Thin Film Oxygen Uptake Test (TFOUT)
"The Oxidation Stability of Gear
Oils in Modern Differentials; A More Hostile Environment: Part Two --
Protocol and Precision of the VDOT Gear Oil Test"
Written by T.W.
Selby and A. Ferruzzi, Savant Laboratories Inc., USA
- Presented by T.W. Selby at the 15th International Colloquium
Tribology,
Technische
Akademie Esslingen, Ostfildern, Germany, January, 2006.
(Full Paper
in
Acrobat)
ABSTRACT
For many different reasons, differential temperatures have increased to
levels that may significantly shorten the life of the fluid and
threaten the durability of the differential. Automotive and
lubricant manufacturers are faced with a serious challenge. They
must develop differential fluids with the ability to withstand
oxidation with its potentially highly adverse multiple effects.
These effects include viscosity increase, deposit formation and
oxidative decomposition of the fluid's functionality. Such an
effort requires an effective bench screening test because of the time,
costs, and limited repeatability associated with fleet tests of
differential fluid performance. With this evident challenge, this
paper reports development of a test protocol called the VDOT -- an
acronym for Viscosity, Deposit, and Oxidation Test. This new test
measures viscosity and oxidation change as well as deposit formation
tendency of gear oils as a means of understanding the relationship
between differential temperatures and fluid degradation.
"The Oxidation Stability of Gear
Oils in Modern Differentials; A More Hostile Environment"
Written by C.A. Engel, DaimlerChrysler USA, T.W.
Selby, Savant, Inc., USA, and D.W. Florkowski, DaimlerChrysler USA
- Presented by T.W. Selby at the 14th International Colloquium
Tribology,
Technische
Akademie Esslingen, Ostfildern, Germany, January, 2004.
(Full Paper
in
Acrobat)
ABSTRACT
For many years, rear axle fluid has been capable of handling steadily
increasing levels of energy transfer. However, rear axle
lubricant temperatures have increased to levels that may significantly
shorten the life of the fluid and threaten the durability of the
differential. The effect of increased temperature is to increase
the rate of oxidation of the differential fluid to the point where it
no longer can serve its role of lubrication. The desirable goal
of developing more dependable differential fluids suggests the
development of bench tests for screening and comparing candidate fluids.
The focus of this work is to examine the use of the Thin Film Oxidation
Uptake Test (TFOUT) apparatus ASTM D4742. Using a specific
catalyst more appropriate for the differential fluid environment, this
portion of the study was focused on to determination of the
relationship between axle fluid temperature and axle fluid
degradation. This paper details the development of a basic test
method and its application to the oxidative stability of some
commercially available gear oil formulations.
"Method of Controlling Base Stock
Production
Quality Using a Thin Film Oxygen Uptake Test Technique"
Written by T.W. Selby, Savant, Inc., USA
- Course presented at the American Chemical Society
Symposium on "The Processing, Characterizaation and Application of
Lubricant
Base Oils: Part II", San Diego, California, March 16-17, 1994.
ABSTRACT
The problems of maintaining quality and consistency of base oils and
the
further problem of appropriately choosing base oils for substitution --
i.e. 'read-across' -- has led to the development of a technique using
the
TFOUT device to appriase the oxidation susceptibility of a base oil by
using a package additive at concentration levels considerably lower
than
desired in order to increase the speed of running the TFOUT method.
"Oxidation Studies With a
Modified
Thin-Film Oxygen Uptake Test"
Written by T.W. Selby, Savant, Inc., USA
- SAE Paper #872127, SAE International Fuels and
Lubricants Meeting and Exposition, Toronto, Ontario, Canada, November
2-5,
1985.
ABSTRACT
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