A rotary device includes: a housing; an impeller disposed in the housing; a rotor disposed in the housing and configured to drive the impeller; and a labyrinth seal disposed between the impeller and the rotor in the housing and configured to control an amount of air injected through the impeller to cool the rotor. A flow path opening that penetrates through the rotor is formed inside the rotor along a rotational axis of the rotor and the labyrinth seal comprises a teeth portion having a predetermined number of steps provided in the labyrinth seal.