An airflow device including: (i) airflow generating means for generating first and second streams of air; (ii) first and second Coanda surfaces; (iii) means for directing the first and second streams of air over first and second Coanda surfaces respectively; and wherein (iv) the first stream of air leaving the first Coanda surface is directed so as to pass over the second Coanda surface.

A compressor, in particular, of a turbomachine. The compressor comprises at least one blade ring and at least two ring segments, wherein the blade ring has at least two equally large ring segments. The compressor also comprises blades, which are arranged in the ring segments of the blade ring in such a way that a first number of blades is arranged in a first ring segment and a second number of blades is arranged in a second ring segment. The first number of blades is not equal to the second number of blades.

The driving device for providing assisted ventilation comprises an air inlet (15), an impeller (7) provided with blades (8) rotatably driven by a motor (6), and an air outlet (5), the rotation of said impeller (7) being caused by the air circulation through a duct (4) from the air inlet (15) to the air outlet (5), wherein said blades (8) of the impeller (7) are flexible, vibrating at least one of its ends by the thrust caused by said circulating air.

It reduces noise to improve user comfort.

An axial flow fan includes a hub and a plurality of fan sets disposed around the hub. The hub rotates around a center axis and has a positive pressure side and a negative pressure side opposite to each other. Each of the fan sets includes at least two blades, and each blade has a wind inlet end, a wind outlet end opposite to the wind inlet end, a negative pressure surface, and a positive pressure surface opposite to the negative pressure surface. The wind outlet end of one of the adjacent two blades corresponds to the wind inlet end of the other one of the adjacent two blades. A gap is provided between the negative pressure surface of one of the adjacent two blades and the positive pressure surface of the other one of the adjacent two blades.

A fan impeller structure includes a hub and a blade set. The hub has a top wall and a circumferential wall extending from a circumference of the top wall. The blade set has multiple upper blades and multiple lower blades. The upper and lower blades are alternately arranged on the circumferential wall. Each upper and lower blade respectively has a first windward face and a second windward face which is extending in a different direction from the first windward face. The first windward face is disposed in such a direction as to face the rear edge of the lower blade on the lower side, while the second windward face is disposed in such a direction as to face the rear edge of the upper blade on the upper side.

An impeller with impeller blades arranged around a rotational axis of the impeller. Integral, seamless, and notch-free transitions are formed into a disc body on at least one of their two axial sides. The disc body connects the impeller blades in the circumferential direction around the rotational axis. Covering portions, between the impeller blades, determine the flow channels of the impeller.

In accordance with one aspect the present invention may comprise a regenerative blower comprising: a housing, a first port and second port in the housing, an airflow channel extending between the first and second ports for airflow between the ports, an impeller rotatable in an impeller channel to promote airflow in the airflow channel from the first port to the second port, a motor to drive the impeller, and an interrupter between the first and second ports to limit airflow from the second port to the first port.

A fan includes a fan impeller. The fan impeller includes an inner frame, an outer frame and a disturbing structure. The inner frame rotates along a rotation axis. The outer frame is disposed around the inner frame. The blades are disposed between the inner frame and the outer frame and arranged radially. The disturbing structure has a plurality of protrusion columns disposed on the outer frame, and the protrusion columns are arranged surrounding the blades. The protrusion columns are provided to generate vortexes in the flow field for disturbing the flow as to reduce noise, and the wind pressure can be increased to obtain better operating characteristics.

A fan includes a hub and a blade assembly. The hub has a central portion and an extension portion. The extension portion is extended outwardly from a peripheral edge of the central portion. The blade assembly includes a plurality of blades. Each blade has a leading edge, each of the leading edges is an end point of each blade that is most close to the central portion. The blades are disposed around the hub. At least a part of the leading edges of the blades are connected to the extension portion, and distances between a center of the central portion and the leading edges of at least two blades are different. Therefore, the factors of fan and the quality of voice could be enhanced, and the multi-frequencies noise could be avoided during operation.

A tray-type fan impeller structure includes a plate body annularly disposed around a hub. The plate body has a connection side connected with the hub and a free side extending in a direction away from the hub. Multiple boss bodies are arranged on a top face or the top face and a bottom face of the plate body at intervals. By means of the boss bodies, the periodical noise problem caused by the conventional blades is improved.