Abstract: A sealing device includes a sealing main body surrounding a rotor shaft rotating about an axis from an outer periphery side. The sealing main body includes an inside surface facing an outside surface of the rotor shaft with clearance and a plurality of hole parts formed recessed to an outer side in a radial direction from the inside surface and arrayed in a circumferential direction of the inside surface and in a direction of the axis. The hole parts have an inner peripheral wall in which a spiral groove extending twisting toward the outer side in a radial direction is formed.

Abstract: A sealing device includes a sealing main body surrounding a rotor shaft rotating about an axis from an outer periphery side. The sealing main body includes an inside surface facing an outside surface of the rotor shaft with clearance and a plurality of hole parts formed recessed to an outer side in a radial direction from the inside surface and arrayed in a circumferential direction of the inside surface and in a direction of the axis. The hole parts have an inner peripheral wall in which a spiral groove extending twisting toward the outer side in a radial direction is formed.

Abstract: The rotary machine includes a rotor, an annular member disposed on an outer circumferential side of the rotor, and a hole pattern seal fixed to the annular member and partitioning a space between the rotor and the annular member into a high-pressure side and a low-pressure side. The hole pattern seal has an annular seal main body covering an outer circumference of the rotor, a hole group provided on an inner circumferential surface of the seal main body, and having holes being aligned at intervals in the direction of an axis of the rotor and a circumferential direction of the axis, and fin sections provided on the inner circumferential surface of the seal main body throughout in the circumferential direction, each of the fin sections having the thickness equal to or smaller than that of the thinnest part of the seal main body, wherein the fin sections are provided on at least the high-pressure side and the low-pressure side of the seal main body.

Abstract: A centrifugal compressor includes: an impeller which is allowed to rotate around an axis; a casing which is provided with a return flow path allowing a fluid pressure-fed from the impeller to flow therein; and a return vane which is disposed inside the return flow path, wherein the return vane is provided with an injection port through which a liquid supplied from the outside is injected to the return flow path. Accordingly, power is further reduced while suppressing pressure loss.