scholarly journals Inverse Approach for Calculating Temperature in Thermal Elasto-Hydrodynamic Lubrication of Line Contacts

10.5772/14821 ◽  
2011 ◽  
Author(s):  
Li-Ming Chu ◽  
Hsiang-Chen Hsu ◽  
Jaw-Ren Lin ◽  
Yuh-Ping Chang
Keyword(s):  
Hydrodynamic Lubrication ◽  
Inverse Approach ◽  
Line Contacts

Numerical Analysis for Influence of Plastic and Elastic Deformation of Rough Surfaces on PEHL for Line Contacts

Tribology ◽  
2005 ◽  
Author(s):  
R. J. Niu ◽  
P. Huang
Keyword(s):  
Plastic Deformation ◽  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Paper Analysis ◽  
Line Contact ◽  
Plastic Deformations ◽  
Rolling Contacts ◽  
Line Contacts ◽  
Elastic And Plastic Deformations ◽  
Strain Relationship

In the present paper, analysis of elasto-plasto-hydrodynamic lubrication (PEHL) in the line contact is carried out to investigate the effect of heavily loaded roll-over on the change in profile of indents. The pressure and film thickness profiles are obtained to solve the Reynolds and film thickness equations simultaneously. And, both the elastic and plastic deformations of the contact, featured with an indent, have been considered. A multi-grid numerical algorithm used in EHL of line contacts is modified and then used for the oil lubricated rolling contacts. In the program, stress and plastic deformation of the indent profile are calculated with the hardening plastic stress-strain relationship according to the theories of plasticity when pressure excesses the yield stress. The results, with and without considering plastic deformation, are compared to show the different influences on the pressure and film thickness. Analysis shows that since the plastic deformation will change the surface roughness, it will significantly change the pressure but film thickness.

Squeeze and Entraining Motion in Nonconformal Line Contacts. Part II—Elastohydrodynamic Lubrication

1989 ◽  
Vol 111 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Rong-Tsong Lee ◽  
B. J. Hamrock
Keyword(s):  
Transient Process ◽  
Peak Pressure ◽  
Initial Conditions ◽  
Hydrodynamic Lubrication ◽  
Elastohydrodynamic Lubrication ◽  
Pressure Profile ◽  
Maximum Pressure ◽  
Steady State Condition ◽  
Maximum Peak ◽  
Line Contacts

A fast numerical approach to the solution of elastohydrodynamic lubrication (EHL) of line contacts in combined entraining and normal squeeze motion is developed. The initial conditions for the pressure profile, the central normal squeeze velocity, and the location of the outlet boundary at any specified dimensionless load and dimensionless entraining velocity were obtained from the hydrodynamic lubrication study in Lee and Hamrock (1988). The pressure and film thickness were obtained by solving the transient Reynolds, elasticity, rheology, and time-dependent central squeeze velocity equations. The squeeze effect on this transient EHL problem has been proved in that the maximum peak pressure was always higher than the maximum pressure calculated at the steady-state condition. The needle-shaped pressure profile during the transient process produced a dimpled shape near the center of the contacts. In general, the maximum peak pressure increased with increasing dimensionless load, decreasing dimensionless entraining velocity, and increasing dimensionless materials parameter. The dynamic performance parameters were plotted and are a function not only of the dimensionless velocity parameter (as described in Lee and Hamrock, (1988)), but also of the dimensionless load, the dimensionless entraining velocity, and the dimensionless materials parameter. The major factor causing the pressure gradient to be infinity during the transient process was the viscosity. A non-Newtonian fluid is suggested to execute the problem for high load and low entraining velocity.

Inverse approach for calculating temperature in EHL of line contacts

2009 ◽  
Vol 42 (8) ◽  
pp. 1154-1162 ◽  
Author(s):  
Li-Ming Chu ◽  
Hsiang-Chen Hsu ◽  
Jaw-Ren Lin ◽  
Yuh-Ping Chang
Keyword(s):  
Inverse Approach ◽  
Line Contacts

Squeeze and Entraining Motion in Nonconformal Line Contacts. Part I—Hydrodynamic Lubrication

1989 ◽  
Vol 111 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Rong-Tsong Lee ◽  
B. J. Hamrock
Keyword(s):  
Hydrodynamic Lubrication ◽  
Dynamic Performance ◽  
Elastohydrodynamic Lubrication ◽  
Constant Load ◽  
Initial Guess ◽  
Maximum Pressure ◽  
Performance Parameters ◽  
Velocity Parameter ◽  
Dimensionless Velocity ◽  
Line Contacts

An analytical solution to the problem of combined entraining and normal squeeze motion in nonconformal line contacts hydrodynamically lubricated with an isoviscous, incompressible lubricant has been obtained without any limitations on dimensionless load, dimensionless entraining velocity, and dimensionless velocity parameter. The dimensionless load and entraining velocity are fixed for a complete range of operating parameters for both normal approach and separation. Results show that the lubrication of the outlet boundary and the location of the maximum pressure move upstream into the inlet region as the central film thickness decreases or the dimensionless velocity parameter increases from negative (normal approach) to positive (normal separation). All the dynamic performance parameters relating to the steady-state bearing performance parameters have been found to be functions of only the dimensionless velocity parameter with constant load and entraining velocity. The dimensionless velocity parameter significantly influenced those dynamic performance parameters. The results of this study will be used as the initial guess for the elastohydrodynamic lubrication of nonconformal line contacts.

Modelling of damping in lubricated line contacts – Applications to spur gear dynamic simulations

2016 ◽  
Vol 230 (7-8) ◽  
pp. 1222-1232 ◽  
Author(s):  
M Ankouni ◽  
AA Lubrecht ◽  
P Velex
Keyword(s):  
Hydrodynamic Lubrication ◽  
Spur Gear ◽  
Operating Conditions ◽  
Spur Gears ◽  
Major Contributor ◽  
Structural Damping ◽  
Dynamic Simulations ◽  
Contact Conditions ◽  
Line Contacts ◽  
Set Up

The various damping mechanisms in elasto-hydrodynamic lubrication contacts are investigated with the objective of deriving damping models representative of the lubricant contributions which can readily be used in gear dynamic simulations. Several simplified models are proposed which make it possible to simulate the damping caused by tooth friction and lubricant squeezing by the teeth with and without momentary contact losses and impacts. A one-degree-of-freedom gear dynamic model is set up which combines these lubricant damping sources along with structural damping. A number of comparisons with benchmark experimental evidence are presented for a range of operating conditions and gear geometries which prove that the proposed approach is sound in the case of spur gears. It is shown that the damping associated with lubricant squeezing contributes for the most part when contact losses and shocks between the teeth occur at critical speeds. For permanent contact conditions, however, structural damping appears as the major contributor to the overall system damping.

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