Abstract: On an inner circumference side of a stator fixed in an inner housing, a rotor is arranged. The rotor rotates through a bearing with respect to a center shaft that is a stationary shaft fixed to outer housings. Oil introduced into a rotor oil inlet path in the center shaft flows through a communication path and a clearance on an outer circumference of the center shaft into an oil path in the rotor. The oil flowing through the oil path cools a permanent magnet, lubricates the bearing, and is discharged from a rotor oil discharge port to the outside of the inner housing. The oil in the clearance is sealed with a thread seal, i.e., an inner thread formed in an inner face of an end ring and is prevented from flowing toward the bearing.

Abstract: On an inner circumference side of a stator fixed in an inner housing, a rotor is arranged. The rotor rotates through a bearing with respect to a center shaft that is a stationary shaft fixed to outer housings. Oil introduced into a rotor oil inlet path in the center shaft flows through a communication path and a clearance on an outer circumference of the center shaft into an oil path in the rotor. The oil flowing through the oil path cools a permanent magnet, lubricates the bearing, and is discharged from a rotor oil discharge port to the outside of the inner housing. The oil in the clearance is sealed with a thread seal, i.e., an inner thread formed in an inner face of an end ring and is prevented from flowing toward the bearing.

Abstract: There are provided a rotational shaft 2, a bearing inner ring 3 which is pressed into the outer periphery of the rotational shaft 2, a foil 4 which is disposed in the outer periphery of the bearing inner ring 3, and a bearing outer ring 5 which is formed in the outer periphery of the foil 4, where the bearing inner ring 3 is provided with a pair of foil displacement regulating portion 6 and 7 which regulates an axial displacement of an inner peripheral side 4a of the foil 4.