Plain bearings � Hydrodynamic plain journal bearings under steady-state conditions

2020 ◽  
Keyword(s):  
Steady State ◽  
Journal Bearings

The Effect of Lubricant Inertia in Journal-Bearing Lubrication

1957 ◽  
Vol 24 (4) ◽  
pp. 494-496
Author(s):  
J. F. Osterle ◽  
Y. T. Chou ◽  
E. A. Saibel
Keyword(s):  
Reynolds Number ◽  
Steady State ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Hydrodynamic Theory ◽  
Simple Relationship ◽  
Inertia Effect ◽  
Laminar Regime ◽  
Steady State Operation

Abstract The Reynolds equation of hydrodynamic theory, modified to take lubricant inertia into approximate account, is applied to the steady-state operation of journal bearings to determine the effect of lubricant inertia on the pressure developed in the lubricant. A simple relationship results, relating this “inertial” pressure to the Reynolds number of the flow. It is found that the inertia effect can be significant in the laminar regime.

Transient Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings Under Dynamic Loading

1998 ◽  
Vol 120 (2) ◽  
pp. 405-409 ◽  
Author(s):  
P. Monmousseau ◽  
M. Fillon ◽  
J. Freˆne
Keyword(s):  
Steady State ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Tilting Pad ◽  
Transient Period ◽  
Final Steady State ◽  
Tilting Pad Journal Bearings

Nowadays, tilting-pad journal bearings are submitted to more and more severe operating conditions. The aim of this work is to study the thermal and mechanical behavior of the bearing during the transient period from an initial steady state to a final steady state (periodic). In order to study the behavior of this kind of bearing under dynamic loading (Fdyn) due to a blade loss, a nonlinear analysis, including local thermal effects, realistic boundary conditions, and bearing solid deformations (TEHD analysis) is realized. After a comparison between theoretical results obtained with four models (ISO, ADI, THD, and TEHD) and experimental data under steady-state operating conditions (static load Ws), the evolution of the main characteristics for three different cases of the dynamic load (Fdyn/Ws < 1, Fdyn/Ws = 1 and Fdyn//Ws > 1) is discussed. The influence of the transient period on the minimum film thickness, the maximum pressure, the maximum temperature, and the shaft orbit is presented. The final steady state is obtained a long time after the appearance of a dynamic load.

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.

Bifurcation Theory Applied to Oil Whirl in Plain Cylindrical Journal Bearings

1984 ◽  
Vol 51 (2) ◽  
pp. 244-250 ◽  
Author(s):  
C. J. Myers
Keyword(s):  
Steady State ◽  
Hopf Bifurcation ◽  
Equilibrium Position ◽  
Small Amplitude ◽  
Bifurcation Theory ◽  
Equations Of Motion ◽  
Journal Bearings ◽  
The Self ◽  
Oil Whirl ◽  
Nonlinear Equations Of Motion

An analysis of the self-excited oscillations of a rotor supported in fluid film journal bearings is presented. It is shown that Hopf bifurcation theory may be used to investigate small-amplitude periodic solutions of the nonlinear equations of motion for rotor speeds close to the speed at which the steady-state equilibrium position becomes unstable. A numerical investigation supports the findings of the analytic work.

Steady-State and Dynamic Behaviour of Multi-Recess Hybrid Oil Journal Bearings

1979 ◽  
Vol 21 (5) ◽  
pp. 345-351 ◽  
Author(s):  
M. K. Ghosh ◽  
B. C. Majumdar ◽  
J. S. Rao
Keyword(s):  
Perturbation Theory ◽  
Steady State ◽  
Theoretical Analysis ◽  
Dynamic Behaviour ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Time Dependent ◽  
Damping Coefficients ◽  
Stiffness And Damping

A theoretical analysis of the steady-state and dynamic characteristics of multi-recess hybrid oil journal bearings is presented. A perturbation theory for small vibrations is used to solve an incompressible, finite journal bearing with a time-dependent term. Load capacity, attitude angle, friction parameter, stiffness and damping coefficients are evaluated for a capillary-compensated bearing.

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