The present invention generally relates to lubricating oil compositions useful for automatic transmissions, and particularly transmission oils for automotive automatic transmissions and/or continuously variable transmissions using wet clutch systems, in particular wet paper clutch containing a small amount of cellulose fiber and/or aramid fiber.

The disclosure relates to methods of operating transmissions and for providing bearing pitting protection and a passing static friction performance according to Caterpillar TO-4 SEQ 1221 in a transmission including lubricating the transmission with a transmission fluid composition comprising: greater than 50 wt. % of a base oil of lubricating viscosity; an amount of one or more overbased calcium sulfonate detergent(s) to provide from about 2000 ppm to about 5000 ppm of calcium; an amount of one or more zinc dialkyl dithiophosphate compound(s) to provide from about 700 ppm to about 1500 ppm of zinc; and an amount of one or more molybdenum-containing compound(s) to provide from about 5 ppmw to about 300 ppmw molybdenum, and the one or more molybdenum-containing compound(s) is selected from the group consisting of molybdenum dithiocarbamates, molybdenum phosphorodithioates, organomolybdenum complexes, molybdenum dialkyldithiophosphates and mixtures thereof. The disclosure also relates to the compositions used in these methods.

A lubricating oil composition which achieves extended anti-shudder durability without causing a decrease in the metal-to-metal friction coefficient, even when the viscosity of the composition is reduced. The lubricating oil composition includes (A) a lubricant base oil, (C) (C-1) a succinimide compound or boronated succinimide compound having a weight-average molecular weight of 4,000 to 7,000, (C-2) a succinimide compound or boronated succinimide compound having a weight-average molecular weight of more than 7,000 to 10,000, and (D) a phosphorus-based extreme pressure agent, the lubricating oil composition does not include zinc dithiophosphate and may optionally include a sulfur-based extreme pressure agent, provided that the content of sulfur-based extreme pressure agent is no more than 0.1 percent by weight of the lubricating oil composition.

The present invention provides an electrorheological fluid, which includes a dielectric particle, a conductor particle and insulating oil, and the dielectric particle is evenly dispersed in the insulating oil; wherein the conductor particle is evenly dispersed in the insulating oil or inlaid in an interior and on a surface of the dielectric particle. The electrorheological fluid has the advantages of high shear stress, long service life, good temperature stability and small leakage current.

There is disclosed an antifoam component for a mechanical device which includes a poly(acrylate) copolymer. The antifoam component has improved thermal stability in finished fluids utilizing dibutyl hydrogen phosphite compounds, such as driveline fluids.

It is an object of this invention to provide a lubricant additive applicable integrally to all of different types of lubricants for various applications. A lubricant additive adapted to be blended to a lubricating oil, which is characterized by comprising a synthesized base oil of the polyolester type, the content of which to be contained in the lubricant additive is in a range of from 30.0 w/w % to 60.0 w/w %, calcium sulfonate containing calcium carbonate formed in the calcite crystal structure, the content of which to be contained in the lubricant additive is in a range of from 5.0 w/w % to 30.0 w/w %, a poly-alpha-olefin oligomer, an anti-oxidant of the zinc dithiophosphate type, succinimide, an extreme pressure agent of the thiadiazole type and an anti-oxidant of the phenol type, is provided.

The disclosure relates to a lubricating composition consisting essentially of a decarboxylated rosin acid (DCR), a base oil, and optional additives, and methods for using same. The decarboxylated rosin acid has a density of 0.9 to 1.0 g/cm3 at 20? C., a viscosity of 15 to 60 cSt at 40? C., and an acid value of <50 mg KOH/g. The lubricating compositions containing the DCR is characterized as having improved anti-wear and friction reducing properties, as well as improved electrical properties, and cooling performance for use in electric and hybrid vehicles. In embodiments, the lubricating composition exhibits a wear scar diameter of <350 ?m, according to ASTM D6079.

This disclosure describes an ashless lubricant additive. The additive is a tertiary amine-containing compound having the following structure:

##STR00001##

where R.sup.1 and R.sup.2 are independently a linear or branched-chain monovalent hydrocarbyl group having two to about twenty carbon atoms, each m is independently from 0 to 2, each p is independently from 0 to 2, for each cyclic moiety m+p is from 2 to 4, and each n is independently from 1 to 6.

A lubricating oil composition which contains a base oil and a fluorine compound and may have improved cooling performance. The base oil may contain a mineral oil. The base oil may have a kinematic viscosity in a range of from 1 to 25 mm.sup.2/s at 40? C. The content of the fluorine compound may be in a range of from 3 to 30% by weight based on the total amount of the composition.

The present invention generally relates to lubricating oil compositions useful for vehicles such as industrial machinery, especially transport, construction, and agricultural machinery. Also disclosed is a method for maintaining friction in said vehicles comprising lubricating said vehicles with said lubricating oil compositions.