An air pump is provided, the air pump comprising: an air pump housing; a first check valve; a main air pump; an airway switching device; an air-supplementing pump; an air pressure sensor; and a control device. The control device is electrically connected to the main air pump, the airway switching device, the air-supplementing pump, and the air pressure sensor, and is configured to: send a main air pump stop signal based on the air pressure sensor detecting a threshold pressure in the inflatable body during operation of the main air pump; and send an air-supplementing pump operation signal based on the air pressure sensor detecting a pressure lower than the threshold pressure in the inflatable body when the main air pump is not in operation.

A compressor includes a housing having an inlet and an outlet and a fluid flow path extending between the inlet and the outlet. An impeller is mounted within the housing and is movable to move a fluid from the inlet along the fluid flow path to the outlet. A plurality of flow interference elements is arranged within the housing at one or more locations along the fluid flow path. When a fluid flows through the fluid flow path in a backwards direction of flow, a disturbance is generated in the fluid adjacent each of the plurality of flow interference elements.

A ventilated seat system for a vehicle includes a seating assembly including a seatback operably coupled to a seat base. A blower is coupled to the seating assembly. The blower generates a sound transmission when activated. The blower includes a housing defining an inlet and an outlet. A first metamaterial silencer is coupled to an interior surface of the housing proximate to the inlet, and a second metamaterial silencer is coupled to the interior surface of the housing proximate to the outlet. Each of the first metamaterial silencer and the second metamaterial silencer reduces the sound transmission generated by the blower.

Provided is an outer enclosure for a turbo blower in which a turbo blower is installed, which includes a housing forming an exterior of the outer enclosure, an outside air inflow chamber which is a space partitioned in one side inside the housing and which communicates with the outside through an outside air inlet, an inverter chamber which is a space partitioned in the other side inside the housing, a motor chamber which is a space partitioned in an upper portion of a space positioned between an inverter chamber and the outside air inflow chamber, and in which a turbo blower including an intake nozzle communicating with the outside air inflow chamber is positioned, and a first refrigerant discharge port is positioned on one side, a refrigerant inflow chamber which is a space in a lower portion of the motor chamber and which communicates with the outside through a refrigerant inlet, in which the upper and lower portions of the inverter chamber are in communication with the motor chamber and the refrigerant inflow chamber, respectively, and the refrigerant inflow chamber is communication with the motor chamber.

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.

A medical, in particular dental-medical, fan for extracting or compressing a gaseous working fluid, in particular air, comprises a compressor unit with an outer housing, which comprises an inlet opening for the working fluid and an outlet opening for the working fluid, which are fluidically connected to one another, and which defines a compressor sector and a drive sector.

A compressor includes: a rotation shaft which is allowed to rotate around an axis; an impeller which is configured to pressure-feed a fluid from one side in an axial direction toward an outside in a radial direction by rotating together with the rotation shaft; a casing surrounding the rotation shaft and the impeller and in which an exit flow path guiding the fluid pressure-fed from the impeller is formed; and an acoustic liner which is installed to face an inside of the exit flow path in the casing. The acoustic liner includes: an acoustic space which is formed inside the acoustic liner; an introduction hole communicating the acoustic space with the exit flow path; and a vortex suppressor which is placed in a connection area between the introduction hole and the acoustic space and is configured to suppress vortexes which occur in the connection area.

An airflow guiding device for the sound- and pressure-optimized supply of an airflow to an inlet nozzle of a fan, in particular a radial fan, wherein the inlet nozzle has a nozzle input opening with an incident flow angle, the airflow guiding device having: a frame device which extends along a longitudinal axis in an axial direction with a height between an inlet opening, through which the airflow flows into the frame device in an operating state, and an outlet opening, through which the airflow flows out of the frame device in the operating state, wherein the inlet opening has an inlet cross section with a minimum inlet cross-sectional width, and the outlet opening has an outlet cross section with a minimum outlet cross-sectional width which corresponds to the minimum inlet cross-sectional width or which is smaller than the minimum inlet cross-sectional width, and the frame device comprises a flow duct which connects the inlet opening and the outlet opening in terms of flow, wherein the outlet opening is configured to be connected in terms of flow to the inlet nozzle of the fan in the operating state, characterized in that the height of the frame device according to the following formula h≥(D−d)/(2.Math.tan(β)) corresponds to a ratio of a difference of the minimum inlet cross-sectional width and a diameter of the inlet nozzle and double the value of the tangent of the incident flow angle or is greater than the ratio, and a grid element, which is arranged on the inlet opening.

A reciprocating compressor is provided that may include a shell including a vibration absorbing member formed to be wound around an outer circumferential surface or an inner circumferential surface or stacked thereon, so that compressor vibration may be attenuated by frictional contact between the shell and the vibration absorbing member or between layers of the vibration absorbing member. Also a noise insulating layer may be formed between the shell and the vibration absorbing member or between the layers of the vibration absorbing member, so that a magnitude of noise may be reduced as vibration noise passes through the noise insulating layer, whereby vibration noise of the compressor, such as noise of a high frequency band, may be further attenuated by fine vibration.

An aeroderivative gas turbine including an air intake plenum; a compressor with a compressor air intake in fluid communication with the air intake plenum; a combustor; a high pressure turbine; a power turbine. A forced air-stream generator is arranged in fluid communication with the air intake plenum. A shutter arrangement is provided in a combustion-air flow path, arranged and controlled to close the combustion-air flow path for pressurizing said air intake plenum by means of the forced air-stream generator to a pressure sufficient to cause pressurized air to flow through the aeroderivative air turbine.