Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Compound of indeterminate structure – prepared by reacting an...
Reexamination Certificate
2000-09-19
2001-10-16
Howard, Jacqueline V. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Compound of indeterminate structure, prepared by reacting an...
C508S527000, C508S528000
Reexamination Certificate
active
06303547
ABSTRACT:
TECHNICAL FIELD
This invention relates to lubricant formulations containing the reaction product of at least one C
5
-C
60
carboxylic acid and at least one amine selected from the group consisting of guanidine, aminoguanidine, urea, thioruea and salts thereof. The lubricant formulations of the present invention exhibit excellent low and high temperature rheology and are particularly suited for use in automotive and industrial gear applications. Lubricants of the present invention exhibit improved performance properties, such as increased axle efficiencies and lower axle temperatures, improved limited slip performance, reduced chatter, improved frictional durability and/or improved power divider performance compared to lubricant formulations that do not contain said reaction products.
BACKGROUND INFORMATION
The primary function of a gear lubricant is to provide a high degree of reliability and durability in the service life of gear equipment. Gear lubricants may also contribute to improving the fuel economy of vehicles by improving the axle efficiency. See, for example, O'Connor et al.,
The Relationship Between Laboratory Axle Efficiency and Vehicle Fuel Consumption
(SAE Paper No. 811206).
In the paper by O'Connor et al., entitled
Axle Efficiency—Response to Synthetic Lubricant Components
(SAE Paper No.821181), the authors state that “[i]nvestigations with both partial- and full-synthetic base formulations have shown improvements compared to conventional petroleum base gear oils. Maximum benefits are gained with total synthetic base type formulations.”
Limited slip differentials are designed to restrict differentiation in a vehicle operating on a slippery surface. The limited slip characteristic is obtained by modifying a standard differential with the addition of a clutch. This clutch has the property of forcing both axle shafts to turn with the ring gear when the vehicle operates on a slippery surface. Limited slip differentials contain a slow-moving clutch. At low sliding velocities this clutch is prone to stick and then slip in a repetitive fashion unless a lubricant with the proper frictional characteristics is used. This stick-slip effect is very objectionable as it can result in loud chatter noises and severe vibration. The paper by John W. Allen, entitled
Lubricants for Limited Slip Differentials
(SAE Paper No. 660779), provides some background on the problems associated with limited slip differentials and some proposed lubricant solutions. The Allen paper does not teach or suggest the additives of the present invention or their use in lubricant formulations.
Power dividers are the linkages in the drivetrain that direct engine torque to gripping wheels rather than slipping wheels. The power divider's application is similar to the limited slip clutches in light duty axles. There are many types of power dividers, their overall purpose is to transmit torque to both sets of wheels or between the front and rear axles. In one particular design, this is accomplished by using a set of wedges between two cylindrical cams whose mating surfaces with the wedges are lobed. These lock for transmittal but slide to avoid torque buildup. When too much torque has built up without sliding, the wedges break the momentary welds formed. This is accompanied by a loud snap that can propel the truck sideways. Malfunctioning power dividers can result in broken axles.
Hutchison et al., in U.S. Pat. No. 4,948,523, discloses a lubricating composition that contains a silver protective agent. The silver protective agent comprises the reaction product of a C
5
-C
60
carboxylic acid and at least one amine selected from the group consisting of: 1) guanidine, urea and thioruea compounds; 2) C
1
-C
20
hydrocarbyl or hydroxy-substituted hydrocarbyl mono-amines, alkylene diamines; and 3) polyalkylene polyamines and N-alkyl glycine. This patent is directed to lubricating oil additives for medium speed diesel engines, such as locomotive engines, which have silver parts in the engine. Large, medium-speed diesel engines often contain silver protected components, such as bearings, and, as such, the lubricating oils may not contain the typical zinc containing wear inhibitors which attack the silver coated parts. This patent does not teach the use of the reaction products of the present invention in gear oil formulations or the improvements in, for example, axle efficiency, limited slip performance or power divider performance exhibited by the compositions of the present invention.
SUMMARY OF THE INVENTION
The present invention is directed to a lubricant composition comprising:
(A) an oil of lubricating viscosity;
(B) the reaction product of at least one C
5
-C
60
carboxylic acid and at least one amine selected from the group consisting of guanidine, aminoguanidine, urea, thioruea and salts thereof; and
(C) a gear additive package.
The lubricant formulations of the present invention exhibit excellent low and high temperature rheology and are particularly suited for use in automotive and industrial gear applications. The lubricant formulations of the present invention exhibit improved performance properties such as increased axle efficiencies and lower axle temperatures, improved limited slip performance, reduced chatter, improved frictional durability and/or improved power divider performance compared to lubricant formulations that do not contain said reaction products. Further, the present invention is directed to the use of the reaction product (B) as an additive for increasing axle efficiencies, lowering axle temperatures, improving limited slip performance, reducing chatter, improving frictional durability in steel-on-steel and steel-on-paper applications and improving power divider performance in automotive and industrial gear applications.
REFERENCES:
patent: 3749702 (1973-07-01), Boehringer et al.
patent: 4871465 (1989-10-01), Hutchison
patent: 4948523 (1990-08-01), Hutchison et al.
patent: 4956122 (1990-09-01), Watts et al.
patent: 5080815 (1992-01-01), Fenoglio et al.
patent: 5403501 (1995-04-01), Schwind
patent: 5883057 (1999-03-01), Roell, Jr. et al.
patent: 0786511 (1997-01-01), None
W.R. Alexander;Lubrication Requirements of the Mack Heavy-Duty Power Divider; SAE Paper 650637.
John W. Allen;Lubricants for Limited Slip Differentials; SAE Paper 660779.
B.M. O'Connor et al;Energy Conservation Through The Use of Multigraded Gear Oils In Trucks; SAE Paper 770833.
B.M. O'Connor et al;The Relationship Between Laboratory Axle Efficiency and Vehicle Fuel Consumption; SAE Paper 811206.
W.T. Brannen, et al;Axle Efficiency, (Panel Discussion presented at the NLGI 47thAnnual Meeting in Toronto, Canada, Oct., 1979.).
B.M. O'Connor, et al;Axle Efficiency—Response to Synthetic Lubricant Components; SAE Paper 821181.
V. Bala, et al;Enhanced Performance Considerations For Automotive Gear Lubricants; ISFL-2000, Mar. 10-12, 2000 New Delhi; pp. 193-198.
V. Bala, et al;Rheological Properties Affecting the Fuel Economy of Multigrade Automotive Gear Lubricants; SAE Paper 2000-01-2051.
V. Bala, et al;Fuel Economy of Multigrade Gear Lubricants; Industrial Lubrication and Tribology, vol. 52—No. 4-2000-pp. 165-173.
Ethyl Corporation
Hamilton Thomas
Howard Jacqueline V.
Moore James T.
LandOfFree
Friction modified lubricants does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Friction modified lubricants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Friction modified lubricants will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2571431