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%.

The variable vane arm mechanism can have an actuator ring defined around a main axis, a set of vanes having a plurality of vanes circumferentially distributed around the main axis, each vane having a vane axis extending from an inner end to an outer end and being rotatable around the vane axis, each vane having a vane arm, a plurality of pins circumferentially distributed around a main axis, slide blocks engaged with corresponding ones of the pins in a manner to rotate around the pins, and guide slots having a length extending away from corresponding ones of the vane axes, each guide slot slidingly receiving a corresponding slide block.

A vacuum pump comprising: a rotor rotatably mounted within a stator; the rotor comprising a plurality of angled blades arranged along a helical path from an inlet to an outlet; the stator comprising a plurality of perforated elements forming a plurality of perforated discs arranged to intersect the helical path at different axial positions, the perforations allowing gas molecules travelling along the helical path to pass through the perforated elements. Each of the perforated discs comprises an outer curved wall forming an outer circumference of the disc and an inner curved wall forming a portion of an inner circumference of the disc, the inner circumference comprising at least one gap where there is no inner wall.

A gear reduction reduces a speed of a fan rotor relative to a speed of a fan drive turbine. A fan case surrounds the fan rotor. A core engine has a compressor section and includes a low pressure compressor. The fan rotor delivers air into a bypass duct defined between the fan case and the core engine. A rigid connection between the fan case and the core engine includes a plurality of aft connecting members rigidly connected to the fan case, and to the core engine. A plurality of fan exit guide vanes are rigidly connected to the fan case, with the fan exit guide vanes including structural fan exit guide vanes which are rigidly connected to the core engine, and non-structural fan exit guide vanes, and the non-structural fan exit guide vanes being provided with an acoustic feature to reduce noise.

A structure is provided that includes a perforated first skin, a second skin and a core. The core includes a first sidewall, a second sidewall, a first baffle and a second baffle. The core forms a plurality of cavities vertically between the perforated first skin and the second skin. The first baffle is connected to the perforated first skin at a first baffle first end. The first baffle is connected to the second skin at a first baffle second end by a first moveable joint. The second baffle is connected to the perforated first skin at a second baffle first end. The second baffle is connected to the second skin at a second baffle second end. A first of the cavities extends laterally between the first sidewall and the second sidewall. The first cavity extends longitudinally between the first baffle and the second baffle.

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.

There is provided a turbofan engine having: a fan rotatable about an axis within a case; a first acoustic treatment lining a first portion of the case upstream of the fan; and a second acoustic treatment lining a second portion of the case downstream of the fan, the first acoustic treatment having different noise-attenuating characteristics relative to the second acoustic treatment.

An air-sending device includes a housing including an inlet air passage communicating with an air inlet and an outlet air passage communicating with an air outlet, a first partition plate partitioning an interior of the housing into the inlet air passage and the outlet air passage, a bell mouth disposed around an opening defined in the first partition plate, and an impeller disposed over the first partition plate across the bell mouth and having a rotation axis that extends in a direction that intersects the first partition plate. The impeller suctions air into the inlet air passage from the air inlet, and blows out air from the air outlet through the outlet air passage. The inlet air passage guides air from the air inlet to the opening along the first partition plate, and has an air-passage wall.

The purpose of the present invention is to provide a slide component that can exhibit sealing performance and lubricity regardless of rotating direction. A pair of slide components 4, 7 that slide relative to each other have sliding faces S that slide relative to each other, and a sealed fluid-side periphery 16 and a leakage-side periphery 15. The sliding face S of at least one slide component 4 of the pair of slide components 4, 7 includes: a fluid introduction groove 13 in communication with the sealed fluid-side periphery 16; a first pressure generation mechanism 12 of which one end is in communication with the fluid introduction groove 13 and the other end is surrounded by a land portion R1; and a second pressure generation mechanism 11 of which one end is in communication with the leakage-side periphery 15 and the other end is surrounded by an annular land portion R2. The fluid introduction groove 13 and the other end 12e of the first pressure generation mechanism 12 include overlapping portions Lp overlapping circumferentially.

The variable vane arm mechanism can have an actuator ring defined around a main axis, a set of vanes having a plurality of vanes circumferentially distributed around the main axis, each vane having a vane axis extending from an inner end to an outer end and being rotatable around the vane axis, each vane having a vane arm, a plurality of pins circumferentially distributed around a main axis, slide blocks engaged with corresponding ones of the pins in a manner to rotate around the pins, and guide slots having a length extending away from corresponding ones of the vane axes, each guide slot slidingly receiving a corresponding slide block.