A High Performance Journal Bearing With Controlled Elastic Deflection

1995 ◽  
Vol 117 (4) ◽  
pp. 702-708 ◽  
Author(s):  
A. K. Tieu ◽  
N. O. Freund
Keyword(s):  
Thermal Effects ◽  
High Performance ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Pressure ◽  
Hydrodynamic Analysis ◽  
Elastic Deflection ◽  
Load Carrying ◽  
Bearing Load ◽  
Generalized Reynolds Equation

A thermo-elasto-hydrodynamic analysis of an undercut journal bearing is presented whereby elastic deflection is introduced in a certain area of the bearing surface. The hydrodynamic pressure is computed from the generalized Reynolds equation, which takes into account thermal effects on viscosity. This is accomplished by solving the full energy equation for temperature. The elastic deflection is obtained from the elasticity equation. This study is then complemented with an elasto-hydrodynamic analysis of the full bearing. The controlled elastic deflection increases the bearing load carrying capacity and reduces friction.

A Contribution to the Analysis of the Thermo-Hydrodynamic Lubrication of Porous Self-Lubricating Journal Bearings

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Porous Matrix ◽  
Journal Bearings ◽  
Governing Equations ◽  
Hydrodynamic Analysis ◽  
Result Show

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.

Study on Lubrication Simulation and Capability of Three-Lobe Journal Bearing

2014 ◽  
Vol 709 ◽  
pp. 210-214
Author(s):  
Kun Qian ◽  
Wei Gang Guo
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Rotation Speed ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Bearing Load ◽  
The Stability ◽  
Eccentric Distance

The lubrication state of three-lobe bearing is simulated by using Reynolds equation. It concluded that the load-carrying capability of three-lobe bearing increases with the eccentric distance between the centers of axis and bearing with a nonlinear way. The largest bearing load-carrying capacity occurs in the eccentric direction of 30 °and making sure the eccentric direction can improve the stability of the system. To improve the rotation speed of the axis is beneficial to promote the load-carrying capacity.

scholarly journals Comparative study of spherical dimple and bump effects on the tribological performances of journal bearing

2018 ◽  
Vol 233 (1) ◽  
pp. 139-157 ◽  
Author(s):  
Chao Gui ◽  
Fanming Meng
Keyword(s):  
Friction Force ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Pressure ◽  
Load Carrying Capacity ◽  
Transform Method ◽  
Cavitation Effect ◽  
Fast Fourier Transform Method ◽  
Load Carrying

In the present study, tribological performances of journal bearings with the representative spherical dimples and bumps are compared numerically. In doing so, the hydrodynamic pressure of the lubricant is solved by the Reynolds equation considering the lubricant cavitation effect. Meanwhile, the elastic deformation is calculated by the continuous convolution fast Fourier transform method. The enhanced load-carrying capacity and the reduced friction force occur only when the dimples are located at pressure rising part of the bearing. The bumps located at the pressure falling part can enhance the load-carrying capacity but increase the friction force. The above dimple and bump effects change at the varied feature sizes and intervals.

A General Solution of Reynolds’ Equation for a Full Finite Journal Bearing

1967 ◽  
Vol 89 (2) ◽  
pp. 203-210 ◽  
Author(s):  
R. R. Donaldson
Keyword(s):  
Fourier Series ◽  
Series Solution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Separation Of Variables ◽  
Hill Equation ◽  
Eigenvalues And Eigenvectors ◽  
General Series ◽  
Bearing Load

Reynolds’ equation for a full finite journal bearing lubricated by an incompressible fluid is solved by separation of variables to yield a general series solution. A resulting Hill equation is solved by Fourier series methods, and accurate eigenvalues and eigenvectors are calculated with a digital computer. The finite Sommerfeld problem is solved as an example, and precise values for the bearing load capacity are presented. Comparisons are made with the methods and numerical results of other authors.

Analysis of Thermal Effects in Hydrodynamic Bearings

1986 ◽  
Vol 108 (2) ◽  
pp. 219-224 ◽  
Author(s):  
R. Boncompain ◽  
M. Fillon ◽  
J. Frene
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Effects ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Heat Transfer Equation ◽  
Reversed Flow ◽  
Theoretical Results ◽  
Generalized Reynolds Equation ◽  
Good Agreement

A general THD theory and a comparison between theoretical and experimental results are presented. The generalized Reynolds equation, the energy equation in the film, and the heat transfer equation in the bush and the shaft are solved simultaneously. The cavitation in the film, the lubricant recirculation, and the reversed flow at the inlet are taken into account. In addition, the thermoelastic deformations are also calculated in order to define the film thickness. Good agreement is found between experimental data and theoretical results which include thermoelastic displacements of both the shaft and the bush.

Theoretical Analysis of Externally Pressurized Air Journal Bearing

1970 ◽  
Vol 12 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. C. Majumdar
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Design Parameters ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Dimensional Parameters ◽  
Bearing Design

A theoretical investigation is made to predict the performance of an externally pressurized air journal bearing having several pressure sources. The pressure distribution, which leads to the determination of load-carrying capacity and flow requirement, is obtained by solving Reynolds equation numerically. The load and flow, expressed in non-dimensional parameters, are presented for different bearing design parameters (dimensionless). The results predicted by this method are compared with others' experimental data.

Behavior of Finite Journal Bearings Under Dynamic Loading Conditions

1980 ◽  
Vol 102 (3) ◽  
pp. 333-338 ◽  
Author(s):  
G. S. A. Shawki ◽  
M. O. A. Mokhtar ◽  
Z. S. Safar
Keyword(s):  
Boundary Conditions ◽  
Computer Program ◽  
Variational Methods ◽  
Axial Length ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
The Third ◽  
Dynamic Loading Conditions ◽  
Generalized Reynolds Equation

Performance characteristics for a complete journal bearing of finite axial length are obtained analytically using a new set of boundary conditions. The generalized Reynolds equation is transformed, in the present analysis, into three ordinary differential equations, two of which being readily integrable while the third is solved by variational methods. By the aid of a specially devised computer program, the validity of the analysis has been assured when applied to prescribed journal loci including stationary, circular, elliptical, and linear harmonic journal oscillation.

A Thermohydrodynamic Coupling Model of Oil Aeration Turbulent Lubrication for Journal Bearing With Interface Effect

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Xiaohui Lin ◽  
Shuyun Jiang ◽  
Chengyu Hua ◽  
Feng Cheng
Keyword(s):  
Velocity Distribution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Coupling Model ◽  
Wall Turbulence ◽  
Volume Distribution ◽  
Bubble Volume ◽  
Coupled Equations ◽  
Generalized Reynolds Equation

Oil aeration lubricant in high-speed journal bearing is composed of mixture of continuous phase liquid and discrete phase bubbles. This work establishes a thermohydrodynamic (THD) coupling model for this lubrication condition. The generalized Reynolds equation is derived by the continuity equation, Navier–Stokes equation, law of wall turbulence model, and bubble volume distribution function, and then a THD oil aeration turbulent lubrication model is established by coupling the generalized Reynolds equation, energy equation, force equilibrium equation of bubble, and population balance equations (PBEs). The coupled-equations are solved numerically to obtain the pressure distribution under oil aeration lubrication state, the equilibrium distribution of bubble volume, the turbulent velocity distribution, the bubble velocity distribution, and the temperature rise. The results show that the load capacity of a bearing with oil aeration lubrication model is higher than that of the same bearing with a pure oil lubrication model, and heat dissipation performance of the bearing under the oil aeration lubrication state is superior.

Comparison of the Load-Carrying Performance of Mechanical Gas Seals Textured With Microgrooves and Microdimples

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Liping Shi ◽  
Xiuying Wang ◽  
Xiao Su ◽  
Wei Huang ◽  
Xiaolei Wang
Keyword(s):  
Reynolds Equation ◽  
Hydrodynamic Pressure ◽  
Area Density ◽  
Low Area ◽  
Optimal Load ◽  
High Area ◽  
Load Carrying ◽  
Small Clearance ◽  
Gas Seals ◽  
Film Stiffness

The effects of microgrooves and microdimples on the load-carrying performance of mechanical gas seals are compared in this study. Numerical model based on the Reynolds equation for compressible Newtonian fluid is utilized to investigate the load-carrying performance including the hydrodynamic pressure, the load-carrying force, and gas film stiffness of the gas seals. The results indicate that both microgrooves and microdimples can improve the load-carrying performance of mechanical gas seals, particularly under a small clearance condition. Furthermore, different texture patterns achieve optimal load-carrying performance at different area density, seal clearance, and depth: microgrooves with a low area density can obtain higher load-carrying force and gas film stiffness than the dimple patterns, but with high area density, elliptical dimples yield better load-carrying performance than the groove patterns.

Thermal-EHD contacts lubricated with oil/refrigerant solutions: a new cavitation modeling approach based on refrigerant solubility

2022 ◽  
pp. 1-19
Author(s):  
Fan Zhang ◽  
Nicolas Fillot ◽  
Rudolf Hauleitner ◽  
Guillermo Morales Espejel
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Conservation Equation ◽  
Point Contacts ◽  
Energy Conservation Equation ◽  
Cavitation Region ◽  
Cavitation Intensity ◽  
Thickness Prediction ◽  
Generalized Reynolds Equation ◽  
Good Agreement

Abstract A first cavitation modeling with thermal effects for oil/refrigerant solutions lubricated ElastoHydroDynamic (EHD) point contacts is reported in this work. The solubility of the oil/refrigerant system is introduced into the Generalized Reynolds equation coupled with the elasticity equation and the energy conservation equation. The numerical results show a very good agreement with the published experimental results concerning film thickness prediction. Moreover, the present model describes the cavitation region on a physical basis. A discussion with other cavitation models from the literature is proposed. It puts into light the necessity of taking into account the solubility of the refrigerant into oil for such problems. Compared to pure oil, oil/refrigerant solutions can potentially reduce the amount of liquid oil for the next contact due to its higher cavitation intensity.

Sign in / Sign up

Export Citation Format

Share Document