<p>A sealed power transmission device (1), adapted to be mounted on a vacuum chamber (2) to supply power to the interior thereof, comprises an insulator (10) and a conductor (20), wherein the insulator (10) has a main insulator body (11) and an insulator flange (12) extending outward from the lower end of the main insulator body (11); the conductor (20) has a main conductor body (21) and a conductor flange (22) extending outward from the main conductor body (21); the vacuum chamber (2) is provided with an insulator mounting hole (2a); the insulator (10) is provided with a conductor mounting hole (110); the insulator (10) is mounted in the insulator mounting hole (2a) and in tightly contact with the inner surface of the insulator mounting hole (2a); the conductor (20) is sleeved in the conductor mounting hole (110) and in tightly contact with the inner surface of the conductor mounting hole (110); and the insulator flange (12) and the conductor flange (22) are tightly secured to the vacuum chamber (2) by fastening screws (40). The sealed power transmission device has a simple structure, better sealing capability and high safety performance.</p>
