To provide a grease-sealed bearing that is superior in fretting wear resistance and sealing performance when used under an oscillation condition with acceleration and deceleration such as a condition used in a robot joint. A grease-sealed bearing 1 includes an inner ring 2 and an outer ring 3 that are raceway rings, a plurality of rolling elements 4 interposed between the inner ring 2 and the outer ring 3, and a grease composition 7 sealed around the rolling elements 4. The bearing oscillates such that a bearing rotational direction changes while accelerating and decelerating. The grease composition contains a base oil and a thickener. The worked penetration of the grease composition is 310 or more. The thickener is a calcium sulfonate complex soap.

The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

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.

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.

A lubricant that enables to improve control stability of an automobile or the like having a vehicle body charged by driving. A lubricant for improving control stability of an automobile includes a base oil and an additive containing a carbon black. A kit for improving control stability of an automobile includes a discharging member including a protrusion that performs a self-discharging by air-ionizing and the lubricant. A method also improves control stability of an automobile.

The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

A gas turbine engine with a rotor having a shaft mounted to the engine with a plurality of electrically insulating bearings is provided. The electrically insulating bearings are coupled to the shaft to support the rotor in the engine. There is at least one electrically conductive bearing coupled to the shaft and that further support the rotor in the engine. An electrically conductive path is defined between the rotor and an electrical ground of the engine. The electrically conductive path is defined through the electrically conductive bearing to reach the electrical ground of the engine. A method for electrostatically discharging a rotor supported in the gas turbine engine is also provided.

Wheel hub assembly for motor vehicles, the group having a radially outer ring with at least one raceway, at least one radially inner ring with a related raceway and at least one ring of rolling bodies interposed between the radially outer ring and the radially inner ring, for sliding inside the raceways, at least one raceway being provided with superficial micropores having a depth (H) between 0.05 μm and 1.5 μm and defining respective micro-tanks for containing a lubricating grease.

A bearing grease includes a base oil and a thickener, and the base oil includes mineral oil and poly-α-olefin. The poly-α-olefin may be a blend of poly-α-olefin having a kinetic viscosity higher than that of the mineral oil and poly-α-olefin having a kinetic viscosity equal to or lower than that of the mineral oil, and the kinetic viscosity of the base oil at 40° C. is in a range of 40 through 90 mm.sup.2/s. The amount of the poly-α-olefin by mass in the base oil is greater than the amount of the mineral oil by mass in the base oil. The worked penetration of the grease is in a range of 200 through 250. The grease reduces flying grease and outgas and has superior low-temperature characteristics.

A ball bearing is provided which includes inner and outer races each having a raceway groove; balls; and a retainer made of a synthetic resin, and in which abnormal noise is reduced. Either the raceway groove of the inner race, or each of the raceway grooves of the inner race and the outer race has a radius of curvature which is 104% or more and 109% or less of the radius of each of the balls.