A centrifugal compressor comprises an impeller including a hub and a plurality of blades. The hub is provided with a through hole. The hub has an external radial surface having an inner external radial surface and an outer external radial surface. The outer external radial surface is formed closer to a back surface than an imaginary curved surface having as a radius a radius of curvature of the inner external radial surface at a radially outer edge thereof.

A turbine or compressor wheel mounted in a housing. The wheel is carried on two radial bearings both mounted in a wall of the housing. The wall has a venting orifice that is not impeded by moving parts such as bearings. The wall also has a circular seal member extending toward a back-disk of the wheel with only a very small clearance. The seal member is composed of a material significantly softer than the material of the wheel.

A centrifugal compressor comprises a rotation shaft, an impeller, and a casing. The impeller has a hub and a plurality of blades. The casing has an opposite surface facing a back surface of the hub, and a projection projecting from the opposite surface toward the impeller. The hub is provided with an accommodation space that accommodates the projection. The accommodation space includes a through hole penetrating the hub from the back surface toward an external radial surface. The through hole opens while avoiding the blades.

A compressor device includes a housing and a shaft supported for rotation within the housing. The compressor device includes a compressor section with a compressor wheel. Also, the compressor device includes a thrust suppression section with a chamber and a thrust balance body disposed within the chamber. Moreover, the compressor device includes a motor configured to drivingly rotate the shaft, the compressor wheel, and the thrust balance body. The thrust balance body divides the chamber into a first sub-chamber and a second sub-chamber. Additionally, the compressor device includes a bleed air system that fluidly connects the compressor section and the thrust suppression section. The bleed air system is configured to bleed air from the compressor section, through the first sub-chamber, to the second sub-chamber, pressurizing the first sub-chamber and generating a counterbalancing thrust load that counterbalances a compressor thrust load on the shaft.

According to one aspect of the present disclosure, a turbo-compressor (100) is provided. The turbo-compressor (100) includes: a rotor assembly (110) extending in an axial direction A and comprising at least one impeller (112) configured for pressurizing a gas; a magnetic bearing (120) supporting the rotor assembly (110) on a high-pressure side (113) of the at least one impeller (112); and a cooling passage (130) configured for directing a first portion of the pressurized gas (P1) through a bearing gap (132) of the magnetic bearing (120) for cooling the magnetic bearing (120). According to a further aspect, a method of operating a turbo-compressor is described.

A method of controlling, by a controller for a compressor (200), pressure at plurality of magnetic motor thrust bearings (360, 370) for a motor (280) disposed within a housing (220) for the compressor (200), wherein the motor (280) and an impeller (270) are disposed on a compressor shaft (260) within the housing, the method including: monitoring current at each of the plurality of magnetic motor thrust bearings (360, 370), controlling a flow regulator (400) in a bypass loop (380) for the impeller (270) to decrease flow through the bypass loop when a first current in a first of the plurality of magnetic motor thrust bearings (360, 370) exceeds a second current in a second of the plurality of magnetic motor thrust bearings (360, 370), and controlling the flow regulator (400) to increase flow through the bypass loop (380) when the second current exceeds the first current.

A single-stage compressor device includes a housing and a rotating group with a shaft and a compressor wheel. The compressor wheel includes a front face and a back face. The front face cooperates with the housing to define a compressor flow path. A motor drives rotation of the rotating group within the housing. Furthermore, the compressor device includes a bleed system fluidly connected to the compressor flow path and configured to receive bleed fluid from the compressor flow path. The bleed system includes a bleed passage. At least a portion of the bleed passage is cooperatively defined by the back face of the compressor wheel and an opposing surface of the housing. The bleed system is configured to pass bleed air from the bleed passage, thereby alleviating thrust loading of the compressor wheel on the rotating group.

An electric motor includes a stator and a rotator that is configured to rotate with respect to the stator. The stator has a length Ls and the rotor has a length Lr. The length Lr of the rotor is less than the length Ls of the stator such that the rotor does not overhang the stator. A compressor and a method of compressing a fluid are also disclosed.

A two-wheel air cycle machine includes a tie rod defining an axis, a turbine mounted on the tie rod, and a compressor mounted on the tie rod and having a rotor portion and a disk portion with at least one aperture. The air cycle machine further includes a compressor inlet fluidly connecting the compressor and an inlet air source, at least one thrust bearing disposed between the turbine and the compressor, and a compressor end shaft coaxial with the tie rod and abutting the compressor disk portion. The compressor end shaft includes a radially-extending seal disk portion and an axially-extending shaft portion having at least one shaft aperture. The at least one disk aperture and the at least one shaft aperture are fluidly connected by a compressor disk cavity defined by a gap between the tie rod and the compressor disk portion. The at least one disk aperture, the compressor disk cavity, and the at least one shaft aperture at least partially define a compressor inlet flow path.

According to one aspect of the present disclosure, a turbo-compressor (100) is provided. The turbo-compressor (100) includes: a rotor assembly (110) extending in an axial direction A and comprising at least one impeller (112) configured for pressurizing a gas; a magnetic bearing (120) supporting the rotor assembly (110) on a high-pressure side (113) of the at least one impeller (112); and a cooling passage (130) configured for directing a first portion of the pressurized gas (P1) through a bearing gap (132) of the magnetic bearing (120) for cooling the magnetic bearing (120). According to a further aspect, a method of operating a turbo-compressor is described.