Abstract: The invention relates to a rotating electric machine including a coil of a wire having thereon an insulating coating comprising a polybenzimidazole. This rotating electric machine is stably maintained for a long time in dielectric strength even under a highly radioactive environment, due to the use of the special insulating coating. With this, the rotating electric machine can be driven stably for a long time. The invention further relates to another rotating electric machine including (a) a rotor having a rotating shaft; (b) a bearing for supporting the rotating shaft; and (c) a grease applied to the bearing. This grease contains (1) a polyphenyl ether having at least three aromatic rings in the molecule and (2) a urea. The rotor of this rotating electric machine is stably supported in the bearing for a long time even under a highly radioactive environment, due to the use of the special grease. Thus, this rotating electric machine can also be rotated stably for a long time.

Abstract: The invention relates to a rotating electric machine including (a) a rotor having a rotating shaft; (b) a bearing for supporting the rotating shaft; (c) a radiation resistant grease applied to the bearing; and (d) a shield layer for shielding the grease from radiation. The shield layer is made of lead and surrounds the bearing. The shield layer includes (1) a first cylindrical shield member that is positioned to cover the bearing, such that the bearing is shielded from a first radiation that is in a direction substantially perpendicular to an axis of the rotating shaft, and (2) second and third disk shield members that are positioned to interpose therebetween the bearing in a direction along the axis of the rotating shaft, such that the bearing is shielded from a second radiation that is in a direction substantially along the axis of the rotating shaft. Thus, the rotor of this rotating electric machine is stably supported in the bearing for a long time even under a highly radioactive environment.

Abstract: A grease composition for rolling bearings is disclosed which contains:(A) 100 parts by weight of a base oil having the kinematic viscosity of 40 to 200 mm.sup.2 /s at 40.degree. C.,(B) 5 to 65 parts by weight of a urea thickener, and(C) 0.05 to 10 parts by weight of zinc dithiocarbamate,the composition being free of boron nitride. This grease composition is suitable for application to rolling bearings in electrical components and accessory devices for automotive vehicles, such as alternators, electromagnetic clutches for car air conditioners, idle pulleys, electric fan motors, or the like.

Abstract: A grease composition for constant-velocity joints which is prepared by blending a lube base oil with (A) a urea-urethane thickening agent comprising a mixture of(a) 20 to 95 mole % of a diurea compound of the formula (1): ##STR1## (b) 4 to 50 mole % of a urea-urethane compound of the formula (2): ##STR2## and (c) 1 to 50 mole % of a diurethane compound of the formula (3): ##STR3## with each mole percentage being based on the total amount of the components (a) to (c), wherein a ratio of the total number of R.sup.2 --NH--, R.sup.3 --NH-- and R.sup.5 --NH-- groups contained in the mixture to the total number of R.sup.6 --O--, R.sup.8 --O-- and R.sup.9 --O-- groups contained therein lies between 40:60 and 95:5,(B) at least one compound selected from oxidized paraffins, diphenyl hydrogenphosphite and hexamethylphosphoric triamide, and(C) at least one organomolybdenum compound selected from molybdenum dithiophosphate and molybdenum dithiocarbamate.

Abstract: 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.