High-speed Centrifugal Compressor

A high-speed centrifugal compressor is provided, including a shell, a stator, and a main shaft; a primary bearing pedestal and a secondary bearing pedestal which are used for supporting the main shaft are respectively mounted on inner sides of two ends of the shell; a thrust collar sleeves the main shaft between a primary diffuser and the primary bearing pedestal; one thrust air bearing is arranged on each of two sides of the thrust collar; a radial air bearing is arranged between each of the primary bearing pedestal and the secondary bearing pedestal and the main shaft; a sealing end cover is arranged between the primary worm wheel and the primary diffuser; several annular slots are arranged between the sealing end cover and the primary worm wheel; several annular slots are arranged between the secondary diffuser and the main shaft; and a backflow air cooling system is arranged in the shell. Several air seals formed in the several annular slots can greatly enhance a sealing effect between high-pressure cavities and a low-pressure cavity and improve the compression efficiency of the high-pressure cavities. The internal air cooling structure is better optimized, and the cooling effect is good. The internal heat can be timely discharged, without being accumulated, so that the situation that the high-speed centrifugal compressor is forced to stop due to an extremely high internal temperature is avoided.