U.S. patent application number 11/887699 was filed with the patent office on 2009-01-08 for lubricants containing multifunctional additive packages therein for improving load-carrying capacity, increasing surface fatigue life and reducing friction.
Invention is credited to Clark V. Cooper, Hongmei Wen.
Application Number | 20090011964 11/887699 |
Document ID | / |
Family ID | 37433747 |
Filed Date | 2009-01-08 |
United States Patent
Application |
20090011964 |
Kind Code |
A1 |
Wen; Hongmei ; et
al. |
January 8, 2009 |
Lubricants Containing Multifunctional Additive Packages Therein for
Improving Load-Carrying Capacity, Increasing Surface Fatigue Life
and Reducing Friction
Abstract
The present invention provides a composition for improving load
carrying capacity, extreme pressure performance, surface fatigue
life, and other performance characteristics of a lubricant. The
composition includes a base stock and a combination of two, three,
or all of a friction modifier, and antiwear additive, an extreme
pressure additive, and a surface fatigue life modifier. The present
invention further provides a method for improving the performance
characteristics of a lubricant. The method includes a step of
mixing a lubricant with the above-described multifunctional
lubricant additive composition or mixing a lubricant base stock
with the above-described multifunctional lubricant additive
composition.
Inventors: |
Wen; Hongmei; (South
Windsor, CT) ; Cooper; Clark V.; (Arlington,
VA) |
Correspondence
Address: |
PRATT & WHITNEY
400 MAIN STREET, MAIL STOP: 132-13
EAST HARTFORD
CT
06108
US
|
Family ID: |
37433747 |
Appl. No.: |
11/887699 |
Filed: |
November 4, 2005 |
PCT Filed: |
November 4, 2005 |
PCT NO: |
PCT/US2005/039763 |
371 Date: |
October 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60625416 |
Nov 4, 2004 |
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Current U.S.
Class: |
508/364 |
Current CPC
Class: |
C10M 2207/289 20130101;
C10M 2223/04 20130101; C10M 137/02 20130101; C10M 137/04 20130101;
C10M 2223/045 20130101; C10N 2030/06 20130101; C10N 2040/02
20130101; C10M 129/76 20130101; C10M 141/08 20130101; C10M 2223/049
20130101; C10M 2219/068 20130101; C10M 2223/041 20130101; C10N
2040/13 20130101; C10M 141/10 20130101; C10N 2030/10 20130101; C10N
2040/25 20130101; C10M 2219/066 20130101; C10N 2040/04 20130101;
C10M 2207/289 20130101; C10M 2207/289 20130101; C10M 2219/068
20130101; C10N 2010/12 20130101; C10M 2223/045 20130101; C10N
2010/04 20130101; C10M 2219/068 20130101; C10N 2010/12 20130101;
C10M 2223/045 20130101; C10N 2010/04 20130101 |
Class at
Publication: |
508/364 |
International
Class: |
C10M 135/18 20060101
C10M135/18 |
Goverment Interests
GOVERNMENT RIGHTS IN THE INVENTION
[0002] The invention was made by, or under contract with, the
National Institute of Standards and Technology of the United States
Government under contract number: 70NANBOH3048.
Claims
1. A multifunctional lubricant composition for improving the
performance characteristics of a lubricant, said composition
comprising: a base stock lubricant; and a friction modifier
comprising at least one of a long-chain organic partial ester and a
short-chain metallo-organic compound, wherein the long-chain ester
has the general formula: ##STR00019## wherein R.sup.1 and R.sup.2
are each a C.sub.iH.sub.2i+1 alkyl group, wherein i is an integer
of about 7.ltoreq.i.ltoreq.15; wherein the short-chain
metallo-organic compound has the general formula: ##STR00020##
wherein X.sup.1 is oxygen or sulfur, wherein R.sup.3 and R.sup.4
are each a C.sub.nH.sub.2n+1 alkyl group, wherein n is an integer
of about 2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4.
2. The composition according to claim 1, wherein the long-chain
organic ester is glycerol monooleate.
3. The composition according to claim 1, wherein the short-chain
metallo-organic compound is molybdenum dithiocarbamate.
4. The composition according to claim 1, further comprising: an
antiwear additive comprising at least one of an alkyl neutral
phosphate, an aryl neutral phosphate, and a zinc dialkyl
dithiophosphate, wherein the alkyl neutral phosphate and the aryl
neutral phosphate have the general formula: ##STR00021## wherein
the R.sup.5, R.sup.6, and R.sup.7 are each a C.sub.nH.sub.2n+1
alkyl group, wherein the R.sup.5, R.sup.6, and R.sup.7 are each a
C.sub.6H.sub.5C.sub.mH.sub.2m+1 aryl group, n is an integer of
about 2.ltoreq.n.ltoreq.10, m is an integer of about
0.ltoreq.m.ltoreq.8; wherein the zinc dialkyl dithiophosphate
compound is represented by the general formula: ##STR00022##
wherein R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each a
C.sub.hH.sub.h+1 secondary alkyl group, h is an integer from about
3.ltoreq.h.ltoreq.11, wherein the secondary alkyl group is
represented by the formula: ##STR00023## wherein R.sup.12 and
R.sup.13 are each an alkyl group C.sub.iH.sub.2i+1, i is an integer
of about 1.ltoreq.i.ltoreq.5.
5. A composition according to claim 4, wherein the aryl neutral
phosphate is tricresyl phosphate.
6. The composition according to claim 1, further comprising: an
extreme pressure additive comprising at least one of an aryl
phosphate, an alkyl phosphate, an alkyl amine phosphite, and an
aryl amine phosphite, represented by the general formula:
##STR00024## wherein R.sup.14, R.sup.15, R.sup.16, R.sup.17,
R.sup.18 and R.sup.19 are each independently a C.sub.jH.sub.2j+1
alkyl group, j is an integer of about 1.ltoreq.j.ltoreq.20;
7. A composition according to claim 6 further including a phenol
compound represented by the general formula: ##STR00025## wherein
R.sup.20, R.sup.20', R.sup.20'', and R.sup.20''' are each
independently a C.sub.pH.sub.2p+1 normal alkyl group, p is an
integer of about 1.ltoreq.p.ltoreq.12, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the following formula: ##STR00026## Wherein
R.sup.22, R.sup.23, and R.sup.24 are each independently a
C.sub.oH.sub.2o+1 alkyl group, wherein o is an integer of about
1.ltoreq.o.ltoreq.20, R.sup.23 and R.sup.24 are tertiary
structures.
8. A composition according to claim 6, wherein the extreme pressure
additive comprises a hindered phosphate comprising
tris-(2,4-ditertertiarybutylphenyl phosphite).
9. A composition according to claim 1, further comprising: a
surface fatigue life modifier comprising an alkylthiocarbamoyl
compound of the following formula: ##STR00027## wherein R.sup.25,
R.sup.26, R.sup.27, and R.sup.28 are each a C.sub.kH.sub.k+1 alkyl
group, wherein k is an integer of about 1.ltoreq.k.ltoreq.30;
R.sup.25, R.sup.26, R.sup.27, and R.sup.28 optionally form a ring
structure as combined with the nitrogen atom to which they are
bonded, wherein (A) consists of S.sub.n (a chain of sulfur atom) or
the following structure: S--(CH.sub.2).sub.m--S wherein n is an
integer of about 1.ltoreq.n.ltoreq.10 and m is an integer of about
1.ltoreq.m.ltoreq.6.
10. The composition according to claim 1, wherein i of the friction
modifier is an integer of about 8.ltoreq.i.ltoreq.10 and n of the
friction modifier is an integer of about 4.ltoreq.n.ltoreq.6.
11. The composition according to claim 4, wherein n of the antiwear
additive is an integer of about 4.ltoreq.n.ltoreq.6, m of the
antiwear additive is an integer of about 1.ltoreq.m.ltoreq.5, and h
of the antiwear additive is an integer 4.ltoreq.h.ltoreq.6.
12. The composition according to claim 6, wherein j of the extreme
pressure additive is an integer of about 4.ltoreq.j.ltoreq.8; p of
the extreme pressure additive is an integer of about
1.ltoreq.p.ltoreq.5; and the composition according to claim 7,
where in o of the extreme pressure additive is an integer of about
2.ltoreq.o.ltoreq.110.
13. The composition according to claim 9, wherein k of the surface
fatigue life modifier is an integer of about
4.ltoreq.k.ltoreq.8.
14. The composition according to claim 1, wherein the base stock
lubricant is present in an amount of about 90% or more by mole
based on the total amount of lubricant.
15. The composition according to claim 1, wherein the base stock
lubricant is present in an amount of about 94% or more by mole
based on the total about of lubricant.
16. The composition according to claim 1, wherein the friction
modifier is present in an amount of about 4% or less by mole based
on the total about of lubricant.
17. The composition according to claim 1, wherein the friction
modifier is present in an amount of about from 0.1% to 3% based on
the total amount of lubricant.
18. The composition according to claim 4, wherein the antiwear
additive is present in an amount of about 4% by mole or less based
on the total amount of lubricant.
19. The composition according to claim 4, wherein the antiwear
additive is present in an amount of about from 0.1% to 3% by mole
based on the total amount of lubricant.
20. The composition according to claim 6, wherein the extreme
pressure additive is present in an amount of about 6% or less by
mole based on the total amount of lubricant.
21. The composition according to claim 6, wherein the extreme
pressure additive is present in an amount of about from 0.1% to 3%
by mole based on the total amount of lubricant.
22. The composition according to claim 9, wherein the surface
fatigue life modifier is present in an amount of about 4% or less
by mole based on the total amount of lubricant.
23. The composition according to claim 9, wherein the surface
fatigue life modifier is present in an amount of about from 0.01%
to 1% by mole based on the total amount of lubricant.
24. The composition according to claim 4, further comprising an
extreme pressure additive comprising at least one of an aryl
phosphate, an alkyl phosphate, an alkyl amine phosphite, and an
aryl amine phosphite, represented by the general formula:
##STR00028## wherein R.sup.14, R.sup.15, R.sup.16, R.sup.17,
R.sup.18 and R.sup.19 are each independently a C.sub.jH.sub.2j+1
alkyl group, j is an integer of about 1.ltoreq.j.ltoreq.20;
25. A composition according to claim 24 further including a phenol
compound represented by the general formula: ##STR00029## Wherein
R.sup.20, R.sup.20', R.sup.20'', and R.sup.20''' are each
independently a C.sub.pH.sub.2p+1 normal alkyl group, p is an
integer of about 1.ltoreq.p.ltoreq.12, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the ##STR00030## following formula: wherein
R.sup.22, R.sup.23, and R.sup.24 are each independently a
C.sub.oH.sub.2o+1 alkyl group, wherein o is an integer of about
1.ltoreq.o.ltoreq.20, R.sup.23 and R.sup.24 are tertiary
structures.
26. A composition according to claim 4, further comprising a
surface fatigue life modifier comprising an alkylthiocarbamoyl
compound of the following formula: ##STR00031## wherein R.sup.25,
R.sup.26R.sup.27, and R.sup.28 are each a C.sub.kH.sub.k+1 alkyl
group, wherein k is an integer of about 1.ltoreq.k.ltoreq.30;
R.sup.25, R.sup.26, R.sup.27, and R.sup.28 optionally form a ring
structure as combined with the nitrogen atom to which they are
bonded, wherein (A) consists of S.sub.n (a chain of sulfur atoms)
or the following structure: S--(CH.sub.2).sub.m--S wherein n is an
integer of about 1.ltoreq.n.ltoreq.10 and m is an integer of about
1.ltoreq.m.ltoreq.6.
27. The composition according to claim 9, further comprising
further comprising: an extreme pressure additive comprising at
least one of an aryl phosphate, an alkyl phosphate, an alkyl amine
phosphite, and an aryl amine phosphite, represented by the general
formula: ##STR00032## wherein R.sup.14, R.sup.15, R.sup.16,
R.sup.17, R.sup.18 and R.sup.19 are each independently a
C.sub.jH.sub.2j+1 alkyl group, j is an integer of about
1.ltoreq.j.ltoreq.20;
28. A composition according to claim 27 further including a phenol
compound represented by the general formula: ##STR00033## wherein
R.sup.20, R.sup.20', R.sup.20'', and R.sup.20''' are each
independently a C.sub.pH.sub.2p+1 normal alkyl group, p is an
integer of about 1.ltoreq.p.ltoreq.12, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the following formula: ##STR00034## Wherein
R.sup.22, R.sup.23, and R.sup.24 are each independently a
C.sub.oH.sub.2o+1 alkyl group, wherein o is an integer of about
1.ltoreq.o.ltoreq.20, R.sup.23 and R.sup.24 are tertiary
structures.
29. A multifunctional lubricant composition comprising: (a) a base
stock lubricant; and at least one of (b), (c), (d) and (e), (b) a
friction modifying (FM) additive comprising: (b1) a long-chain
organic partial ester having the general formula: ##STR00035##
wherein R.sup.1 and R.sup.2 are each independently a
C.sub.iH.sub.2i+1 normal alkyl group, wherein i is an integer of
about 7.ltoreq.i.ltoreq.15; (b2) a short chain metallo-organic
compound represented by the general formula: ##STR00036## Wherein
X.sup.1 is oxygen and/or sulfur, wherein R.sup.3 and R.sup.4 are
each a C.sub.nH.sub.2n+1 alkyl group, n is an integer of about
2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4; and/or (b3) a combination of (b1) and (b2);
(c) an antiwear (AW) additive comprising: (c1) an alkyl neutral
phosphate or an aryl neutral phosphate represented by the formula:
##STR00037## wherein the R.sup.5, R.sup.6, and R.sup.7 are each
C.sub.nH.sub.2n+1 alkyl groups of an alkyl neutral phosphate or
C.sub.6H.sub.5C.sub.mH.sub.2m+1 aryl groups of an aryl neutral
phosphate, n is an integer of about 2.ltoreq.n.ltoreq.10, and m is
an integer of about 0.ltoreq.m.ltoreq.8; (c2) a zinc dialkyl
dithiophosphate represented by the general formula: ##STR00038##
wherein R, R.sup.9, R.sup.10, and R.sup.11 are each a
C.sub.hH.sub.h+1 secondary alkyl group, h is an integer from about
3.ltoreq.h.ltoreq.11, and wherein the secondary alkyl group is
represented by the formula: ##STR00039## wherein R.sup.12 and
R.sup.13 are each an alkyl group C.sub.iH.sub.2i+1, and i is an
integer of about 1.ltoreq.i.ltoreq.5; and/or (c3) a combination of
(c1) and (c2); and (d) an extreme pressure (EP) additive
comprising: (d1) an aryl phosphate, an alkyl phosphate, an alkyl
amine phosphite, or an aryl amine phosphite represented by the
general formula: ##STR00040## wherein R.sup.14R.sup.15, R.sup.16,
R.sup.17, R.sup.18 and R.sup.19 are each independently a
C.sub.jH.sub.2j+1 alkyl group, j is an integer of about
1.ltoreq.j.ltoreq.20; (d2) a combination of (d1) and a phenol
compound represented by the general formula: ##STR00041## wherein
R.sup.20, R.sup.20', R.sup.20'', and R.sup.20''' are each
independently a C.sub.pH.sub.2p+1 normal alkyl group, p is an
integer of about 1.ltoreq.p.ltoreq.12, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the following formula: ##STR00042## wherein
R.sup.22, R.sup.23, and R.sup.24 are each independently a
C.sub.oH.sub.2o+1 alkyl group, wherein O is an integer of about
1<O<20, and R.sup.23 and R.sup.24 are tertiary structures;
and (e) a surface fatigue life (SFL) modifier represented by an
alkylthiocarbamoyl compound of the following formula: ##STR00043##
wherein R.sup.25R.sup.26, R.sup.27 and R.sup.28 are each a
C.sub.kH.sub.k+1 alkyl group, wherein k is an integer of about
1.ltoreq.k.ltoreq.30; R.sup.25, R.sup.26, R.sup.27, and R.sup.28
optionally form a ring structure as combined with the nitrogen atom
to which they are bonded, wherein (A) consists of S.sub.n (a chain
of sulfur atoms) or the following structure: S--(CH.sub.2).sub.m--S
wherein n is an integer of about 1.ltoreq.n.ltoreq.10, and m is an
integer of about 1.ltoreq.m.ltoreq.6.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Application No. 60/625,416 filed Nov. 4, 2004, and is
related to the following co-pending and commonly-owned applications
which were filed herewith and are hereby incorporated by reference
in full: "Lubricant Additive Packages for Improving Load-Carrying
Capacity and Surface Fatigue Life" (Attorney Docket No. 0002290WOU,
EH-11605), U.S. Ser. No. ______; "Multifunctional Lubricant
Additive Package" (Attorney Docket No. 0002291WOU, EH-11679), U.S.
Ser. No. ______; and "Multifunctional Lubricant Additive Package
for a Rough Mechanical Component Surface" (Attorney Docket No.
0002295WOU, EH-1 1698), U.S. Ser. No. ______.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a lubricant that includes a
multifunctional additive composition or package for improving the
performance characteristics of a lubricant. More particularly, the
present invention relates to a lubricant that includes a
multifunctional additive composition or package for providing a
lubricant with superior performance characteristics such as
improved load-carrying capacity, anti-scuffing (anti-scoring)
capacity, friction reduction, and improved surface-fatigue
life.
[0005] 2. Description of Related Art
[0006] Mechanical systems such as manual or automatic
transmissions; single and multi-speed aviation transmissions,
including but not limited to those used to propel rotorcraft and
those used to alter the rotational speed of sections within gas
turbine engines, push-belt type continuous variable transmissions,
and traction drive continuous variable transmissions, have large
surface areas of contact zones. These contact portions or zones,
such as drive rolling surfaces, and gear and ball-and roller
bearings, are known to be susceptible to high surface pressures. In
addition, internal combustion engines and other propulsion devices,
especially those that are common for high-performance and racing
applications, are subject to taxing demands in the form of inertial
loading, high sliding and/or rolling speeds, and marginal
lubrication. Moreover, the need for reducing friction, improving
scuffing (scoring) resistance, and increasing surface fatigue life
within larger contact zones of mechanical systems is increased by
many recently developed transmission systems that are designed to
be miniaturized or weight-reduced to maximize transmission
throughput capacity.
[0007] To address these severe application demands, lubricants,
especially those containing specific additives, play a critical
role in protecting and minimizing the wear and scuffing (scoring)
of surfaces. The lubricants generally reduce principal damage
accumulation mechanisms of lubricated components caused by surface
fatigue and overloading.
[0008] Examples of known lubricants are discussed in the following
publications, which are hereby incorporated in full by reference:
Phillips, W. D., Ashless phosphorus-containing lubricating oil
additives, Lubricant Additives Chemistry and Application 45-111 (L.
R. Rudick, Marcel Dekker, Inc. 2003); and D. Kenbeck, and T. F.
Buenemann, Organic Modifiers, Lubricant Additives Chemistry and
Application 203-222 (L. R. Rudick, Marcel Dekker, Inc. 2003).
[0009] Recently developed system-optimization approaches for
increasing overall power throughput of mechanical systems
underscore the need for new and better performing lubricant
additives. By reducing friction, wear, and pressure, and improving
scoring (scuffing) resistance, these additives prolong surface
fatigue life for lubricated contacts within transmission systems
and propulsive devices.
[0010] The present invention provides a lubricant for improving the
performance characteristics of mechanical systems, such as
increasing load-carrying capacity, increasing surface fatigue life
and reducing friction.
SUMMARY OF THE INVENTION
[0011] The present invention provides a lubricant that includes an
additive package comprising elements or components that are
intended to enhance the performance characteristics of the
lubricant. The additive package includes anti-wear (AW), extreme
pressure (EP), friction modifying (FM), and/or surface fatigue life
(SFL) modifying compositions.
[0012] In a preferred embodiment, this invention provides a
lubricant having a multifunctional lubricant additive composition
included therein for improving the performance characteristics of
the lubricant for use in transmission fluid products that meet both
civil and military specifications.
[0013] In another embodiment, the present invention provides a
lubricant having a multifunctional lubricant additive composition
included therein for use in improving the performance of metals and
alloys of power transmission components, including gears, bearings,
spines, shafts and springs.
[0014] In another embodiment, this invention provides a lubricant
having a multifunctional lubricant additive composition included
therein for improving the performance characteristics of engines
and related propulsive devices used to power automobiles, both
stock (production) and specialty (e.g. racing and other high
performance) varieties, and heavy on- and off-road equipment, such
as farm implements and construction equipment.
[0015] In another embodiment, the present invention provides a
lubricant having a multifunctional lubricant additive composition
included therein that beneficially reduces friction and scuffing
(scoring), and increases resistance to surface degradation,
including but not limited to fatigue, including micro- and
macro-pitting, and wear.
[0016] In yet another embodiment, the present invention provides a
lubricant having a multifunctional lubricant additive composition
included therein for improving the performance characteristics of
an applied mechanical system. Embodiments of this lubricant
comprise the following components:
[0017] (a) a base stock lubricant and at least one of the (b), (c),
(d) and (e) additive/modifiers described below;
[0018] (b) a friction modifying (FM) additive comprising: [0019]
(b1) a long-chain organic partial ester having the general
formula:
##STR00001##
[0020] wherein R.sup.1 and R.sup.2 are each independently a
C.sub.iH.sub.2i+1 normal alkyl group, wherein i is an integer of
about 7.ltoreq.i.ltoreq.15; [0021] (b2) a short chain
metallo-organic compound represented by the general formula:
##STR00002##
[0022] wherein X.sup.1 is oxygen or sulfur, wherein R.sup.3 and
R.sup.4 are each a C.sub.nH.sub.2n+1 alkyl group, n is an integer
of about 2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4; and/or [0023] (b3) a combination of (b1) and
(b2); and/or
[0024] (c) an antiwear (AW) additive comprising: [0025] (c1) an
alkyl neutral phosphate or an aryl neutral phosphate represented by
the formula:
##STR00003##
[0026] wherein the R.sup.5, R.sup.6, and R.sup.7 are each a
C.sub.nH.sub.2n+1 alkyl group of an alkyl neutral phosphate or a
C.sub.6H.sub.5C.sub.mH.sub.2m+1 aryl group of an aryl neutral
phosphate, n is an integer of about 2.ltoreq.n.ltoreq.10, and m is
an integer of about 0.ltoreq.m.ltoreq.8; [0027] (c2) a zinc dialkyl
dithiophosphate represented by the general formula:
##STR00004##
[0028] wherein R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each a
C.sub.hH.sub.h+1 secondary alkyl group, h is an integer from about
3.ltoreq.h.ltoreq.11, and wherein the secondary alkyl group is
represented by the formula:
##STR00005## [0029] wherein R.sup.12 and R.sup.13 are each an alkyl
group C.sub.iH.sub.2i+1, and i is an integer of about
1.ltoreq.i.ltoreq.5; and [0030] (c3) a combination of (c1) and
(c2); and/or
[0031] (d) an extreme pressure (EP) additive comprising: [0032]
(d1) an aryl phosphate, an alkyl phosphate, an alkyl amine
phosphite, or an aryl amine phosphite, preferable hindered
phosphite, represented by the general formula:
##STR00006##
[0033] wherein R.sup.14R.sup.15, R.sup.16, R.sup.17, R.sup.18 and
R.sup.19 are each independently a C.sub.jH.sub.2j+1 alkyl group, j
is an integer of about 1.ltoreq.j.ltoreq.20; [0034] (d2) a
combination of (d1) and a phenol compound represented by the
general formula:
##STR00007##
[0035] wherein R.sup.20, R.sup.20', R.sup.20'', and R.sup.20''' are
each independently a C.sub.pH.sub.2p+1 normal alkyl group, p is an
integer of about 1.ltoreq.p.ltoreq.12, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the following formula:
##STR00008## [0036] wherein R.sup.22, R.sup.23, and R.sup.24 are
each independently a C.sub.oH.sub.2o+1 alkyl group, wherein o is an
integer of about 1.ltoreq.o.ltoreq.20, and R.sup.23 and R.sup.24
are tertiary structures; and/or
[0037] (e) a surface fatigue life (SFL) modifier represented by an
alkylthiocarbamoyl compound of the following formula:
##STR00009##
[0038] wherein R.sup.25, R.sup.26, R.sup.27, and R.sup.28 are each
independently a C.sub.kH.sub.k+1 alkyl group, wherein k is an
integer of about 1.ltoreq.k.ltoreq.30; R.sup.25, R.sup.26,
R.sup.27, and R.sup.28 optionally form a ring structure as combined
with the nitrogen atom to which they are bonded, wherein (A)
consists of a chain of sulfur atoms, S.sub.n, or the following
structure:
S--(CH.sub.2).sub.m--S
[0039] Wherein n is an integer of about 1.ltoreq.n.ltoreq.10, and m
is an integer of about 1.ltoreq.m.ltoreq.6.
BRIEF DESCRIPTION OF THE DRAWING
[0040] The FIGURE shows the relationship between the average
traction (friction) coefficient and average load stage for various
lubricants. The vertical arrows 11, 21, 31 indicate the average
scuffing (scoring) failure load stage (load carrying capacity) of
Hatco HXL-7944 Oil 10, Exxon-Mobil Jet Oil II 20; and Formulation
#4 30, respectively. A higher scuffing (scoring) failure load stage
indicates greater load-carrying capacity of the lubricant.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The present invention provides a multifunctional lubricant
composition. One preferred non-limiting embodiment of this
multifunctional lubricant composition includes the following: (1) a
base stock lubricant (a) in a concentration of about 90% or more by
mole, preferably more than about 94% by mole; (2) about 4% or less
by mole, preferably about 0.1% to 3% by mole, of friction modifying
additive(s) (b); (3) about 4% or less by mole, preferably about
0.1% to 3% by mole, of antiwear additive(s) (c); (4) about 6% or
less by mole, preferably about 0.1% to 3% by mole, of extreme
pressure additive(s) (d); and about 4% or less by mole, preferably
about 0.01% to 1% by mole, of a surface fatigue life modifier(s),
all based on the total amount of lubricant. The total amount of
additives (b)-(e) should not exceed about 10% by mole, based on the
total amount of the lubricant. The present invention contemplates
the use of one or more of the additives (b)-(e) with the base stock
lubricant (a).
[0042] Various types of lubricants, greases, etc., especially
synthetic polyol ester (POE) based lubricants, can be used as the
lubricating base stock material in this invention.
[0043] The lubricant compositions of this invention are prepared by
mixing the following components:
[0044] (a) a base stock lubricant, which is preferably a synthetic
oil (i.e., a synthetic polyol ester (POE) oil);
[0045] (b) a friction modifying (FM) additive comprising: [0046]
(b1) a long-chain organic partial ester (i.e., glycerol mono-oleate
(GMO)), having the general formula:
##STR00010##
[0047] wherein R.sup.1 and R.sup.2 are each independently a
C.sub.iH.sub.2i+1 normal alkyl group, wherein i is an integer of
about 7.ltoreq.i.ltoreq.15, preferably about 8.ltoreq.i.ltoreq.10;
[0048] (b2) a short-chain metallo-organic compound (i.e.,
molybdenum dithiocarbamate) represented by the general formula:
##STR00011##
[0049] wherein X.sup.1 is oxygen and/or sulfur, wherein R.sup.3 and
R.sup.4 are each a C.sub.nH.sub.2n+1 alkyl group, n is an integer
of about 2.ltoreq.n.ltoreq.10, preferably about
4.ltoreq.n.ltoreq.6, and m is an integer of about
0.ltoreq.m.ltoreq.4; and/or [0050] (b3) a combination of (b1) and
(b2);
[0051] (c) an antiwear (AW) additive comprising: [0052] (c1) an
alkyl neutral phosphate or an aryl neutral phosphate (i.e.,
tricresyl phosphate (TCP)) represented by the formula:
[0052] ##STR00012## [0053] wherein the R.sup.5, R.sup.6, and
R.sup.7 are each C.sub.nH.sub.2n+1 alkyl groups of an alkyl neutral
phosphate or C.sub.6H.sub.5C.sub.mH.sub.2m+1 aryl groups of an aryl
neutral phosphate, n is an integer of about 2.ltoreq.n.ltoreq.10,
preferably about 4.ltoreq.n.ltoreq.6, and m is an integer of about
0.ltoreq.m.ltoreq.8, preferably about 1.ltoreq.m.ltoreq.5; [0054]
(c2) a zinc dialkyl dithiophosphate (i.e., Zinc
O,O-dibutylphosphorodithioate) represented by the general
formula:
##STR00013##
[0055] wherein R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each a
C.sub.hH.sub.h+1 secondary alkyl group, h is an integer from about
3.ltoreq.h.ltoreq.11, preferably about 4.ltoreq.h.ltoreq.6, and
wherein the secondary alkyl group is represented by the
formula:
##STR00014## [0056] wherein R.sup.12 and R.sup.13 are each an alkyl
group C.sub.iH.sub.2i+1, and i is an integer of about
1.ltoreq.i.ltoreq.5, preferably about 1.ltoreq.i.ltoreq.3; and/or
[0057] (c3) a combination of (c1) and (c2); and
[0058] (d) an extreme pressure (EP) additive comprising: [0059]
(d1) an aryl phosphate, an alkyl phosphate, an alkyl amine
phosphite, or an aryl amine phosphite, preferably a hindered
phosphate (i.e. Tris-(2,4-di-tertiary-butyl-phenyl)Phosphite)
represented by the general formula:
[0059] ##STR00015## [0060] wherein R.sup.14, R.sup.15,
R.sup.16R.sup.17, R.sup.18 and R.sup.19 are each independently a
C.sub.jH.sub.2j+1 alkyl group, j is an integer of about
1.ltoreq.j.ltoreq.20, preferably 4.ltoreq.j.ltoreq.8; [0061] (d2) a
combination of (d1) and a phenol compound (i.e., Pentaerythritol
Tetrakis-(methylene-3,5-di-tert-butyl-4-hydroxyhydrocinnamate)
represented by the general formula:
[0061] ##STR00016## [0062] wherein R.sup.20, R.sup.20', R.sup.20'',
and R.sup.20''' are each independently a C.sub.pH.sub.2p+1 normal
alkyl group, p is an integer of about 1.ltoreq.p.ltoreq.12,
preferably about 1.ltoreq.p.ltoreq.5, wherein R.sup.21, R.sup.21',
R.sup.21'', and R.sup.21''' are each independently a phenol group
represented by the following formula:
[0062] ##STR00017## [0063] wherein R.sup.22, R.sup.23, and R.sup.24
are each independently a C.sub.oH.sub.2o+1 alkyl group, wherein O
is an integer of about 1.ltoreq.o.ltoreq.20, preferably about
2.ltoreq.o.ltoreq.10, and R.sup.23 and R.sup.24 are tertiary
structures; and/or
[0064] (e) a surface fatigue life (SFL) modifier represented by an
alkylthiocarbamoyl compound (i.e., Tetra-n-butylthiuram) of the
following formula:
##STR00018##
[0065] wherein R.sup.25, R.sup.26, R.sup.27, and R.sup.28 are each
independently a C.sub.kH.sub.k+1 alkyl group, wherein k is an
integer of about 1.ltoreq.k.ltoreq.30, preferably about
4.ltoreq.k.ltoreq.8; R.sup.25, R.sup.26, R.sup.27, and R.sup.28
optionally form a ring structure as combined with the nitrogen atom
to which they are bonded, wherein (A) consists of S.sub.n (a chain
of sulfur atoms) or the following structure:
S--(CH.sub.2).sub.m--S
[0066] wherein n is an integer of about 1.ltoreq.n.ltoreq.10, and m
is an integer of about 1.ltoreq.m.ltoreq.6, preferably about
1.ltoreq.n.ltoreq.6 and 1.ltoreq.m.ltoreq.3.
[0067] In embodiments, the base stock lubricant of component (a) is
present in a concentration of about 90% or more by mole, preferably
about 94% or more by mole, based on the total amount of
lubricant.
[0068] In embodiments, the friction modifying additive of component
(b) is present in a concentration of about 4% or less by mole,
preferably from about 0.1% to 3% by mole, based on the total amount
of lubricant.
[0069] In embodiments, the antiwear additive of component (c) is
present in a concentration of about 4% or less by mole, preferably
from about 0.1% to about 3% by mole based on the total amount of
lubricant.
[0070] In embodiments, the extreme pressure additive of component
(d) is present in a concentration of about 6% or less by mole,
preferably about 0.1% to 3% by mole, based on the total amount of
lubricant.
[0071] In embodiments, the surface fatigue life modifier of
component (e) is present in a concentration of less than about 4%
by mole, preferably about 0.01% to 1% by mole, based on the total
amount of lubricant.
[0072] In embodiments, the total concentration of the four
additives (b)-(e) is about 10% or less by mole based on the total
amount of lubricant.
[0073] The lubricants of the present invention can be used as
improved gear oil, bearing oil, sliding surface lubrication oil,
chain lubricating oil, and/or engine oil. In a preferred
embodiment, various types of lubricants, greases, especially
synthetic polyol ester (POE) based lubricants, can be used as the
base stock lubricant.
[0074] The lubricants of this invention are useful as aviation
(aerospace) and/or automotive lubricants. These lubricants improve
engine and transmission power generation and throughput, increase
system power density and component surface fatigue life, and reduce
friction.
[0075] These lubricants may also be used as turbine engine and/or
transmission oils, and can be designed to meet civil (FAA) and
military (DoD) specifications and requirements.
[0076] These lubricants may also be used to improve scuffing
(scoring) performance of metals and alloys that are commonly used
for power transmission components, including but not limited to
gears, bearing, spines shafts, springs, and the like. As such,
these lubricants decrease the incidence of component and system
failure and rejection during customer acceptance test protocols
(ATPs). These lubricants also improve pitting fatigue life (surface
fatigue life) and reduce the rate of component and system
degradation due to wear and other phenomena.
[0077] The following formulations and experimental results
illustrate some non-limiting embodiments of the novel lubricants of
this invention.
Formulation #2
[0078] In this embodiment, a multifunctional additive package was
added to Exxon-Mobil Jet Oil II (a standard version of
MIL-PRF-23699, a 5 cSt gas turbine oil) to create Formulation #2.
Formulation #2 contained the following additives:
TABLE-US-00001 Additive Mole % Supplier Friction Modifying Glycerol
Monooleate 1.0 Crompton Additive Compound (b) Extreme Pressure
Tris-(2,4-di-tertiary-butyl- 0.45 Strem Additive phenyl) Phosphite
Chemicals Compound (d) Extreme Pressure Pentaerythritol Tetrakis-
0.05 Sigma- Additive (methylene-3,5-di-tert- Aldrich Compound (d)
butyl-4- hydroxyhydrocinnamate)
[0079] Exxon-Mobil Jet Oil II typically has excellent lubricant
performance compared to other brands and versions of MIL-PRF-23699
oil. This multifunctional additive package increased the load
carrying capacity (i.e., scuffing performance) of the Exxon-Mobil
Jet Oil II about 1.43 times. Additionally, the components that were
tested with Formulation #2 had a surface fatigue life of at least
about 2.9 times that of the components that were tested with the
Exxon-Mobil Jet Oil II alone (unmodified by any additive package of
this invention).
Formulation #4
[0080] In this embodiment, a multifunctional additive package was
added to Hatco HXL-7994 oil to create Formulation #4. Hatco
HXL-7994 oil contains an anti-oxidant package and a yellow metal
corrosion inhibitor and uses a 5 cSt polyol ester base stock,
HXL-1570, having the typical properties noted in Table A below.
TABLE-US-00002 TABLE A Properties of HXL-1570 PROPERTY TYPICAL
VALUES Viscosity, cSt @ 100.degree. C. 4.95 Viscosity, cSt @
40.degree. C. 24 Viscosity, cSt @ -40.degree. C. 7500 Viscosity
Index 133 Specific Gravity 25/25.degree. C. 0.985 Appearance Clear
yellow liquid Hydroxyl, mg KOH/g 2 Density, lbs/usg15.5.degree. C.
8.25 Fire Point 2.82 Evaporation Loss % (6.5 h @ 204.degree. C.) 4
Avg. Molecular Weight 570
Formulation #4 contained the following additives
TABLE-US-00003 Product Additive Mole % CAS# Formula Supplier Name
Friction Molybdenum, 0.5 71342-89-7 C54H108Mo2N2O2S6 R T MolyVan
Modifying bis(ditridecylcarbamodithioato) di-u- Vanderbilt 822/#
Additive oxodioxo-di-sulfurized 29150 Compound (b) Antiwear Zinc
O,O- 0.5 6990-43-8 C16H36O4P2S4Zn Flexsys Vocol Additive
dibutylphosphorodithioate ZBPD Compound (c) Extreme
Tris-(2,4-di-tertiary-butyl- 0.5 31570-04-4 C42H63O3P Strem 15-7720
Pressure phenyl) Phosphite Chemicals Additive Compound (d) Surface
Tetra-n-butylthiuram 0.4 1634-02-2 C18H36N2S4 R T 40850 Fatigue
Vanderbilt Life Modifier Additive Compound (e)
[0081] This multifunctional additive package of Formulation #4
increased the load-carrying capacity of the Hatco HXL-7994 oil
about 3.94 times, which is superior to conventional oils such as
Exxon-Mobil Jet Oil II (a standard version of MIL-PRF-23699, a 5
cSt gas turbine engine oil), which typically has excellent
lubricant performance as compared to other brands and versions of
MIL-PRF-23699 oil. As can be seen in the FIGURE and Table 1 below,
the Hatco HXL-7994 oil 10 had an average scuffing (scoring) failure
load stage at about 5.7 (arrow 11), the Exxon-Mobil Jet Oil II 20
had an average scuffing (scoring) failure load stage at about 19.2
(arrow 21), and Formulation #4 30 had an average scuffing (scoring)
failure load stage at about 22.5 (arrow 31), which indicates that
Formulation #4 has a load carrying capacity about 3.94 times that
of the Hatco HXL-7994 Oil, and that Formulation #4 has a load
carrying capacity about 1.17 times that of the Exxon-Mobil Jet Oil
II.
TABLE-US-00004 TABLE 1 Average Micro- Macro- Scuffing scuff scuff
(Scoring) (score) (score) Failure Test Lubricant Ball Disc/t.d.
Stage Stage Stage UTLCC6 HXL-7944 UTLCC6-9a 9-10a/3.2 4 16 (Base
Oil) UTLCC7 HXL-7944 UTLCC6-9b 9-10a/3.1 6 20 (Base Oil) UTLCc8
HXL-7944 UTLCC5-9b 9-10a/3.0 7, 16 17 5.7 (Base Oil) UTLCC16
Formulation #4 UTLCC16-9a 9-10b/2.9 24 UTLCC17 Formulaiton #4
UTLCC16-9b 9-10b/2.8 21 22.5 UTLCC1 Exxon-Mobil SBAD12-9a 9-10a/3.7
25 Jet Oil II UTLCC2 Exxon-Mobil SBAD12-9b 9-10a/3.6 15 Jet Oil II
UTLCC3 Exxon-Mobil UTLCC3-9a 9-10a/3.5 24 Jet Oil II UTLCC4
Exxon-Mobil UTLCC3-9b 9-10a/3.4 25 Jet Oil II UTLCC5 Exxon-Mobil
UTLCC5-9a 9-10a/3.3 7 15 19.2 Jet Oil II
Experimental Results
I. Load-Carrying Capacity (Scuffing Performance)
[0082] The load-carrying capacity experimental results for the two
Formulations of this invention and the two base oils noted above
were obtained using a generally accepted modified variation of the
Wedeven Associates, Inc. WAM Load Capacity Test Method ("WAM
Test"). The WAM Test is designed to evaluate the load-carrying
capacity of lubricants and load bearing surfaces by evaluating the
wear, tear, and scuffing thereof over a large temperature
range.
[0083] Table 2 below gives a summary of the WAM Test conditions
that were utilized to test various lubricants of this
invention.
TABLE-US-00005 TABLE 2 Ball: AISI 9310; Ra: 10-12 .mu.in Disc: AISI
9310; Ra: 6; .mu.in Ball Velocity: 234 in/sec Disc Velocity: 234
in/sec Disc Hardness: 62.5-63.5 HRC Ball Hardness: 62.5-63.5 HRC
Rolling Velocity: 158 in/sec Sliding Velocity: 345 in/sec
Entraining Velocity: 158 in/sec Velocity Vector Angle (Z):
95.degree. Temperature: Ambient (~22.degree. C.)
[0084] For a detailed description of the WAM Test, see WAM High
Speed Load Capacity Test Method, SAE Aerospace AIR4978, Revision B,
2002, and U.S. Pat. No. 5,679,883 to Wedeven, both of which are
hereby incorporated in full by reference.
[0085] High load-carrying oils frequently result in test suspension
at load stage 30 without a scuffing event. To differentiate
candidate formulations that reach test suspension, tests can be run
with a modified test protocol. The modified protocol operates at a
lower entraining velocity than the standard test protocol, which
reduces the EHD film thickness and increases the test severity by
causing greater asperity interaction; essentially operating at a
reduced film thickness to surface roughness (h/a) ratio.
[0086] The modified test protocol was developed for high
load-carrying oils used for aviation gearboxes. These oils include
the DOD-PRF-85734 oils for the U.S. Navy and the Def Stan 91-100
oils for the U.K. Ministry of Defense. With the modified test
protocol, the highest load-carrying oils currently used in military
aircraft experience scuffing failures at load stages that range
from approximately 19 to 28.
AISI 9310 Specimen Preparation:
[0087] Formulation #4 and the Hatco HXL-7944 oil, and Formulation
#2 and the Exxon-Mobil Jet Oil II, were comparatively evaluated for
scuffing (scoring) resistance using the modified WAM Test method
described above. The test method used ball and disc specimens. The
ball specimens were 13/16-inch diameter, and the disc specimens
were 4 inches in diameter and 1/2 inch thick. Material composition,
hardness and surface finish were closely controlled. The specimens
were fabricated from AISI 9310 steel, a surface-carburizing alloy
that is very common for gear applications.
[0088] AISI 9310 balls, or "Hard Ground" balls were heat-treated
and ground in a ball manufacturing process. The balls were
fabricated through the hard grinding stage. The surface finish
following this operational stage was between 10-12 micro inch Ra
(arithmetic average roughness).
[0089] The composition, hardness and surface finish of the
specimens are given below:
TABLE-US-00006 Disc Specimens Hardness (HRC) Surface Finish
(.mu.in. Ra) AISI 9310 63 6 Pyrowear 63 60-61 6 Pyrowear 53 60-61
1-2 superfinished
Scuffing (Scoring) Results:
[0090] The scuffing (scoring) results of Formulation #4 as compared
to the Hatco HXL-7944 Oil are summarized in Table C, and the
results of Formulation #2 as compared to the Exxon-Mobil Jet Oil II
are summarized in Table D. Some of these results are also depicted
graphically in the FIGURE.
TABLE-US-00007 TABLE C Average Micro- Macro- Scuffing Increased
scuff scuff (Scoring) Load- (score) (score) Failure Carrying
Lubricant Ball Disc/t.d. Stage Stage Stage Capacity HXL-7944
UTLCC6-9a 9-10a/3.2 4 16 HXL-7944 UTLCC6-9b 9-10a/3.1 6 20 HXL-7944
UTLCC5-9b 9-10a/3.0 7, 16 17 5.7 1 Formulation #4 UTLCC16-9a
9-10b/2.9 24 Formulation #4 UTLCC16-9b 9-10b/2.8 21 22.5 3.94
TABLE-US-00008 TABLE D Average Micro- Macro- Scuffing Increased
scuff scuff (Scoring) Load- (score) (score) Failure Carrying
Lubricant Ball Disc/t.d. Stage Stage Stage Capacity Exxon-Mobil Jet
Oil II SBAD12-9a 9-10a/3.7 25 Exxon-Mobil Jet Oil II SBAD12-9b
9-10a/3.6 15 Exxon-Mobil Jet Oil II UTLCC3-9a 9-10a/3.5 24
Exxon-Mobil Jet Oil II UTLCC3-9b 9-10a/3.4 25 Exxon-Mobil Jet Oil
II UTLCC5-9a 9-10a/3.3 7 15 19.2 1 Formulation #2 UTLCC12-9a
9-10b/3.3 27 Formulation #2 UTLCC12-9b 9-10b/3.2 28 27.5 1.43
[0091] The load carrying capacity is indicated by an average
scuffing (scoring) failure stage (load stage). Increased
performance is observed with higher load stages.
[0092] Using this modified WAM Test protocol, it was found that the
multifunctional additive package utilized in Formulation #4
increased the load carrying capacity (i.e., scuffing performance)
of the Hatco HXL-7944Oil about 3.94 times. As can be seen in the
attached FIGURE and Table C, the Hatco HXL-7944 Oil had an average
scuffing failure load stage at about 5.7 (arrow 11), and
Formulation #4 had an average scuffing failure load stage at about
22.5 (arrow 31), which indicates that Formulation #4 has a load
carrying capacity about 3.94 times that of the Hatco HXL-7944
Oil.
[0093] Using this modified WAM Test protocol, it was also found
that the multifunctional additive package utilized in Formulation
#2 increased the load carrying capacity (i.e., scuffing
performance) of the Exxon-Mobil Jet Oil II about 1.43 times. As can
be seen in the attached FIGURE and Table D, the Exxon-Mobil Jet Oil
II had an average scuffing failure load stage at about 19.2 (arrow
21), and Formulation #2 had an average scuffing failure load stage
at about 27.5 (not shown on the FIGURE), which indicates that
Formulation #2 has a load carrying capacity about 1.43 times that
of the Exxon-Mobil Jet Oil II.
II. Surface Fatigue Life Measurement by Spur Gear Testing
[0094] Spur gear blanks, having a pitch diameter of 4 inches (100
mm), were fabricated from the Carpenter Technology alloy, Pyrowear
alloy 53, in vacuum-induction-melted, vacuum-arc-remelted (VIM/VAR)
condition. Following rough machining, gear blanks were given a
standard heat treatment and carburization cycle and were finish
ground to produce gears that conform to minimum standards of AGMA
class 12. The arithmetic average surface roughness of the spur gear
involute surfaces that resulted from the final grinding operation
was nominally 16 pin. Following final grinding, some gears were
afforded an isotropic superfinishing operation to refine the
surface finish on the involute surfaces to a nominal arithmetic
average value of 2 .mu.in.
[0095] Spur-gear tests were performed on a "four-square" test
machine, in which two pairs of identical, mated gears are exposed
to the same conditions of contact stress, rotational speed,
oil-film thickness, and oil temperature. The employed test protocol
called for experimental conditions to remain imposed on the spur
gears until incipient failure was detected by in situ
accelerometers, in which the accelerometer signal amplitude
exceeded a predetermined threshold. Visual examination was used to
confirm surface failure of the spur-gear involute surface. Specific
conditions that were applied for the conducted spur-gear tests
included a rotational speed of 3500 min.sup.-1, an inlet oil
temperature of approximately 115.degree. F. (46.degree. C.), and an
oil film thickness of approximately 6 .mu.in (152 nm). Discrete
contact stresses of 235 Ksi (1.62 GPa) or 280 Ksi (1.93 GPa) were
applied and maintained until surface failure was detected and
confirmed. The ball and disc were composed of AISI 9310 and had a
surface hardness, using the Rockwell "C" scale (HRC) surface
hardness, of Rc 63 (63 HRC).
[0096] Results from the spur-gear tests are summarized in Table 3
below. As indicated in Table 3, the average life to surface-fatigue
life of as-ground gears lubricated with Formulation #2 at a contact
stress of 235 Ksi (1.62 GPa) is a factor of 2.9 times greater than
that for as-ground gears lubricated with Exxon-Mobil Jet Oil II.
Similarly, the surface-fatigue life of isotropically superfinished
(ISF) spur gears lubricated with Formulation #2 at a contact stress
of 280 Ksi (1.93 GPa) is a factor of more than 3.3 times greater
than that for ISF-processed gears lubricated with Exxon-Mobil Jet
Oil II.
TABLE-US-00009 TABLE 3 Surface Contact Power Surface Life Surface
Roughness Stress Increase Life, N.sub.f Increase Condition (.mu.in)
Lubricant (Ksi) Factor (.times.10.sup.6) Factor As-Ground 16
Exxon-Mobil 235 1.00 16.6 1.0 Jet Oil II Formulation #2 235 1.00
48.3 2.9 ISF- 2 Exxon-Mobil 263 1.25 >61.9 >3.7 Processed Jet
Oil II 280 1.42 37.6 2.3 Formulation #2 280 1.42 >55.1
>3.3
[0097] While the embodiments described above are directed to
lubricants of the polyol ester (POE) type, a skilled artisan would
recognize that the compositions apply equally to other lubricant
stock compositions including, but not limited to, lubricants
comprising grease, mineral (hydrocarbon-based), polyalkylene glycol
(PAG), aromatic naphthalene (AN), alkyl benzenes (AB) and
polyalphaolefin (PAO) types.
[0098] It should therefore be understood that the foregoing
description is only illustrative of the present invention. A
skilled artisan, without departing from the present invention, can
devise various alternatives and modifications. Accordingly, the
present invention is intended to embrace all such alternatives,
modifications and variations that fall within the scope of the
appended claims.
* * * * *