Provided is a vacuum pump regarding which compression can be improved at low costs.

Included is a plurality of Siegbahn exhaust mechanisms in which a helical groove is provided to a stator disc. The Siegbahn exhaust mechanisms are provided on both faces of an upstream side and a downstream side of the stator disc. An end portion of the helical groove provided on the upstream side and a start portion of the helical groove provided on the downstream side are situated at least partially overlapping in a circumferential direction. A width of a channel of a switchback portion of the upstream side and the downstream side is equivalent or less than a depth of a channel of the Siegbahn exhaust mechanisms.

A gas turbine engine includes a fan section, a compressor section, and a turbine section. The fan section has a plurality of vane assemblies spaced circumferentially about an engine axis. The vane assemblies each include an airfoil extending between a leading edge and a trailing edge, a control rod extending through the airfoil, and a mechanism driven by the control rod to change the shape of the airfoil. A vane system for a gas turbine engine is also disclosed.

An electric motor assembly includes an electric motor, a fan assembly coupled to the electric motor and configured to rotate therewith about an axis. The bower assembly also includes a shroud coupled to the electric motor and extending about the fan assembly. The shroud includes a central hub coupled to the electric motor, an inlet ring, and a plurality of arms extending between the central hub and the inlet ring. Each arm of the plurality of arms includes a curved radial portion extending from the central hub and a planar axial portion extending from the radial portion to the inlet ring.

A two-way flow control device including: a housing defining a first opening interface and a second opening interface, a rotor having a plurality of blades, each blade controllable to be angled in a range of positive and negative blade angles to generate respective positive and negative flows between the first opening interface and the second opening interface, first stator vanes mounted to the housing between the blades and the first opening interface, each including a respective stator vane slope having a stator vane angle which are collectively positive or negative angled; second stator vanes mounted to the housing between the blades and the second opening interface, each including a respective stator vane slope having a stator vane angle which are collectively opposite angled to the stator vane angles of the first stator vanes, the second stator vanes mounted to be circumferentially offset with respect to the first stator vanes.

In accordance with some embodiments of the present disclosure, a pressure recovery axial compressor blade is provided. The blade may comprise a high pressure surface and a low pressure surface connected at a leading edge and a trailing edge of the blade. Both the high and low pressure surfaces extend span wise from a first end to a second end. At least one of the high and low pressure surfaces has a finite discontinuity in curvature at an intermediate position along the chord of the blade.

A blade including at least one web and a vane having a leading edge and a trailing edge, wherein, for at least one aerofoil of the vane in the vicinity of the web, a maximum sweep angle associated with a position along a chord of the aerofoil extending from the leading edge to the trailing edge of the vane corresponding to a relative chord length of at least 50%.

An air moving device includes a housing member, an impeller assembly, and a nozzle assembly. The nozzle assembly can include one or more angled vanes set an angle with respect to a central axis of the air moving device. The air moving device can output a column of moving air having an oblong and/or rectangular cross-section. A dispersion pattern of the column of moving air upon the floor of an enclosure in which the air moving device is installed can have an oblong and/or rectangular shape. The dimensions of the dispersion pattern may be varied by moving the air moving device toward or away from the floor, and/or by changing the angles of the stator vanes within the nozzle assembly.

Provided is an axial fan including: a rotor blade having a rotation axis along an air-blowing direction; and a casing, wherein the casing includes: an outer frame portion housing the rotor blade; a cylindrical base portion located on the rotation axis; and a fixed blade provided between an inner peripheral surface of the outer frame portion and an outer peripheral surface of the base portion and downstream of the rotor blade in the air-blowing direction, the fixed blade includes a wind receiving surface, and the wind receiving surface in a first cross section, along the air-blowing direction, of the fixed blade has a smaller blade curvature than the wind receiving surface in a second cross section of the fixed blade along a cutting plane line at a position moved in a rotation direction of the rotor blade from a cutting plane line of the first cross section.

The invention relates to a profiled structure elongated in a direction in which the structure has a length exposed to an airflow and transversely to which the structure has a leading edge and/or a trailing edge, at least one of which is profiled and has, along said direction of elongation, geometric serration patterns defined by a succession of peaks and troughs. Along the profiled leading edge and/or trailing edge, the serration patterns have a geometric pattern that is repeated in the direction of elongation, the shape of which is stretched and/or contracted transversely to the direction of elongation and/or in the direction of elongation.

A turbomachine airfoil element includes an airfoil that has pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 3.46-3.76 inch (87.8-95.5 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 1.98-2.28 inch (50.2-57.8 mm). The airfoil element includes at least one of a first mode with a frequency of 1056 ± 10% Hz and a second mode with a frequency of 1582 ± 10% Hz.