Provided are: a lubricating oil composition satisfying both high viscosity index and high shear stability, which contains a base oil having a kinematic viscosity at 40 C. of 4.0 mm.sup.2/s or more and less than 6.0 mm.sup.2/s, a kinematic viscosity at 100 C. of 1.0 mm.sup.2/s or more and less than 2.0 mm.sup.2/s, and a flash point of 140 C. or higher, and a polymethacrylate having a specific structure; and a lubrication method and a transmission each using the lubricating oil composition.

Provided is a lubricating oil composition which has an excellent effect of reducing the friction coefficient even when a member having a low surface roughness in a low oil temperature region is lubricated, by means of a lubricating oil composition which contains a mineral base oil (A), a polymer (B) having a weight average molecular weight (Mw) of 100 to 15,000, and a molybdenum-based friction modifier (M) and has a kinematic viscosity at 40? C. of 35.0 mm.sup.2/s or less.

A lubricating oil composition, containing a base oil (A) that satisfies the following requirements (A-1) to (A-4), and a polymer (B) that satisfies the following requirements (B-1) and (B-2): (A-1): a 100? C. kinematic viscosity is 2.0 mm.sup.2/s or more and less than 7.0 mm.sup.2/s, (A-2): a viscosity index is 100 or more, (A-3): a content of cycloparaffin is 35.0% by volume or less based on a total volume of the base oil (A), (A-4): an aromatic content (% CA) is less than 1.0, (B-1): a ratio of a mass-average molecular weight (Mw) to a number-average molecular weight (Mn), [Mw/Mn] is 1.0 or more and less than 6.0, (B-2): a ratio of a peak integral value (I.sub.10) at a chemical shift 10.0 to 11.0 ppm to a peak integral value (I.sub.14) at a chemical shift 13.5 to 14.5 ppm, as determined in .sup.13C-NMR analysis, [I.sub.10/I.sub.14] is 0.05 or more.

Provided are: a lubricating oil composition containing a mineral oil (A) having a kinematic viscosity at 40 C. of 5 to 15 mm.sup.2/s and a flash point of 180 C. or higher, a synthetic oil (B) having a kinematic viscosity at 40 C. of 5 to 15 mm.sup.2/s and a flash point of 190 C. or higher, an amide compound (C) and a polyol ester compound (D), which has a low viscosity and fuel saving performance, which can be used in high-temperature environments, and which has excellent gear anti-seizing property and anti-shudder performance; and a lubrication method and a transmission using the lubricating oil composition.

A lubricating oil composition with enhanced deposit control capability is disclosed for engines operating under sustained high load conditions, such as natural gas engines and low-speed or medium-speed diesel engines. The composition comprises (a) a first base oil component selected from a Group I base stock, a Group II base stock, a Group III base stock, or a combination thereof, each having a kinematic viscosity at 100? C. of from 8.5 to 15 mm.sup.2/s; and (b) a second base oil component selected from a Group I base stock, a Group II base stock, a Group III base stock, or a combination thereof, each having a kinematic viscosity at 100? C. of from 4.0 to less than 8.5 mm.sup.2/s; wherein the weight ratio of the first base oil component to the second base oil component is in a range of from 1:10 to 1:1.15.

A broadband vibration motor and an electronic device are provided. The broadband vibration motor comprises a case, a vibrator, a coil and a reset part. The case comprises an inner cavity; the vibrator is arranged in the inner cavity, and the outer peripheral surface of the vibrator is provided with lubricating regulating oil, and the vibrator is suspended in the inner cavity through the lubricating regulating oil; the coil is used to drive the vibrator to vibrate, and the coil is arranged around the outside of the vibrator; the reset part is magnetic, and at least one reset part is correspondingly provided at both ends of the vibrator in the vibrating direction, and the reset part is disposed with the same pole opposite to the vibrator.

A lubricating oil composition that is hard to increase in viscosity in the low temperature range and is easy to increase in viscosity in the high temperature range. The lubricating oil composition contains a base oil and a viscosity index improver. The base oil contains a mineral oil and an oxygen-containing synthetic oil. The viscosity index improver contains a comb-shaped polymer. The lubricating oil composition has a kinematic viscosity of 100? C. of 9.3 mm.sup.2/s or less, a viscosity index of 280 or more, and a content Y (% by mass) of the oxygen-containing synthetic oil based on the total amount of the lubricating oil composition satisfying the following expression (1): ??Y<?3.7 ln(X)+? (1), where ?=0.5, ?=19, and X represents a ratio of the number of carbon atoms and the number of oxygen atoms per one molecule of the oxygen-containing synthetic oil.

A composition is provided to comprise a non-aqueous medium and a 3,4-oxypyridinone compound of structure (I):

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with each A being oxygen and/or sulfur, and with a variety of substituents at R.sub.1-R.sub.5 to enable a solution or an at least semi-stable emulsion to be formed in the non-aqueous medium. Methods of use are included herein, which may be focused on situations where the composition can be used as a lubricant and/or coolant.

Grease compositions may be made from an oil basestock. For example, a grease composition may include: an oil basestock having: a kinematic viscosity (ASTM D445, 40? C.) of from 320 cSt to 520 cSt, a kinematic viscosity (ASTM D445, 100? C.) of from 22 cSt to 36 cSt, a viscosity index (ASTM D2270) of from 80 to 119, a pour point (ASTM D97) of ?6? C. or less, and a saturate content (ASTM D7419) of 90 wt % or greater; and from 0.5 wt % to 15 wt % of a thickener, by total weight of the grease composition.

A rolling bearing (1) includes an outer ring (2), an inner ring (4), and a plurality of rolling elements (6) arranged between the outer and inner ring (2, 4). The rolling bearing (1) is provided with lubricant. The outer ring (2) has an outer contact width (b.sub.o) between the outer ring (2) and the rolling elements (6). The inner ring (4) has an inner contact width (b.sub.i) between the inner ring (4) and the rolling elements (6). A ratio =b.sub.i/b.sub.o between the inner and outer contact width (b.sub.i, b.sub.o) is larger than 1.65 or a ratio =b.sub.i/b.sub.o between the inner and outer contact width (b.sub.i, b.sub.o) is larger than 0.97 and smaller than 1.06 or a ratio =b.sub.i/b.sub.o between the inner and outer contact width (b.sub.i, b.sub.o) is smaller than 0.68.