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.

Multiple Design Objectives in Hydrodynamic Journal Bearing Optimization

1984 ◽  
Vol 106 (1) ◽  
pp. 54-60 ◽  
Author(s):  
S. M. Metwalli ◽  
G. S. A. Shawki ◽  
M. O. A. Mokhtar ◽  
M. A. A. Seif
Keyword(s):  
Journal Bearing ◽  
Design Procedure ◽  
Oil Viscosity ◽  
Novel Approach ◽  
Design Variables ◽  
Loss Maximum ◽  
Hydrodynamic Journal Bearing ◽  
Bearing Design ◽  
Maximum Minimum ◽  
Selection Of

A novel approach is presented to optimize the finite journal bearing performance under steady loading conditions. Closed form expressions representing the behavior of the bearing as explicit functions of the design variables are utilized. Different competing objectives are assumed to suit various design applications. A method of multiplying objectives and raising to different exponents has been adopted. The basic competing objectives are minimum power loss, maximum-minimum film thickness, minimum side leakage, minimum temperature rise, and minimum bearing size. A journal bearing design procedure for optimum performance is thus devised for the selection of optimum bearing length, clearance, and oil viscosity. A numerical example is also presented.

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.

Effect of Journal Misalignment on the Oil Film Pressure and Temperature Distribution of 3-Lobe Offset Journal Bearing

2005 ◽  
Author(s):  
S. Strzelecki ◽  
Z. Towarek
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Good Stability ◽  
Rotating Machines ◽  
Film Pressure ◽  
Bearing Design ◽  
Journal Misalignment ◽  
Oil Film Pressure

The design of turbines and compressors operating at the high rotational speeds applies the 3-lobe journal bearings. In many cases the classic 3-lobe journal bearings supporting the rotors, are showing the problem of rotor stability. This problem can be avoided by the application of 3-lobe Offset bearings. This type of bearing fulfils the conditions of reliable bearing design and good stability in the case of high speed rotating machines.

Empirical Treatment of Hydrodynamic Journal Bearing Performance in the Superlaminar Regime

1970 ◽  
Vol 12 (2) ◽  
pp. 116-122 ◽  
Author(s):  
H. F. Black
Keyword(s):  
Reynolds Number ◽  
Field Equation ◽  
Experimental Work ◽  
Reynolds Equation ◽  
Pressure Field ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Theoretical Treatment ◽  
Hydrodynamic Journal Bearing

The application of a perturbation in terms of simple correlations for friction in turbulent Couette and ‘screw’ flows, together with a further empirical assumption consonant with the experimental work of Smith and Fuller (1), leads to a pressure field equation identical in form with the Reynolds equation. The load capacity of journal bearings throughout most of the superlaminar range may be represented by a single curve, and existing laminar solutions may be applied with the parameters modified by Reynolds number. The theory is compared with published experimental results, and with the most successful theoretical treatment (4). The correlations obtained confirm the adequacy of the theory to predict performance in the superlaminar régime.

Comparison of Effects of Dimensional Manufacturing Tolerances and Journal Out-of-Roundness on Stability of Hydrodynamic Journal Bearing System

2011 ◽  
Vol 121-126 ◽  
pp. 1966-1971
Author(s):  
Wu Bin Xu ◽  
De Jian Zhou ◽  
Peter Ogrodnik ◽  
Mike Goodwin
Keyword(s):  
Theoretical Analysis ◽  
Taguchi Method ◽  
Journal Bearing ◽  
Journal Bearings ◽  
System Stability ◽  
Design Stage ◽  
Analysis Method ◽  
Manufacturing Tolerances ◽  
Hydrodynamic Journal Bearing ◽  
Bearing System

The manufacturing tolerances of a hydrodynamic journal bearing system are inevitable in manufacturing process. To examine and understand the effect of manufacturing tolerances on the system stability can help engineers to confidently choose reasonable tolerances at design stage. This study presented a theoretical analysis method to determine and compare the effects of dimensional manufacturing tolerances and journal out-of-roundness on system stability by Taguchi method. The results show that the journal out-of-roundness has the most significant effect on the system stability and the journal out-of-roundness appears to stabilize the system. The authors suggest that both dimensional manufacturing tolerances and journal roundness should be taken into account in the design of cylindrical journal bearings.

The Effect of Oil Supply Pressure on the Circumferential Pressure Profile in Hydrodynamic Journal Bearing

2013 ◽  
Vol 315 ◽  
pp. 809-814 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Nik Rosli Abdullah
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Pressure Profile ◽  
Journal Bearings ◽  
Maximum Pressure ◽  
Oil Supply ◽  
Supply Pressure ◽  
Machine Elements ◽  
Hydrodynamic Journal Bearing ◽  
Circumferential Pressure

In hydrodynamic lubrication, the pressure condition of the fluid is critical to ensure good performance of the lubricated machine elements such as journal bearings. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on pressure profile around the circumference of a journal bearing. A journal diameter of 100mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 Mpa) and the circumferential pressure results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the maximum pressure values were affected by changes in oil supply pressure.

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.

scholarly journals Reliability of a Hydrodynamic Journal Bearing

2015 ◽  
Vol 789-790 ◽  
pp. 342-352
Author(s):  
Khadim Diop ◽  
Abdérafi Charki ◽  
Stéphane Champmartin ◽  
Abdelhak Ambari
Keyword(s):  
Failure Probability ◽  
Structural Reliability ◽  
Reynolds Equation ◽  
New Technologies ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Design Quality ◽  
Technical Requirements ◽  
Reliability Method ◽  
Hydrodynamic Journal Bearing

Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel).

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.

Friction Reduction in Journal Bearings by High-Molecular-Weight Polymers

1975 ◽  
Vol 189 (1) ◽  
pp. 279-286 ◽  
Author(s):  
L. G. Hampson ◽  
H. Naylor
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Friction Reduction ◽  
Frictional Torque ◽  
Flow Conditions ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Hydrodynamic Journal Bearing

The effect of high-molecular-weight polymer drag-reducing agents on the performance of a plain hydrodynamic journal bearing operating under turbulent flow conditions has been studied. Reduction of the frictional torque by up to 45 per cent was observed for polymer concentrations in the range 5–200 μg/g using solutions in water of Polyox WSR 301 of molecular weight 4 times 105.*** The polymer solutions had a stabilizing effect against half-speed oil-film whirl. Degradation of the polymer by mechanical shear was fairly rapid.

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