scholarly journals Effects of Texture Bottom Profile on Static and Dynamic Characteristics of Journal Bearings

2021 ◽  
Vol 2021 ◽  
pp. 1-25 ◽  
Author(s):  
Peng Li ◽  
Fang Zeng ◽  
Sen Xiao ◽  
Dong Zhen ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Journal Bearing ◽  
Numerical Technique ◽  
Isosceles Triangle ◽  
Journal Bearings ◽  
Performance Parameters ◽  
Flat Bottom ◽  
Stability Performance ◽  
Texture Parameters ◽  
Static Performance ◽  
Selection Of

The purpose of this paper is to numerically study the effect of texture bottom profile on static, dynamic, and stability performance parameters of hydrodynamic journal bearings. The different performance parameters of square textured journal bearings with different bottom profiles are numerically investigated and compared with those of smooth journal bearing. There are five bottom profiles of this square texture: flat, curved, isosceles triangle (T1), oblique triangle (T2), and oblique triangle (T3). The static and dynamic coefficients are calculated by solving the steady-state Reynolds equation and the perturbation equations with FDM numerical technique. The performance characteristics under different texture distribution, depth, and bottom profiles are studied, and the current numerical results show that the selection of texture parameters is crucial to improve the static, dynamic, and stability performances of hydrodynamic journal bearing. Meanwhile, it is also found that the square texture with a flat bottom profile has a higher improvement in the values of static performance parameters in comparison to those other bottom profiles. Moreover, the simulation results indicate that the dynamic and stability performances improvement of textured journal bearing is also significant, especially when the eccentricity ratio is smaller.

Numerical study on steady state performance enhancement of partial textured hydrodynamic journal bearing

2019 ◽  
Vol 71 (9) ◽  
pp. 1055-1063 ◽  
Author(s):  
Sanjay Sharma ◽  
Gourav Jamwal ◽  
R.K. Awasthi
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Performance Enhancement ◽  
Surface Texturing ◽  
Journal Bearings ◽  
Enhancement Ratio ◽  
Content Type ◽  
Maximum Value ◽  
Static Performance ◽  
Hydrodynamic Journal Bearing

Purpose The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For this, the bearings inner surface is textured with triangular shape with different texture depths and a number of textures in pressure increasing region. The textured region acts as a lubricant reservoir, which provides additional film-thickness and reduce friction. Therefore, enhance the overall performance of bearing. Design/methodology/approach In the present study, the effect of triangular shaped texture on the static performance characteristics of a hydrodynamic journal bearing has been studied. Different values of texture depths and a number of textures have been numerically simulated in pressure developing region. The static performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous Newtonian fluid. The performance enhancement ratio, which is the ratio of load carrying capacity (LCC) to the coefficient of friction (COF) has been calculated from results to finalized optimum design parameters. Findings The paper provides numerically obtained results indicate that surface texturing can improve bearing performance if the textured region is placed in the pressure increasing region. Moreover, surface texturing is the most effective at bearing performance enhancement when the bearing operates at lower eccentricity ratios and texture depth. The performance enhancement ratio, which is the ratio of LCC to the COF is found to be a maximum value of 2.198 at texture depth of 1.5, eccentricity ratio of 0.2 and the textured region located in the increasing pressure region. Research limitations/implications The present study is based on a numerical based research approach, which has its limitations. So, researchers are encouraged to investigate the same work experimentally. Practical implications The paper includes implications to be beneficial for designers for designing better hydrodynamic journal bearings. Originality/value For the triangular shaped texture, considered in the present study, the optimum values of texture depth and texture distribution region have also been determined. While designing, designers should focus on those values of texture depth, texture region and a number of textures, which give the maximum value of performance enhancement ratio, which represents maximum LCC at the lowest value of the COF.

Behaviour of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and micropolar lubricant

2017 ◽  
Vol 69 (6) ◽  
pp. 844-862 ◽  
Author(s):  
Chandra B. Khatri ◽  
Satish C. Sharma
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Technique ◽  
Surface Texturing ◽  
Textured Surface ◽  
Performance Parameters ◽  
Content Type ◽  
Fluid Theory ◽  
Bearing System

Purpose The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing. Design/methodology/approach In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique. Findings The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing. Originality/value The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.

Combined Influence of Misalignment and Orifice Diameter on the Static Performances of Hydrostatic, Water-Lubricated Journal Bearings

2014 ◽  
Vol 607 ◽  
pp. 608-611
Author(s):  
Hui Hui Feng ◽  
Chun Dong Xu ◽  
Feng Feng Wang
Keyword(s):  
Finite Difference ◽  
Finite Difference Method ◽  
Film Thickness ◽  
Power Loss ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Orifice Diameter ◽  
Rigid Rotor ◽  
Static Performance

The water-lubricated bearings have gained an increasing focus to overcome the disadvantages of the oil film bearings and gas bearings. In this paper, the influences of orifice diameter in aligned and misaligned conditions on the static performance of two hydrostatic, four-recess, water-lubricated journal bearings used to support a rigid rotor, are investigated. The steady Reynolds equation for the journal bearing for the turbulent bulk flow and the film thickness expression considering tilting angles are used and numerically solved by finite difference method. Results demonstrate that the static performances, such as the quality, power loss and temperature rise are affected by the tilting angles, orifice diameter to some degree.

scholarly journals Selection of Suitable Material for Journal Bearing by Tribology

2020 ◽  
Vol 8 (6) ◽  
pp. 4392-4399
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Journal Bearing ◽  
Sem Analysis ◽  
Journal Bearings ◽  
Inconel 625 ◽  
Molybdenum Disulphide ◽  
Suitable Material ◽  
Low Wear ◽  
Selection Of

Wear is an influencing parameter which reduces the overall life of a machine and its parts. The wear rate and coefficient of friction under the same conditions of speed, load, lubrication and time were calculated for a set of materials used as journal bearings. Since journal bearings are important in a variety of applications, a wise selection of material with a constant low wear rate and low coefficient of friction is essential. The four materials tested for this purpose include Molybdenum Disulphide (MoS2 ), Stainless Steel (SS 304), Nylon 66, INCONEL 625. The basic methodology for determining wear and friction of these materials involves the use of a pin-on-disc test apparatus. The materials taken for testing are made into a pin of diameter and length 8 mm and 25 mm respectively. Scanning Electron Microscope (SEM) analysis and surface roughness measurements were carried out to study the properties. Hence, INCONEL 625 was found to be the ideal material for journal bearing applications due to its low wear rate, no fluctuation in wear rate, lower coefficient of friction and better mechanical properties compared to others.

Analysis of Gas-Lubricated Foil Journal Bearings

1983 ◽  
Vol 105 (4) ◽  
pp. 647-655 ◽  
Author(s):  
H. Heshmat ◽  
J. A. Walowit ◽  
O. Pinkus
Keyword(s):  
Differential Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Bearing Surface ◽  
Operational Parameters ◽  
Operational Variables ◽  
Bearing Behavior ◽  
Load Angle ◽  
Gas Journal Bearing ◽  
Selection Of

This work is concerned with an evaluation of the performance of a gas journal bearing using a spring supported compliant foil as the bearing surface. The analysis, conducted for both single and multipad configurations, is concerned with the effects that the various structural, geometric, and operational variables have on bearing behavior. Following the solution of the relevant differential equation, tabular or graphical solutions are provided for a range of relevant geometric and operational parameters. The solutions include values of the colinear and cross-coupled spring coefficients due to both structural and hydrodynamic stiffness. Desirable design features with regard to start of bearing arc, selection of load angle, number of pads and degree of compliance are discussed.

A Locally Refined Finite Element Approach for Journal-Bearing System Analysis

2005 ◽  
Author(s):  
S. W. Xiong ◽  
Q. Jane Wang ◽  
W. K. Liu ◽  
Chih Lin ◽  
D. Zhu ◽  
...  
Keyword(s):  
System Analysis ◽  
Journal Bearing ◽  
Numerical Technique ◽  
Point Contact ◽  
Contact Problems ◽  
Journal Bearings ◽  
Mixed Lubrication ◽  
Special Technique ◽  
Simulation Techniques ◽  
Refined Meshes

The effect of roughness should be taken into consideration in the lubrication and geometric design of heavy-duty machine elements. Deterministic simulation techniques have been developed for the investigation of point-contact mixed-lubrication problems. Such approaches should also been extended to deterministic mixed lubrication solutions for journal-bearing conformal-contact systems. However, journal-bearing mixed lubrication involves a much larger area of surface interaction as compared to point contact problems. It is difficult to use similar micro/nano scale meshes directly to journal bearings under the current computer capability. It is a great challenge to develop a new deterministic numerical technique for the mixed lubrication of journal bearing systems with the consideration of the effect of surface roughness design. This paper presents a special technique for deterministic analyses of journal-bearings in mixed lubrication conditions, in which the coarse mesh is used to determine the elastic deformation of the journal bearing, whilst locally refined meshes are used for the effect of roughness. Journal-bearing systems in heavy machinery are often subject to dynamic loading. Therefore, a transient refinement scheme is also introduced.

Thermohydrodynamic Analysis of Journal Bearing Operating Under Nanolubricants

2011 ◽  
Author(s):  
K. Prabhakaran Nair ◽  
P. K. Rajendra Kumar ◽  
K. Sreedhar Babu
Keyword(s):  
Journal Bearing ◽  
Numerical Technique ◽  
Load Capacity ◽  
Performance Characteristics ◽  
Nano Particles ◽  
Engine Oil ◽  
Al2o3 Nanoparticles ◽  
Static Performance ◽  
Energy Equations ◽  
Commercial Lubricant

The static performance characteristics of thermo hydrodynamic journal bearing operating under lubricant Veedol SAE 15W 40 multi grade engine oil with CuO, CeO2 and Al2O3 nanoparticles are presented. These static performance characteristics mainly depend on the viscosity of the lubricant. The addition of nano particles on commercially available lubricant may enhance the viscosity of lubricant and in turn changes the performance characteristics. In the proposed work CuO, CeO2 and Al2O3 nano particles are used with commercial lubricant Veedol SAE 15W 40 multi grade engine oil. To obtain pressure and temperature distribution, modified Reynolds and energy equations are used and these equations are solved by using the powerful numerical technique, Finite Element Method. An iterative procedure is used to establish the film extent. The static performance characteristics in terms of load capacity, attitude angle, end leakage and friction force are evaluated when the bearing operates under nanolubricants for the following cases. 1. Isoviscous; 2. Thermoviscous.

Elasto-hydrodynamic analysis of journal bearing operating with nanolubricants

2020 ◽  
pp. 135065012093197 ◽  
Author(s):  
Pravez Khan ◽  
Anil Dhanola ◽  
HC Garg
Keyword(s):  
Power Law ◽  
Journal Bearing ◽  
Maximum Pressure ◽  
Performance Parameters ◽  
Increase With Increase ◽  
Force Increase ◽  
Load Carrying ◽  
Static Performance ◽  
Index Value ◽  
Power Law Index

In this study, performance parameters of a rigid and flexible journal bearing using non-Newtonian nanolubricants have been investigated and compared. Krieger-Dougherty viscosity model has been implemented with a non-Newtonian model (power law) to evaluate the effective viscosity of nanolubricants. In order to attain the pressure field of nanolubricants, a numerical solution of the modified Reynolds equation has been derived with initial assumptions and boundary conditions using finite difference method. The static performance parameters for both the bearings have been examined at different values of power law index and eccentricity ratio. The results demonstrate that the load-carrying capacity, maximum pressure and friction force increase significantly using nanolubricant in comparison to base lubricant. Also, the values of these parameters increase with increase of power law index. An insignificant effect of elastic deformation is observed on performance parameters except attitude angle at a particular power law index value.

Optimum Design of Hydrodynamic Journal Bearings

1969 ◽  
Vol 91 (3) ◽  
pp. 516-521 ◽  
Author(s):  
A. Seireg ◽  
H. Ezzat
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Automated System ◽  
Optimal Programming ◽  
Programming Techniques ◽  
Design Systems ◽  
Hydrodynamic Journal Bearing ◽  
Bearing Design ◽  
Lubricant Viscosity ◽  
Selection Of

This paper presents an automated system for the selection of the length, clearance, and lubricant viscosity which optimize the performance of a hydrodynamic journal bearing, under specified values or ranges of load and speed. The study illustrates the feasibility of applying optimal programming techniques for the development of bearing design systems.

scholarly journals Sensibility Analysis of Design Parameters for Journal Bearings Optimization of Mass Balancing Systems

2005 ◽  
Author(s):  
L. Morais ◽  
L. A. Ferreira
Keyword(s):  
Film Thickness ◽  
Power Loss ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Radial Clearance ◽  
Maximum Pressure ◽  
Minimum Film Thickness ◽  
Mass Balancing ◽  
Sensibility Analysis ◽  
Selection Of

This work presents a sensibility analysis for the journal bearings of combustion engines mass balancing systems. Applying it, it’s possible to improve the journal bearings and avoid possible failures. This analysis consists on studying the effects of the variation of the journal bearings main parameters (radial clearance, journal bearing diameter and journal bearing length) on the journal bearings operating conditions (minimum film thickness, maximum pressure and power loss). The analysis also includes the comparison and selection of the different metallic materials that can be used in these journal bearings, as well as the selection of the lubrication system groove suitable for the journal bearings used in this kind of application. This sensibility analysis shows that: increasing the radial clearance the minimum film thickness increases, the maximum pressure remains approximately the same and the power loss decreases; increasing the journal bearing length, the minimum film thickness and power loss increase and the maximum pressure decreases; increasing the journal bearing diameter, the minimum film thickness and power loss increase and the maximum pressure decreases. At last, it’s found that the white metals (Babbitts) are considered the most advantageous and indicated materials for these journal bearings, and that the lubrication system grooves should be circumferential.

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