A scroll casing of a centrifugal compressor includes a scroll part forming a scroll passage of the centrifugal compressor. The scroll part has a near-circular scroll cross-section which includes a first arc portion extending from a connection position with a hub-side passage surface of a diffuser passage of the centrifugal compressor (first position) to a one-direction side (side toward fourth position), a second arc portion formed on the one-direction side of the first arc portion so as to include at least a part of a region between an outermost end in the radial direction (second position) and an innermost end in the radial direction (fourth position), and a third arc portion formed on the one-direction side of the second arc portion so as to include an end position of the scroll part on the one-direction side (fifth position) and satisfies a relationship of R2>R3, where R2 is a curvature radius of the second arc portion, and R3 is a curvature radius of the third arc portion.

The air compressor includes: a housing assembly, wherein the housing assembly has a first installation cavity, a second installation cavity and a rotation-shaft cooperating cavity, and the first installation cavity has a gas inlet and a gas outlet; a rotor shaft, wherein the rotor shaft is rotatably fitted inside the rotation-shaft cooperating cavity, and extends into the first installation cavity and the second installation cavity; a pressure wheel, wherein the pressure wheel is nested to the rotor shaft and is located inside the first installation cavity, and the housing assembly is provided with a controlling flow channel for communicating the gas-intake side and the wheel-back side of the pressure wheel; and a driving assembly, wherein the driving assembly is nested to the rotor shaft and is located inside the second installation cavity.

The fuel cell control system includes: a reactor; an air compressor, wherein the air compressor has a compressing cavity, the compressing cavity has a gas inlet and a gas outlet, a rotatable pressure wheel is disposed inside the compressing cavity, and the gas outlet is in communication with the reactor; a control flow channel, wherein a first end of the control flow channel is in communication with the gas-intake side of the pressure wheel, a second end of the control flow channel is in communication with the wheel-back side of the pressure wheel, and the control flow channel is provided with a return valve for regulating the flow rate of the control flow channel; and a central control unit, wherein the central control unit is communicatively connected to the return valve to control the opening degree of the return valve.

Various embodiments are provided herein for a system and method for air compression. In at least some embodiments provided herein, there is provided a compressor device having an annular chamber, at least one inlet port, at least one blade, at least one dynamic partition wall and at least one outlet, wherein when the at least one partition wall is in a closed position, the at least one blade approaching the at least one partition wall causes the air to compress and wherein when the at least one partition wall is in the open position, at least one blade moves from a first side to a second side of the at least one partition wall. The compressor device may contain a gearbox train configured to move the at least one partition wall from the closed position to the open position when the at least one blade is within a predetermined distance.

A rotary machine includes a compression section that is disposed between the pair of radial bearings in a casing and compresses a fluid, an expansion section that is disposed side by side with the compression section and expands the fluid, and a thrust bearing that is disposed at a position close to a first end portion or a second end portion of a rotary shaft in an axial direction with respect to the compression section and the expansion section. Among a compression section suction port, a compression section discharge port, an expansion section suction port, and an expansion section discharge port, the compression section suction port is disposed at a position closest to the first end portion in the axial direction, and the expansion section discharge port is disposed at a position closest to the second end portion in the axial direction.

An air blower capable of suppressing movement of an impeller in a thrust direction is provided. A first case includes a first air inlet and a first air outlet. A second case includes a second air inlet communicating with the first air inlet and a second air outlet communicating with the first air outlet. An impeller is provided inside the second case. A motor rotates the impeller. A first flow channel is provided between the motor and the second case on the opposite side of the first air inlet and the second air inlet relatively to the impeller. A second flow channel is provided between the first case and the second case and communicates with the first flow channel, the first air inlet, and the second air inlet.

An aircraft turbomachine having a centrifugal compressor, an annular combustion chamber, an annular casing extending around the chamber and delimiting an annular space (E) in which the chamber is situated, and a heat exchanger. The heat exchanger can include a first circuit supplied with exhaust gas from the turbomachine, and a second circuit connected by first and second volutes respectively to an outlet of the compressor and to the annular space. The first and second volutes can be positioned at an axial distance from one another, and the second volute is can be connected to the annular space by a straightener which is situated at least in part outside the casing and which is integrated into an annular connecting pipe which connects the second volute to this casing.

A blower includes a motor, a fan driven by the motor to rotate about a first axis, a power supply device, and a housing assembly accommodating the motor and including an inner duct and an outer duct assembly. The inner duct is formed with an inner air inlet. The outer duct assembly surrounds the inner duct. The outer duct assembly includes an outer duct and a hood, where the outer duct is disposed on a front side of the hood, an outer air outlet is formed at an end of the outer duct facing away from the hood, an outer air inlet is formed on the hood and has a front end portion and a rear end portion along a direction of the first axis, and the inner air inlet is disposed between the front end portion and the rear end portion along the direction of the first axis.

A first elastic member is interposed between an outer peripheral surface of the circular core back portion and an inner wall surface of the second motor housing in a radial direction, both outer peripheral ends of the core back portion in the axial direction of the rotor are covered with the first elastic member, the first elastic member is assembled by being pinched between end surfaces of the first motor housing and the second motor housing which faces each other, and a second elastic member is assembled by being stacked between the bearing assembled in one of the pair of bearing housings and the bearing housing.

A head-mountable flow generator is configured to deliver a flow of breathable gas at a continuously positive pressure with respect to ambient air pressure to a patient interface in communication with an entrance to a patient's airways including at least an entrance of the patient's nares, while the patient is sleeping, to ameliorate sleep disordered breathing. The flow generator includes a motor, an impeller assembly and housing that encases the motor and the impeller assembly. The housing is configured to be mounted on the patient's head and comprises an inlet to receive the flow of breathable gas and a pair of opposing outlets to deliver the flow of breathable gas. In addition, the impeller assembly is configured to pressurize the flow of breathable gas received from the inlet, and the housing is configured to convey the pressurized flow of breathable gas through both outlets.