Mitsubishi Electric Corporation

Toshikatsu Arai

Hitoshi Kikuchi

Tatsushi Murakami

Tomoya Fukui

Tsutomu Takahashi

Hiromichi Aoki

Chikage Kadoi

Yuuya Kousaka

An air-sending device includes a propeller fan to rotate about a rotational axis, and a ducted bell mouth surrounding an outboard area of the propeller fan. The propeller fan includes a plurality of blades. Each of the blades includes, in its outboard portion, a reflexed part bent upstream of an airflow that is generated in the direction of the rotational axis by rotation of the propeller fan. In the propeller fan, within an area that is closer to the trailing edge than is the near mid-chord area, the propeller fan is inclined downstream of the airflow from the inboard edge to the reflexed part. In at least a portion of an area where the cylindrical part of the bell mouth and the outboard edge of each blade face each, the reflexed part has a reflex angle of greater than or equal to 90 degrees.

Air-sending device

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.

Impeller and axial flow fan

An axial flow fan has a boss portion rotationally driven by a motor; a plurality of rotary blades extending radially from a periphery of the boss portion and configured to force air to flow in a direction of a rotation axis of the motor; and a bellmouth accommodating the plurality of rotary blades, the bellmouth comprising a suction-side round portion having a curved surface expanded in a radial direction of the bellmouth, and a discharge-side round portion having a curved surface expanded in the radial direction of the bellmouth, the plurality of rotary blades each being entirely inclined to have an outer peripheral portion in a downstream side in an airflow direction, entirety of the outer peripheral portion being located on the downstream side in the air flow direction with respect to the suction-side round portion.

Axial flow fan

An axial flow fan improves air capacity and static pressure characteristics, and can ease stress at a leading edge portion of a blade base, even when a shape for noise reduction is adopted. An axial flow fan includes a boss portion and rotor blades. A rotor blade is segmented into a first area extending from the boss portion toward the outer peripheral side, and a second area connected to the first area and extending from the first area to the outermost periphery of the rotor blade. The distribution of a forward sweep angle varies quadratically in the first area, and the maximum forward sweep angle in the first area is not larger than the forward sweep angle in the second area. The distribution of chord-pitch ratio varies in a curved manner from the base as the minimum value in the first area, and is linear in the second area.

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Tokyo, Japan

Toshikatsu Arai