Compressible fluid film lubrication of rollers with thermal effects

2020 ◽  
Vol 28 (4) ◽  
pp. 1009-1022
Author(s):  
N. Jalatheeswari ◽  
Dhaneshwar Prasad
1988 ◽  
Vol 110 (4) ◽  
pp. 653-658 ◽  
Author(s):  
Dhaneshwar Prasad ◽  
Punyatma Singh ◽  
Prawal Sinha

A theoretical analysis of heavily loaded rigid cylindrical roller bearings lubricated by a thin compressible fluid film, considering cavitation, is presented. The lubricating fluid is assumed to follow the non-Newtonian power law model and the consistency as well as density varies exponentially with pressure and temperature. The modified Reynolds and energy equations (adiabatic case) for a compressible power law fluid are obtained and are solved simultaneously. It is observed that the compressible fluid film pressure is comparatively higher than the incompressible one whereas this trend is reversed in case of temperature. Moreover, consistency and density variations, especially in the pressure peak region, are quite significant.


1973 ◽  
Vol 95 (1) ◽  
pp. 1-32 ◽  
Author(s):  
J. H. Rumbarger ◽  
M. J. Devine ◽  
L. Stallings ◽  
M. Petronio ◽  
W. A. Glaeser ◽  
...  

The volume of lubrication literature continued to expand, reflecting increased experimental and theoretical attention being focused upon this discipline. The following eleven categories of lubrication technology are summarized by authorities in each particular field: Developments in Lubrication (including synthetics and greases); Metal-working Lubricants; Plain Bearings; Frictional Behavior of Materials; Wear; Solid Lubrication; Rolling Bearings; Incompressible and Compressible Fluid Film Lubrication and Bearings; Static and Dynamic Seals; Gears and Splines. Over 600 reference publications are included in the review.


2020 ◽  
Vol 15 ◽  
Author(s):  
Revathi Gadamsetty ◽  
Venkata Subrahmanyam Sajja ◽  
P. Sudam Sekhar ◽  
Dhaneshwar Prasad

Author(s):  
T. Lloyd ◽  
H. McCallion

Developments in high-speed electronic computers have greatly influenced the progress in fluid film lubrication over the past ten years. Static and dynamic oil film parameters have been computed for a wide range of finite geometries, for hydrostatic and hydrodynamic bearings lubricated by compressible and incompressible lubricants. These are either sufficient in themselves or else act as a yardstick against which approximate formulas may be tested. Much use has been made of iterative finite difference schemes, which are particularly well suited to digital computers, and these methods are now more fully understood. Other methods of solution include direct inversion of finite difference matrices and solution by expression of the pressure by some infinite series, a finite number of terms of which give adequate representation. Besides the increase in design data available, there has been substantial progress through a re-examination of the effects of modifying some of the assumptions inherent in most of the available solutions of the Reynolds equation. These include the assumption of constant lubricant viscosity, of rigid surfaces and of laminar flow. Major progress has been witnessed in two fields. The interaction of the lubricant film with elastic boundaries has been shown to be of prime importance in highly loaded contacts such as gears. This has led to the development of the special topic of elastohydrodynamic lubrication theory. The applicability of gas bearings in such growing industries as computers, space vehicles and nuclear reactors has resulted in great activity and progress in this field.


Wear ◽  
1980 ◽  
Vol 63 (1) ◽  
pp. 25-40 ◽  
Author(s):  
J.B. Medley ◽  
A.B. Strong ◽  
R.M. Pilliar ◽  
E.W. Wong

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Toshiharu Kazama ◽  
Yukihito Narita

The mixed and fluid film lubrication characteristics of plain journal bearings with shape changed by wear are numerically examined. A mixed lubrication model that employs both of the asperity-contact mechanism proposed by Greenwood and Williamson and the average flow model proposed by Patir and Cheng includes the effects of adsorbed film and elastic deformation is applied. Considering roughness interaction, the effects of the dent depth and operating conditions on the loci of the journal center, the asperity-contact and hydrodynamic fluid pressures, friction, and leakage are discussed. The following conclusions are drawn. In the mixed lubrication regime, the dent of the bearing noticeably influences the contact and fluid pressures. For smaller dents, the contact pressure and frictional coefficient reduce. In mixed and fluid film lubrication regimes, the pressure and coefficient increase for larger dents. Furthermore, as the dent increases and the Sommerfeld number decreases, the flow rate continuously increases.


2000 ◽  
Vol 122 (4) ◽  
pp. 866-869 ◽  
Author(s):  
Toshiharu Kazama

The optimum design of hydrostatic spherical bearings in fluid film lubrication is examined theoretically. The analytical solutions are derived for both fitted and clearance types of bearings with capillary and orifice restrictors. The optimal size based on the minimum power loss and the maximum stiffness is presented, and the difference between two types of bearings is discussed. [S0742-4787(00)02204-9]


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