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/

Effect of roughness on sealing performance of oil seals with surface texture

2019 ◽  
Vol 72 (4) ◽  
pp. 525-532
Author(s):  
Fuying Zhang ◽  
Junmei Yang ◽  
Haoche Shui ◽  
Chengcheng Dong
Keyword(s):  
Film Thickness ◽  
Surface Texture ◽  
Equilateral Triangle ◽  
Friction Torque ◽  
Working Environment ◽  
Correct Selection ◽  
Deformation Analysis ◽  
Rotating Shaft ◽  
Pumping Rate ◽  
Content Type

Purpose This paper aims to obtain the film thickness, friction torque and pumping rate and analyze the effects of roughness and surface micro-dimple texture (circular, square and equilateral triangle) on the performance of the oil seal. Design/methodology/approach On the basis of elastohydrodynamic lubrication and the pumping mechanism of rotating shaft seal, this paper establishes a numerical model of hybrid lubrication of oil seal in sealing area. The model is coupled with fluid mechanics, rough peak contact mechanics and deformation analysis. Findings The results show that surface texture significantly improves the lubrication properties of the oil seal. The oil seal with the square texture has the largest oil film thickness, while the equilateral triangle texture has a better effect on the pumping rate. Originality/value To get closer to the real working environment of the oil seal, based on the surface roughness, this paper studies the effect of the texture shapes applied to the oil seal lip surface on the performance of the oil seal. The critical roughness and rotational speed values with zero pumping rate are obtained, which provides a theoretical basis for the correct selection of oil seals.

Surface virtual texturing of the journal bearings of a three-cylinder ethanol engine

2020 ◽  
Vol 72 (9) ◽  
pp. 1059-1073
Author(s):  
Gabriel Welfany Rodrigues ◽  
Marco Lucio Bittencourt
Keyword(s):  
Peer Review ◽  
Power Loss ◽  
Mathematical Formulation ◽  
Surface Texturing ◽  
Elastohydrodynamic Lubrication ◽  
Element Model ◽  
Content Type ◽  
Linear Elastic ◽  
Numerical Experimentation ◽  
Coupling Procedure

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/

scholarly journals Numerical Simulation and Experimental Study on Sealing Performance and Frictional Property of Rotary Lip Seal

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Huifang Dong ◽  
Jian Hu
Keyword(s):  
Friction Pair ◽  
Solution Process ◽  
Friction Torque ◽  
Contact Load ◽  
Necessary Condition ◽  
Bench Test ◽  
Frictional Property ◽  
Pumping Rate ◽  
Lip Seal ◽  
Sealing Performance

The hydrodynamic theoretical lubrication model of the friction pair between the rotary shaft and the lip seal under the state of full film lubrication was established in this paper. The Reynolds equation was solved by using the finite difference method, and the influence of the viscosity-temperature characteristics of the lubricant was taken into account in the solution process. The distribution of the film thickness and the hydrodynamic pressure in the sealing area was obtained. At the same time, the bench test was carried out and the correctness of the model was verified by comparing the simulation results and test results of reverse pumping rate and friction torque under different rotational speed of the shaft. The microasperity of the lip surface is a necessary condition for achieving the sealing effect. Therefore, the influences of the contact load of the seal and the root mean square deviation of the lip surface on the sealing performance and frictional property were analyzed by using the theoretical model. The analysis results show that the sealing performance and frictional property can be changed by changing the contact load and surface roughness of the lip, but a single increase in the influence of a certain factor cannot achieve good results, and comprehensive consideration is required in product design.

On the characteristics of gas foil conical bearings considering misalignment

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hongyang Hu ◽  
Ming Feng ◽  
Tianming Ren
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Critical Role ◽  
Friction Torque ◽  
Misalignment Angle ◽  
Content Type ◽  
Stiffness Model ◽  
Dynamic Performances

Purpose The purpose of this paper is to study the characteristics of gas foil conical bearings (GFCBs) considering the misalignment, the static and dynamic performances with different misalignment cases were studied. Design/methodology/approach A test rig on the air compressor supported by GFCBs has been developed to measure the practicability. A nonlinear bump stiffness model and one-dimensional beam top foil stiffness model were used as a basis for the calculation of static and dynamic performance. The finite element method and finite difference method are adopted to solve the Reynolds equation and the film thickness equation coupled, in which different misalignment cases were considered by changing the film thickness. Findings The supporting performance of GFCB is excellent, and the film clearance plays a critical role. The misalignment effects depend on the assembled angle and the misalignment angle. The load capacity, friction torque, temperature of GFCB decrease when the misalignment assembled angle is between 120° and 240°, while the dynamic bearing stability is improved. The static and dynamic performances show the opposite law for the other assembled angles, and the misalignment effect is more dramatic when there is a larger misalignment angle. Moreover, the bearing and running parameters largely affect the bearing performance. Originality/value The present study focuses on the static and dynamic characteristics of GFCB and investigates the effects of misalignment on the bearing performance. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0117

Effect of slip position on the hydrodynamic performance of liquid film seal

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yun-lei Wang ◽  
Jiu-hui Wu ◽  
Zhen-tao Li ◽  
Lu-shuai Xu
Keyword(s):  
Mathematical Model ◽  
Liquid Film ◽  
Peer Review ◽  
Slip Surface ◽  
Design Method ◽  
Hydrodynamic Performance ◽  
Boundary Slip ◽  
Content Type ◽  
Navier Slip ◽  
Sealing Performance

Purpose The purpose of this paper is to investigate the effect of slip position on the performance of liquid film seal. Design/methodology/approach A mathematical model of liquid film seal with slip/no-slip surface was established based on the Navier slip model and JFO boundary condition. Liquid film governing equation was discretized by the finite difference method and solved by the SOR relaxation iterative algorithm and the effects of slip position on sealing performance are discussed. Findings The results indicate that boundary slip plays an important role in the overall performance of a seal and a reasonable arrangement of slip position can improve the steady-state performance of liquid film seal. Originality/value Based on the mathematical model, the optimal parameters for liquid film seal with boundary slip at groove are obtained. The results presented in this study are expected to provide a theoretical basis to improve the design method of liquid film seal. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0082/

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
Keyword(s):  
Peer Review ◽  
Surface Texture ◽  
High Performance ◽  
Combustion Engine ◽  
Surface Texturing ◽  
Laser Surface Texturing ◽  
Content Type ◽  
Lubrication Performance ◽  
Simulation Results ◽  
The Cost

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.

Coupling analysis of the fatigue life and the TEHL contact behavior of ball screw under the multidirectional load

2020 ◽  
Vol 72 (10) ◽  
pp. 1285-1293
Author(s):  
Jia-Jia Zhao ◽  
Ming-Xing Lin ◽  
Xian-Chun Song ◽  
Nan Wei
Keyword(s):  
Fatigue Life ◽  
Film Thickness ◽  
Peer Review ◽  
Elastohydrodynamic Lubrication ◽  
Contact Model ◽  
Ball Screw ◽  
Content Type ◽  
Entrainment Velocity ◽  
Contact Points ◽  
Lubrication Performance

Purpose This paper aims to provide thermal elastohydrodynamic lubrication (TEHL) contact model to study all balls’ lubrication performance of the ball screw when the multidirectional load is applied. Design/methodology/approach A new TEHL contact model combining the multidirectional load and the roughness surface texture is established to describe fatigue life of the ball screw. Meanwhile, the authors use the Reynolds equation to study the lubrication performance of the ball screw. Findings When the multidirectional load is applied, contact load, slide-roll ratio and entrainment velocity of all balls have a periodic shape. The TEHL performance values at the ball-screw contact points including contact stress, shear stress, minimum film thickness and temperature rise are higher than that at the ball-nut contact points. The TEHL performance values increase with the increase of root mean square (RMS) except for the film thickness. In addition, the radial load of the ball screw has a significant effect on the fatigue life. Originality/value The results of the studies demonstrate the new TEHL contact model that provides the instructive significance to analyze the fatigue life of the ball screw under the multidirectional load. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0097/

Effect of angular speed of cam on oil film variation in the line contact thermal EHL of a cam-tappet pair

2020 ◽  
Vol 72 (6) ◽  
pp. 713-722
Author(s):  
Hongwei Tang ◽  
Jing Wang ◽  
Nannan Sun ◽  
Jianrong Zhu
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Elastohydrodynamic Lubrication ◽  
Grid Method ◽  
Angular Speed ◽  
Content Type ◽  
Sliding Motion ◽  
Oil Characteristics ◽  
Thermal Ehl ◽  
Wedge Effect

Purpose The influence of the cam angular speed on the pressure, film thickness and temperature profiles at some selected angular positions together with the oil characteristics are investigated. Design/methodology/approach A high-order polynomial cam is used, and thermal elastohydrodynamic lubrication (EHL) calculations are carried out by the multi-grid method and line-line scanning technique. Findings It is found that the film thickness decreases with a decrease in angular speed. The depth of the dimple that occurred in the reverse motion is also reduced because of the recession in the “temperature–viscosity wedge” effect. Originality/value It is revealed that the reduction in the cam angular speed makes the classical big surface dimple evolve into a small centralized dimple during the opposite sliding motion. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0327

Thermoelastohydrodynamic characteristics of supercritical CO2 spiral groove face seals

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Delei Zhu ◽  
Shaoxian Bai
Keyword(s):  
Critical Temperature ◽  
Peer Review ◽  
Spiral Groove ◽  
Supercritical Regime ◽  
Content Type ◽  
Lubricating Film ◽  
Sealing Performance ◽  
Face Seals ◽  
The Face ◽  
Energy Equations

Purpose The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO2 (S-CO2) spiral groove face seals in the supercritical regime. Design/methodology/approach The spiral groove face seal was used as the research object. The distribution of lubricating film pressure and temperature was analysed by solving the gas state, Reynolds and energy equations using the finite difference method. Furthermore, the influence law of sealing performance was obtained. Findings Close to the critical temperature of S-CO2, face distortions produced by increasing pressure lead to divergent clearance and resulted in reduced opening force. In the state of S-CO2, the face distortions generated by increasing seal temperature lead to convergent clearance, which enhances the opening force. In addition, near the critical temperature of S-CO2, the opening force may be reduced by 10%, and the leakage rate of the seal sharply increases by a factor of four. Originality/value The thermoelastohydrodynamic characteristics of supercritical CO2 face seals are illustrated considering the actual gas effect including compressibility, heat capacity and viscosity. Face distortions and sealing performance were calculated under different seal pressures and seal temperatures in the supercritical regime, as well as with N2 for comparison. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0169/

Discrete element analysis of friction performance for tire-road interaction

2020 ◽  
Vol 72 (7) ◽  
pp. 977-983
Author(s):  
Jiale Lu ◽  
Baofeng Pan ◽  
Tiankai Che ◽  
Dong Sha
Keyword(s):  
Fractal Dimension ◽  
Friction Coefficient ◽  
Peer Review ◽  
Surface Texture ◽  
Discrete Element ◽  
Surface Wear ◽  
Content Type ◽  
Pavement Surface ◽  
Friction Performance ◽  
Pavement Friction

Purpose This study aims to investigate the influence of surface texture distribution in respect to the procedure of pavement surface wear on friction performance. Design/methodology/approach The Weierstrass–Mandelbrot (W-M) equation is used to appropriate pavement surface profile. Through this approximation, artificial rough profiles by combining fractal parameters and conventional statistical parameters for different macro-texture are created to simulate the procedure of pavement surface wear. Those artificial profiles are then imported into discrete element model to calculate the interaction forces and friction coefficient between rolling tire and road. Furthermore, wavelet theory is used to decompose the profiles into different scales and explore the correlation between the profiles of each scale and pavement friction. Findings The influence of tire vertical displacement (TVD) on friction coefficient is greater than fractal dimension of road surface texture. When TVD decreases, the profiles can provide higher friction, but the rolling stability of tire is poor. The optimal fractal dimension of road surface is about 1.5 when considering friction performance. The pavement friction performance improves with wavelength from 0.4 to 6.4mm and decreases with wavelength from 12.8 to 51.2mm. Originality/value Artificial fractal curves are generated and analyzed by combining W-M function with traditional parameter, which can also be used to analyze the influence of texture distribution on other pavement performance. The preliminary research provides a potential approach for the evaluation of pavement friction performance. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0499/

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