Performance of Water-Lubricated Flat Spiral Groove Bearings

1985 ◽  
Vol 107 (2) ◽  
pp. 268-272 ◽  
Author(s):  
Yoshiro Furuishi ◽  
Takuya Suganami ◽  
Sakuei Yamamoto ◽  
Kiyonori Tokumitsu
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Pressure ◽  
Load Carrying Capacity ◽  
Spiral Groove ◽  
Pressure Distributions ◽  
Capacity Limit ◽  
Maximum Value ◽  
Load Carrying ◽  
Flat Spiral ◽  
Solid Type

The 8.6 cm diameter spiral groove bearings, solid type and support type, are designed for water-lubricated thrust application. The load-carrying capacity limit is obtained experimentally. The major conclusions are as follows: (1) The load-carrying capacity depends significantly upon the deformations of the bearing and the runner, which are caused by the temperature and hydrodynamic pressure distributions. (2) The load-carrying capacity limit is determined primarily by the surface roughness and the film thickness, and the maximum value of the load-carrying capacity obtained in this experiment is above 5 × 104 N. (3) The support type bearing gives better load-carrying capacity than the solid type.

Analysis of misaligned water-lubricated polymer bearing with axial grooves

2019 ◽  
Vol 71 (3) ◽  
pp. 411-419 ◽  
Author(s):  
Fangrui Lv ◽  
Chunxiao Jiao ◽  
Donglin Zou ◽  
Na Ta ◽  
Zhu-shi Rao
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Pressure ◽  
Maximum Pressure ◽  
Load Carrying Capacity ◽  
Misalignment Angle ◽  
Content Type ◽  
Load Carrying ◽  
Polymer Bearing ◽  
Journal Misalignment ◽  
Practical Implications

Purpose The purpose of this paper is to analyze the lubrication behavior of misaligned water-lubricated polymer bearings with axial grooves. Design/methodology/approach A lubrication model considering journal misalignment, bush deformation and grooves is established. In dynamic analyses of shaft systems, bearings are usually simplified as supporting points. Thus, an approach for solving the equivalent supporting point location is presented. The influence of misalignment angle and groove number on film thickness, hydrodynamic pressure distribution, load-carrying capacity and ESP location is investigated. Findings As the misalignment angle increases, the location of the maximum pressure and ESP are shifted toward the down-warping end, and the load-carrying capacity of the bearing decreases. In comparison to the nine-groove bearing, the six grooves bearing has a higher load-carrying capacity and the ESP is located closer to the down-warping end for an equivalent misalignment angle. Practical implications The results of this study can be applied to marine propeller shaft systems and other systems with misaligned bearings. Originality/value A study on the lubrication behavior of misaligned water-lubricated polymer bearings with axial grooves is of significant interest to the research community.

Improvement of Punch Profiles for Elastic Circular Contacts

2006 ◽  
Vol 128 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Marilena Glovnea ◽  
Emanuel Diaconescu
Keyword(s):  
Carrying Capacity ◽  
Numerical Evaluation ◽  
Pressure Profile ◽  
Electrical Contacts ◽  
Machine Design ◽  
Load Carrying Capacity ◽  
Uniform Pressure ◽  
Pressure Distributions ◽  
Load Carrying ◽  
Double Integrals

Machine design and electrical contacts involve frequently elastic circular contacts subjected to normal loads. Depending on geometry, these may be Hertzian or surface contacts. Both possess highly nonuniform pressure distributions which diminish contact load carrying capacity. The achievement of a uniform pressure distribution would be ideal to improve the situation, but this violates stress continuity. Instead, the generation of a uniform pressure over most of contact area can be sought. Generally, equivalent punch profile which generates this pressure is found by numerical evaluation of double integrals. This paper simplifies the derivation of punch profile by using an existing correspondence between a polynomial punch surface and elastically generated pressure. First, an improved pressure profile is proposed seeking to avoid high Huber-Mises-Hencky stresses near contact surface. Then, this is approximated by the product between typical Hertz square root and an even polynomial, which yields directly the punch profile. Formulas for normal approach and central pressure are derived.

AN ANALYSIS OF HYDRODYNAMIC PRESSURE DISTRIBUTION AND LOAD CARRYING CAPACITY OF A CONICAL SLIDE BEARING LUBRICATED WITH NON -NEWTONIAN SECOND GRADE FLUI

Tribologia ◽  
2019 ◽  
Vol 284 (2) ◽  
pp. 83-95
Author(s):  
Andrzej Miszczak ◽  
Adam Czaban
Keyword(s):  
Partial Differential Equations ◽  
Small Parameter ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Velocity Vector ◽  
Hydrodynamic Pressure ◽  
Parameter Method ◽  
Load Carrying Capacity ◽  
Small Parameter Method ◽  
Load Carrying

In this paper, the authors present the equations of the hydrodynamic lubrication theory for conical slide bearings lubricated with the oil with properties described by the Rivlin-Ericksen model. It is assumed, that the considered lubricating oil shows non-Newtonian properties, i.e. it is an oil for which, apart from the classic dependence of oil viscosity on pressure, temperature and operating time, there is also a change in dynamic viscosity values caused by the changes of shear rate. The method of a small parameter was used to solve the conservation of momentum, stream continuity, and energy conservation equations. The small parameter method consists in presenting the sought functions (pressure, temperature, components of the velocity vector) in the form of a uniformly convergent series expansion in powers of a constant small parameter. These functions are substituted into the system of basic equations, and then the series are multiplied by the Cauchy method. By a comparison of the coefficients with the same powers of a small parameter, we obtain systems of partial differential equations, from which the subsequent approximations of unknowns of the sought functions are determined. The small parameter method separates the non-linear system of partial differential equations and creates several linear systems of equations. The aim of this work is to derive the equations describing and allowing the determination of the temperature distribution, hydrodynamic pressure distribution, velocity vector components, load carrying capacity, friction force and friction coefficient in the gap of conical slide bearing, lubricated with the oil of the properties described by the Rivlin-Ericksen model, taking into account its viscosity changes due to time of operation.

Analytical Solutions for Incompressible Spiral Groove Viscous Pumps

1974 ◽  
Vol 96 (3) ◽  
pp. 365-369 ◽  
Author(s):  
F. C. Hsing
Keyword(s):  
Carrying Capacity ◽  
Thrust Bearing ◽  
Present Theory ◽  
Load Carrying Capacity ◽  
Governing Equations ◽  
Spiral Groove ◽  
Design Charts ◽  
Load Carrying ◽  
Analytical Expressions ◽  
Dynamic Perturbation

Exact solutions for a class of incompressible spiral-grooved viscous pumps were obtained by solving the dynamic perturbation equations based on the governing equations of the well-known narrow groove theory. The resulting closed-form analytical expressions contain two integration constants which can be determined by appropriate boundary conditions pertinent to a specific application and design. A flat thrust bearing was chosen to illustrate the application of these results. The load-carrying capacity calculated from present theory was compared with those obtained by other investigator [2]. The agreement is extremely good. No attempt was made to generate design charts for various designs since the resulting expressions obtained in this work can be used quite easily in a straightforward fashion.

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.

Isothermal hydrodynamic pressure and load carrying capacity of parallel rough surfaces based on FFT techniques

2020 ◽  
Vol 44 (4) ◽  
pp. 602-612
Author(s):  
Wan Ma
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Rough Surfaces ◽  
Hydrodynamic Pressure ◽  
Radius Of Curvature ◽  
Real Surface ◽  
Load Carrying Capacity ◽  
Time Saving ◽  
Lubricated Contacts ◽  
Load Carrying

In lubricated contacts, the component macrogeometry (radius of curvature) determines the pressure generation, and the surface microgeometry (i.e., roughness) alters it somewhat. However, for parallel surfaces, the microgeometry completely determines the hydrodynamic lubrication. This paper extends earlier work to numerically solve the isothermal hydrodynamic pressure generation and load carrying capacity (LCC) of surfaces with more complicated roughness features. A fast Fourier transform (FFT)-based method is described to quickly obtain the pressure distribution. The method is applicable to both real surface topographies and artificially generated rough surfaces. Results show that it enables one to predict the hydrodynamic pressure, when cavitation is negligible. The relative error of the LCC over the central domain is smaller than 8% and a 500× time saving, compared with the numerical method, is obtained.

THE CHANGE OF FRICTION AND LOAD- CARRYING CAPACITY OF THE JOURNAL BEARING WITH THE CONSIDERATION OF THE OIL AGEING

Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 171-181
Author(s):  
Grzegorz SIKORA ◽  
Andrzej MISZCZAK
Keyword(s):  
Shear Rate ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Hydrodynamic Pressure ◽  
Load Carrying Capacity ◽  
Motor Oil ◽  
Temperature Influence ◽  
Load Carrying ◽  
Viscosity Changes

This paper presents numerical calculations of the hydrodynamic pressure distribution, carrying capacity, and friction coefficient in the gap of a journal bearing. The analysed bearing is lubricated using motor oil. In this paper, oil ageing and temperature influence on viscosity are taken into account. Viscosity changes in the pressure and shear rate are not considered. These changes will be considered in other papers. For the hydrodynamic lubrication analysis, laminar flow of the lubrication fluid and non-isothermal lubrication model of the journal bearing were assumed. As the constitutive equation, the classical, Newtonian model was used. This model was extended by the viscosity changes in temperature and exploitation time. For the considerations, the cylindrical journal bearing with the finite length and smooth bearing, with the full angle of wrap were taken.

THE ANALYSIS OF HYDRODYNAMIC PRESSURE DISTRIBUTION AND LOAD CARRYING CAPACITY IN THE GAP OF SLIDE JOURNAL BEARINGS WITH MICRO-GROOVES

Tribologia ◽  
2018 ◽  
Vol 272 (2) ◽  
pp. 119-126
Author(s):  
Andrzej MISZCZAK
Keyword(s):  
Friction Force ◽  
Carrying Capacity ◽  
Hydrodynamic Pressure ◽  
Load Carrying Capacity ◽  
Isothermal Model ◽  
Slide Bearing ◽  
Flow Parameters ◽  
Load Carrying ◽  
Wrap Angle ◽  
Research Show

The purpose of this paper is to analyse the distribution of hydrodynamic pressure, load carrying capacities, and friction force in the gap of the slide bearing on account of the type, number, and size of micro-grooves on the surface of the sleeve. It was assumed that micro-grooves were distributed equally on the circumference of the sleeve as well as parallel to its axis. Micro-bearings with micro-grooves are more and more often utilized in the technical applications, e.g., in HDD disks or in computer fans. It is advisable to carry out a numerical analysis on the influence of the number and the size of micro-grooves on the value of the basic flow parameters in the slide micro-bearing. A laminar flow of lubricating fluid and an isothermal model of the lubrication of the slide bearing was used for the analysis. A classical Newtonian model was applied as the constitutive equation. A cylindrical slide bearing with the finished length and smooth sleeve, and a full wrap angle was used for the research. The density and thermal conductivity of the oil were considered to be constant in the thin film of oil. The results of measurements of shape and sizes of micro-grooves in real micro-slide bearings were presented by the author in the previous publications. The results of that research are used at present to determine the preliminary assumptions concerning the shape and the size of the micro-grooves. The results obtained in the research show the minor influence of micro-grooves on the value of the friction force and a few percentages rate influence of micro-grooves on the value of load carrying capacity.

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