A closed impeller includes an impeller body including a plurality of blade portions, and a shroud fitted on the impeller body. The shroud is press formed into a curved shape along end portions of the blade portions. The shroud includes a plurality of protrusions protruding from a surface facing the impeller body and extending, and curved, along the end portions of the plurality of blade portions. An amount of protrusion of each of the protrusions is less than a thickness of the shroud. A brazing material is provided at least on end portions of the protrusions.

The present invention relates to a blower. A blower according to an embodiment of the present invention comprises: a lower case having a suction hole in through which air flow; an upper case which is disposed at the upper side of the lower case and which has a discharge port through which the air is discharged; a fan motor for providing rotating force; and a fan disposed inside the lower case and fixed to a motor shaft of the fan motor, wherein the fan includes: a hub having an outer surface, which is extended to be inclined at a first angle with respect to the motor shaft; a plurality of blades coupled to the hub; and a shroud having an inner surface which is extended to be inclined, with respect to the motor shaft, at a second angle that is greater than the first angle, and which faces the outer surface of the hub with respect to the blade, and thus the air discharged from the fan can change into an ascending current.

Methods and apparatus for blowing out birthday candles are presented. The apparatus may include a rotor comprising at least two blades and attachable to a wind-up launcher for imparting a rotational impulse to the rotor. Each blade of the rotor may include a blade scoop extending from a central hub of the rotor to an outer safety ring positioned around an outer circumference of the rotor and coupled to each of the central hub and the outer safety ring. The blade scoop may have a convex shaped leading edge. The blade may also include a blade overhang for pushing air from the blade scoop out from the rotor. The blade overhang may have a trailing edge positioned below the central hub, with a portion of the blade forming the trailing edge having a tangent that is angled between 30 and 60 degrees below a plane of the outer safety ring.

The present disclosure is of a jet pump system, and reverse power generation system and other desirable applications consisting of an impeller with inlet vortex vanes and outlet vortex vanes. The inlet vortex vane induces rotational movement on mass entering the impeller inlet. The outlet vortex vanes remove swirl from mass exiting the impeller outlet. Embodiments include a jet pump system involving a pulley and belt which can allow for obstruction free movement of mass. In another embodiment the impeller is connected via an electromagnetic connection. In another embodiment the impeller acts as a rim-driven generator of electrical power. In another embodiment the drive pulley is a centrifugal clutch or uses a chain sprocket or tandem jet system in series.

A fan includes a hub configured to be driven by motor to rotate about a fan rotational axis, blades that protrude radially from the hub and a band that surrounds the rotational axis and connects the tips of the blades. The band includes structurally-reinforcing ribs that protrude from the hub-facing surface of the band. A rib is disposed between respective tips of each pair of adjacent blades. Each rib bridges a knit-line of the band, and has a circumferential dimension that is at least 40 percent of a distance between the respective tips of the adjacent blades.

A fan includes a hub configured to be driven by motor to rotate about a fan rotational axis, blades that protrude radially from the hub and a band that surrounds the rotational axis and connects the tips of the blades. The band includes structurally-reinforcing thickened regions that protrude from outer surface of the band in a direction away from the hub. A thickened region is disposed between respective tips of each pair of adjacent blades. Each thickened portion bridges a knit-line of the band.

A fan blade assembly using air bearing features to reduce frictional losses, reduce physical wear and tear, and allow for faster acceleration of the fan blade within the assembly is disclosed. A fan blade housing incorporates inlets for pressurized air which create a pressurized area between the fan blade and the housing. The pressurized area functions as an air bearing interface and the fan blade is kept at a controlled distance from the fan blade housing as it spins. In an alternate embodiment, the fan blade assembly has pass-through inlets which use air pressure generated by the fan itself as it spins to provide the pressurized air for the pressurized area.

A fan cowling assembly for mounting to a working machine, the fan cowling assembly including: a support for mounting to a working machine, the support defining an opening for receiving a plurality of rotatable blades of a fan, in use; a fan ring mounted to the support by a ring mounting arrangement, the fan ring being arranged to surround the plurality of rotatable blades, in use; wherein the ring mounting arrangement is configured such that the fan ring is moveable relative to the support when mounted thereto.

A counter-rotating fan, comprising two impellers and a motor. The motor is used for driving the two impellers to rotate. The two impellers are axially spaced apart from each other, and are divided into a first-stage impeller and a second-stage impeller. When the counter-rotating fan operates, airflow is blown to the direction of the second-stage impeller by means of the first-stage impeller. At least one impeller has turns of blades arranged in the radial direction of the impeller. Blades of each turn are spaced apart from each other around a hub of the impeller, and a spacer ring is connected between two adjacent turns of blades. The counter-rotating fan is stable in rotation and good in cooling effect, it is not easy to deform, and the wind is strong in the center.

A counter-rotating axial air moving device is disclosed. A front rotor includes a front hub, front first blades, a front annular sheet, front second blades, a front first radial zone and a front second radial zone. A rear rotor is disposed on a rear side of the front rotor and includes a rear hub, rear first blades, a rear annular sheet, rear second blades, a rear first radial zone and a rear second radial zone. A better performance is achieved by optimal matching designs of each radial partition, and the deterioration of vibration and noise is avoided.