A new scuffing test using contra-rotation
File(s)
Accepted version
Author(s)
Ingram, M
Hamer, C
Spikes, H
Type
Journal Article
Abstract
The mode of lubricant failure known as scuffing provides a significant design constraint in high sliding gears, cams and metal cutting and forming processes. It is therefore important to have an effective test method to measure the scuffing resistance of lubricant formulations. In most existing scuffing bench tests, a moving surface is rubbed against a stationary one at a fixed sliding speed and the load at which scuffing occurs is determined. This approach has two disadvantages. One is that wear of the stationary surface can lead to a large decrease in effective contact pressure during a test. The second is that viscous lubricants often generate significant elastohydrodynamic films at the sliding speeds employed. This means that the scuffing tests measure a complex combination of the influence of the fluid and boundary film-forming properties of the lubricant on scuffing rather than reflecting solely the influence of lubricant formulation.
This paper describes a new scuffing test method in which the two metal surfaces are rubbed together in mixed rolling–sliding with the two surfaces moving in opposite directions with respect to the contact, i.e. in contra-rotation. This enables the sliding speed to be decoupled from the entrainment speed so that the scuffing properties of a lubricant can be determined in boundary lubrication conditions over a wide range of sliding speeds. Also, because both surfaces move relative to the contact, wear is distributed and this minimises changes in contact pressure during a test.
This paper describes a new scuffing test method in which the two metal surfaces are rubbed together in mixed rolling–sliding with the two surfaces moving in opposite directions with respect to the contact, i.e. in contra-rotation. This enables the sliding speed to be decoupled from the entrainment speed so that the scuffing properties of a lubricant can be determined in boundary lubrication conditions over a wide range of sliding speeds. Also, because both surfaces move relative to the contact, wear is distributed and this minimises changes in contact pressure during a test.
Date Issued
2015-02-19
Date Acceptance
2015-01-30
Citation
Wear, 2015, 328-329, pp.229-240
ISSN
1873-2577
Publisher
Elsevier
Start Page
229
End Page
240
Journal / Book Title
Wear
Volume
328-329
Copyright Statement
© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Science & Technology
Technology
Engineering, Mechanical
Materials Science, Multidisciplinary
Engineering
Materials Science
Lubricated wear including scuffing
Gears
Lubricant additives
Boundary lubrication
CONTACTS
Publication Status
Published