Provided is a transformer oil that has high environmental compatibility and is expected to be further improved in transformer cooling properties. The transformer oil is a transformer oil prepared by mixing a plant oil and a silicone oil and containing no mineral oil, in which a volume ratio of the plant oil to the silicone oil is 3:7 to 7:3 and magnetic particles (for example, temperature-sensitive magnetic particles) are dispersed.

The invention provides a hydraulic fluid composition comprising a hydrocarbon component comprising more than 5 wt % of naphthenic oil and up to 95 wt % of renewable or recycled isoparaffinic oil, based on the total weight of the composition. The hydraulic fluid composition is useful as an arctic hydraulic fluid composition, shock absorber or automatic transmission fluid.

A drive arrangement for an electrically driven vehicle includes an electric motor that is configured to accelerate the vehicle, the electric motor has a rotor, which is arranged inside a stator having stator windings and is arranged on a rotor shaft. The drive arrangement also includes a drive shaft coupled to a drive wheel of the vehicle, and a shaft coupling that transmits torque output by the rotor shaft such that said torque is conducted to the drive shaft, wherein the shaft coupling has a torque receiving element that receives the torque output by the electric motor, and a torque output element that is mechanically coupled to the torque receiving element and outputs the torque in a direction of the drive shaft. An electrically insulating grease is arranged between the torque receiving element and the torque output element.

The present invention provides a novel surface-modified inorganic substance obtained by modifying the surface of an inorganic nitride or an inorganic oxide with a boronic acid compound, and a heat dissipation material, a thermally conductive material, and a lubricant which use the surface-modified inorganic substance. The present invention also provides a method for manufacturing the surface-modified inorganic substance, and provides, as a novel method for modifying the surface of an inorganic substance selected from an inorganic oxide and an inorganic nitride with an organic substance, a method for modifying the surface of an inorganic nitride or an inorganic oxide with an organic substance that includes making a contact between the inorganic nitride or the inorganic oxide with a boronic acid compound.

A composition for producing a tribological composite material includes at least one platelet-shaped solid-state lubricant, at least one type of inorganic, platelet-shaped pigment particles, at least one surface-active compound which possesses at least one hydrophilic group and at least one hydrophobic group, and a curable binder system comprising at least one organic polymer or oligomer having one or more functional groups, or a precursor thereof.

A grease composition may contain a base oil (A) and a urea-based thickener (B). Particles containing the urea-based thickener (B) in the grease composition may satisfy requirement (I). The base oil (A) may be a mixed base oil containing a high-viscosity base oil (A1) having a kinematic viscosity at 40? C. of 250 mm.sup.2/s to 550 mm.sup.2/s, a low-viscosity base oil (A2) having a kinematic viscosity at 40? C. of 5.0 mm.sup.2/s to 110 mm.sup.2/s, and an ultra-high viscosity hydrocarbon-based synthetic oil (A3) having a number average molecular weight (Mn) of 2,500 to 4,500 and a kinematic viscosity at 40? C. of 25,000 mm.sup.2/s to 50,000 mm.sup.2/s. The base oil (A) may have a kinematic viscosity at 40? C. of 25 mm.sup.2/s to 105 mm.sup.2/s and a viscosity index of 120 or more. Both low-temperature characteristics and a lubricating life can be achieved.

This vibration damping device (10) includes a magnetorheological fluid composition in a cylinder (12). The magnetorheological fluid composition includes magnetic particles; a dispersant having the magnetic particles dispersed therein; and a friction modifier. The friction modifier is an ester-based additive having a hydrocarbon chain having 14 to 22 carbon atoms, preferably an alkyl chain or an alkenyl chain. The content of the friction modifier is 0.1 to 5 mass %.

Provided are microalgal compositions and methods for their use. The microalgal compositions include lubricants that find use in industrial and other applications.

A grease composition which contains a base oil (A), a urea-based thickener (B), a sarcosine derivative (C), and a fatty acid zinc salt (D), wherein particles containing the urea-based thickener (B) in the grease composition satisfies Requirement (I). The base oil (A) is a blended base oil containing a high viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A1). A low viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A2). An ultra-high viscosity hydrocarbon-based synthetic oil has a number average molecular weight (Mn) of 2,500 to 4,500 and a specific kinematic viscosity (A3). A 40? C. kinematic viscosity of the base oil (A) is 500 mm.sup.2/s to 1,500 mm.sup.2/s. A viscosity index of the base oil (A) is 140 or more. A content of the fatty acid zinc salt (D) is 10 mass % to 20 mass % based on a total amount of the grease composition.

A lubricating oil composition having a high temperature high shear (HTHS) viscosity at 150 C. in a range of about 1.3 to about 2.3 cP is disclosed. The composition comprises (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100 C. in a range of 1.5 to 6.0 mm.sup.2/s; and (b) a molybdenum-succinimide complex providing 200 to 1500 ppm by weight of molybdenum to the lubricating oil composition.