摘要:
A ball screw (1) as a linear motion device according to the invention has retaining pieces (21) each having two concave surfaces (23) facing adjacent ones of rolling elements (9) respectively. Each of the retaining pieces (21) is disposed between adjacent ones of the rolling elements (9). A carbonitrided layer containing residual austenite of 15-40% by volume is provided in the surface layer of each of the rolling elements (9).
摘要:
The centerline average roughness of the raceway surface of at least the fixed ring of bearing rings is controlled to be 0.025 to 0.075 μmRa, thereby suppressing the rotation slip of the rolling elements so as to prevent flaking that is accompanied by a structural change. This enables prolongation of the life of bearings. At least the fixed ring of the bearing rings contains, as alloy ingredients at a ratio of from 0.50 to 1.20% by mass of carbon, from 0.10 to 1.50% by mass of silicon, from 0.1 to 2.0% by mass of manganese, from 3.0 to 6.0% by mass of chromium, 2.0% by mass or less of molybdenum, and 1.0% by mass or less of vanadium, whereby the necessary hardness is obtained and the structure is stabilized. This enables prolongation of the life of bearings.
摘要:
A grease composition for EV/HEV driving motor bearing, containing a diurea thickener of the following formula (A): wherein R1, R2 and R3 are defined, with the ratio of the number of moles of the straight-chain or branched alkyl group having 16 to 20 carbon atoms to the total number of moles of the cyclohexyl group and the straight-chain or branched alkyl group having 16 to 20 carbon atoms, expressed as [((the number of alkyl group)/(the number of cyclohexyl group+the number of alkyl group))×100] being 60 to 80%, and a base oil which has a kinematic viscosity at 40° C. of 15 to 50 mm2/s and includes a trimethylolpropane ester oil in an amount of 80 mass % or more based on the total base oil mass. The grease composition can exhibit a long bearing lubrication life at high temperature and high speed, and satisfactory low-temperature flowability.
摘要:
A grease composition having an apparent viscosity at −30° C. of 5 to 200 Pa·s is sealed in a rolling bearing which retains a plurality of rolling elements between an inner ring and an outer ring in such a way that the rolling elements can freely roll. Thereby, there is provided a rolling bearing which has a satisfactory lubricating performance and generates less abnormal noise even under a low temperature of around −40° C.
摘要:
The rolling bearing of the invention to be incorporated in the compressor for fuel cell system comprises a fluorine-based grease containing a fluororesin and a fluorine-based oil, a urea grease containing a urea compound and a synthetic oil or a lithium complex grease containing a lithium complex and a synthetic oil encapsulated therein. In this arrangement, the grease deterioration of the rolling bearing incorporated in the compressor for force-feeding various fluids between machines can be prevented, making it possible to provide a fuel cell system which can maintain stable operation over an extended period of time.
摘要:
A rolling bearing includes a plurality of rolling elements rotatably retained at substantially uniform intervals between inner and outer rings via a retainer, and a grease composition which contains a conductive substance in the proportion of 0.1 to 10 wt % and is sealed in the rolling bearing.
摘要:
A grease composition for a rolling bearing comprising, based on 100 parts by weight of a base oil, 10 to 60 parts by weight of a mixture of diurea compounds as a thickener having a composition of 25 to 90 mol % of a diurea compound represented by the formula (1), 9 to 50 mol % of a diurea compound represented by the formula (2), 1 to 30 mol % of a diurea compound represented by the formula (3), wherein R.sup.1 stands for an aromatics-containing hydrocarbon group having 7 to 12 carbon atoms, R.sup.2 stands for a divalent aromatics-containing hydrocarbon group having 6 to 15 carbon atoms, and R.sup.3 stands for a cyclohexyl group or an alkylcyclohexyl group having 7 to 12 carbon atoms, a value of (number of R.sup.1 /(number of R.sup.1 +number of R.sup.3)) in the mixture being 0.55 to 0.95. ##STR1##
摘要:
The rolling bearing of the invention to be incorporated in the compressor for fuel cell system comprises a fluorine-based grease containing a fluororesin and a fluorine-based oil, a urea grease containing a urea compound and a synthetic oil or a lithium complex grease containing a lithium complex and a synthetic oil encapsulated therein. In this arrangement, the grease deterioration of the rolling bearing incorporated in the compressor for force-feeding various fluids between machines can be prevented, making it possible to provide a fuel cell system which can maintain stable operation over an extended period of time.
摘要:
A grease composition comprising a lubricating base oil, at least one diurea compound represented by one of the general formulas (1) to (3) below, a naphthenic acid salt, and succinic acid or a derivative thereof, wherein each of the proportions of the diurea compounds represented by general formulas (1) to (3) satisfies the conditions represented by inequalities (4) and (5) below, and each of the proportions of the naphthenic acid salt and the succinic acid or its derivative is 0.1-10% by mass based on the total amount of the grease composition. [wherein R1 represents a C7-12 aromatic ring-containing hydrocarbon group, R2 represents a C6-15 divalent hydrocarbon group, and R3 represents a cyclohexyl group or a C7-12 alkylcyclohexyl group] 5≦W1+W2+W3≦35 (4) 0≦(W1+0.5×W2)/(W1+W2+W3)≦0.55 (5) [wherein W1, W2 and W3 represent the proportions of diurea compounds represented by general formulas (1) to (3), respectively, based on the total amount of the grease composition (% by mass)].
摘要:
In a rolling bearing, a plurality of rolling elements are rollably retained by a retainer between an inner ring and an outer ring, while being substantially equidistantly arranged. The rolling bearing is filled with a grease composition which contains a base oil including of fluorocarbon polymer oil, and a thickening agent including a polytetrafluoroethylene. A conductive material is added in an amount of 0.1 to 10 wt %, based on the total weight of the grease composition, to the grease composition.