A ball joint (10) capable of stabilizing sliding torque while suppressing cost increase is provided. The ball joint (10) includes a first lubricant (G1) interposed between a ball part (40) of a ball stud (14) and a bearing sheet (13). The ball joint (10) includes a second lubricant (G2) having a higher friction coefficient than the first lubricant (G1) and enclosed inside a dust cover (15).

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; a second sliding portion having a second lubricant placed between second parts of a second friction sliding mechanism; and a third sliding portion having a third lubricant placed between third parts of a third friction sliding mechanism. The first sliding portion is in contact with the third lubricant, and the second sliding portion is not in contact with the third lubricant. The second lubricant contains an additive containing conductive carbon, and the third lubricant contains no conductive carbon. The second lubricant contains a relatively larger amount of the conductive carbon than the first lubricant.

To provide a grease composition for a tapered roller bearing having superior bearing lifetime under a condition of high temperature and a condition of high load, and a tapered roller bearing in which the grease composition for the tapered roller bearing is filled. A tapered roller bearing 11 includes an inner ring 12 having a raceway surface 12a, an outer ring 13 having a raceway surface 13a and a plurality of tapered rollers 14, and a flange part of the inner ring 12 gets into sliding contact with the tapered rollers 14. Grease 16 is filled around the tapered rollers 14. The grease 16 includes a base oil, a thickener and an additive. A frequency in which a storage modulus, which varies depending on frequency, of the grease 16 becomes minimum is equal to 7 Hz or more.

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; a second sliding portion having a second lubricant placed between second parts of a second friction sliding mechanism; and a third sliding portion having a third lubricant placed between third parts of a third friction sliding mechanism. The first sliding portion is in contact with the third lubricant, and the second sliding portion is not in contact with the third lubricant. The second lubricant contains an additive containing conductive carbon, and the third lubricant contains no conductive carbon. The second lubricant contains a relatively larger amount of the conductive carbon than the first lubricant.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

A bearing assembly having a conductive medium. The bearing unit is mountable on a shaft and includes a bearing unit including a radially inner bearing ring including a radially inner race, wherein the radially inner bearing ring is rotatable with the shaft. The bearing unit further includes a radially outer bearing rings including a radially outer race, wherein the radially outer bearing ring is stationary with respect to the shaft; and a plurality of rolling elements supported to roll between the radially inner race of the radially inner bearing ring and the radially outer race of the radially outer bearing ring. An annular chamber body is disposed adjacent the bearing unit. A conductive medium is disposed within the chamber body.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

A ball joint includes a first lubricant interposed between a ball part of a ball stud and a bearing sheet. The ball joint includes a second lubricant having a higher friction coefficient than the first lubricant and enclosed inside a dust cover.

An assembly providing a bearing, a lubricant and a contamination sensor for determining a level of contamination in the lubricant. The sensor includes an EM wave generator for generating an EM signal, and an EM sensing element arranged in contact with the lubricant. The EM sensing element receives the generated EM signal and transmits an output signal whose properties are responsive to real and imaginary parts of a complex relative permittivity of the lubricant. The output signal is received by an EM measuring device that measures first and second parameters of the output signal, which are respectively representative of the real and imaginary parts of the complex relative permittivity. The EM measuring device determines a level of water contamination in the lubricant, based on the measured first parameter alone and determines a level of metal particle contamination in the grease, based on the measured first and second parameters.

The present invention provides an abnormality detector for a rolling bearing including an outer race, and an inner race. The abnormality detector includes a filter configured to prevent metal pieces contained in lubricating oil flowing through the bearing space between the outer and inner races from passing through the filter, while allowing the lubricating oil to pass through the filter so as to flow to the outside space of the bearing space; an electric circuit including a pair of permanent magnets mounted, as a pair of electrodes, to the filter so as to be spaced apart from each other, and lines extending from the respective electrodes to a power source; and an output detector configured to detect a change in electrical output from the electric circuit when metal pieces adhere between the pair of permanent magnets, thereby detecting the state of metal pieces contained in the lubricating oil.