The invention relates to turbo molecular pumps enabling high pumping speed. The disclosure suggests using one or more cage-like rotor stages to optimize pumping speed on vacuum systems with low gas flows and low ultimate pressures. This allows for a smaller motor as well as smaller overall form factor and makes it well suited, in particular, for compact mass spectrometers and desk-top mass spectrometers.

Provided is a radial diffuser that includes a housing, a plurality of diffuser vanes, and a plurality of deswirl vanes and at least one vane extension providing a service routing. Each of the vane extensions is disposed after a radial section and may extend into or through a transition and into the deswirl cascade. At least a portion of the vane extensions include a service passage extending therethrough. Each service passage is configured to allow a service conduit to extend therethrough without adversely crossing either a diffusion flow passage or a transition flow passage.

An electronic device with a heat-dissipating function and a liquid-cooling radiator module are provided. The electronic device includes a first circuit board, a second circuit board and a liquid-cooling radiator module. The second circuit board is mounted on the first circuit board. The liquid-cooling radiator module is attached on the second circuit board and in thermal contact with an electronic component of the second circuit board. The liquid-cooling radiator module includes plural airflow channels and a fan. The plural airflow channels are in parallel with the second circuit board. The fan produces airflow toward the plural airflow channel. After the airflow passes through the plural airflow channels, the airflow is outputted in a direction parallel with the second circuit board. Since the airflow is not obstructed by the adjacent function circuit boards, the heat-dissipating efficiency is enhanced.

A wind wheel including a first air plate, a second air plate, and a plurality of blades disposed between the first air plate and the second air plate. The first air plate includes a central part and an air inlet disposed in the central part; each two adjacent blades form an air duct. The plurality of blades each includes an inlet section next to the air inlet, an intermediate section, and an outlet section. The thickness of the intermediate section is greater than the thickness of the inlet section and the thickness of the outlet section.

A gas turbine engine includes a combustor having a combustor air inlet, an axial-centrifugal compressor, a shroud, a secondary flow duct, and a valve. The shroud surrounds at least a portion of the axial-centrifugal compressor and has a surge bleed plenum defined therein that is in fluid communication with, and receives compressed air from, the axial compressor outlet. The secondary airflow duct has a duct inlet that is in fluid communication with the surge bleed plenum, and a duct outlet that is in fluid communication with the combustor air inlet. The valve is mounted on the secondary airflow duct and is movable between a closed position, in which the secondary airflow duct does not provide fluid communication between the surge bleed plenum and the combustor air inlet, and an open position, in which the secondary airflow duct provides fluid communication between the surge bleed plenum and the combustor air inlet.

A compressor for a gas turbine engine is disclosed. The compressor includes a first compression stage mounted for rotation about a central axis that includes a plurality of first-stage blades. The compressor also includes a second compression stage mounted along the central axis aft of the first compression stage to receive air compressed by the first compression stage. The second compression stage includes a plurality of second-stage blades.

A refrigerant compressor assembly (20A, 20B, 20C) includes an axial compressor (22B, 22C, 22) that includes at least one axial stage. A downstream compressor (24) is located fluidly downstream of the axial compressor (22B, 22C, 22) and includes one of a mixed-flow impeller (46) or a centrifugal impeller (96). At least one motor (26, 27) is in driving engagement with at least one of the axial compressor (22B, 22C, 22) and the downstream compressor (24).

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

A centrifugal fan with axial-flow wind includes a centrifugal fan wheel and a cover shell. The centrifugal fan wheel has a rotating core structure and a plurality of centrifugal vanes arranged around the rotating core structure; a circular wind guide surface is disposed on an internal side of the cover shell and around the rotating core structure and covered onto the centrifugal vanes, such that the circular wind guide surface can change a centrifugal airflow at the external periphery of the centrifugal vane into an axial-flow airflow.