LABYRINTH SEAL, CENTRIFUGAL COMPRESSOR, AND SUPERCHARGER

摘要

A labyrinth seal used in a centrifugal compressor is provided with: an impeller along which fluid flows radially; and a stationary member provided on the rear surface side of the impeller. The labyrinth seal is further provided with: a plurality of first protrusions individually circumferentially arranged at a plurality of radial positions on the rear surface of the impeller; and second protrusions circumferentially arranged on the stationary member so that the front end of each of the protrusions is located between adjacent first protrusions. A labyrinth-shaped flow passage including a plurality of minimum clearance sections formed between the first protrusions and the second protrusions is formed radially between the rear surface of the impeller and the stationary member. With respect to the direction of flow of leakage passing through the minimum clearance sections formed between the first protrusions and the second protrusions, the stationary member is located upstream of the minimum clearance sections, and the rear surface of the impeller is located downstream of the minimum clearance sections.