A locking structure of a compressor impeller, which includes: a rotary shaft; a lock nut arranged on an end of the rotary shaft by means of a threaded connection and provided with waist-shaped holes extending along a circumferential direction thereof; an impeller sleeved on the end of the rotary shaft and located on an inner side of the lock nut, the impeller is provided with threaded holes in communication with the waist-shaped holes of the lock nut; a nose piece located on an outer side of the lock nut and provided with through holes in communication with the waist-shaped holes of the lock nut; and bolts passing through the through holes and the waist-shaped holes in turn into the threaded holes, thereby fixing the nose piece, the lock nut and the impeller together.

A compressor system includes a compressor housing and a driveshaft rotatably supported within the compressor housing. The compressor system further includes an impeller that imparts kinetic energy to incoming refrigerant gas upon rotation of the driveshaft, a thrust disk coupled to the driveshaft, and a bearing assembly mounted to the compressor housing. The impeller includes an impeller bore having an inner surface, and the thrust disk includes an outer disk and a hub. The bearing assembly rotatably supports the outer disk of the thrust disk. The hub is disposed within the impeller bore, and includes a hub outer surface in contact with the inner surface of the impeller bore. A first contact force between the hub outer surface and the inner surface of the impeller bore increases with increased rotational speed of the driveshaft.

An impeller includes: a disk which is supported so as to be rotatable around an axis and which includes an outer peripheral surface expanding toward an outside in a radial direction of the disk as it goes to a downstream side in an axial direction of the axis; blades which are arranged on the outer peripheral surface of the disk at intervals in a circumferential direction of the disk; and a cover which is disposed at a position facing the outer peripheral surface of the disk so as to cover the blades. A leading edge of each of the blades includes: a straight portion which extends toward the downstream side in the axial direction of the axis as it goes to the disk from the cover; and a protrusion portion close to the disk and which is protruded from an extension of the straight portion.

A compressor housing includes: an intake flow path-forming section configured to form an intake flow path; a shroud portion including a shroud surface curved in a protruding manner to face blades of an impeller; and a scroll flow path-forming section configured to form a scroll flow path through which gas is guided outside the compressor housing. A groove portion extending in a circumferential direction is defined in the shroud surface and, in a cross-sectional view taken along an axis of the impeller, the groove portion includes a downstream side wall surface, wherein a distance from the axis of the impeller to the downstream side wall surface increases toward an upstream side from a downstream side end portion of the groove portion, and an upstream side curved surface that is recessed between an upstream end of the downstream side wall surface and an upstream side end portion of the groove portion.

An impeller for a centrifugal turbomachine includes: a hub having a small-diameter portion positioned at a first end portion in an axial direction and a large-diameter portion positioned at a second end portion in the axial direction, the large-diameter portion having a greater diameter than the small-diameter portion; and a blade having a first edge positioned at an axial-directional position of the small-diameter portion and a second edge positioned at an axial-directional position of the large-diameter portion, the blade being disposed on an outer peripheral surface of the hub. The impeller is configured such that, when a first radial-directional cross section is a cross section of the impeller at an axial-directional position passing a tip of the first edge, at least a part of the first radial-directional cross section in a blade-height range of 50% or more is inclined downstream in a rotational direction of the impeller with respect to a radial direction.

A turbine shaft used for a turbocharger including a turbine and a compressor includes a turbine impeller, and a rotor shaft joined on one end side to the turbine impeller. The rotor shaft includes a fitting region configured to fit with a compressor impeller of the compressor by inserting the other end side of the rotor shaft into a through hole formed in the compressor impeller, a fastening region formed between the fitting region and the other end side of the rotor shaft, and configured to allow fastening by a fastening part, and a tapered part having a maximum outer diameter at a position closest to the turbine impeller in the fitting region and formed such that an outer diameter of the rotor shaft decreases from the position closest to the turbine impeller toward a tip side of the compressor impeller.

An impeller of a centrifugal compressor is an impeller 5 of a centrifugal compressor, that is, a compressor impeller 5 and includes a hub, at least one airfoil portion erected on a hub surface of the hub, and a first fillet. The at least one airfoil portion has a trailing edge configured such that a distance between the trailing edge and an axis of the centrifugal compressor increases with increasing distance from a back surface of the hub. The first fillet is formed on a radially outer side of an outer peripheral surface of a back plate portion forming a back surface portion of the hub. The first fillet connects the outer peripheral surface of the back plate portion and the trailing edge of the at least one airfoil portion.

A centrifugal compressor includes: an impeller which is allowed to rotate around an axis; a casing in which the impeller is accommodated and a guide flow path guiding fluid to the impeller is formed; and a guide vane which is disposed in the guide flow path and is extended from a hub side wall surface of the guide flow path, which is continued to a hub side of the impeller, to a shroud side wall surface of the guide flow path to a shroud side of the impeller, wherein the guide vane is twisted forward the impeller in a rotating direction thereof as close to the shroud side wall surface from the hub side wall surface.

A gas turbine engine includes a main compressor section with a downstream most location. A turbine section has a high pressure turbine. A tap line is connected to tap air from a location upstream of the downstream most location in the main compressor section. The tapped air is connected to a heat exchanger and then to a cooling compressor. The cooling compressor compresses air downstream of the heat exchanger, and is connected to deliver air into the high pressure turbine. A bypass valve is positioned downstream of the main compressor section, and upstream of the heat exchanger. The bypass valve selectively delivers air directly to the cooling compressor without passing through the heat exchanger under certain conditions.

A turbine rotor blade according to at least one embodiment of the present invention is to be connected to a rotational shaft so as to be rotatable around an axis and includes: a hub having a hub surface inclined with respect to the axis in a cross-section along the axis; at least one rotor blade disposed on the hub surface; and a connection passage disposed inside the turbine rotor blade and connecting a first opening disposed in the at least one rotor blade and a second opening disposed downstream of the first opening in the turbine rotor blade.