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.

Provided are a magneto-rheological rotating load device and a method of controlling the same. A magneto-rheological rotating load device according to the present invention includes a housing, a yoke part disposed in the housing, a shaft rotatably installed in the housing, one or more rotary rings connected to the shaft and configured to rotate in conjunction with a rotation of the shaft, a coil part disposed in the housing, a magneto-rheological fluid with which at least a part in the housing is filled, a cover part disposed at an upper end of the yoke part, and a bearing part disposed to be in contact with an outer peripheral surface of the shaft and configured to support the rotation of the shaft, in which a leak prevention means configured to prevent a leak of the magneto-rheological fluid is at least provided between the bearing part and the cover part.

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 malfunction detection device compares detected data on a condition at a predetermined part of an apparatus with a threshold so as to determine a malfunction of the apparatus. The malfunction detection device varies the threshold in accordance with a type of a lubricant used for movable parts of the apparatus.

A variable stiffness bushing assembly includes: an inner tubular member; an outer tubular member coaxially surrounding the inner tubular member; and an elastic member connected between the inner and outer tubular members. The inner tubular member includes a tubular inner yoke, a coil coaxially wound around the inner yoke, and a pair of outer yokes each attached to the inner yoke at an axially outer end thereof and opposing the other outer yoke at an axially inner end thereof so as to define an annular gap therebetween, and the elastic member internally defines a pair of first liquid chambers which communicate with each other via a first communication passage provided by the annular gap. The first liquid chambers and the first communication passage are filled with a magnetic fluid having a viscosity that changes in dependence on an intensity of a magnetic field applied thereto.

A variable stiffness bushing includes: inner and outer tubular members; an elastic member connecting these tubular members. At least one pair of circumferentially separated liquid chambers is defined in the elastic member such that first axial ends and second axial ends of the liquid chambers are defined by first and second end walls of the elastic member, respectively. The liquid chambers of each pair communicate with each other by a corresponding communication passage including a circumferential passage provided in one of the tubular members, which includes a coil wound coaxially therewith and a yoke provided with at least one gap constituting the circumferential passage. A magnetic fluid fills the liquid chambers and the communication passage(s). The first and second end walls are configured such that when the tubular members are axially displaced relative to each other, a difference is created between volumes of the liquid chambers of each pair.

The invention relates to a bearing device comprising a first surface and a second surface which are moveable relative to one another, wherein the first and second surfaces are separated by a bearing gap filled with a lubricant, which is a magnetorheological or electrorheological liquid, or a lubricant having a temperature dependent viscosity, or a lubricant having a controllable slip velocity. The bearing device further comprising one or more supply inlets in the first or second surface, and one or more activators embedded in the first surface or second surface and configured to locally increase a viscosity or decrease the slip velocity of the lubricant in at least one obstruction zone, thereby inhibiting a flow of the lubricant in the obstruction zone.

Grease composition contains (A) a straight-chain perfluoropolyether having a kinematic viscosity of 2-110 mm.sup.2/s at 40 C., (B) a branched perfluoropolyether having a kinematic viscosity of 2-100 mm.sup.2/s at 40 C., and (C) a fluorocarbon resin powder having a primary particle size of 1 m or less, wherein the contained amount of the fluorocarbon resin powder is 25-40 wt % with respect to the weight of the grease composition, and the weight ratio of the straight-chain perfluoropolyether (A) to the branched perfluoropolyether (B) is 15:85 to 70:30.

One aspect of the disclosure relates to a sliding member. The sliding member includes: a first sliding portion having a first lubricant placed between first parts of a first friction sliding mechanism; and a second sliding portion having a second lubricant placed between second parts of a second friction sliding mechanism. The first sliding portion has a lubricant feed port from which the first lubricant is fed, and the second sliding portion has no lubricant feed port from which the second lubricant is fed. The first lubricant contains base oil and an additive. The second lubricant contains base oil and an additive containing conductive carbon. The second lubricant contains a relatively larger amount of conductive carbon than the first lubricant.