Lubrication Capacity of Gears of Circular-Arc Tooth-Profile

1988 ◽  
Vol 110 (4) ◽  
pp. 699-703 ◽  
Author(s):  
Awny Y. Attia ◽  
Ahmed M. M. El-Bahloul
Keyword(s):  
Film Thickness ◽  
Carrying Capacity ◽  
Helix Angle ◽  
Load Carrying Capacity ◽  
Test Rig ◽  
Oil Viscosity ◽  
Oil Film ◽  
Lubricant Oil ◽  
Linear Dimensions ◽  
Load Carrying

The paper presents the results of an experimental investigation carried out at Mansoura University Laboratories aiming at studying the effect of change of speed, oil viscosity, and helix angle on the load carrying capacity of the oil film. A three pairs of test gears of 6 DP, 91.5 mm pitch diameter with 22.3, 33.6 and 42.25 deg helix angles were run in power circulating test rig at 100 to 3000 r.p.m. speeds and transmitting tooth load ranging from 185 to 1090 Kp. The test gears were lubricated with oils of 200, 462, and 653 cSt at 40°C kinematic viscosities. The oil film thicknesses between contacting teeth were measured by measuring the changes in capacitance between test gears and transferred to linear dimensions by calibration curves drawn by knowing the changes in capacitance through the gaps between teeth of values known through the amount of backlash. The experimental results show that; Oil film thickness decreases with tooth load, while increases with speed and viscosity of the lubricant. Oil film thickness versus helix angle give an inversed parabola for the smallest and medium tooth loads, while oil film thickness decreases with increasing the helix angle under increased tooth loads. Load carrying capacity increases with speeds and viscosity of the lubricant while decreases with increasing the helix angle.

Influence of Position Errors on EHD Lubrication in Spiral Bevel Gears

2010 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Friction Factor ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Oil Viscosity ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Spiral Bevel

The thermal elastohydrodynamic analysis of lubrication is applied to investigate the influence of misalignments of the meshing members on lubrication in spiral bevel gears. The calculation is based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace’s equations. The full thermal EHD lubrication analysis is applied, therefore, the oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. By using the corresponding computer program, the influence of pinion’s running offset and axial adjustment errors, and angular position error of pinion axis on maximum oil film pressure and temperature, EHD load carrying capacity, and on power losses in the oil film is investigated. On the basis of the obtained results it can be concluded that the EHD load carrying capacity and the friction factor are very sensitive to misalignments of the mating members in the spiral bevel gear pair, the friction factor is reduced by the increase of EHD load carrying capacity and vise versa, and the maximum inlet oil temperature is almost insensitive to the misalignments.

Study on Tribological Performances for Textured Bearing of ICE

2013 ◽  
Vol 690-693 ◽  
pp. 1999-2002
Author(s):  
Fan Ming Meng ◽  
Tao Yang ◽  
Tao Long
Keyword(s):  
Friction Coefficient ◽  
Internal Combustion Engine ◽  
Carrying Capacity ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Load Carrying Capacity ◽  
Oil Film ◽  
Load Carrying ◽  
Inner Surface ◽  
Coupling Algorithm

The influence of dimples on the inner surface of big end bearing in internal combustion engine (ICE) on tribological performances of the bearing was investigated based on Navier-Strokes equation and other associated equations. In doing so, the CFD modulus in the software ANSYS12 version is used to analyze the dimple effect on the tribological performances of the bearing using two-way fluid-solid coupling algorithm. Some mechanisms are revealed about the dimple effect on the load-carrying capacity and friction coefficient of oil film, and the deformation and stress for the textured big end bearing.

The Performance of Hydrodynamic Lubricating Films With Viscosity Variations Perpendicular to the Direction of Motion

1972 ◽  
Vol 94 (1) ◽  
pp. 44-48 ◽  
Author(s):  
E. B. Qvale ◽  
F. R. Wiltshire
Keyword(s):  
Film Thickness ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
End Effects ◽  
Parametric Curves ◽  
One Dimensional ◽  
Lubricating Film ◽  
Families Of Curves ◽  
Load Carrying ◽  
The Coefficient Of Friction

The effects of prescribed viscosity variations across a hydrodynamic lubricating film are studied. The film is strictly one dimensional and end effects are neglected. The viscosity variations are given by three families of curves. The considerable decreases (in the limit 100 percent) and occasional increases in the coefficient of friction that can occur for constant film thickness and load-carrying capacity are evaluated and the results are presented in terms of parametric curves. Important physical situations where these viscosity variations may be observed or produced are described.

Optimal Tooth Modifications in Face-Hobbed Spiral Bevel Gears to Reduce the Influence of Misalignments on Elastohydrodynamic Lubrication

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Carrying Capacity ◽  
Optimization Procedure ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Spiral Bevel

In this study, an optimization methodology is proposed to systematically define the optimal tooth modifications introduced by head-cutter geometry and machine-tool settings to minimize the influence of misalignments on the elastohydrodynamic (EHD) lubrication characteristics in face-hobbed spiral bevel gears. The goal is to simultaneously maximize the EHD load-carrying capacity of the oil film and to minimize power losses in the oil film when different misalignments are inherent in the gear pair. The proposed optimization procedure relies heavily on the EHD lubrication analysis developed in this paper. The core algorithm of the proposed nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated on a face-hobbed spiral bevel gear example. A drastic increase in the EHD load-carrying capacity of the oil film and a reduction in the power losses in the oil film were obtained.

A Theory of Liquid-Solid Lubrication in Elastohydrodynamic Regime

1989 ◽  
Vol 111 (3) ◽  
pp. 440-444 ◽  
Author(s):  
M. M. Khonsari ◽  
S. H. Wang ◽  
Y. L. Qi
Keyword(s):  
Particle Size ◽  
Film Thickness ◽  
Carrying Capacity ◽  
Theoretical Study ◽  
Solid Particles ◽  
Solid Lubrication ◽  
Load Carrying Capacity ◽  
Line Contact ◽  
Load Carrying ◽  
Bounding Surfaces

A theoretical study of the effectiveness of solid particles dispersed in oil in the elastohydrodynamic line contact is presented. The analysis includes the variation of the viscosity and density of the lubricant as a function of pressure. The deformation of solid particles and that of the bounding surfaces are taken into consideration. Results are presented for the variation of the film thickness and the load carrying capacity as a function of the particle size, concentration, and properties of various types of particles.

The Axial Load-Carrying Capacity of Radial Cylindrical Roller Bearings

1970 ◽  
Vol 92 (1) ◽  
pp. 129-134 ◽  
Author(s):  
H. Korrenn
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Oil Viscosity ◽  
Application Range ◽  
Roller Bearings ◽  
Load Carrying ◽  
Thrust Load ◽  
Cylindrical Roller

Thrust load transmission at the contact areas of roller ends and flanges occurs under conditions of pure sliding. Recent theoretical and experimental investigations showed that with adequately designed roller ends and flanges and with a satisfactory lubricant high thrust loads can be accommodated over a wide speed range with fully hydrodynamic lubrication. The conventional methods used for the determination of the safe thrust load should be revised and supplemented. Oil viscosity should be introduced as an important parameter. Contrary to present opinion the hydrodynamic load-carrying capacity at the flange increases with increasing speed. This new knowledge broadens the application range of radial cylindrical roller bearings.

Summary 1: The Influence of Engine Component Inertia Forces on Minimum Oil Film Thickness in Connecting Rod Big-End Bearings

1966 ◽  
Vol 181 (2) ◽  
pp. 155-155
Author(s):  
J. F. Booker ◽  
F. A. Martin
Keyword(s):  
Film Thickness ◽  
Graphical Form ◽  
Load Carrying Capacity ◽  
Eccentricity Ratio ◽  
Connecting Rod ◽  
Oil Film ◽  
First Approximation ◽  
Load Carrying ◽  
The Many ◽  
Inertia Forces

when Designing steadily loaded bearings the designer can usually predict the position of the journal centre quite easily with the aid of one of the many load carrying capacity/eccentricity relationships available. With dynamically loaded bearings, however, the journal path will vary in magnitude and direction throughout the loading cycle and one of the designer's interests is in the trends of maximum eccentricity ratio and the corresponding oil film thickness for various bearing and engine conditions. From experience with journal path predictions for big-end bearings it has been found that the eccentricity ratio in the bearing due to the peak firing load seldom exceeds that obtained by the inertia load loop (although this load is smaller) and therefore, as a first approximation, it is thought justifiable to neglect the gas forces. The results of this inertia study (numerical solution) applied to big-end bearings are presented in a general graphical form. Further work can be carried out on the same basis for main bearings, but this is more difficult to present in a general fashion as there are many more variables to consider, such as the phasing and magnitude of the crank out of balance and the firing order. This report therefore concentrates on the first step, i.e. that of big-end bearings.

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