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.