10 (9) ◽  
pp. 1452-1462
Author(s):  
Zhitao Cui ◽  
Zhiwei Guo ◽  
Chengqing Yuan
Keyword(s):  
Surface Texture ◽  
Hydrodynamic Lubrication ◽  
Thermoplastic Polyurethane ◽  
Industrial Applications ◽  
Heavy Load ◽  
Abrasive Particles ◽  
Surface Textures ◽  
Wide Range ◽  
3D Printed ◽  
Microscopic Surface

Water lubrication has gradually replaced oil lubrication for a wide range of marine stern bearings. However, due to poor water carrying capacity, the tribological performances of water lubricated bearings can be improved by incorporating surface textures. In this work, rhombic textured thermoplastic polyurethane (TPU) specimens, 3D-printed with different heights/depths, 1 mm bulge, 0.5 mm bulge, 0.5 mm dimple, and 1 mm dimple, were tested for their tribological performances when they were lubricated by water and were compared to nontextured specimens. The friction coefficient, wear mass, and microscopic surface topography of the specimens were collected at a common working load (0.4 MPa) and speed (from 50 to 350 rpm), and at low-speed and heavy load (50 rpm and 0.8 MPa) conditions. Experimental results reflect that the rhombic surface texture can effectively improve the friction and wear performances of TPU materials. The friction coefficients of most textured specimens are smaller than those of non-textured specimens under various working conditions. The surface wear conditions of all textured specimens are superior to non-textured specimens, since the rhombic surface texture produces additional hydrodynamic lubrication by creating converge and cavitation effects and prevents abrasive particles from accumulating on the friction surface. Through experimental demonstration, the 1 mm bulge rhombic texture is the best of all the tested textured specimens. This finding can provide a reference for practical industrial applications.

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