Disclosed herein is a turbomachinery including a labyrinth seal easy to fabricate and adapted to prevent unstable vibration of a rotor.
A turbomachinery according to this invention includes a labyrinth seal 2 formed by dividing the seal into segments 7 in a circumferential direction and combining the segments 7 whose comb teeth 5 differ in height. The labyrinth seal 2 preferably includes two kinds of segments 7 whose comb teeth 5 differ in height for each kind of segment, and the segments 7a of the greater comb tooth height are arranged in a certain reference direction on a cross section right-angled to a rotational axis, and in a direction opposite to the reference direction, and the segments 7b of the smaller comb tool height are arranged in a direction right-angled to the reference direction, and in a direction opposite to that right-angled to the reference direction.