ANSI/AGMA 9005- E02
(Revision of
ANSI/AGMA 9005--D94)
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005- E02
Industrial Gear Lubrication
American
National
Standard
Industrial Gear Lubrication
ANSI/AGMA 9005--E02
(Revision of ANSI/AGMA 9005--D94)
Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus and other criteria for approval have been met by the
standards developer.
Consensus is established when, in the judgment of the ANSI Board of Standards Review,
substantial agreement has been reached by directly and materially affected interests.
Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a
concerted effort be made toward their resolution.
The use of American National Standards is completely voluntary; their existence does not
in any respect preclude anyone, whether he has approved the standards or not, from
manufacturing, marketing, purchasing or using products, processes or procedures not
conforming to the standards.
The American National Standards Institute does not develop standards and will in no
circumstances give an interpretation of any American National Standard. Moreover, no
person shall have the right or authority to issue an interpretation of an American National
Standard in the name of the American National Standards Institute. Requests for interpretation of this standard should be addressed to the American Gear Manufacturers
Association.
CAUTION NOTICE: AGMA technical publications are subject to constant improvement,
revision or withdrawal as dictated by experience. Any person who refers to any AGMA
Technical Publication should be sure that the publication is the latest available from the
Association on the subject matter.
[Tables or other self--supporting sections may be quoted or extracted. Credit lines should
read: Extracted from ANSI/AGMA 9005--E02, Industrial Gear Lubrication, with the permission of the publisher, the American Gear Manufacturers Association, 500 Montgomery
Street, Suite 350, Alexandria, Virginia 22314.]
Approved December 31, 2002
ABSTRACT
This standard provides lubrication guidelines for enclosed and open gearing which is installed in general
industrial power transmission applications. It is not intended to supplant specific instructions from the gear
manufacturer.
Published by
American Gear Manufacturers Association
500 Montgomery Street, Suite 350, Alexandria, Virginia 22314
Copyright  2002 by American Gear Manufacturers Association
All rights reserved.
No part of this publication may be reproduced in any form, in an electronic
retrieval system or otherwise, without prior written permission of the publisher.
Printed in the United States of America
ISBN: 1--55589--800--9
ii
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Contents
Page
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
1
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2
Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3
Overview of lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4
Minimum performance requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6
Open gearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Annexes
A
Lubricant properties and methods of measurement . . . . . . . . . . . . . . . . . . . . . . 11
B
Guideline for lubricant viscosity grade selection . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C
Guideline for determining lubricant type based on application . . . . . . . . . . . . . . 24
D
Guideline for lubrication of open gearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
E
Guideline for condition monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
F
Lubrication system maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Tables
1
Minimum performance requirements for inhibited (RO) oils . . . . . . . . . . . . . . . . . 4
2
Minimum performance requirements for antiscuff/antiwear (EP) oils . . . . . . . . . 5
3
Minimum performance requirements for compounded (CP) oils . . . . . . . . . . . . . 6
4
Viscosity grade requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
iii
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Foreword
[The foreword, footnotes and annexes, if any, in this document are provided for
informational purposes only and are not to be construed as a part of ANSI/AGMA Standard
9005--E02, Industrial Gear Lubrication.]
AGMA formed the Lubrication Committee in 1938 to study gear lubrication problems. This
committee drafted tentative standard 250.01, Lubrication of Enclosed and Open Gearing,
which was accepted in 1943 and adopted as a full standard in 1946. Lubrication Standard
250.01 was revised to include only industrial enclosed gearing and was accepted by the
membership in 1955 as AGMA 250.02. AGMA 250.03, which was published in 1972,
superseded AGMA 250.02 as well as AGMA 250.02A, Typical Manufacturer’s Oils Meeting
AGMA Standard 250.02, May, 1956; and AGMA 252.02, Mild Extreme Pressure
Lubricants, May, 1959. The list of Typical Manufacturer’s Oils was eliminated due to
difficulties in keeping such a list up to date. AGMA 250.03 contained instead, a list of
detailed specifications which had to be met before an oil could be recommended for use in
AGMA rated gear drives. It then became the responsibility of the oil supplier to certify a
particular product as meeting AGMA specifications. AGMA 250.04, published in 1981,
eliminated lead naphthenate as an EP additive and adjusted the AGMA lubricant numbering
system to be coincident with the viscosity ranges established by the American Society for
Testing Materials (ASTM 2422), the British Standards Institute (B.S. 4231), and the
International Standards Organization (ISO 3448).
The elimination of open gearing, where the bearings are lubricated separately, from AGMA
250.02 created the need for a new standard to cover this area of lubrication. AGMA
Standard AGMA 251.01, Lubrication of Industrial Open Gearing, was approved in April,
1963. This standard was revised in September, 1974. AGMA 251.02 extended coverage to
bevel gears. Other changes included the addition of AGMA Lubricant Numbers based on
the ASTM viscosity system and complete specifications for R & O gear oils and EP gear
lubricants, and the addition of an appendix on test procedures and limits.
AGMA Standard 9005--D94 again combined enclosed and open gearing, superseding
AGMA 250.04 and AGMA 251.02. In addition, it was updated to reflect market changes in
availability of heavy bodied open gear lubricants. It was also expanded to provide coverage
of modern technology in the area of synthetic oils. Synthetic oils were recognized as a
separate class of lubricants with their own specification requirements. Specifications of EP
oils were upgraded to reflect advances in technology. EP oils were no longer recommended
for wormgear service. Pitchline velocity replaced center distance as the parameter for
lubricant selection in other than double enveloping wormgear applications. Annex B
provided a copy of table 3 from AGMA 250.04 for information only.
References to Saybolt viscosity (SSU) were eliminated in favor of kinematic viscosity
(mm2/s, commonly referred to as cSt). This was consistent with practices of the American
Society for Testing Materials, the Society of Tribologists and Lubrication Engineers, the
British Standards Institution, and industry in general. Annex A provided information on the
theory of elastohydrodynamic lubrication.
ANSI/AGMA 9005--E02 attempts to offer the end user and equipment builder more
definitive guidelines for selecting lubricants based on current theory and practice in the
industry, and attempts to align with current ISO standards. The document is focused on
providing the correct viscosity and performance level for the application by providing the
user a series of informative tables to match their equipment type, operation, and needs to
define an appropriate finished lubricant. The end user is encouraged to work with their
equipment builder and lubricant supplier to achieve the most reliable system for their needs.
iv
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
The first draft of ANSI/AGMA 9005--E02 was made in May, 1999. It was approved by the
AGMA membership on March 13, 2003. It was approved as an American National Standard
on December 31, 2002.
Suggestions for improvement of this standard will be welcome. They should be sent to the
American Gear Manufacturers Association, 500 Montgomery Street, Suite 350, Alexandria,
Virginia 22314.
v
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
PERSONNEL of the AGMA Industrial Gear Lubrication Committee
Chairman: Brian M. O’Connor . . . . . . . . . . . . . . . . . . . The Lubrizol Corporation
ACTIVE MEMBERS
T. Barnes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.D. Barrett . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.B. Cardis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S.W. Eliot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R. Gapinski . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M.A. Garcia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.R. Gonnella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.C. Henderson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S.R. Hutchens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J.J. Kolonko . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.A. Lauer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.J. Speck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.G. Woodley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J.A. Zakarian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Harnischfeger Corporation
Castrol Industrial North America, Inc.
ExxonMobil R&E Company
ExxonMobil L&S Company
The Lubrizol Corporation
Repsol--YPF
Equilon Enterprises L.L.C.
Equilon Enterprises L.L.C.
Cone Drive Operations, Inc.
The Falk Corporation
Kluber Lubrication N.A.L.P.
The Lubrizol Corporation
Equilon Enterprises L.L.C.
Chevron Texaco Global Lubricants
ASSOCIATE MEMBERS
K.E. Acheson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.C. Becker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
K. Brinker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R. Ciesko . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R.J. Drago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R. Errichello . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T. Glasener . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S. Granger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J.E. Hardy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
G. Henriot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F. Hunscher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V. Ivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B. Kearney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.G. Milburn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M. Peculis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.E. Phillips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V.Z. Rychlinski . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
L.J. Smith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R.G. Smith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D. Townsend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.C. Uherek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. Wallace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi
The Gear Works – Seattle, Inc.
Nuttall Gear L.L.C.
General Motors Corporation
RC Associates – Consultants
Boeing Defense & Space Group
GEARTECH
Xtek, Inc.
Equilon Enterprises L.L.C.
Cone Drive Operations, Inc.
Consultant
Meritor Automotive
Xtek, Inc.
Elco Corporation
Milburn Engineering
Cleveland Gear Company
Rockwell Automation/Dodge
Brad Foote Gear Works, Inc.
Consultant
Philadelphia Gear Corporation
Townsend Engineering
Flender Corporation
Iron Ore Company of Canada
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
American National Standard --
worm. These guidelines may or may not be
applicable to non--metallic gears.
Industrial Gear
Lubrication
This standard does not address grease lubricated
enclosed drives, aerospace applications or address
special regulatory requirements associated with
food or drug handling or manufacturing equipment.
This standard is not intended to replace any existing
standards such as in automotive applications where
similar gearing may be used.
NOTE: This standard is not intended to supplant any
specific recommendations of gear manufacturers.
1 Scope
This standard provides the end user, original equipment builder, gear manufacturer, and lubricant
supplier with guidelines for minimum performance
characteristics for lubricants suitable for use in
general power transmission applications. These
guidelines cover both open and enclosed gearing
which have been designed and rated in accordance
with applicable AGMA standards. The types of
gearing included herein are metallic spur, helical
including herringbone, straight and spiral bevel, and
ISO number
ISO 2160:1998
ASTM number
ASTM D130--94
ISO 2592:2000
ASTM D92--97
ISO 2909:1991
ASTM D2270--93
ISO 3104:1994
ASTM D445--96
ISO 3448:1992
ISO 4263:1995
ASTM D2422--97
ASTM D943--95
ISO 6247:1998
ASTM D892--95
ISO 7120:1987
ASTM D665--95
ISO 12937:2000
ASTM D6304--00
ISO 14635--1:2000
ASTM D5182--97
-- --
ASTM D2711--99
-- --
ASTM 2893--99
-- --
ASTM D2983--87
2 Normative references
The following standards contain provisions, which
through reference in this text, constitute provisions of
this standard. At the time of publication, the editions
listed were valid. All standards are subject to
revision and parties to agreements based on this
standard are encouraged to apply the most recent
editions of the standards indicated below.
Title
Petroleum products -- Corrosiveness to copper -- Copper strip
test
Determination of flash and fire points -- Cleveland open cup
method
Petroleum products -- Calculation of viscosity index from
kinematic viscosity
Petroleum products -- Transparent and opaque liquids -Determination of kinematic viscosity and calculation of
dynamic viscosity
Industrial liquid lubricants -- ISO viscosity classification
Petroleum products – Determination of water -- Coulometric
Karl Fischer titration method
Petroleum products -- Determination of foaming
characteristics of lubricating oils
Petroleum products and lubricants -- Petroleum oils and other
fluids -- Determination of rust--preventing characteristics in the
presence of water
Petroleum products – Determination of water in liquid
petroleum products by Karl Fischer reagent
Gears -- FZG Test procedures -- Part 1: FZG test method
A/8,3/90 for relative scuffing load--carrying capacity of oils
Standard test method for demulsibility characteristics of
lubricating oils
Standard test method for oxidation characteristics of
extreme--pressure lubrication oils
Standard test method for low--temperature viscosity of
automotive fluid lubricants measured by Brookfield viscometer
1
ANSI/AGMA 9005--E02
3 Overview of lubrication
When one thinks of gear lubrication, the primary
concern is usually about the gears. In addition to the
gears themselves, there are many other components that must also be served by the fluid in the
gearbox. Consideration should also be given to the
bearings, seals, and other auxiliary equipment, e.g.,
pumps and heat exchangers, that may be affected
by the choice of lubricant. With many open gear
drives, the bearings are lubricated independently of
the gears, thus allowing for special fluid requirements should the need arise. However, most
enclosed and semi--enclosed gear drives utilize one
lubricant and lubricant source of supply for the gears,
bearings, seals, pumps, etc. Therefore, selecting
the correct lubricant for a gear drive system includes
addressing the lubrication needs of not only the
gears, but also all other associated components in
the system.
3.1 General
A lubricant is used in gear applications to control
friction and wear between the mating surfaces, and
in enclosed gear drive applications, to transfer heat
away from the contact area. It also serves as a
medium to carry the additives that may be required
for special functions. There are many different
lubricants available to accomplish these tasks.
Lubricant properties can be quite varied depending
on the source of the base stock(s) and the type of
additive(s) used. Terminology describing the performance properties of lubricants can be just as varied
depending on the definition used. The descriptions
provided in this standard are not intended to replace
those found in AGMA, ASTM, ISO, SAE or other
technical society documents. It is merely intended to
provide the user with more information about the
term, how it is applied in this standard, and how it is
measured. Examples of some properties used to
assess lubricant suitability for gear applications are
discussed in annex A.
The physical properties of a lubricant, such as
viscosity and pour point, are largely derived from the
2
AMERICAN NATIONAL STANDARD
base stock(s) from which they are produced. While
viscosity is the most common property associated
with a lubricant, there are many other properties that
contribute to the makeup and character of the
finished product. The properties of finished gear
lubricants result from a combination of base stock
selection and additive technology.
3.2 Lubricant selection
The key functions provided by the lubricant are to
minimize the friction and wear between surfaces in
relative motion, and to remove heat generated by the
mechanical action of the system. In order to
accomplish these tasks, the lubricant must have
sufficient viscosity to separate the mating surfaces
as much as possible, and also have the appropriate
chemical (additive) system to minimize thermal and
oxidative degradation, and provide antiwear and
antiscuff performance for transient peak operating
situations.
The choice of the appropriate lubricant depends in
part on matching its properties to the particular
application. A detailed elastohydrodynamic (EHD)
analysis of the gearbox is the most desirable and
thorough assessment of the gear lubrication requirements, but this is not always practical due to the
amount of information required. For more information about this approach the reader is recommended
to review the information provided in ANSI/AGMA
2101--C95 [1] and AGMA 925--A02 [2].
In the absence of detailed information about gear
geometry, loading, etc., it is recommended that the
user follow the tables offered in annex B. The tables
listed in annex B provide estimates of the appropriate viscosity grade (VG) based on both operating
speed and temperature. Annex B contains four
tables because the viscosity grade will also be
dependent upon the viscosity--temperature characteristics or viscosity index (VI) of the fluid used. The
four VIs chosen were considered representative of
most fluids used in industrial applications today.
They include VIs of 90, 120, 160, and 240.
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
The user must still ascertain certain performance
attributes for the gearbox to make a reasonable
lubricant selection. The user should be prepared to:
-- determine the type of gearing used in the
transmission;
-- determine the materials of construction of all
system components, such as:
--
gears;
--
bearings;
--
seals;
--
piping;
--
sightglasses;
3.3.2 Antiscuff/antiwear oils (EP)
-- determine selected operating conditions,
such as:
--
ambient temperature;
--
operating oil temperature;
-- minimum
velocities;
formulated with highly refined petroleum or synthetic
base oils and contain additives that enhance oxidation stability, provide corrosion protection, and
suppress foam. Their superior oxidation stabilities
typically set them apart from other gear oil types.
However, their load--carrying capabilities (as measured by standard tests that assess these characteristics) may be less than others. These oils are
generally associated with higher speed and lighter
load applications.
and
maximum
pitch
line
-- determine any critical special circumstances,
such as:
--
low temperature start--up;
--
ambient temperatures above 50°C;
--
high, transient loads.
Using the above information, one can estimate the
appropriate viscosity for the particular application
based on the effective operating temperature the
gears will see in service. Since industrial gear
applications involve a wide variety of operating
conditions and gear types, oils are classified according to their general performance as well as by their
viscosity.
3.3 Lubricant classifications
For the purposes of this document, lubricants are
considered to be in one of three distinct classes:
inhibited; antiscuff/antiwear; or compounded. Each
class has its own set of requirements and is intended
to provide the correct performance for each application.
3.3.1 Inhibited oils (RO)
These are commonly referred to as rust and
oxidation inhibited, or R&O lubricants. They are
In addition to protection against corrosion and
oxidation, these oils contain additives which provide
protection against unacceptable wear and scuffing.
These oils are formulated with refined petroleum or
synthetic base oils. They are generally used in ISO
VGs of 150 and above, and were developed to
protect geared systems operating at high loads and
severe impact or reversal conditions.
3.3.3 Compounded oils (CP)
Compounded gear oils are a blend of petroleum
base oils with three to ten percent of natural or
synthetic fatty oils. These lubricants are frequently
used in wormgear drives.
4 Minimum performance requirements
The tables provided in this section list the minimum
requirements for lubricants designated for use as
inhibited, antiscuff/antiwear, and compounded oils.
These represent minimum standards in the absence
of specific guidelines issued by the equipment
manufacturer. In addition to the minimum requirements outlined in tables 1, 2, and 3, the choice of
lubricant should also consider any special circumstances or modes of operation not addressed here.
Examples of special circumstances might include
low start--up temperatures, abrasive contaminants,
higher than normal operating temperatures, etc.
These issues should be reviewed with the equipment manufacturer and/or lubricant supplier to
ensure the proper lubricant is chosen for the
conditions.
3
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Table 1 -- Minimum performance requirements for inhibited (RO) oils
Test
method:
ISO/ASTM
Property
Viscosity grade
Viscosity @ 40°C,
3448/D2422
mm2/s
Requirements
32 46
68 100 150 220 320 460 680 1000--3200
3104/D445
Viscosity @ 100°C, mm2/s
3104/D445
Viscosity index2), min.
2909/D2270
Bulk fluid dynamic viscosity
@ cold start--up3), mPa⋅s,
max.
None/D2983
>3200
Report1)
See table 4
Report1)
90
85
Report1)
150 000
Flash point, °C, min.
2592/D92
180
Resistance to aging -Hours @ 95°C to reach 2.0
acid number, min.
4263/D943
1500
Water content4), ppm, max.
12937/D6304
Foam suppression -Volume of foam (mL), max.
after:
6247/D892
Cleanliness
None/None
Visual
Water separation 5)
-- % H2O in oil after 5h
test, max.
-- Cuff after centrifuging,
mL, max.
-- Total free H2O collected
during entire test, starting
with 45 mL, H2O mL, min.
None/D2711
(Procedure
A)
200
750
Report1)
500
Report1)
300
Temperature
Seq. I
24°C
Seq. II
93.5°C
Seq. III
24°C
5 min blow 10 min settle
50
0
50
0
50
0
5 min
blow
75
75
75
10 min
settle
10
10
10
Must be free of visible suspended or settled contaminants at the time it
is installed for use
0.5
2.0
Report1)
2.0
4.0
Report1)
30.0
30.0
Report1)
Rust prevention, part B
7120/D665
Pass
Copper corrosion
prevention, 3 h @ 121°C,
rating, max.
2160/D130
1b
NOTES:
1) Lubricant supplier to report value in accordance with stated test method for informational purposes.
2) Viscosity indices less than the minimum values listed are acceptable if agreed upon by the end user and equipment
manufacturer and/or lubricant supplier.
3) Start--up temperature to be specified by end user. Report temperature for 150 000 mPaSs.
4) Water content of virgin lubricant as packaged. Acceptable value may be greater for some full synthetics, e.g., polyglycols
(PAG), synthetic blends, or blends of synthetic and mineral base fluids. Value may be agreed upon by the end user and equipment manufacturer and/or lubricant supplier.
5) Maximum values shown are for mineral oils. Acceptable values may be greater for some full synthetics, e.g., polyglycols
(PAG), synthetic blends, or blends of synthetic and mineral base oils. Acceptable values may be agreed upon by the end user
and equipment manufacturer and/or lubricant supplier.
5 Applications
5.1 Operating conditions
5.1.1 Speed
The following guidelines are directly applicable to
helical, herringbone, bevel, and spur gears which
operate at or below 3600 revolutions per minute, or a
4
pitchline velocity of not more than 40 meters per
second, or both. They are also directly applicable to
wormgears which operate at or below 2400 rpm
(worm speed) or 10 meters per second sliding
velocity. The guidelines may be applicable at higher
speeds, but special considerations are generally
required. Therefore, the gear manufacturer should
be consulted when operating speeds exceed those
listed above.
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Table 2 -- Minimum performance requirements for antiscuff/antiwear (EP) oils
Test
method:
ISO/ASTM
Property
Viscosity grade
Viscosity @ 40°C,
3448/D2422
mm2/s
46
68
100
150
3104/D445
Viscosity @ 100°C, mm2/s
3104/D445
Viscosity index 2), min.
2909/D2270
Bulk fluid dynamic viscosity
@ cold start--up3), mPa⋅s,
max.
None/D2983
Flash point, °C, min.
Requirements
32
2592/D92
Resistance to aging @
121°C -- max. % increase
in kinematic viscosity @
100°C
None/D2893
Water content 4), ppm, max
12937/D6304
Foam suppression -Volume of foam (mL), max
after:
6247/D892
Cleanliness
None/None
Visual
Water separation 5)
-- % H2O in oil after 5h
test, max.
-- Cuff after centrifuging,
mL, max.
-- Total free H2O collected
during entire test, starting
with 90 mL H2O, mL, min.
None/D2711
(Procedure
B)
220
320
1000--3200
>3200
Report1)
Report1)
90
Report1)
85
150 000
180
200
6
8
10
Report1)
15
Report1)
300
Temperature
Seq. I
24°C
Seq. II
93.5°C
Seq. III
24°C
5 min blow
50
50
50
5 min
blow
75
75
75
10 min settle
0
0
0
10 min
settle
10
10
10
Must be free of visible suspended or settled contaminants at the time it is
installed for use
2.0
2.0
Report1)
1.0
4.0
Report1)
80.0
50.0
Report1)
7120/D665
Pass
Copper corrosion
prevention, 3 h @ 100°C,
rating, max.
2160/D130
1b
14635--1/
D5182
680
See table 4
Rust prevention, Part B
Scuffing load capacity, FZG
visual method, A/8.3/90, fail
stage, min.
460
10
12
>12
NOTES:
1) Lubricant supplier to report values in accordance with stated test method for informational purposes.
2) Viscosity indices less than the minimum values listed are acceptable if agreed upon by the end user and equipment manufacturer
and/or lubricant supplier.
3) Start--up temperature to be specified by end user. Report temperature for 150 000 mPaSs.
4) Water content of virgin lubricant as packaged. Acceptable value may be greater for some full synthetics, e.g., polyglycols (PAG),
synthetic blends, or blends of synthetic and mineral base fluids. Value may be agreed upon by the end user and equipment manufacturer
and/or lubricant supplier.
5) Maximum values shown are for mineral oils. Acceptable values may be greater for some full synthetics, e.g., polyglycols (PAG),
synthetic blends, or blends of synthetic and mineral base oils. Acceptable values may be agreed upon by the end user and equipment
manufacturer and/or lubricant supplier.
5
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Table 3 -- Minimum performance requirements for compounded (CP) oils
Test method:
ISO/ASTM
Property
Viscosity grade
3448/D2422
Viscosity @ 40°C, mm2/s
Viscosity @ 100°C,
mm2/s
Requirements
100
150
220
320
460
3104/D445
See table 4
3104/D445
Report1)
680
1000 – 3200
Viscosity index, min.2)
2909/D2270
Bulk fluid dynamic
viscosity @ cold
start--up3), mPa⋅s, max.
None/D2983
150 000
2592/D92
200
Resistance to aging @
95°C -- max. % increase in
kinematic viscosity @
100°C
None/D2893
Report1)
Water content4), ppm,
max.
12937/D6304
Foam suppression -Volume of foam (mL),
max. after:
6247/D892
Content of fatty or
synthetic fatty oil, mass %
None/None
3 to 10
Cleanliness
None/None
Visual
Must be free of visible suspended or settled contaminants at the time it is
installed for use
Rust prevention, Part B
7120/D665
Pass
Copper corrosion
prevention, 3 h @ 100°C,
rating, max.
2160/D130
1b
Flash point, °C, min.
90
85
Report1)
300
Seq. I
Seq. II
Seq. III
Temperature
24°C
93.5°C
24°C
5 min blow
50
50
50
10 min settle
0
0
0
5 min
blow
75
75
75
10 min
settle
10
10
10
NOTES:
1) Lubricant supplier to report value in accordance with stated test method for informational purposes.
2) Viscosity indices less than the minimum values listed are acceptable if agreed upon by the end user and equipment manufacturer
and/or lubricant supplier.
3) Start--up temperature to be specified by end user. Report temperature for 150 000 mPaSs.
4) Water content of virgin lubricant as packaged. Acceptable value may be greater for some full synthetics, e.g., polyglycols (PAG),
synthetic blends, or blends of synthetic and mineral base fluids. Value may be agreed upon by the end user and equipment manufacturer and/or lubricant supplier.
5.1.2 Ambient temperature
In general, the installed gears may be exposed to an
ambient temperature range of -- 40°C to + 55°C.
The ambient temperature is defined as the dry bulb
air temperature in the immediate vicinity of the
installed gears. Specific type and viscosity grade will
be determined, in part, by ambient temperature.
5.1.3 Oil sump temperature
The allowable maximum oil sump temperature for a
6
given application is dependent on the choice of base
oil type and additive chemistry. Consult the lubricant
supplier for specifics on the oil being chosen. Many
lubricants are unstable above their stated maximum
temperature.
CAUTION -- Sump temperatures in excess of 95° C
may require special materials for non--metallic components such as oil seals and shims. Consult component
supplier for recommended temperature limits.
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Table 4 -- Viscosity grade requirements
ISO viscosity
grade
ISO VG 32
ISO VG 46
ISO VG 68
ISO VG 100
ISO VG 150
ISO VG 220
ISO VG 320
ISO VG 460
ISO VG 680
ISO VG 1000
ISO VG 1500
ISO VG 2200
ISO VG 3200
Mid--point viscosity
at 40°
40°C
mm2/s1)
32
46
68
100
150
220
320
460
680
1000
1500
2200
3200
Kinematic viscosity limits at 40°°C
mm2/s1)
min
max
28.8
35.2
41.4
50.6
61.2
74.8
90.0
110
135
165
198
242
288
352
414
506
612
748
900
1100
1350
1650
1980
2420
2880
3520
Former AGMA grade
equivalent2)
0
1
2
3
4
5
6
7
8
8A
9
10
11
NOTES:
1) The preferred unit for kinematic viscosity is mm2/s, commonly referred to as centistoke (cSt).
2) With the change from AGMA viscosity grade equivalents to ISO viscosity grade classifications, the designations S,
EP, R and COMP will no longer be used as part of the viscosity grade nomenclature.
5.1.4 Other considerations
Machinery exposed to the direct rays of the sun will
run hotter than the same equipment in an identical
application which is sheltered. Conditions that may
require more frequent lubricant changes include:
-- ambient conditions of extreme dust, dirt,
moisture and/or chemical fumes;
-- sustained lubricant sump temperature approaching 95°C;
-- duty cycle or ambient conditions causing
large and rapid temperature changes;
-- seasonal ambient temperatures resulting in
changes of recommended lubricant grade.
5.1.5 Low temperature gear oils
Gear drives operating in cold areas must be provided
with oil that circulates freely and does not cause high
starting torques. An acceptable low temperature
gear oil, in addition to meeting the specifications of
this standard, should have a pour point at least 5°C
lower than expected minimum ambient start--up
temperature. Lubricant viscosity must be low
enough to allow the oil to flow freely at the start--up
temperature, but high enough to carry the load at the
operating temperature. Gear drives equipped with
an oil pump should also consider the maximum
viscosity that the pump can deliver.
5.1.6 Sump heaters
If a suitable low temperature gear oil is not available,
the gear drive must be provided with a sump heater
to bring oil up to a temperature at which it will
circulate freely for starting. The heater, preferably
equipped with thermostatic control, should be designed so as to avoid excessive localized heating,
which could result in rapid degradation of the
lubricant. A rating of 0.8 watts per cm2 of heater
surface area is considered conservative for most
applications. Higher watt densities may be used with
good circulation within the sump.
5.1.7 Coolers
Provision should be made for cooling the lubricant
where normal continuous operation of the gearing
would raise bulk fluid over recommended temperatures. Thermostatic control is recommended.
5.2 Methods of application
5.2.1 Splash and idler immersion systems
These are the simplest methods of lubricating gears.
The gear or an idler in mesh with the gear is allowed
to dip into the lubricant carrying it around to the
mesh. Splash systems are generally limited to pitch
7
ANSI/AGMA 9005--E02
line velocities below 15 meters per second for
non--worm gears and 10 meters per second sliding
velocity for worms, since the lubricant may be thrown
off at higher speeds. However, with the incorporation of appropriate design features, splash systems
have been successfully used in non--worm gear
drives operating with pitch line velocities up to 25
meters per second. Idler immersion systems are
generally limited to pitch line velocities below 1.5
meters per second. See annexes B, C and D for
lubricant selection guidelines for these systems.
5.2.2 Gravity feed or forced drip
This method of lubrication involves one or more
oilers or a cascade pan which allows oil to drip into
the gear mesh at a set rate. Guidelines for selection
of oils and rates of application for this method of
lubrication are shown in annex D. This method of
application is limited to open gearing with pitch line
velocities of 7.5 meters per second or less.
5.2.3 Hand or brush application
This method may be used with heavier grades and
residual compounds. Frequency of application may
be determined by observation.
5.2.4 Spray systems
Spray systems apply a continuous or intermittent
supply of lubricant to the gear teeth under pressure.
5.2.4.1 Enclosed gear units
Gears and bearings are lubricated by the same
circulating pump system to provide continuous
lubrication. The oil runs back to a sump and is
recirculated through the system. This system may
also consist of temperature and pressure controls
and employ suitable oil filtration. Lubricant selection
guidelines for continuous pressure lubrication can
be found in annexes B and C.
5.2.4.2 Open gearing
Intermittent mechanical spray systems are used with
open gearing and depend on the use of heavy oil,
grease, or residual compounds which will remain on
the gear teeth through several revolutions. The
spray is activated automatically or by hand at certain
timed intervals. The spraying time should equal the
time for one or preferably two revolutions of the gear
to ensure complete coverage. Periodic inspections
should be made to ensure that sufficient lubricant is
being applied to give proper protection. Two hours is
the maximum interval permitted between applica8
AMERICAN NATIONAL STANDARD
tions of lubricant. More frequent application of small
quantities is preferred. Guidelines for lubricant
selection and lubricant quantities using this method
of application are shown in annex D.
Spray nozzles must be sufficient in number and
properly spaced to provide adequate lubricant
coverage across the entire face of the gear teeth. As
a guideline, for slow speed open gearing operating
up to 10 meters per second, the end nozzles are
generally placed 50 to 65 millimeters from the gear
face edge with the remaining nozzles spaced on 130
to 180 millimeter centers. Nozzle location is also a
function of the spray pattern. Spray nozzles are
generally positioned to direct the lubricant at the
loaded profiles of the gear teeth and are typically
located a distance of 150 to 200 millimeters
maximum from the gear teeth.
As a guideline, for open or enclosed gearing
operating above 10 meters per second, the function
of the lubricant as a coolant must be considered.
5.2.4.3 Protective devices
Protective devices are recommended, where applicable, to warn of failure of timers, coolers, system
pressure, lubricant supply, as well as dirty filters.
5.3 Lubricant selection
Proper selection of a gear lubricant is essential to
achieving maximum service life in a given
application. The recommendations of the gear
manufacturer should be followed, when available, in
selecting a gear lubricant. In the absence of such
information, annexes B and C give guidelines for
lubricant selection in the form of tables based on
operating temperature, velocities, and mode of
operation. In the case of wormgear drives, ambient
temperature is selected as a criteria because
operating temperature is generally not known at the
time of installation. It is important to maintain proper
viscosity at the operating temperature. Therefore,
parameters such as temperature, noise and vibration should be closely monitored at start--up with
appropriate changes in lubricant viscosity grade, if
necessary. Annex B provides guidelines for ISO
viscosity grade selection for various operating
conditions.
While these guidelines will generally provide satisfactory selections, a detailed engineering analysis is
always preferred, especially in critical applications
and high speed units. Such an analysis is beyond the
scope of this standard; however, annex A includes
AMERICAN NATIONAL STANDARD
information and references on the subject. ISO
viscosity grade guidelines in annex B are empirical,
representing an accumulation of gear industry
experience.
6 Open gearing
Open gearing is similar to enclosed gearing except,
as the name implies, these gears are not enclosed
within a housing. These gears may be of any type,
but commonly are spur and helical gears. Their
lubrication requirements are similar to enclosed
gears, but the method of application is usually
different. Several factors must be considered when
determining the lubricant to be used with open gears.
These include: degree of enclosure; speed of the
gears; size (pitch diameter); environment; accessibility of the gears; and, method of lubricant application. Since open gears have a tendency to throw off
conventional oils such as those used with most
enclosed drives, much higher viscosity lubricants,
sprayable greases, or residual oils are typically used
for these applications.
Open gears are also exposed to a variety of
environmental conditions which can be quite harsh
ANSI/AGMA 9005--E02
in some cases. Some examples might include
gearing for draw bridges exposed to corrosive salt
water atmosphere, drive mechanisms for dryer rolls
in paper mills where humidity and ambient temperature are high, and ring gears on rotating grinding
mills and kilns which operate over wide temperatures and in dusty environments.
If there is no means of lubricant recovery, such as
with a sump, then open gears must be lubricated on
the all--loss principle regardless of the method of
application. To counter run--off, the lubricant should
possess a high viscosity and a persistence to
maintain a film on the surface of the teeth.
Regardless of whether the lubricant can be recovered or not, it must protect the surfaces from the
environmental conditions in which they operate.
Annex D outlines the viscosity recommendations for
a variety of open gear applications. These include
continuous and intermittent lubricant application for
both splash and pressure fed systems. It further
delineates the choices according to ambient temperature and type of operation. Application rates for
intermittent lubrication methods as a function of gear
size are also provided.
9
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
(This page is intentionally left blank.)
10
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Annex A
(informative)
Lubricant properties and methods of measurement
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
A.1 Air entrainment
Air entrainment is also referred to as the air release
property of a fluid. With industrial oils, this property is
determined by establishing the density of the fluid in
its natural state, aerating it, and measuring the time it
takes to return to its original density. Viscosity and
temperature will affect the rate at which a fluid will
release entrained air. The ability of the bulk fluid to
release entrained air is an inherent property of the
base fluid. A base fluid with marginal air release
capabilities in neat form can develop severe air
entrainment with the use of the wrong combination of
additives and/or the use of too high a concentration
of additives. The same applies to a base fluid with
excellent inherent air release properties if the
additive level is excessive. Therefore, the doping of
gear oil with additional additives, especially foam
inhibitors, should only be attempted under the
careful guidance of the lubricant supplier. The
addition of improper or too much additional additive(s) can lead to major gear drive operational
problems and possible irreversible damage to the
gears and/or bearings. Also see A.9.
A.2 Cleanliness
Although lubricants are produced under relatively
clean conditions, they can travel through many
conduits and be placed in intermediate storage tanks
before being packaged. Additionally, they may be
transported in bulk to the end user’s facility before
being stored in drums or in a bulk tank. This handling
provides many opportunities for contaminants such
as elastomeric particles, metal flakes, scale, rust
and/or sand to be introduced into the lubricant before
it is installed in, or applied to, machinery.
Storage tanks can be a source of particulate
contamination if air breathers are fitted improperly or
are absent. An assessment of a lubricant’s
cleanliness prior to putting it into service is highly
recommended. During a lubricant’s service life it
may have opportunity to be contaminated with
particulate matter from poor maintenance practices,
the operating environment (airborne particulates),
the machinery (wear), and oil degradation
byproducts. Cleanliness assessments of lubricants
while they are in service enable the end user to take
appropriate corrective action before irreversible
damage occurs to the lubricated equipment
components.
Lubrication system cleanliness refers to the degree
to which machinery is free of contaminants.
Although manufacturers, rebuilders, end users, etc.
may exercise care during the manufacturing,
assembly, packaging, shipping and installation of
gear drives, the ingress of contaminants is inevitable. Depending on the size and type of gear drive
installation, foundry sand, machining chips, grinding
dust, weld splatter, dirt, scale or other contaminants
can be present in gear drives prior to their being
placed into service.
While several methods have been used to define
lubricant cleanliness, the current practice is to use
ISO 4406 [3] cleanliness code levels. In this
standard, the number and size (in micrometers) of
solid particles in a milliliter of fluid is determined
using an approved laboratory particle counting
procedure. From these values, a cleanliness rating
is determined.
Gear drives utilizing oil circulating systems should be
monitored to insure that the oil charge in--service and
make--up oil are free of solid contaminants.
Circulating oil systems should be equipped with the
appropriate in--line filtration to achieve the oil system’s target cleanliness level. The use of auxiliary or
kidney loop filtration may be required to reach the
target cleanliness level if in--line filtration alone is not
sufficient. Consult the lubricant and filter supplier to
insure compatibility of the filter with the lubricant and
to determine the most appropriate filter rating for the
application and lubricant used.
Sump/splash lubricated gear drives many times do
not have a filtration system. In these cases, the
lubricant may need to be changed on a time
scheduled basis to minimize the presence of particulate and/or water contamination. The use of portable
filtration devices to remove contaminants has
11
ANSI/AGMA 9005--E02
proven beneficial in extending the service life of
these gear oils.
Routine oil sampling and condition analysis, when
practical, are beneficial for all enclosed gear drives.
The oil should be replaced when its degradation or
level of contamination exceeds predetermined limits. These limits are typically set on a case by case
basis after reviewing the operating condition and
environment of the gear drive. This practice can
provide increased protection of the gear drive from
wear due to particulate and/or water contamination.
See annex E.
A.3 Compatibility
Mineral oils are the most widely used lubricant and,
in general, are compatible with most paint/coatings
and rust preventatives. Traditionally, mineral oils
and mineral oils formulated with antiwear or antiscuff
(EP) additives formed the basis for drive gear
lubrication. Enclosed gear drive materials were
selected with the understanding they would be
exposed to mineral oil.
In contrast to mineral oils, which in general have
similar properties, synthetic lubricants can be very
different. When selecting synthetic lubricants special care is needed. A wide variety of synthetic
lubricants are available, but only a few are commonly
used for gear lubrication. These include synthetic
hydrocarbons, particularly polyalphaolefins (PAO),
polyalkylene glycols (PAG), and various esters.
Polyalphaolefins are compatible with mineral oils, so
there is less risk in using these over other synthetics.
Polyalkylene glycols, in general, are not compatible
with mineral oils, so extra caution is needed when
these are selected. PAG’s are not compatible with
many paints, although epoxy paint is acceptable.
Compatibility of the gear lubricant being installed
with the rust preventative used to coat the gears and
internal surfaces of the gearbox should be checked
and assessed. Proper flushing may first be required.
The residual presence of some rust preventatives
has been known to cause excessive foaming. Esters
have significantly more restrictions when used with
commonly used surface treatments. It is recommended to leave surfaces unpainted when using
esters. If surfaces must be painted, use an epoxy
paint. Acrylic paints should not be used with esters.
Another category of lubricants called semi--synthetics is a blend of synthetic and mineral oil. Blends can
12
AMERICAN NATIONAL STANDARD
be equal parts of synthetic and mineral oil, but in
general, mineral oil makes up the greater percentage. Check what type synthetic is used and refer to
the synthetic information above or consult the
lubricant supplier.
A.4 Corrosion
There are several types of corrosion tests for
petroleum products depending upon the classification or the application of the lubricant. In order to
examine the corrosion characteristics of a lubricant,
tests are defined for conditions that approximate the
conditions encountered in service. In general,
properly formulated gear lubricants are not considered corrosive to steel or copper containing alloys.
The corrosion test methods used in this standard are
intended to measure the ability of a lubricant to
prevent corrosion on a metal surface in contact with
oil. These tests indicate the tendency of the lubricant
to prevent corrosion of the gears and bearings while
in service under normal operating conditions. If
adverse conditions are expected, such as high
operating temperatures or high contamination levels, other considerations may be required to protect
steel and cupric metal parts from corrosive attack.
The ISO 2160/ASTM D130 copper corrosion test
method measures the corrosive nature of lubricating
oil on a copper strip that is immersed under static
conditions in the oil. Sulfur containing compounds
are the main sources of tarnishing or corroding of the
copper and cupric metal alloys. The extent of the
reactivity of the copper with the oil is classified by
comparing the appearance to standard coupons.
The method consists of placing a polished, cleaned
copper strip in a test tube with the oil sample. The
test may be run for 3 hours at either 100°C or 121°C.
Discoloration of the copper is matched against
reference standards and the oil is rated on a scale of
increasing corrosivity from 1 to 4. An acceptable
gear oil is required to have a maximum rating of 1b,
which is considered slight tarnish.
The ISO 7120/ASTM D665 test method evaluates
the ability of an oil to prevent the rusting of ferrous
parts in the event water becomes mixed with the oil.
The method consists of two parts: Procedure A using
distilled water, and Procedure B using synthetic
seawater. In this test method, 10% water (distilled or
synthetic seawater) is mixed in the oil and a polished
ASTM 1018 grade carbon steel rod is immersed in
the stirred mixture for 24 hours at 60°C. If there is no
AMERICAN NATIONAL STANDARD
rust on the specimen, the oil passes the test. AGMA
9005--E02 requires gear oils to pass Procedure B.
A.5 Demulsibility
Demulsibility, also known as water separation, is the
ability of a lubricating fluid to separate from water.
The demulsibility test method for gear oils used in
this standard, ASTM D2711, is also known as the
Wheeling steel demulsibility test. It was developed
to measure the water separation properties of oils
used to lubricate steel rolling mill stands. In the
ASTM D 2711, Procedure A test method, 405 mL of
oil and 45 mL of water are stirred together at 4500
rpm for 5 minutes in a separatory funnel at 82°C.
After settling for 5 hours, a 50 mL sample is
withdrawn from near the top and centrifuged to
determine the “percentage of water in oil, volume,
%”. The free water is drained from the bottom of the
funnel, and then a second volume of 100 mL of oil
and water emulsion is withdrawn and centrifuged.
The initial amount of free water drawn off plus the
centrifuged water is recorded as “total free water”.
The amount of water and oil remaining as emulsion
after centrifuging is recorded as “emulsion, mL”.
This method was developed specifically for rust and
oxidation inhibited oils. For antiscuff/antiwear (EP)
gear oils, the method, known as Procedure B, is
modified by reducing the amount of oil to 360 mL,
increasing the water to 90 mL, and slowing the stirrer
speed to 2500 rpm.
A.6 Elastomer compatibility
Lubricant compatibility with elastomers can be
measured in a number of ways depending on the
sealing system and its requirements. Two major
methods are static immersion testing and dynamic
testing. Dynamic tests require special rigs and are
often conducted to an equipment manufacturer’s
preferred duty cycle. A test can last 500 to 1000
hours or more. Dynamic testing is usually assessed
by quantifying the amount of leakage that occurs
during the course of the test. When complete, some
test procedures require additional analysis of the
seal itself. This also requires specialized equipment,
which is usually only available at the seal vendor’s
laboratory.
Static immersion tests are popular and relatively
simple to conduct. ASTM D 5662 [4] is an example of
such a method. The test usually consists of
suspending samples of the elastomer in a glass test
tube containing the oil to be assessed. The test tube
ANSI/AGMA 9005--E02
is placed in a controlled heated bath for a specified
length of time. At the end of the specified time the
elastomer samples are removed and rinsed with a
hydrocarbon solvent to remove the oil. The elastomer is then evaluated for changes in volume,
hardness, and elongation.
Although ASTM D 5662 specifies certain elastomer
types and test conditions, these can be modified to
accommodate the needs of specific end user
applications. Regardless of the method chosen to
determine elastomer compatibility, it is always recommended that the results are compared with a
standard, or the results obtained with a reference oil,
preferably one with a positive field service history.
A.7 Filterability
Oil with poor filterability characteristics will plug
filters and can cause inadequate lubrication of vital
machine components. It has been found that the
poor filterability characteristics of some industrial
lubricants are caused by the use of certain base
stocks or additives, or the combination of certain
base stocks and additives. Filterability has been
assessed by several methods, with ISO 13357--1 [5]
and 13357--2 [6] the first to become widely accepted.
Equipment manufacturers have long been aware of
the importance of filterability. Several have developed in--house filterability test methods. As with ISO
13357--2, some of the methods determine the time to
filter a quantity of water--free oil through a specified
filter under prescribed conditions.
Since many types of filter media are adversely
affected by the presence of water, some filterability
test methods like ISO 13357--1 will measure the
filterability of a mixture of oil and water after it has
been subjected to an aging procedure. This test
method is meant to simulate in--service conditions
and to assess whether filtration efficiency is impaired
after the oil has been in service for some time.
A.8 Flash point/fire point
Flash point is the minimum temperature of a
petroleum product or other combustible fluid at
which vapor is produced at a rate sufficient to yield a
combustible mixture. Specifically, it is the lowest
sample temperature at which the air/vapor mixture
will “flash” in the presence of a source of ignition.
Fire point is the minimum sample temperature at
which vapor is produced at a sufficient rate to
maintain combustion. Specifically, it is the lowest
sample temperature at which the ignited vapor
13
ANSI/AGMA 9005--E02
persists in burning for at least 5 seconds. The fire
point of commercial petroleum oils is normally
approximately 30°C above the corresponding flash
point. Fire point is commonly omitted from petroleum product data sheets.
Flash and fire points have obvious safety connotations. It is assumed that the higher the flash point,
the less the hazard exists for fire or explosion. Of
comparable significance is their value in providing a
simple indication of volatility, where a lower flash
point denotes a more volatile fluid. The dilution of a
gear oil with a fluid such as Stoddard solvent, for
example, can significantly lower the flash point of the
lubricant, and would be detected by performing an
ISO 2592/ASTM D92 flash point test.
Flash and fire points should not be confused with
auto--ignition temperature, the temperature at which
combustion occurs spontaneously without an external source of ignition.
A.9 Foaming
Foaming in a gear oil can be detrimental to the
performance and durability of the gear drive in which
it is being used. It can also create housekeeping
problems if it escapes the confines of the gear drive.
Foaming in a lubricant may be controlled through the
use of a foam inhibitor. These additives cause the
foam to dissipate more rapidly by promoting the
agglomeration of small bubbles into large bubbles
which burst more easily. Foam inhibitors are
commonly produced from silicones or other polymeric compounds. Also see A.1.
A.10 Coefficient of friction
Friction is the resistance to motion that is experienced when two surfaces in contact are forced to
slide relative to each other. More specifically, friction
is the resisting force tangential to the common
boundary between two bodies when, under the
action of an external force, one body moves or tends
to move relative to the surface of the other. It is
common to express this as the coefficient of friction
rather than the absolute value. Coefficient of friction
is the ratio of the tangential force resisting motion
between the two bodies to the normal force pressing
these bodies together. It can be influenced by
material, texture, fluid lubricity, lubricant additive
system(s), and operating conditions.
Two types of friction are considered in most applications: static or break away; and, dynamic or kinetic.
14
AMERICAN NATIONAL STANDARD
Their importance is a function of the application in
which they are being measured. In lubricated
systems the starting friction, generally referred to as
the static friction, is often higher than the kinetic
friction. For low speed applications or those that
encounter start--stop situations, this could be a
critical parameter to obtaining smooth operation.
High static values relative to those obtained at higher
speeds could be indicative of a stick--slip phenomena and could be associated with scuffing on a micro
scale. The stick--slip phenomena will generally
manifest itself as noise or vibration. This is most
important in clutch type applications. For gears, the
coefficient of friction is an indicator of the efficiency of
the system. Excessively high friction values are
indicative of scuffing.
The coefficient of friction of any system can be
measured if one knows two parameters: the normal
force acting on the contact; and, the reaction force
that results when the bodies are put in motion. Most
tribometers used in laboratories today have this
capability. These would include configurations such
as the four ball tester, pin--on--disk, ring--on--block,
disk--on--disk, ball--on--flat, and two--disk machines
to mention just a few.
The real issue is defining the relationship between
the laboratory test and the component in actual
practice. This includes matching the contact materials, surface roughness, and operating conditions,
among others. Since most systems are variable, a
range of conditions is likely required to define the
friction envelope.
A.11 Oxidation resistance & thermal stability
Oxidation is a chemical process in which oxygen
combines with the free radicals within a lubricant to
produce acids that can corrode metals, and polymers that produce sludge formation. Another
product of oxidation is an increase in viscosity.
Oxidation is enhanced by elevated temperature and
the presence of a catalyst such as iron, copper, water
or foreign matter. Thermal stability is often, but
inappropriately, interchanged with oxidation. Thermal stability is the property of a lubricant that
characterizes its relative chemical stability in response to thermal stress.
A thermally unstable compound can decompose in
response to heat alone, without the contribution of
the oxidative processes. Thermal decomposition,
like oxidation, may be catalyzed by metals, water, or
other chemical compounds. Thermal breakdown
AMERICAN NATIONAL STANDARD
products may themselves be reactive and promote
oxidation, corrosion, or sludge formation.
The outcomes of oxidation and thermal breakdown
are closely related, and the net effect may be
referred as thermo--oxidative. However, these
processes should be distinguished separately because in any given lubricant formulation they may be
widely divergent. ISO 4263/ASTM D943, ASTM
D2893 (95°C), ASTM D5763 (120°C) [7] and ASTM
D4871 [8] are methods used to determine the
oxidative characteristic of fluid lubricants. The
ASTM D5579 [9] Cincinnati Milicron thermo--oxidative test is another method used to determine the
thermal stability of a fluid lubricant.
Oxidation is an important measure of the functionality and useful service life of a lubricant. A lubricant’s
base oil and additive package are equally important
determinants of its oxidation life. Operating temperature, however, is normally the most influential
variable impacting the rate of oxidation. In any gear
drive, localized heating (“hot spots”) must be taken
into account, in addition to bulk lubricant operating
temperature. These areas of localized heating can
be sites where accelerated oxidative aging and
thermal decomposition occurs. Examples of localized heating include instantaneous frictional heat at
the mesh point of the gear teeth (referred to as flash
temperature), the point of highest load in support
bearings, and the surfaces of heating devices that
come in direct contact with the lubricant.
ANSI/AGMA 9005--E02
A.13 Viscosity -- kinematic
The viscosity of a liquid lubricant or a semi--solid
(grease) lubricant’s base fluid may be determined
using various test methods. Historically, these have
included the Saybolt, Kinematic, Engler and Redwood test methods. With these test methods,
viscosity is reported as Saybolt Universal Seconds
(SUS), mm2/s (cSt or centistoke), degrees Engler
and Redwood, respectively.
The International
Organization for Standardization (ISO) classifies
and specifies fluid lubricants using kinematic viscosity. AGMA, as well as many national standards
organizations such as AFNOR (Association of
French Normalization), ASTM (American Society for
Testing Materials), ANSI (American National Standards Institute), BSI (British Standards Institute) and
DIN (German Institute for Normalization) have
adopted the ISO 3104/ASTM D445 method of
measuring and specifying fluid viscosity. The
preferred unit for kinematic viscosity is mm2/s,
commonly referred to as centistoke (cSt).
For fluid classification purposes, the viscosity of a
lubricant is stated at a standard temperature, e.g.,
ISO 3448 specifies viscosity at 40°C. However, gear
drives rarely operate at 40°C. Viscosity of the
lubricant at operating temperature must be correct
for optimal gear drive performance and service life.
Although AGMA and drive manufacturers may
provide suggested lubricant viscosity grades for
general applications, these are guidelines based on
an assumed bulk lubricant operating temperature of
approximately 50°C to 65°C.
A.14 Viscosity -- dynamic (Brookfield)
A.12 Pour point
Pour point is an indicator of the lowest temperature
at which an oil flows under the influence of gravity.
Pour point should not be used as the only indicator of
the low temperature limit at which a lubricant may
function acceptably. Initial agitation by gears,
bearings or a pump can break down the crystal wax
structure of paraffinic oils and allow the gear oil to
flow or to be pumped at temperatures well below its
pour point. Naphthenic and synthetic lubricating oils
contain little or no wax and reach their pour point
through increase in viscosity. ISO 3016/ASTM D97
[10] is used to determine pour point. It is recommended that the pour point of the oil used should be
at least 5°C lower than the minimum ambient
temperature expected.
The Brookfield viscosity refers to the dynamic
viscosity of a lubricant as measured at low shear rate
by a rotating spindle in a Brookfield viscometer. The
dynamic viscosity is commonly reported in units of
centipoise, cP, and is related to the kinematic
viscosity as follows:
Dynamic viscosity (cP) = Kinematic viscosity
(cSt) × Density (g/mL)
(where all terms are measured at the same temperature)
NOTE: In the International System of Units (SI),
1 cSt = 1 mm2/s and 1 cP = 1 mPa⋅s.
The Brookfield viscosity is frequently used as a
measure of the flowability or fluidity of automotive
gear and transmission lubricants at low temperature.
In the early 1970s, the Society of Automotive
15
ANSI/AGMA 9005--E02
Engineers chose the Brookfield viscosity, as measured by ASTM D2983, to categorize low temperature flow in the SAE J306 [11] viscosity classification
system.
Studies [12, 13] have shown that the Brookfield
viscosity correlates very well with the time required
to adequately lubricate an automotive differential.
Testing of axles in cold rooms at General Motors
Research established a critical lubricant viscosity
value of 150,000 cP [12]. Viscosities above this
value were associated with failures due to inadequate splash lubrication, particularly in the front
pinion bearing.
Further work with axle test stands at AutoResearch
Labs, Inc. produced an excellent correlation between the temperature for a specific axle lubrication
time at cold start and the temperature at which the
lubricant achieved a Brookfield viscosity of 150,000
cP [13]. The authors concluded that the Brookfield
viscosity was the best method, compared to channel
point and pour point, for evaluating and specifying
the cold fluidity properties of automotive gear oils.
Based on the experience of automotive gear
manufacturers, the same critical Brookfield viscosity
limit of 150,000 cP has been proposed for industrial
gear applications. Because of the wide variety of
field conditions, the temperature for the maximum
Brookfield viscosity is not specified in this standard.
Rather, the temperature should be specified by the
end user and it should relate to the lowest actual
lubricant temperature at cold startup.
A.15 Viscosity index
The viscosity index (VI) of fluid lubricants and the
base fluid of semi--solid lubricants (greases) is
internationally determined using ISO 2909. A
lubricant’s VI may be a natural physical property of
the base fluid, or the result of chemical enhancement
through the addition of a VI improver. VI improvers
are typically polymers. Low molecular weight
polymer VI improvers are generally more resistant to
shear degradation than high molecular weight
polymer VI improvers. When considering the use of
a gear oil with a high VI, it is important to select a
product that retains its VI over the expected drain
and change interval. Selecting a product containing
a VI improver susceptible to shear degradation can
negate the anticipated advantages of using a high VI
gear oil.
16
AMERICAN NATIONAL STANDARD
A gear oil with a low VI may be acceptable in
applications where ambient startup temperatures
remain constant, the drive operating temperature
varies minimally, or the drive operating temperature
is close to the ambient temperature. The use of a
gear oil with a VI greater than 120 may be desirable
in applications where ambient startup temperatures
are much lower than normal operating environment
or when ambient temperatures vary widely.
Although viscosity index is an indicator of a lubricant’s flowability over a broad temperature range, it
does not establish its minimum or maximum operating temperatures. Pour point, thermal stability and
durability, oxidation resistance and other properties
of the fluid must also be considered when selecting
the appropriate lubricant. For example, a gear oil’s
pour point may not be any lower in a high VI product
than in a low VI product.
A.16 Wear modes
See ANSI/AGMA 1010--E95 [14].
Abrasive wear -- Abrasive wear, or abrasion, is
caused by the displacement of material from a solid
surface due to hard particles or protuberances
sliding along the surface. Abrasive wear is also
referred to as rubbing wear or polishing. This wear
process involves the removal of material as a result
of a two or three--body interaction between the
contacting surfaces.
Adhesive wear -- Adhesive wear has been identified, with varying degrees of accuracy, by the terms
scoring, galling, seizing, and scuffing. This wear
mode involves the transfer (loss) of material from
one surface to another as a result of a welding -tearing process during the two or three--body
interaction between the contacting surfaces. It is
brought about in lubricated applications by loss of
supporting film and/or inadequate protection of the
surface(s).
Corrosive wear -- This wear mode is loss of material
from a surface due to aggressive chemical action on
the material. This can be due to some inherent
property of the fluid or a result of some external
contaminant that acts in a corrosive manner.
Erosive wear -- Also referred to as erosion, this wear
mode is the loss of material from a solid surface due
to relative motion in contact with a fluid that contains
solid particles. The term abrasive erosion is
sometimes used to describe erosion in which the
solid particles move nearly parallel to the solid
AMERICAN NATIONAL STANDARD
surface; the term impingement, or impact, erosion is
used to describe erosion in which the relative motion
of solid particles is nearly normal to the solid surface.
Fatigue wear -- Fatigue is an aging process
common to all solids. It is a progressive, localized
permanent structural change in materials subjected
to fluctuating stresses and strains such as gears and
rolling element bearings. The number of cycles of
stress and strain before failure occurs is referred to
as the fatigue life. When materials such as steel are
subjected to cyclic deformation, surface and subsurface microcracks develop at grain boundaries.
Surface fatigue cracks may be initiated by various
surface imperfections such as scratches, dents,
imbedded debris, or by hard contaminant particles in
the lubricant passing through the contact zone.
Asperities may also be viewed as surface imperfections that may limit fatigue life.
Subsurface initiated cracks are often associated
with hard inclusions in the metal at a point of
maximum shear stress, which, in the ideal case,
occurs below the surface. With continuing cycles,
microcracks grow and propagate until a loss of
material from the surface occurs, usually in the form
of large (relative) flakes or areas. Pits visible to the
naked eye on the pressure flanks of gear teeth or the
raceways of rolling element bearings are examples
of surface fatigue.
Surface initiated cracks may propagate in the area of
new surface stress due to imperfections. When this
occurs, it is possible for many small (10--20 mm) pits
to be formed resulting in the phenomenon known as
micropitting. Surface initiated cracks may also
propagate below the surface into the region in which
the higher Hertzian stresses dominate. In this case,
individual larger pits or spalls may be formed.
Industrial oils often contain dissolved or dispersed
water. The presence of water in a lubricant may
reduce fatigue life of wear components by the
mechanism of hydrogen embrittlement. Additives
such as rust inhibitors and demulsifiers may, in
ANSI/AGMA 9005--E02
addition to their intended function, overcome the
deleterious effect of water on fatigue life.
The factors influencing gear and bearing fatigue are
complex and often interdependent. Additionally, the
response of lubricant additives is dependent on
conditions such as temperature, rolling and sliding
velocities, and contact stress. Ideally, testing for
predicting fatigue life should minimally be carried out
at the calculated or known contact stress and
rolling/sliding velocities expected in the application.
Lubricant viscosity, moisture, surface finish and
temperature should also be carefully selected for
each application.
The physical and chemical properties of the lubricant
can significantly affect fatigue life. Proper selection
of lubricant viscosity helps prolong fatigue life by
providing the appropriate film thickness to separate
the surfaces under operating conditions. Lubricant
additives, especially those that impart antiwear or
antiscuff (EP) properties can have a significant effect
on fatigue life, both positive and potentially negative.
Because testing reported in literature usually use
generic terminology for additives and base oils, and
because the effects on fatigue life are chemistry
specific, it is important to evaluate individual lubricant--application combinations for fatigue properties.
Fretting wear -- Fretting wear is a phenomenon that
occurs between two closely mated surfaces. It is
initially adhesive in nature, being cause by vibration
or small--amplitude oscillation. Fretting is frequently
accompanied by corrosion. In general, fretting
occurs between two tight--fitting surfaces that are
subjected to a cyclic, relative motion of extremely
small amplitude. Fretting generally occurs at
contacting surfaces that are intended to be fixed in
relation to each other, but actually undergo minute
alternating relative motion that is usually the result of
vibration. For example, fretting corrosion is commonly encountered as a reddish--black staining of
the surfaces of the bore of a bearing housing and the
outer ring of the bearing.
17
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Annex B
(informative)
Guideline for lubricant viscosity grade selection
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
B.1 Guidelines
In the absence of a rigorous EHD analysis, the
following tables are offered for the user to select an
appropriate viscosity grade for their application. The
viscosity selection must be complemented with an
appropriate performance additive to provide a finished lubricant with properties sufficient to meet the
overall needs of the application. Tables B--1 through
B--4, for spur, helical and bevel gears, provide the
estimated ISO viscosity grades for a given operating
18
temperature – pitch line velocity combination covering four representative viscosity index type fluids.
For the purpose of these estimates, operating
temperatures were assumed to be nominally 45°C
above the ambient temperature. Tables B--5 and
B--6 provide guidelines for cylindrical and globoidal
wormgearing. In the case of multiple reduction gear
drives, it is recommended to use the pitch line
velocity for the lowest speed mesh. Consideration
should be given to the viscosity requirements of the
bearings in these instances.
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
B.2 Spur, helical and bevel gears
Table B--1 -- Viscosity grade1) at bulk oil operating temperature for oils
having a viscosity index of 902)
Pitch line velocity, m/s3)
10.0
15.0
Temp
°C
10
1.0 -- 2.5
15
46
32
20
68
46
32
25
68
46
32
30
100
68
46
32
35
100
100
68
46
32
40
150
100
68
46
45
220
150
100
50
320
220
150
55
460
220
150
60
460
320
65
680
70
2.5
5.0
20.0
25.0
30.0
32
32
32
68
46
46
32
32
100
46
46
46
32
100
68
68
68
46
220
150
68
68
68
46
460
320
220
150
100
100
68
1000
680
320
220
150
100
100
68
75
1500
680
460
320
220
150
150
100
80
2200
1000
680
460
220
220
220
150
85
3200
1500
1000
460
320
220
220
150
90
3200
2200
1000
680
460
320
320
220
95
3200
1500
1000
460
460
320
220
100
3200
2200
1000
680
460
460
320
32
NOTES:
1)
Consult gear, bearing and lubricant suppliers if a viscosity grade of less than 32 or greater than 3200 is
indicated.
Review anticipated cold start, peak and operating temperatures, service duty and range of loads when
considering these viscosity grades.
Select the viscosity grade that is most appropriate for the anticipated stabilized bulk oil operating temperature
range.
Baseline stabilized bulk oil operating temperature and bearing lubrication requirements.
2)
This table assumes that the lubricant retains its viscosity characteristics over the expected oil change interval.
Consult the lubricant supplier if this does not apply.
3) Determine pitch line velocity of all gear sets. Select viscosity grade for critical gear set taking into account cold startup
conditions.
19
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Table B--2 -- Viscosity grade1) at bulk oil operating temperature for oils
having a viscosity index of 1202)
Pitch line velocity, m/s3)
10.0
15.0
Temp
°C
10
1.0 -- 2.5
15
46
32
20
68
46
32
25
68
46
32
32
30
100
68
46
32
35
150
100
68
46
32
40
150
100
68
46
45
220
150
100
50
320
220
55
320
60
20.0
25.0
32
32
32
68
46
46
32
32
100
100
68
46
46
46
220
150
100
68
68
46
46
460
320
220
150
68
68
68
46
65
680
460
320
150
100
100
100
68
70
1000
460
320
220
150
150
100
68
75
1000
680
460
220
150
150
150
100
80
1500
1000
460
320
220
220
150
100
85
2200
1000
680
460
220
220
220
100
90
2200
1500
1000
460
320
320
220
150
95
3200
2200
1000
680
320
320
320
220
2200
1500
680
460
460
320
220
100
2.5
5.0
30.0
32
NOTES:
1)
2)
Consult gear, bearing and lubricant suppliers if a viscosity grade of less than 32 or greater than 3200 is
indicated.
Review anticipated cold start, peak and operating temperatures, service duty and range of loads when
considering these viscosity grades.
Select the viscosity grade that is most appropriate for the anticipated stabilized bulk oil operating temperature
range.
Baseline stabilized bulk oil operating temperature and bearing lubrication requirements.
This table assumes that the lubricant retains its viscosity characteristics over the expected oil change interval.
Consult the lubricant supplier if this does not apply.
3) Determine pitch line velocity of all gear sets. Select viscosity grade for critical gear set taking into account cold startup
conditions.
20
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Table B--3 -- Viscosity grade1) at bulk oil operating temperature for oils
having a viscosity index of 1602)
Pitch line velocity, m/s3)
10.0
15.0
Temp
°C
10
1.0 -- 2.5
2.5
32
32
15
46
32
32
20
68
46
32
25
68
46
32
32
30
100
68
46
32
35
150
100
68
46
32
40
150
100
68
46
45
220
150
100
50
220
150
55
320
60
5.0
20.0
25.0
30.0
32
32
32
68
46
46
32
100
68
46
46
46
32
220
150
100
68
68
46
32
460
220
150
100
68
68
68
46
65
460
320
220
150
100
100
68
46
70
680
460
220
150
100
100
100
68
75
680
460
320
220
150
150
100
68
80
1000
680
320
220
150
150
150
100
85
1500
680
460
320
220
220
150
100
90
1500
1000
680
320
220
220
220
150
95
2200
1500
680
460
320
220
220
150
100
3200
1500
1000
460
320
320
220
150
NOTES:
1)
Consult gear, bearing and lubricant suppliers if a viscosity grade of less than 32 or greater than 3200 is
indicated.
Review anticipated cold start, peak and operating temperatures, service duty and range of loads when
considering these viscosity grades.
Select the viscosity grade that is most appropriate for the anticipated stabilized bulk oil operating temperature
range.
Baseline stabilized bulk oil operating temperature and bearing lubrication requirements.
2)
This table assumes that the lubricant retains its viscosity characteristics over the expected oil change interval.
Consult the lubricant supplier if this does not apply.
3) Determine pitch line velocity of all gear sets. Select viscosity grade for critical gear set taking into account cold startup
conditions.
21
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Table B--4 -- Viscosity grade1) at bulk oil operating temperature for oils
having a viscosity index of 2402)
Pitch line velocity, m/s3)
10.0
15.0
Temp
°C
10
1.0 -- 2.5
46
2.5
46
5.0
15
68
46
32
20
25
68
100
68
68
32
32
32
32
30
100
68
32
32
32
35
150
68
68
46
32
32
40
150
100
68
46
32
32
32
45
220
100
100
68
46
32
32
50
220
100
100
68
46
46
46
32
55
320
150
150
68
68
46
46
32
60
320
150
150
100
68
68
46
46
65
460
220
150
100
100
68
68
46
70
460
320
220
150
100
68
68
46
75
80
85
90
95
100
680
680
1000
1000
1000
1500
320
460
460
680
680
1000
220
220
320
320
460
460
150
150
220
220
320
320
100
100
150
150
150
220
100
100
100
150
150
150
68
100
100
100
150
150
68
68
68
100
100
100
20.0
25.0
30.0
NOTES:
1)
2)
Consult gear, bearing and lubricant suppliers if a viscosity grade of less than 32 or greater than 3200 is
indicated.
Review anticipated cold start, peak and operating temperatures, service duty and range of loads when
considering these viscosity grades.
Select the viscosity grade that is most appropriate for the anticipated stabilized bulk oil operating temperature
range.
Baseline stabilized bulk oil operating temperature and bearing lubrication requirements.
This table assumes that the lubricant retains its viscosity characteristics over the expected oil change interval.
Consult the lubricant supplier if this does not apply.
3) Determine pitch line velocity of all gear sets. Select viscosity grade for critical gear set taking into account cold startup
conditions.
22
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
B.3 Cylindrical and globoidal wormgearing
Table B--5 -- ISO viscosity grade guidelines for enclosed cylindrical wormgear drives1) 2)
Pitch line velocity
of final reduction stage
ISO viscosity grades
Ambient temperature, °C
--40 to --10
--10 to +10
+10 to +55
220
460
680
220
460
460
Less than 2.25 m/s
Above 2.25 m/s
NOTES:
1) Wormgear applications involving temperatures outside the limits shown above, or speeds exceeding 2400 rpm
or 10 m/s sliding velocity should be addressed by the manufacturer. In general, for higher speeds a pressurized
lubrication system is required along with adjustments in the recommended viscosity grade.
2)
This table applies to lubricants with viscosity index of 100 or less. For lubricants with viscosity index greater than 100,
wider temperature ranges may apply. Consult the lubricant supplier.
Table B--6 -- ISO viscosity grade guidelines for enclosed globoidal wormgear drives1) 2)
Center distance of
final reduction
stage
Up
p to 305 mm
Over 305 mm to 610
mm
Over 610 mm
Worm speed of final
reduction stage, rpm
< 300
300 -- 700
> 700
< 300
300 -- 500
> 500
< 300
300 -- 600
> 600
--40 to --10
460
320
220
460
320
220
460
320
220
ISO viscosity grades
Ambient temperature, °C
--10 to +10
10 to 35
680
1000
460
680
320
460
680
1000
460
680
320
460
680
1000
460
680
320
460
35 to 55
1500
1000
680
1500
1000
680
1500
1000
680
NOTES:
1) Wormgear applications involving temperatures outside the limits shown above, or speeds exceeding 2400 rpm
or 10 m/s sliding velocity, should be addressed by the manufacturer. In general, for higher speeds a pressurized
lubrication system is required along with adjustments in recommended viscosity grade.
2)
This table applies to lubricants with viscosity index of 100 or less. For lubricants with viscosity index greater than 100,
wider temperature ranges may apply. Consult the lubricant supplier.
23
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Annex C
(informative)
Guideline for determining lubricant type based on application
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
Table C--1 provides a general guideline to aid in the
choice of lubricant classification to be used in a given
application. Consult the OEM and lubricant supplier
when considering the use of oils containing extreme
pressure/antiscuff, antiwear or friction modifiers in
wormgearing or drives with internal backstops or
load brakes.
Table C--1 -- Lubricant classification guidelines
Operation of driving unit
Uniform
Light shocks
Moderate shocks
Heavy shocks
Uniform
RO
RO
EP
EP
Operation of driven unit
Light shocks
Moderate shocks
RO/EP
EP
RO/EP
EP
EP
EP
EP
EP
Heavy shocks
EP
EP
EP
EP
NOTE:
1. RO are inhibited oils.
EP are antiscuff/antiwear oils.
2. Compounded oils are not included in table C--1 because they are specialized oils generally restricted to wormgear
applications.
Table C--2 -- Examples of operation for driving units as they relate to table C--1
Mode of operation
Driving unit
Uniform
Electric motor, steam or gas turbine operating uniformly, i.e., low, infrequent starting
torques
Light shocks
Steam or gas turbine, hydraulic or electric motor with high, frequent starting torques
Moderate shocks
Multi--cylinder combustion engine
Heavy shocks
Single--cylinder combustion engine
Table C--3 -- Examples of operating modes of driven units – industrial gears
Driven unit
Mode of operation
Uniform
Power generators, uniformly fed conveyors or apron feeders, lightweight elevators,
packaging machines, feed drives of machine tools, fans,lightweight centrifuges, rotary
pumps, agitators and mixers for light fluids or substances of uniform density, cutters,
presses, punches, rotary units, drive units
Light shocks
Intermittently fed conveyors or apron feeders, main drive of machine tools, heavy elevators, rotary units of cranes, industrial and mining fan systems, heavy centrifuges,
rotary pumps, agitators and mixers for viscous fluids or substances of varying density,
multi--cylinder piston pumps, feeding pumps, extruders in general, calenders, rotary
kilns, rolling mills
Moderate shocks
Heavy shocks
24
Rubber extruders, intermittently operating mixers for rubber and synthetic materials,
lightweight ball mills, woodworking machines, blooming mills, lifting units, single-cylinder piston pumps
Excavators, bucket wheel and chain drives, screen drives, dredging shovels, rubber
kneaders, stone and ore crushers, mining machinery, heavy feed pumps, rotary drilling
installations, brick presses, debarking drums, peeling machines, cold belt rolling mills,
briquette presses, edge mills
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Annex D
(informative)
Guideline for lubrication of open gearing
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
Low temperature operating conditions and the
necessity of heating needs to be considered when
designing the system and choosing the lubricant.
Consideration should be given to the need for
applied heating to avoid channeling of the lubricant
in splash lubricated applications.
Table D--1 -- Minimum viscosity recommendations for open gearing -- Continuous lubricant
application1)
Ambient
temperature,
p
, °C
--10 to +10
+10 to +30
30 to 50
Pressure fed
Idler immersion
lubrication
Pitch line velocity2) Pitch line velocity2) Pitch line velocity2)
vt<5 m/s vt >5 m/s vt <5 m/s vt >5 m/s
vt ≤ 1.5 m/s
220
150
220
150
680 – 1500
Splash lubrication
Type of operation
Continuous
Reversing or
start – stop
Continuous
Reversing or
start – stop
460
320
220
150
680 – 1500
460
320
460
320
1500 -- 2200
1500
680–1000
460
320
1500 -- 2200
Continuous
2200
1500
460
320
4600
Reversing or
start – stop
2200
1500
460
320
4600
NOTES:
1) All viscosities shown are in mm2/s at 40°C.
2) Pitch line velocity = (Pitch Diameter in millimeters X RPM) ÷ 19098 = meters/second
Table D--2 -- Minimum viscosity recommendations for open gearing -- Intermittent lubricant
application (vt < 7.5 m/s)
Ambient
temperature,
temperature
°C
--10 to +5
+5 to +20
20 to 50
Intermittent spray
Non--residual lubricant
40°C1)
4140 cSt at
6120 cSt at 40°C2)
190 cSt at 100°C3)
Residual type lubricant
Gravity feed or forced
drip
428.5 cSt at 100°C4)
857 cSt at 100°C5)
857 cSt at 100°C5)
4140 cSt at 40°C1)
6120 cSt at 40°C2)
190 cSt at 100°C3)
NOTES:
1) Formerly AGMA 11 EP and 11S.
2) Formerly AGMA 12 EP and 12S.
3) Formerly AGMA 13 EP and 13S.
4) Formerly AGMA 14 R.
5) Formerly AGMA 15 R.
25
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
Table D--3 -- Lubricant quantity guidelines for open gearing intermittent methods of application –
automatic, semi--automatic, hand spray, gravity feed or forced drip systems (vt < 7.5 m/s) 1) 2) 3)
Gear
diameter
in meters
2.4
3.1
3.7
4.3
4.9
5.5
6.1
6.7
7.3
7.9
8.5
9.1
9.8
10.4
11.1
11.6
12.2
12.8
13.4
152
0.34
0.44
0.54
0.64
0.74
0.84
0.94
1.04
1.14
1.24
1.34
1.44
1.54
1.64
1.74
1.84
1.94
2.04
2.14
Milliliter of lubricant required per minute of drive operation4)
Face width in millimeters
254
356
457
559
660
762
864
965
0.44
0.54
0.64
0.74
0.84
0.94
1.04
1.14
0.54
0.64
0.74
0.84
0.94
1.04
1.14
1.24
0.64
0.74
0.84
0.94
1.04
1.14
1.24
1.34
0.74
0.84
0.94
1.04
1.14
1.24
1.34
1.44
0.84
0.94
1.04
1.14
1.24
1.34
1.44
1.54
0.94
1.04
1.14
1.24
1.34
1.44
1.54
1.64
1.04
1.14
1.24
1.34
1.44
1.54
1.64
1.74
1.14
1.24
1.34
1.44
1.54
1.64
1.74
1.84
1.24
1.34
1.44
1.54
1.64
1.74
1.84
1.94
1.34
1.44
1.54
1.64
1.74
1.84
1.94
2.04
1.44
1.54
1.64
1.74
1.84
1.94
2.04
2.14
1.54
1.64
1.74
1.84
1.94
2.04
2.14
2.24
1.64
1.74
1.84
1.94
2.04
2.14
2.24
2.34
1.74
1.84
1.94
2.04
2.14
2.24
2.34
2.44
1.84
1.94
2.04
2.14
2.24
2.34
2.44
2.54
1.94
2.04
2.14
2.24
2.34
2.44
2.54
2.64
2.04
2.14
2.24
2.34
2.44
2.54
2.64
2.74
2.14
2.24
2.34
2.44
2.54
2.64
2.74
2.84
2.24
2.34
2.44
2.54
2.64
2.74
2.84
2.94
1016
1.19
1.29
1.39
1.49
1.59
1.69
1.79
1.89
1.99
2.09
2.19
2.29
2.39
2.49
2.59
2.69
2.79
2.89
2.99
NOTES:
1) Where the lubricant is applied to the driven gear, spraying application time should equal 1, and preferably 2 revolutions
of the driven gear, i.e., @ 16 RPM of the driven gear, lubricant application time should be from 3.75 to 7.5 seconds in
duration to insure complete coverage.
2) Where the lubricant is applied to the driving gear, spraying application time should equal 4, and preferably 8 revolutions of the driving gear, i.e., @ 50 RPM of the driving gear, lubricant application time should be from 4.8 to 9.6 seconds
in duration to insure complete coverage.
3) Periodic visual inspections of the working pressure flanks of the driving and driven gears should be performed by qualified personnel to ensure that sufficient lubricant is being applied, as well as the lubrication system/method is providing
proper protection.
4) The more frequent application of small quantities of lubricant is preferred. However, where a diluent is used to thin
the lubricant for spraying, the intervals between applications must be sufficient to permit complete diluent evaporation.
26
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Annex E
(informative)
Guideline for condition monitoring
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
Condition monitoring can provide very useful information about the health of the equipment in service.
It is not, however, a one time analysis. To be
effective, the equipment must be sampled on a
regular basis and records maintained which will
allow the user to observe trends and spot adverse
changes in the state of the lubricant. The sampling
rate will be dependent on the type of equipment,
service usage, type of operation, and availability. In
order to be effective, one must also pay attention to
sampling technique and prescribe analyses that are
pertinent to the operation of the equipment.
Interpretation of the results obtained from the
analyses is also critical to prevent premature
change--out of the oil or oversights of impending
problems with the system. It is highly recommended
that the lubricant supplier be consulted when initiating a condition monitoring program.
Generally, when one refers to condition monitoring it
means that one will take a sample from the
equipment in service at the prescribed interval and
send it to a laboratory for analysis. However, there
are a number of quick spot checks that can be
performed on--site by the user. These on--site
methods are not meant to be definitive, but rather to
provide the user with another tool to help maintain
the equipment. These spot tests can be performed
as often as necessary and can supplement the
findings of the analytical results from the laboratory.
E.1 Lubricant sampling
The effectiveness of a lubricant analysis program,
whether it is on--site or laboratory, depends on
proper sampling techniques. The following guidelines should be employed as part of any condition
monitoring program.
The sample should be representative of the bulk of
the lubricant in operation. Sampling from stagnant
pool areas of the equipment may produce unreasonably high levels of contaminants, while sampling
from a high speed stream may give very low
readings of contaminants. An example might be
taking the initial sample of oil emerging from the
drain or sampling valve. This would typically be a
dead zone and likely collecting an undue amount of
particulate and wear debris. It is best to discard the
first portion of the effluent and capture a portion of
the oil from the sump.
Consistency in sampling is another critical element
to obtain an effective trend analysis from the data.
Sampling should be done, whenever possible, from
the same location in the equipment and at the same
point in the duty cycle. Varying either of these could
lead to significant variation in the results obtained.
An example would be sampling one time when the
unit is hot and the next time when that same unit has
been idle and returned to some lower ambient
temperature. There could be a significant variation
in the amount of water observed. In some cases it is
desirable to know this, but it should be noted that the
sampling time or condition was different from the
routine sampling.
Cleanliness is very important. The intent of the
monitoring program is to follow the condition of the oil
in the equipment. Therefore, it is imperative to
prevent external contaminants to enter the oil during
the sampling process. Since most of the analytical
tests are looking for elements or components that
are on the order of 10’s or 100’s parts per million
(ppm), using dirty equipment to sample or store the
oil could defeat this objective very easily. Therefore,
it is recommended that sampling equipment should
be kept clean and, where possible, dedicated to a
particular piece or series of equipment, and that
clear, plastic sample bottles be used to store and
ship the oil to the laboratory. Another cleanliness
issue to help the condition monitoring program is to
ensure that the area around the sampling port is
clean before opening the valve or port for sampling.
This will prevent ingress of any unwanted debris or
other contaminant to the system.
Lastly, it is important to document the sample being
taken from the equipment. As a minimum, the
sampler should identify the unit from which the
sample was taken, the date, number of hours of
operation (if available), and any additional information that may be useful to the interpretation of the
27
ANSI/AGMA 9005--E02
AMERICAN NATIONAL STANDARD
results later on, i.e., unit idle for long period, noisy
operation, etc.
the solids feel gritty they are likely sand, dirt or
non--ferrous debris.
E.2 On--site analysis
E.6 Crackle test
As part of the condition monitoring program, a few
simple, on--site tests can be performed to supplement the laboratory analyses. These simple tests
allow the user to check for undue oxidation or
contamination of the oil as often as necessary. Since
these are very subjective methods, any comparisons are best done to a sample of the new oil at the
time of the comparison.
If the presence of water is suspected from the
appearance test, the following simple test can be
used to confirm it. Place a small drop of the oil in
question onto a hot plate that has been warmed to
135°C. If the sample bubbles, it is possible water is
present in excess of 0.05% (500 ppm). If the sample
bubbles and crackles, the water level could be in
excess of 0.1% (1000 ppm). This should be
confirmed with the laboratory analysis.
E.3 Appearance test
This method is useful to identify potential problems
with gross contamination or oxidation. Place a
sample of the lubricant in a clean, glass bottle (tall,
narrow bottle is best). Compare the sample from the
equipment to a new oil sample in the same type
container. The oil should appear clear and bright. A
hazy, cloudy, or milky appearance suggests the
presence of water; if so, run the “crackle” test. A
darkened color may indicate oxidation or contamination with very fine wear particles. Tilting the bottles
(new and used oil samples) simultaneously will give
an indication of changes in viscosity which could be
related to oxidation or shear losses. Look for
sediment in the bottom of the sample bottle; if
present, run the sedimentation test.
E.4 Odor test
Carefully sniff the oil sample and compare it to the
sample of new oil. Oils that have oxidized noticeably
will have a burnt odor or smell acrid, sour or pungent.
E.7 Laboratory analysis
There are many analytical methods available today
that can be used to provide information about the
condition of the lubricant. In all cases, comparisons
should be made to a sample of the new oil that was
actually used in the equipment. The baseline
analyses should not come from a brochure, but
rather from analysis of the actual sample, to be sure
that the starting material was within the specified
limits stated by the supplier. The basic analyses
used as a starting point should include:
Property
Viscosity . . . . . . . . . . . . . . . . . . .
Water content . . . . . . . . . . . . . . .
Acid number . . . . . . . . . . . . . . . .
Additive and wear elements . . .
Test Method
ASTM D445
ASTM D6304
ASTM D664 [15]
ASTM D5185 [16]
Supplemental analyses can always be conducted
for special applications or if there are questions
raised from the basic analyses listed above. Some
of these additional tests might include:
E.5 Sedimentation test
--
If sediment is noted during the appearance test, the
following test should be performed to supplement or
confirm this. Place a sample of the oil in a clean,
white plastic cup and allow it to stand covered for two
days. The cup should be covered or stored in a
clean, dust free area to prevent external contaminants from the environment influencing this test.
Carefully pour off all but a few milliliters of the oil. If
any particles are visible at the bottom of the cup,
contaminants are present. If the particles respond to
a magnet under the cup then these contain ferrous
debris. If there is no response from the magnet and
-- chemical tests for specific elements, i.e., sulfur, nitrogen, etc.;
28
--
ferrographic analysis;
particulate matter and size distribution.
As a note of caution, one should refrain from making
generalizations or putting undo emphasis on these
analyses. They should be viewed as a valuable
piece of information which, when used and interpreted properly for the equipment in question, can
provide the user with a useful aid to assess the state
of that equipment.
For further information, see AGMA 921--A97 [17].
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Annex F
(informative)
Lubrication system maintenance
[The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be
construed as a part of ANSI/AGMA 9005--E02, Industrial Gear Lubrication.]
F.1 Initial lubricant change period
F.3.1 Cleaning with solvents
The initial start--up and operating oil of a new gear
drive should be thoroughly drained after a period of
500 operating hours or four weeks, whichever
occurs first. The importance of a thorough gear case
cleaning with flushing oil to remove particle matter
during the first lubricant change cannot be
overemphasized. Consult the manufacturer if this is
intended to be a fill--for--life application.
The use of a solvent should be avoided unless the
gear drive contains deposits of oxidized or
contaminated lubricant which cannot be removed
with a flushing oil. When persistent deposits
necessitate the use of a solvent, a flushing oil should
then be used to remove all traces of solvent from the
system.
F.2 Subsequent lubricant change interval
Under normal operating conditions, the lubricants
should be changed every 2500 operating hours or
six months, whichever occurs first. Extending the
change period may be acceptable based on the type
of lubricant, amount of lubricant, system down time,
or environmental consideration of the used lubricant.
This can be done by proper implementation of a
comprehensive monitoring program. Such a program may include examining for:
CAUTION: When solvents are used, consult the unit
manufacturer to assure compatibility with paint, seals,
sealant and other components.
F.3.2 Used lubricants
Used lubricant and flushing oils should be
completely removed from the system to avoid
contaminating the new charge, and properly
disposed.
CAUTION: Care must be exercised not to mix
lubricants with different additive chemistry.
F.3.3 Inspection
--
change in appearance and odor;
--
lubricant viscosity;
--
lubricant oxidation, e.g., total acid number;
The interior surfaces of the gear drive should be
inspected, where possible, and all traces of foreign
material removed. The new charge of lubricant
should be added and circulated to coat all internal
parts.
--
water concentration;
F.4 Protective coatings
--
contaminants concentration;
--
percentage sediment and sludge;
--
additive depletion.
For gearing which may be subjected to extended
shipment or storage periods, consideration should
be given to applying a protective coating formulated
to prevent rusting.
These coatings must be
compatible with the lubricant to be used in service
and all other components.
New lubricant specification should be used to
establish a base line for comparison. Follow unit
manufacturer and lubricant supplier’s recommendations for appropriate subsequent testing intervals.
CAUTION: Some lubricants may foam due to reaction
with rust preventatives. If necessary, flush out residues
from the unit.
F.3 Cleaning and flushing
F.5 Filtration
When the gear drive reaches normal operating
temperature, lubricant should be drained
immediately after shutdown. The drive should be
cleaned with a flushing oil. Flushing oil must be
clean and compatible with the operating oil. Oils
specially blended for flushing, or clean operating oil
are commonly used for flushing.
Gear drives with pressurized oil systems should
have a filter on the pressure side of the system to
remove contamination particles. As a guideline, in
the absence of specific manufacturer’s recommendations, the filter should be no coarser than 50 µm
(microns) absolute for gear drives with ball or roller
bearings, and 25 mm absolute for gear drives with
29
ANSI/AGMA 9005--E02
journal bearings. In addition, a screen may be used
on the suction side to protect the pump. This should
be in combination with a filter and must have a
coarse mesh to avoid flow restriction.
CAUTION: Lubricants should not be filtered through
fuller’s earth or other types of filters which could remove
the additives of the original formulation.
30
AMERICAN NATIONAL STANDARD
F.6 Gear tooth wear
There are numerous modes of damage associated
with gear teeth. See ANSI/AGMA 1010--E95.
Proper selection, application, and maintenance of
lubricants is therefore essential to avoiding
premature wear. If premature wear occurs, lubricant
selection should be reviewed.
AMERICAN NATIONAL STANDARD
ANSI/AGMA 9005--E02
Bibliography
The following documents are either referenced in the text of ANSI/AGMA 9005--E02, Industrial Gear
Lubrication, or indicated for additional information.
1. ANSI/AGMA 2101--C95, Fundamental Rating Factors and Calculation Methods for Involute Spur and
Helical Gear Teeth
2. AGMA 925--A02, Effect of Lubrication on Gear Surface Distress
3. ISO 4406:1999, Hydraulic fluid power -- Fluids -- Method for coding the level of contamination by solid
particles
4. ASTM D5662--99, Standard Test Method for Determining Automotive Gear Oil Compatibility with Typical
Oil Seal Elastomers
5. ISO 13357--1:2000, Petroleum products – Determination of the filterability of lubricating oils – Part 1:
Procedure for oils containing water
6. ISO 13357--2:1998, Petroleum products – Determination of the filterability of lubricating oils -- Part 2:
Procedure for dry oils
7. ASTM D5763--95, Test Method for Oxidation and Thermal Stability Characteristics of Gear Oils Using
Universal Glassware
8. ASTM D4871--00, Guide for Universal Oxidation/Thermal Stability Test Apparatus
9. ASTM D5579--00, Test Method for Evaluating the Thermal Stability of Manual Transmission Lubricants in
a Cyclic Durability Test
10. ISO 3016:1994 (ASTM D97--96a), Petroleum products -- Determination of pour point
11. SAE J306, Automotive Gear Lubricant Viscosity Classification
12. Osborne, R.E., “New Trends in Gear Lubricant Viscosity”, NLGI Spokesman, September, 1977, pp.
187--191
13. Hitchcox, H.F. and Powell, D.L., “ASTM Study of Fluidity of Automotive Gear Oils at Low Temperatures”,
SAE Paper 780939
14. ANSI/AGMA 1010--E95, Appearance of Gear Teeth -- Terminology of Wear and Failure
15. ASTM D664--95(2001)e1, Test Method for Acid Number of Petroleum Products by Potentiometric Titration
16. ASTM D5185--97, Test Method for Determination of Additive Elements, Wear Metals, and Contaminants in
Used Lubricating Oils and Determination of Selected Elements in Base Oils by Inductively Coupled Plasma
Atomic Emission Spectrometry (ICP--AES)
17. AGMA/AWEA 921--A97, Recommended Practices for Design and Specification of Gearboxes for Wind
Turbine Generator Systems
18. ISO 2719:1988 (ASTM D93--97), Petroleum products and lubricants -- Determination of flash point -Pensky--Martens closed cup method
19. ISO 9120:1997, Petroleum and related products -- Determination of air--release properties of steam
turbine and other oils -- Impinger method
31
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1500 KING STREET, ALEXANDRIA, VIRGINIA 22314