Effects of Surface Finish

1941 ◽  
Vol 8 (2) ◽  
pp. A49-A58
Author(s):  
J. T. Burwell ◽  
J. Kaye ◽  
D. W. van Nymegen ◽  
D. A. Morgan

Abstract Various commercial surface finishes are produced on steel shafts and in Part 1 it is found that the finish has little effect on the operation of a journal bearing in the region of hydrodynamic lubrication but does markedly affect the load capacity. In Part 2 a chemical method of detecting iron in oil is developed with a sensitivity of one part in ten million. This method is used to measure the iron removed during “running-in” from shafts with different surface finishes and under different loads.

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer

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.


Author(s):  
M. Böhle

The numerical prediction of load capacity, stiffness, power loss etc. of hydrostatic journal bearings must be performed for technical applications. CFD offers one possibility but is time consuming. In the present contribution a fast working numerical method is introduced based on the numerical solution of the Reynolds equation for hydrodynamic lubrication (REHL). It is applied in order to examine the flow inside three-dimensional journal bearings. The emphasis lies on the treatment of journal bearings with porous material. By the application of porous material the lubricant can be fed uniformly around the shaft and therefore improves the reliability of the journal bearing. The contribution gives a short outline of the possibilities and limitations of the application of the REHL. A detailed description of a finite difference method is given by which the REHL is solved. It is described in detail how the load capacity, stiffness, volume flow rate etc. of classical hydrodynamic journal bearings and journal bearings with porous material can be treated by the REHL whereby the emphasis lies on the treatment of journal bearings with porous material. Darcy’s law is implemented in the numerical method in order to take into account the pressure loss of the porous material which is the flow restrictor of the journal bearing. Many results are shown and discussed. Pressure distributions, load capacity, volume flow rates through the porous material, direction of force for a hydrodynamic and porous bearing etc. are shown and discussed in dependence of the eccentricity of the shaft.


1959 ◽  
Vol 81 (2) ◽  
pp. 245-252 ◽  
Author(s):  
F. W. Ocvirk ◽  
G. B. DuBois

A method of relating surface finish to minimum oil-film thickness and the corresponding load capacity of plain journal bearings is presented with supporting experimental data. The effect of clearance on load capacity and friction are shown on graphs indicating an optimum bearing clearance.


2004 ◽  
Vol 126 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Tomoko Hirayama ◽  
Takeo Sakurai ◽  
Hiroshi Yabe

Performances of an oil-lubricated spiral-grooved journal bearing are investigated in this paper with special attention paid to cavitation occurrence. The “equivalent flow model,” which is a theoretical scheme for taking the cavitation occurrence into hydrodynamic lubrication theory, is applied to the analyses by a finite difference treatment of the Reynolds equation that deals with the geometry of a finite number of grooves. The calculated results are compared with experimental results under eccentric states, and verified in terms of cavitation map and pressure distribution. The cavitated area ratio, load capacity and bearing stiffness are also theoretically calculated. The difference between the theoretical results with and without consideration of the cavitation occurrence is considerable, and thus the influence of cavitation occurrence should not be ignored in theoretical studies on bearing characteristics.


Author(s):  
D. W. Garside ◽  
S. Hother-Lushington

Experiments are described into the effect of surface finish and clearance upon the value of ZN/P at which a water-lubricated plain journal bearing begins to operate hydrodynamically. It is shown that clearance ratio has only a small effect and that the measured values of the critical ZN/P are between values calculated from the narrow bearing theory of Dubois and Ocvirk and those calculated from the infinitely long bearing solution of Cameron and Wood.


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