Full Film Lubrication of Strip Rolling

1994 ◽  
Vol 116 (3) ◽  
pp. 569-576 ◽  
Author(s):  
Chung-Yeh Sa ◽  
William R. D. Wilson
Keyword(s):  
Hydrodynamic Lubrication ◽  
Thermal Analyses ◽  
Speed Ratio ◽  
Process Variables ◽  
Strip Rolling ◽  
Polyphenyl Ether ◽  
Roll Torque ◽  
Global Condition ◽  
Roll Separating Force ◽  
Film Lubrication

A mathematical model for liquid lubricated strip rolling in the full-film regime is developed. The model combines slab plasticity, hydrodynamic lubrication and thermal analyses to relate local and global condition to process variables and material properties. The predictions of the model are compared with experimental measurements of outlet speed ratio, roll separating force and roll torque in rolling 1100-H14 aluminum with a viscous mineral oil and 5P4E polyphenyl ether as lubricants. The excellent agreement which is obtained provides powerful support of the validity of the model.

Computer-Aided Analysis of the Deformations and Temperatures in Strip Rolling

1978 ◽  
Vol 100 (2) ◽  
pp. 159-166 ◽  
Author(s):  
G. D. Lahoti ◽  
S. N. Shah ◽  
T. Altan
Keyword(s):  
Computer Program ◽  
Metal Flow ◽  
Rolling Process ◽  
Strip Rolling ◽  
Roll Torque ◽  
Computer Aided Analysis ◽  
Before And After ◽  
Theoretical Predictions ◽  
Roll Separating Force ◽  
Simultaneous Heat

This paper describes the principles and the application of two mathematical models, developed for predicting the significant variables of the strip rolling process. The first model and the associated computer program ROLING can estimate the roll-separating force and the roll torque. This model includes the most up-to-date analyses of (a) the plastic deformation in the strip, (b) the elastic compression and recovery of the strip before and after rolling, and (c) the elastic deformation of the rolls. The second model and the associated computer program ROLTEM have been developed to simulate the metal flow and temperatures in strip rolling. They consider simultaneous heat generation, heat transport, and heat transfer during rolling using a finite-difference algorithm. The predictions made by the computer programs ROLING and ROLTEM have been compared with existing experimental data. The results indicate that the agreement of theoretical predictions with experimental results is well within acceptable engineering accuracy.

scholarly journals Elastic hydrodynamic lubrication analysis for a sine movable tooth drive

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881410 ◽  
Author(s):  
Lizhong Xu ◽  
Wentao Song
Keyword(s):  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Normal Operation ◽  
Speed Ratio ◽  
Input Shaft ◽  
Load Carrying ◽  
Radial Dimension ◽  
Lubrication Condition ◽  
Shaft Rotation Angle ◽  
Large Speed

The sine movable tooth drive has small radial dimension such that the heat, caused by friction, becomes an important factor in deciding its load-carrying ability. It is important to determine the amount of tooth lubrication in order to reduce the heat caused by the friction. This study provides equations for the meshing performance and provides the forces for the sine movable tooth drive. Using these equations, the minimum oil film thickness for the drive system is investigated. Results show that the minimum film thickness between the movable tooth and input shaft or shell changes periodically along the input shaft rotation angle. A large movable tooth radius and a movable tooth rotation radius could increase the film thickness between the movable tooth and the input shaft or the shell. In addition, a large speed ratio could increase the film thickness between the movable tooth and the input shaft, but this would also decrease the film thickness between the movable tooth and the shell. A large sine amplitude could increase the film thickness between the movable tooth and the input shaft, but this does not change the film thickness between the movable tooth and the shell. Under normal operation speeds, the hydrodynamic lubrication condition occurs between the movable tooth and the input shaft, and the partial membrane hydrodynamic state occurs between the movable tooth and the shell.

Hydrodynamic Lubrication in Rolling of Thin Strips

1972 ◽  
Vol 94 (1) ◽  
pp. 317-328 ◽  
Author(s):  
B. Avitzur ◽  
G. Grossman
Keyword(s):  
Dimensionless Parameter ◽  
Hydrodynamic Lubrication ◽  
Strip Thickness ◽  
Thin Strip ◽  
Strip Rolling ◽  
Roll Velocity ◽  
The Subject ◽  
Hydrodynamic Effects ◽  
Lubrication Effect ◽  
Lubricant Viscosity

The process of thin strip rolling is analyzed considering the hydrodynamic lubrication effect. Hydrodynamic lubrication prevails when a film of lubricant fully separates the rolls from the strip. The conditions which produce hydrodynamic effects are the subject of this study. A dimensionless parameter, the Sommerfeld Number, is defined as a function of lubricant viscosity, roll velocity, strip thickness, and yield strength of the material. The critical Sommerfeld Number for occurrence of hydrodynamic lubrication is determined. Increasing lubricant viscosity and roll velocity or decreasing flow stress and strip thickness produce a larger Sommerfeld Number with an increased tendency for hydrodynamic effects. The thickness of the lubricant film and the velocity of the emerging strip are both determined as functions of the Sommerfeld Number, reduction in strip thickness, and of roll diameter. Graphical and numerical examples are presented.

Evaluation of Lubricants for High-Temperature Ball Bearing Applications

1968 ◽  
Vol 90 (1) ◽  
pp. 106-112 ◽  
Author(s):  
R. J. Parker ◽  
E. N. Bamberger ◽  
E. V. Zaretsky
Keyword(s):  
Ball Bearing ◽  
Hydrodynamic Lubrication ◽  
Rolling Contact Fatigue ◽  
Percent Level ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Low Oxygen ◽  
Outer Race ◽  
Polyphenyl Ether ◽  
Paraffinic Oil

Several lubricants that are considered candidates for ball bearing applications in the temperature range of 500 to 700 deg F were investigated in full-scale ball bearings and in a rolling-contact fatigue rig. Bearing endurance tests indicate that a synthetic paraffinic oil with an antiwear additive can perform beyond catalog rating at temperatures up to 600 deg F in a low oxygen environment. In a rolling-contact fatigue tester, this synthetic paraffinic oil exhibited at least twice the fatigue life at the 10 percent level of a fluorocarbon and a polyphenyl ether. Based on bearing race groove appearance, elasto-hydrodynamic lubrication was apparent at outer-race temperatures up to 700 deg F.

Roll-Force and Torque Coefficients for Hot-Strip Steel Mill

1960 ◽  
Vol 82 (3) ◽  
pp. 683-688
Author(s):  
B. N. Garudachar ◽  
H. A. Peterson
Keyword(s):  
Rolling Mill ◽  
Roll Force ◽  
Steel Mill ◽  
Strip Rolling ◽  
Steel Rolling ◽  
Strip Steel ◽  
Roll Torque ◽  
Hot Strip ◽  
Flat Strip ◽  
Cold Mill

This paper provides results of an analytical and computer investigation to determine the numerical coefficients involved in the roll-force and roll-torque equations pertaining to a single stand in a multistand, tandem, steel rolling mill. To the authors’ knowledge, such information has not appeared in the literature to date. The coefficients for a typical hot mill are compared with those obtained for a typical cold mill. The principles of gage control are discussed. The theories on flat-strip rolling are reviewed briefly.

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