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 ceiling fan assembly having a motor with a rotor and a stator, at least one blade operably coupled to the stator, a motor shaft extending from the stator and having an internal wire passage and a wire opening in a side of the motor shaft, with the wire opening providing access to the internal wire passage, a control mounting plate having a motor shaft opening through which the motor shaft extends and an electronic control unit carried by a side of the control mounting plate.

System for selectively contacting a cleaning composition with a surface of a turbine engine component is presented. The system includes a cleaning apparatus and a manifold assembly. The cleaning apparatus includes an upper portion and a lower portion defining a cleaning chamber configured to allow selective contact between the cleaning composition and a surface of the first portion of the turbine engine component. The upper portion includes a plurality of fill holes in fluid communication with the cleaning chamber, and the lower portion includes a plurality of drain holes in fluid communication with the cleaning chamber. The manifold assembly is configured to selectively circulate the cleaning composition from a reservoir to the cleaning chamber via the plurality of fill holes, and recirculate the cleaning composition from the cleaning chamber to the reservoir via the plurality of drain holes. Methods for selectively cleaning a turbine engine component is also presented.

A vacuum pump, vacuum pump set and method for evacuating a semiconductor processing chamber is disclosed. The vacuum pump is configured for mounting to a semiconductor processing chamber to evacuate the chamber to pressures between 1 mbar and 5×10.sup.−2 mbar. The vacuum pump comprises: a rotor rotatably mounted within a stator. The rotor comprises a plurality of angled blades arranged along a helical path from an inlet to an outlet. The stator comprises a plurality of perforated elements arranged to intersect the helical path, the perforations allowing gas molecules travelling along the helical path to pass through the perforated elements. The rotor mounted on a magnetically levitated bearing; and the perforated elements located towards an inlet of the vacuum pump comprise a transparency of more than 40% and the perforated elements located towards an outlet of the vacuum pump comprise a transparency of more than 30%.

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 fan blade device includes a plurality of main fan blades and extension fan blades. Each main fan blade includes a main fan blade body arranged obliquely, a plurality of first protrusions, and at least one engaging groove. Each extension fan blade includes an extension fan blade body arranged obliquely and having a top surface that is contiguously flush with a top surface of the main fan blade body of a respective main fan blade, a plurality of second protrusions respectively abutting against the first protrusions of the respective main fan blade, and at least one engaging piece engaging the at least one engaging groove of the respective main fan blade.

A blade pivot of adjustable orientation for a turbomachine fan hub includes: a block having a retaining device configured to retain a fan blade root and a coupling device for the transmission of a torque; a ball type rolling bearing for taking up centrifugal forces having an inner ring; a clamping nut screwed onto an external thread of the block in order to clamp the inner ring of the ball type rolling bearing for taking up centrifugal forces to the block; a rolling bearing for taking up transverse forces; a pitch setting transmission ring positioned inside the inner radial end of the block and equipped with a coupling device cooperating with the coupling device of the block, and a device for locking the pitch setting transmission ring on the block.

A ceiling fan mount assembly having a downrod assembly with a downrod and a motor assembly comprising motor and including a motor shaft. The ceiling fan mount assembly further includes a downrod plate coupled to the downrod and a shaft coupler coupled to the motor shaft and coupled to the downrod plate, whereby coupling the downrod plate to the shaft coupler suspends the motor from the downrod.

A convertible ducted fan engine and mounting system. The convertible ducted fan engine has a shroud encircling a mechanical fan. The convertible ducted fan engine includes a fluid-propulsion configuration in which the mechanical fan rotates freely with respect to the shroud to produce thrust through fluid flow, and a drive-wheel configuration in which the shroud rotates about the rotational axis.

In an axial flow fan according to the present invention, a plurality of blades rotate about a rotation axis of the blades to convey a fluid. In the axial flow fan, the plurality of blades each have a leading edge at a leading side in a rotational direction, a trailing edge at a trailing side in the rotational direction, and an outer peripheral edge connecting the leading edge and the trailing edge. The leading edge of one of the plurality of blades and the trailing edge of another blade adjacent to the leading edge of the blade in the rotational direction are connected by a plate-shaped connection portion. The plurality of blades each have at least one plate-shaped reinforcement rib extending from a periphery of the rotation axis toward the outer peripheral edge of the blade.