This information sheet is designed to provide
currently available tribological information pertaining
to oil lubrication of industrial gears for power
transmission applications. It is intended to serve as
a general guideline and source of information about
gear oils, their properties, and their general tribological
behavior in gear contacts. Manufacturers and
end--users are encouraged, however, to work with
their lubricant suppliers to address specific concerns
or special issues that may not be covered here (such
as greases).
The equations provided herein allow the user to
calculate specific oil film thickness and instantaneous
contact (flash) temperature for gears in
service. These two parameters are considered
critical in defining areas of operation that may lead to
unwanted surface distress. Surface distress may be
scuffing (adhesive wear), fatigue (micropitting and
macropitting), or excessive abrasive wear (scoring).
Each of these forms of surface distress may be
influenced by the lubricant; the calculations are
offered to help assess the potential risk involved with
a given lubricant choice. Flow charts are included as
aids to using the equations.
This information sheet is a supplement to ANSI/
AGMA 2101--C95 and ANSI/AGMA 2001--C95. It
has been introduced as an aid to the gear manufacturing
and user community. Accumulation of feedback
data will serve to enhance future developments
and improved methods to evaluate lubricant related
surface distress.
It was clear from the work on the revision of standard
ANSI/AGMA 2001--C95 (ANSI/AGMA 2101--C95,
metric version) that supporting information regarding
lubricant properties and general tribological
understanding of contacting surfaces would aid in
understanding of the standard and provide the user
with more tools to make an informed decision about
the performance of a geared system. One of the key
parameters is the estimated film thickness. This is
not a trivial calculation, but one that has significant
impact on overall performance of the gear pair. It is
considered in performance issues such as scuffing,
wear, and surface fatigue. This information sheet
provides sufficient information about key lubricant
parameters to enable the user to generate reasonable
estimates about surface distress based on the
collective knowledge available.
AGMA 925-A03-2003 history
2003AGMA 925-A03-2003 Effect of Lubrication on Gear Surface Distress