A new experimental methodology to assess gear scuffing initiation

ABSTRACT

This paper investigates the strong coupling between friction power losses and film thickness that prevent from clearly identifying the mechanism of scuffing through classical test procedures. As the film thickness appears of great influence on the phenomena, a new test method is presented, allowing scuffing initiation study with the film thickness as a key parameter. This new test method allows film thickness variation with minimal friction losses and bulk temperature variations. This procedure has been developed with nitrided steels and a synthetic base oil on a twin disks test rig. Even though asperity contact is considered necessary in literature for scuffing, the test result shows that it can be reached in full film lubrication, potentially through the collapse of the oil film. Different test methods allowing triggering scuffing through different parameters are identified, which shows that a variety of parameters is able to influence scuffing.

KEYWORDS:

• Gear scuffing
• twin disks
• oil film thickness
• bulk temperature
• friction losses
• scuffing experiments
• base oil
• nitrided steel

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors would like to thank SAFRAN Transmission Systems for funding this research and ANRT for their financial support.