A sealing apparatus includes: an annular reinforcement ring around an axis; and an annular elastic body part around the axis, which is attached to the reinforcement ring and is formed of an elastic body. The elastic body part has: a side lip, an intermediate lip, and a grease lip. A grease as a lubricant is applied to respective inner peripheral side surfaces of the side lip, the intermediate lip, and the grease lip. A thickener of the grease includes no urea-based thickener. In a usage state of the sealing apparatus, a cross sectional area of an inter-lip space enclosed by the side lip, the intermediate lip, and a hub ring is equal to or greater than 3.5 mm.sup.2.

Disclosed is a bearing assembly for an electric motor for a vehicle, providing at least one main bearing configured to support a rotational element of the electric motor, and a sacrificial bearing. The main bearing includes at least one inner ring, at least one outer ring and at least one plurality of rolling elements. The sacrificial bearing provides an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring. A value of a breakdown voltage for the sacrificial bearing is less than a value of the breakdown voltage for the at least one main bearing.

A bearing assembly for an electric motor for a vehicle, having at least one main bearing configured to support a rotational element of the electric motor, and a sacrificial bearing. The main bearing includes at least one inner ring having at least one inner raceway, at least one outer ring having at least one out raceway, and at least one plurality of rolling elements disposed between the raceways. The sacrificial bearing provides an outer ring having an outer raceway, an inner ring having an inner raceway, and a plurality of rolling elements disposed between the outer ring and the inner ring. The sacrificial bearing is provided with an electrically conductive lubricant configured to lubricate the rolling elements of the sacrificial bearing. The main bearing is provided with an isolating lubricant configured to lubricate the rolling elements of the main bearing, wherein the isolating lubricant is electrically isolating.

The invention has an object of providing grease reduced in an amount of the flying grease and an amount of the outgas, and superior in low-temperature characteristic, an antifriction bearing using the grease, an antifriction bearing device, and an information recording/reproducing device. A grease includes a base oil, and a thickener, the base oil includes mineral oil and poly-α-olefin, the poly-α-olefin is higher in mass than the mineral oil, the poly-α-olefin includes poly-α-olefin higher in kinetic viscosity than the mineral oil, the kinetic viscosity of the base oil at 40° C. is in a range of 40 through 90 mm.sup.2/s, and worked penetration is in a range of 200 through 250. Further, an antifriction bearing, an antifriction bearing device, and an information recording/reproducing device use the grease.

Embodiments are directed to solid lubricant assemblies for providing over temperature protection for bearings and gears in rotorcraft systems. A solid lubricant enters a fluid state above a certain temperature and is positioned so that fluid lubricant is applied to the bearings or gears.

There is provided a grease composition for improving the chemical stability of the grease composition and increasing the fatigue life of a member in which the grease composition is used. The problems can be solved by a grease composition including a poly-α-olefin; a urea-based thickener; molybdenum dithiophosphate; and barium sulfonate, wherein a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less.

To provide a hub bearing that is capable of reducing a delay in a response of the hub bearing and improving a steering stability of a vehicle. A hub bearing 1 includes an outer ring 2 serving as a stationary side raceway ring, a hub wheel 3 and an inner ring 5 serving as a rotatable side raceway ring, balls 4 serving as a plurality of rolling elements disposed between a raceway surface of the stationary side raceway ring and a raceway surface of the rotatable side raceway ring, and grease that lubricates a rolling contact part between each of the raceway surfaces and the rolling elements. The surface roughness of at least one raceway surface selected from the raceway surface of the stationary side raceway ring and the raceway surface of the rotatable side raceway ring in the rolling contact part is 0.03 μmRa or less. Further, the grease has a traction coefficient in the rolling contact part of 0.04 or less at 40° C. when a vehicle speed is 20 km/h or more.

A rolling bearing arrangement having a first and a second raceway element, and rolling bodies being arranged between the two raceway elements so that the two raceway elements are rotatable against each other in the manner of a rolling bearing, a space between the raceway elements in which the rolling bodies are rolling off comprising a lubricating grease, at least one sensor element for sensing temperature, at a specific point of the rolling bearing, particularly in the space, and for sensing speed of the rolling bearing and a unit receiving the sensed temperature and speed, calculating from the profiles of the sensed temperature over time and from the speed over time via a calculated energy imposed on the grease a used and/or remaining period of the grease life-time.

A grease composition including: an ester base oil; and a thickener, in which the thickener contains diurea expressed by the following formula (1): R1-NHCONH-C6H4-CH2-C6H4-NHCONH-R2 (1), in which R1 and R2 each independently represents one of: (A) an alicyclic group A expressed by R3-C6H10- (R3 represents hydrogen, a 2-methyl group, a 3-methyl group, or a 4-methyl group); (B) an alkyl group B expressed by n-CmH2m+1 (m represents an integer of 6 to 10); and (C) an alkyl group C expressed by n-CmH2m+1 (m represents an integer of 16 to 20), and in which the diurea is arranged so that the alicyclic group A is 5 to 35 mol %, a total of the alicyclic group A and the alkyl group B is 55 to 95 mol %, and the remainder is the alkyl group C, based on a total of R1 and R2.

To provide a grease composition that is capable of effectively preventing an early-flaking caused by hydrogen embrittlement, and a grease-sealed bearing in which the grease composition is sealed. A grease composition 7 contains a base oil, a thickener, and an additive. The additive contains sodium molybdate, and zinc alkyldithiophosphate having a 1-30 C primary alkyl group. The grease composition contains 0.1-5 mass % of the sodium molybdate relative to the whole of the grease composition. The grease composition contains 0.1-5 mass % of the zinc alkyldithiophosphate relative to the whole of the grease composition.