Provided is an axial fan including multiple forward-swept blades. An angle of advance of a trailing edge of the forward-swept blade is larger than an angle of advance of a leading edge of the forward-swept blade. An outer portion of the trailing edge, being positioned further in an outer periphery of the trailing edge than an intermediate portion of the trailing edge with respect to a rotary shaft of the axial fan, advances as the trailing edge advances radially outward of a ventilation channel of the axial fan.

A heating, ventilating, and air conditioning (HVAC) system that includes a fan. The fan includes a plurality of blades coupled to a hub. A shroud is coupled to the plurality of blades, wherein the shroud focuses a flow of air along a rotational axis of the fan and reduces the flow of the air radially outward from the fan.

A serial-type diagonal fan assembly having a first fan and at least one second fan is provided. The first fan has a first front fan frame and a first fan wheel. A first hub of the first fan wheel has a radial cross-sectional area increased from a top toward a bottom of the first hub. The second fan has a second front fan frame and a second fan wheel, the second hub of the second fan wheel has an axial cross-sectional area increased from a top to a bottom of the second hub. The first fan and the second fan are arranged in a series. A spoiler is arranged on a second air inlet of the second front fan frame, an outer edge of the spoiler is embedded in a positioning groove of the second front fan frame without protruding from the second front fan frame.

This invention is directed toward a propeller with one of more propeller blades. The propeller blades have some combination of a sharpened leading edge, one or more steps on the upper or lower surface of the propeller blade, and an S shape. The combination of these radical changes from traditional propeller design creates a quieter, more efficient propeller that has applications on any device that uses propellers: from quadcopters and airplanes to boats and fans. Propellers with one, two, three, four, five and more propeller blades are contemplated depending upon the substance the propeller is intended for use in.

An impeller includes: a boss portion driven to rotate by a motor; and a plurality of rotating blades projecting radially from the boss portion in a direction in which a diameter increases from a rotational axis of the motor and generating airflow in an axial direction of the rotational axis. The rotating blades have an S-shaped radial cross section in which an inner peripheral side portion is protruded with respect to the airflow and an outer peripheral side portion is recessed with respect to the airflow, and a recess-shaped portion of the rotating blades has a distribution of a radius of curvature value such that the radius of curvature value gradually decreases toward a blade trailing edge portion from a blade leading edge portion and a rate of the gradual reduction becomes smaller toward the blade trailing edge portion.

A mixed-flow fan includes a base including a bottom channel, an outer cover disposed on the base, a motor disposed on the base, a hub located between the outer case and the motor, and a blade connected to the hub. A main channel is formed between the outer cover and the hub, and is connected to the bottom channel. The main channel extends in the first direction, and the bottom channel extends in the second direction.

A fan wheel has a hub cup and a plurality of blades extending radially outward from an outer wall of the hub cup, which is in particular at least substantially cylindrical. Each blade has a leading edge and a trailing edge, wherein for at least one blade, the progression of a relative position of the blade's leading edge and/or the progression of a relative position of the blade's trailing edge has an aperiodically wave-like shape. There is also described a radiator fan module with a fan wheel of the type described above, and a motor vehicle with such a radiator fan module.

Provided is an air-sending device in which, in blades, an upstream end of a blade outer periphery is more on an upstream side than an upstream end of a blade inner periphery as seen along a rotation axis, and a downstream end of a blade outer periphery is more on a downstream side than a downstream end of the blade inner periphery, and in which, in the blades, when an angle formed by a line segment, which connects a point internally dividing a line segment connecting the downstream end and the upstream end of an outer periphery of the blades along the rotation axis and a point internally dividing a line segment connecting the downstream end and the upstream end of an inner periphery of the blades along the rotation axis at the same ratio to each other, and a reference line is defined as , and a direction inclined toward the downstream side is defined as positive, the angle is changed from negative to positive at a duct portion.

The present disclosure relates to a blade structure and a fan and a generator having the same. In accordance with the present disclosure, there is the effect that can ultimately enhance efficiency of the generator by forming the sweep structure or the spline structure on the blade in the inflow direction side of fetid to reduce a low-speed region around the tip of the blade.

A fan wheel for an axial fan may include a hub and a plurality of blades extending from the hub. Each blade of the plurality of blades may include a blade root coupled to the hub, a blade tip radially distant from the hub, a blade central region lying radially between the blade root and the blade tip, a blade front side facing a pressure side, a blade back side facing a suction side, a transverse profile lying in a cross-sectional plane extending perpendicularly to a radial direction, and a transverse curvature in the transverse profile configured such that the blade front side is curved concavely toward the pressure side and the blade back side is curved convexly toward the suction side. The transverse curvature of at least one blade of the plurality of blades may decrease from the blade central region to the blade tip.