This disclosure is related to a thin type counter-rotating axial air moving device. The ratio of the front hub diameter to the front blade diameter is about 0.3 to about 0.85. The front average pitch angle of the front blades is greater than about 46 degrees. The ratio of the rear hub diameter to the rear blade diameter is about 0.3 to about 0.85. The rear average pitch angle of the rear blades is less than about 38 degrees. The ratio of the total thickness to the greater one between the front blade diameter and the rear blade diameter is less than or equal to about 0.75.

A refractory metal core (RMC) finishing method according to an exemplary aspect of the present disclosure includes, among other things, performing a plurality of finishing operations on a plurality of RMC samples, analyzing one or more properties of at least a portion of the plurality of RMC samples and selecting a combination of finishing operations for generating an RMC having desirable properties for manufacturing a part free from defects.

A vacuum pump includes a rotor provided with a plurality of rotor blades and a rotor cylinder portion, a driving portion, a bearing, stator blades, a thread groove stator that is disposed downstream of the stator blades and has an inner peripheral surface facing an outer peripheral surface of the rotor cylinder portion, and a heat insulating wall disposed downstream of the thread groove. The heat insulating wall includes a ring-shaped annular portion, and a substantially cylindrical wall portion extending from an inner portion of the annular portion in the radial direction to the upstream side and forming a flow path on the outer peripheral surface side. A first corner portion is formed between an upstream-side surface of the annular portion and the outer peripheral surface of the wall portion, the first corner portion being formed in an arc shape.

A concentrator nozzle attachment for a blower device is disclosed that increases the airflow velocity of the blower without sacrificing the field of the jetting air. The concentrator nozzle is formed of an outer ring with a centrally located guide surface and is placed at the exit of an air tube. As the air exits the air tube, it's forced to flow around the guide surface, thus increasing its velocity. The attachment is secured to the end of the air tube and so does not alter the outer diameter through which the air exits. In this way, air velocity is increased without reducing its effectiveness.

An air cleaner includes a fan that is configured to suck air in an axial direction and discharge air between the axial direction and a radial direction. The air cleaner further includes a fan motor that is configured to rotate the fan. The air cleaner further includes an air guide unit that includes a cylindrical outer wall and an inner wall that is located in a center portion of the outer wall and that defines a space that is configured to receive the fan motor. The air guide unit defines an annular air flow path that is configured to receive air discharged by the fan and that is defined by an inner circumferential surface of the outer wall and an outer circumferential surface of the inner wall. The air guide unit further includes a plurality of guide ribs. The air guide unit further includes a plurality of flow guide protrusions.

A fan, and a silencer that silences a sound generated by the fan are provided, in which the silencer has a resonance characteristic, the silencer is disposed at a position connected to a sound field space of the sound generated by the fan, and a sum of an absorbance and a reflectivity of the silencer at a resonance frequency is 10% to 43% and a standardized half-width of the silencer is more than 0.05 and 0.25 or less.

An axial fan that includes a casing having an inner space that penetrates in one direction, and a rotor blade disposed in the inner space of the casing, and a silencer that is disposed at a position connected to the inner space of the axial fan are provided, in which the axial fan has a sound pressure distribution having a position at which a sound pressure is high and a position at which the sound pressure is low in a circumferential direction in the inner space during driving, and the silencer is disposed at the position of the axial fan in the circumferential direction at which the sound pressure is high and is not disposed at the position at which the sound pressure is low.

A turbomachine compressor module comprising an annular array of struts provided with pivotable flaps. The struts can define inter-strut spaces between two circumferentially adjacent struts, and variably oriented stator vanes are disposed at least partially in the inter-strut spaces. Also, a turbomachine having such a module and a row of rotor blades directly downstream of the module.

A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.

An assembly for the compressor stator of a turbomachine. The assembly comprises: a shroud, in various instances an inner shroud, that is axially divided into two parts; a pocket formed in the shroud; a bearing located in the pocket; and an orientable vane pivotably mounted in the bearing about a pivot axis. The shroud comprises an axial interface separating the parts that is axially offset from the pivot axis of the orientable vane. The invention also provides a process for assembling the assembly.