A diffuser for a centrifugal compressor and a centrifugal compressor having the same. The diffuser (100) comprises a drive component (110), a transmission assembly (120), an adjustment assembly (130), a spool valve assembly (140) and a rear wall (150); wherein the transmission assembly is used for transmitting power produced by the drive component to the adjustment assembly, the adjustment assembly is capable of circumferentially reciprocating with respect to the rear wall and driving the spool valve assembly to reciprocate axially; and wherein a rolling element (160) is provided between the adjustment assembly and the rear wall. Intervention of a mechanism for adjusting a flow passage width is better achieved by such an arrangement in combination with an existing configuration of the diffuser; and a low-friction fit between the adjustment assembly and the rear wall is achieved by the rolling element.

A turbine comprises a housing defining a turbine chamber with a turbine wheel supported for rotation about an axis. The housing further defines first and second inlet volutes which each spiral radially inwards and extend from a respective inlet to adjoin the turbine chamber and a volute tongue for each inlet volute. The tongue of the first volute radially separating a downstream portion of the first volute adjacent the chamber from an upstream portion of the first volute adjacent said inlet of the first volute, and the tongue of the second volute radially separating a downstream portion of the second volute adjacent the chamber from an upstream portion of the second volute adjacent said inlet of the second volute. The tongues having a turbine scroll tongue overlap which is substantially zero or positive; and the first volute tongue is angularly spaced about the axis from the second volute tongue.

A closed system that captures energy derived from the head differential rather than open-water flows velocities while reducing potential environmental damages and costly maintenance due to bio-fouling. This energy density available in a tidal range is increased substantially via convergent nozzles to produce an optimal speed for power generations with the turbine sections, thereby significantly increasing the tidal energy captured by this system, even at sites where tidal energy is low (e.g., small to medium tide ranges, such as found along the East and Gulf Coasts of the United States).

An assembly of a first element with a second element includes an elongate thin lip belonging to the second element being inserted in an elongate narrow slot formed by three sides of an elongate flat plate fixed in parallel to a flat wall of the first element. At least one element forming a guide is secured to a long side of the elongate flat plate forming an edge of the slot. The element forming a guide includes a sliding surface extending in the continuation of the elongate flat plate and diverging from the flat wall away from the first element. The at least one element forming a guide cooperates with the lip so that the insertion of the lip into the slot begins with the sliding of the lip on the sliding surface and then continues as the lip advances, with progressive insertion of the lip into the slot.

A turbocharger device includes an annular spring element for axially clamping a guide device of a variable turbine geometry against a turbine housing. The annular spring element rests radially outwardly on the bearing housing and radially inwardly on a component of the guide device. The spring element has an annular radial outer flange in contact with the bearing housing, and a plurality of tabs which extend from the outer flange radially inwardly in the direction of the guide device and come into contact with a component thereof. An annular spring element for such a turbocharger is also provided.

A closed system that captures energy derived from the head differential rather than open-water flows velocities while reducing potential environmental damages and costly maintenance due to bio-fouling. This energy density available in a tidal range is increased substantially via convergent nozzles to produce an optimal speed for power generations with the turbine sections, thereby significantly increasing the tidal energy captured by this system, even at sites where tidal energy is low (e.g., small to medium tide ranges, such as found along the East and Gulf Coasts of the United States).

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.

A negative pressure air suction type fluid-driven power machine comprises a fluid pressure accumulation bin, a necking port, a flow inlet, a flow guiding cover, a fluid-inlet flow guiding cover, turbine driving blades, a turbine housing, a turbine shaft, a turbine bracket, nozzles surrounding peripheries of the turbine driving blades, a turbine fluid outlet, a fluid negative-pressure flow guiding cover, a fluid negative-pressure outlet, an external driving fluid inlet, an external driving fluid flow guiding cover, and nozzles. The negative pressure air suction type fluid-driven power machine is formed using a gravity acceleration fluid generated by a fluid flowing to a direction opposite to operation of an object as a main driving power source and using a fluid air suction phenomenon as an auxiliary power source, and can replace some effects of steam engines, internal combustion engines, motors and the like.

A variable-geometry ducted fan may include an air duct having a longitudinal axis, the air duct including an inlet of the variable-geometry ducted fan, a fan rotatably mounted within the air duct downstream from the inlet, the fan including fan blades defining a fan area, and a variable-area nozzle coupled to the air duct downstream from the fan, the variable-area nozzle including an exhaust of the variable-geometry ducted fan having a variable exhaust area.

Disclosed herein are linear hydraulic turbines in which the linear machine converts the majority of available energy in the flowing water into useful torque directly in the runner, leaving the outflow with very little velocity.