An air turbine drive spindle capable of suppressing a pressure increase inside a through hole is provided. A spindle includes a rotary shaft and an outer circumferential member (a housing assembly, a cover and a nozzle plate). The rotary shaft is provided with a through hole. The outer circumferential member includes a bearing sleeve configured to surround at least a portion of an outer circumferential surface of the rotary shaft. The outer circumferential member includes a gas supply portion and a gas exhaust hole. The spindle includes a second gas exhaust portion (a first gas exhaust hole and a first gas flow passage). The second gas exhaust portion is independent of the gas exhaust hole and continuous to outside from a gas exhaust space.

A coated article includes a substrate and an MCrAlY coating supported on the substrate. The M includes at least one of nickel, cobalt, and iron, Cr is chromium, Al is aluminum, and Y is yttrium. The composition of the MCrAlY coating varies in an amount of at least one of Cr, Al, and Y by location on the substrate with respect to localized property requirements. In one example, the coated article is an article of a gas turbine engine.

A coated article includes a substrate and an MCrAlY coating supported on the substrate. The M includes at least one of nickel, cobalt, and iron, Cr is chromium, Al is aluminum, and Y is yttrium. The composition of the MCrAlY coating varies in an amount of at least one of Cr, Al, and Y by location on the substrate with respect to localized property requirements. In one example, the coated article is an article of a gas turbine engine.

The combined radial-axial turboexpander (1) comprises a casing (3) and a shaft (5) arranged in the casing (3) for rotation therein. A radial impeller (25) and an axial expansion wheel (43) are mounted on the shaft (5). The axial expansion wheel (43) is arranged downstream of the radial impeller (25). A working fluid expands sequentially in the radial impeller and in the axial expansion wheel.

The combined radial-axial turboexpander (1) comprises a casing (3) and a shaft (5) arranged in the casing (3) for rotation therein. A radial impeller (25) and an axial expansion wheel (43) are mounted on the shaft (5). The axial expansion wheel (43) is arranged downstream of the radial impeller (25). A working fluid expands sequentially in the radial impeller and in the axial expansion wheel.

A multi-stage turboexpander and a method for generating mechanical power therewith are disclosed. The multi-stage turboexpander includes a casing and a shaft, arranged for rotation in the casing. The shaft is supported by a first bearing at a first shaft end portion and a second bearing at a second shaft end portion. A first radial impeller and a second radial impeller are arranged between the first bearing and the second bearing on the shaft for co-rotation therewith around a rotation axis.

A multi-stage turboexpander and a method for generating mechanical power therewith are disclosed. The multi-stage turboexpander includes a casing and a shaft, arranged for rotation in the casing. The shaft is supported by a first bearing at a first shaft end portion and a second bearing at a second shaft end portion. A first radial impeller and a second radial impeller are arranged between the first bearing and the second bearing on the shaft for co-rotation therewith around a rotation axis.

An air turbine drive spindle capable of suppressing a pressure increase inside a through hole is provided. A spindle includes a rotary shaft and an outer circumferential member (a housing assembly, a cover and a nozzle plate). The rotary shaft is provided with a through hole. The outer circumferential member includes a bearing sleeve configured to surround at least a portion of an outer circumferential surface of the rotary shaft. The outer circumferential member includes a gas supply portion and a gas exhaust hole. The spindle includes a second gas exhaust portion (a first gas exhaust hole and a first gas flow passage). The second gas exhaust portion is independent of the gas exhaust hole and continuous to outside from a gas exhaust space.

An air turbine drive spindle capable of suppressing a pressure increase inside a through hole is provided. A spindle includes a rotary shaft and an outer circumferential member (a housing assembly, a cover and a nozzle plate). The rotary shaft is provided with a through hole. The outer circumferential member includes a bearing sleeve configured to surround at least a portion of an outer circumferential surface of the rotary shaft. The outer circumferential member includes a gas supply portion and a gas exhaust hole. The spindle includes a second gas exhaust portion (a first gas exhaust hole and a first gas flow passage). The second gas exhaust portion is independent of the gas exhaust hole and continuous to outside from a gas exhaust space.

A gas expander includes: a casing where a swirl chamber for a gas to be expanded is formed; a turbine wheel that is housed in the casing and rotationally driven by the expanded gas; a diffuser that is mounted to the casing in a direction of a rotating shaft of the turbine wheel and includes a flow path for the expanded gas to flow in the direction of the rotating shaft; a swirl stopper that is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partition the flow path in the diffuser.