Relating High-Temperature, High-Shear Viscosity to Bearing Oil Film Thickness Measurements

Author(s):  
SA Cryvoff ◽  
AK Deysarkar
2015 ◽  
Vol 27 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Emil Nowiński ◽  
Bolesław Giemza ◽  
Marek Domański

Abstract This paper presents problems of oil film thickness measurements, especially during tribological experiments. There are many methods of oil layer measurement. More of them is used in measurement apparatus. Most popular method to oil film thickness is electric method. Authors indicate that triboelectrical phenomenon disrupts the real value of resistance because of charge particles which change conductance of the oil layer.


2015 ◽  
Vol 47 ◽  
pp. 102-108 ◽  
Author(s):  
Prateek Sharma ◽  
Tzvetelin T. Dessev ◽  
Peter A. Munro ◽  
Peter G. Wiles ◽  
Graeme Gillies ◽  
...  

Author(s):  
G. M. Hamilton ◽  
W. G. Robertson

The shear stresses in an elastohydrodynamic oil film have been calculated. In the inlet region they are of the order of 107 and in the outlet 109 dyn/cm2. While such stresses do not affect mineral oils they are liable to cause breakdown of polymers in multigrade oils. To test this film thickness measurements were carried out in a four-disc machine with a range of polymer solutions. It was found that the degree of viscosity loss varied greatly; some polymer solutions showed no loss whilst others merely exhibited their base oil viscosity. By measuring the viscosity of samples scraped from the disc surfaces it was possible to divide the observed viscosity loss into permanent and temporary components.


Author(s):  
J. Wang ◽  
P. Yang ◽  
M. Kaneta

The Newtonian thermal EHL analyses of point contacts with two-sided surface roughness have been performed under pure rolling, sliding/rolling and simple sliding conditions. Thermal results are compared with isothermal ones. It has been found that the sliding motion produces high temperature rise and reduces the film thickness greatly. The influence of amplitude and wavelength of the surface roughness on variation of tribo-characteristics of oil film is also discussed.


Author(s):  
Yan-Qin Zhang ◽  
Ji-Chang Sun ◽  
Peng-Rui Kong ◽  
Xiang-Bin Kong ◽  
Xiao-Dong Yu

In order to improve the lubrication performance of the double-rectangular cavity hydrostatic thrust bearing, this paper selects the temperature rise characteristics of hydrostatic bearing as the research object under the conditions of changing oil film thickness and different working conditions. Using the dynamic mesh method with variable viscosity dynamic simulation, the changing temperature rise curves under different inlet flow velocities and rotating speeds are obtained. This paper obtains the changing laws of oil film thickness and temperature under the hydrostatic bearing running in no-load, load 2.5 t, load 10 t and the rotating speeds of 40 r/min, 60 r/min and 80 r/min. Under the low rotating speed, the high temperature region in the oil cavity mainly concentrates on the counter flow side. With the increase of working speed, the high temperature region on the counter flow side expands to the oil seal side obviously. When the oil film thickness was in the range of 0.04 mm to 0.07 mm, the temperature of oil seal edge increased with the increase of the inlet flow velocity. Using the FLUENT software, the variable viscosity simulation of hydrostatic bearing is carried out under different oil film thickness, and the temperature distribution of oil cavity is obtained. Finally, the correctness of theoretical analysis and simulation are verified by conducting experiment.


Author(s):  
H Moreau ◽  
P Maspeyrot ◽  
D Bonneau ◽  
J Frène

This paper describes the experimental measurements and the theoretical calculations of oil-film thickness in a dynamically loaded connecting-rod big-end bearing. Four eddy current gap sensors for each bearing are used to measure the oil-film thickness and to deduce the bearing trajectories. Experimental data for crankshaft main bearings are easy to obtain but connecting-rod bearings are more difficult to control due to the difficulty of installing instrumentation on connecting-rods that are rotating and reciprocating. The solution uses a mechanical linkage fixed under the piston axis. The elastohydrodynamic model considers connecting-rod elastic deformations. The calculation process uses finite element and Newton-Raphson methods for the numerical analysis. Comparisons of both the load and crankshaft speed effects are made between experiment and the theory.


Sign in / Sign up

Export Citation Format

Share Document