Abstract: An axial flow fan includes a hub driven to rotate and configured to serve as a rotation axis of the axial flow fan and a blade connected to the hub. The blade has a leading edge and a trailing edge. The trailing edge has an indentation indenting toward the leading edge. The indentation narrows from the trailing edge to the leading edge, and has an apex being a point closest to the leading edge from among the points constituting the indentation. The blade has, at the indentation, a maximum thickness portion at which a thickness of the blade is maximum, and which is positioned radially inside of the apex.

Abstract: An axial fan includes a hub having a rotation shaft and configured to be driven to rotate and blades provided to the hub. The blades each have a front edge portion and a rear edge portion. A first blade section is a section of a portion between the front edge portion and the rear edge portion of each of the blades along a direction in which the blades rotate, and the first blade section is an area of each of the blades that is further inward than an outer periphery edge portion that is a most radially outer periphery in each of the blades. In the first blade section, the blades each have a projection portion and a first recess portion. The projection portion projects from a portion of a pressure surface of each of the blades. The first recess portion recedes from a portion of the pressure surface that is between the projection portion and the rear edge portion.

Abstract: An axial-flow fan includes a hub that is to be rotated and defines a rotation axis, and a vane provided on a circumference of the hub. The vane includes a leading edge, a trailing edge, an outer circumferential edge, and an inner circumferential edge. The vane is shaped such that a first line chart in a first diagram includes a downward convex portion that is convex further downward than a first virtual line chart, the first virtual line chart being a linear line connecting a point representing a size of an outlet angle formed at a point of the trailing edge that is at the inner circumferential edge and a point representing a size of the outlet angle formed at a point of the trailing edge that is at the outer circumferential edge.

Abstract: An outdoor unit of an air-conditioning apparatus includes a bell mouth that has a first tapered portion and a straight pipe portion. The first tapered portion has a linking portion that is continuous with a first bent portion and a second bent portion in a region located between the first and second bent portions and that has an inner surface extending linearly. The angle of inclination of the inner surface of the linking portion relative to a direction along an axis of the straight pipe portion is 33 degrees or more. The ratio of the sum of a first length of the first tapered portion and a second length of the straight pipe portion to the total length of the bell mouth is less than 0.76.

Abstract: A propeller fan includes a shaft portion disposed on a rotation axis, and a blade disposed on an outer peripheral side of the shaft portion and including a leading edge and a trailing edge. The blade includes a negative pressure surface in which a plurality of recesses are formed, and the plurality of recesses include a first recess and a second recess disposed on the trailing edge side than the first recess in a circumferential direction about the rotation axis as a center. The first recess has a depth larger than a depth of the second recess.

Abstract: An axial-flow fan includes a hub that is to be rotated and defines a rotation axis, and a vane provided on a circumference of the hub. The vane includes a leading edge, a trailing edge, an outer circumferential edge, and an inner circumferential edge. The vane is shaped such that a first line chart in a first diagram includes a downward convex portion that is convex further downward than a first virtual line chart, the first virtual line chart being a linear line connecting a point representing a size of an outlet angle formed at a point of the trailing edge that is at the inner circumferential edge and a point representing a size of the outlet angle formed at a point of the trailing edge that is at the outer circumferential edge.

Abstract: An outdoor unit for an air-conditioning apparatus includes a bellmouth having a first tapered portion with an inner diameter in upstream of the bellmouth from which air flows being larger than that in downstream of the bellmouth, and a straight pipe portion extending straight from the first tapered portion to the downstream side of airflow. The first tapered portion includes a first bend portion forming an air inlet, a second bend portion connecting to the straight pipe portion and having an inner diameter smaller than that of the first bend portion, and a connection portion connecting to the first bend portion and the second bend portion and having an inner surface extending straight. A length of at least a part of the first tapered portion along an axial direction of the straight pipe portion is larger than the straight pipe portion along the axial direction of the straight pipe portion.

Abstract: An axial flow fan includes a hub and a blade provided around the hub and having a leading edge and a trailing edge. The blade has a thickness portion. The thickness portion includes a first thickness portion located adjacent to the leading edge and a second thickness portion located adjacent to the trailing edge.

Abstract: An outdoor unit of an air-conditioning apparatus includes a bell mouth that has a first tapered portion and a straight pipe portion. The first tapered portion has a linking portion that is continuous with a first bent portion and a second bent portion in a region located between the first and second bent portions and that has an inner surface extending linearly. The angle of inclination of the inner surface of the linking portion relative to a direction along an axis of the straight pipe portion is 33 degrees or more. The ratio of the sum of a first length of the first tapered portion and a second length of the straight pipe portion to the total length of the bell mouth is less than 0.76.

Abstract: A propeller fan includes a shaft portion disposed on a rotation axis, and a blade disposed on an outer peripheral side of the shaft portion and including a leading edge and a trailing edge. The blade includes a negative pressure surface in which a plurality of recesses are formed, and the plurality of recesses include a first recess and a second recess disposed on the trailing edge side than the first recess in a circumferential direction about the rotation axis as a center. The first recess has a depth larger than a depth of the second recess.

Abstract: A propeller fan includes a shaft portion disposed on a rotation axis, and a blade disposed on an outer peripheral side of the shaft portion and including a leading edge and a trailing edge. The blade includes a negative pressure surface in which a plurality of recesses are formed, and the plurality of recesses include a first recess and a second recess disposed on the trailing edge side than the first recess in a circumferential direction about the rotation axis as a center. The first recess has a depth larger than a depth of the second recess.

Abstract: An air-sending device includes a propeller fan, a bell mouth surrounding an outer periphery of the propeller fan, a fan grille disposed downstream of the bell mouth and including a plurality of first crosspieces. An edge of the air outlet of the bell mouth includes a varying portion whose distance from a rotation axis of the propeller fan varies. In a cross-section of any of the plurality of first crosspieces that is perpendicular to a longitudinal direction of the any of the plurality of first crosspieces, a virtual line segment connecting an upstream side end portion and a downstream side end portion is defined as a first virtual line segment. At the portions of the plurality of first crosspieces disposed on the inner circumference side of the varying portion, the angle between a virtual line segment parallel to the rotation axis and the first virtual line segment is changed.

Abstract: An air-sending device includes a fan and a grille provided downstream of the fan in a direction of airflow generated by the fan. The grille includes a first grille that includes a plurality of first bars spaced from each other, and a second grille that includes a plurality of second bars spaced from each other. The plurality of second bars are more densely arranged than the plurality of first bars. The second grille is provided upstream of the first grille in the direction of the airflow generated by the fan, and spaced from the first grille to face the first grille.

Abstract: An axial flow fan includes a hub driven to rotate and configured to serve as a rotation axis of the axial flow fan and a blade connected to the hub. The blade has a leading edge and a trailing edge. The trailing edge has an indentation indenting toward the leading edge. The indentation narrows from the trailing edge to the leading edge, and has an apex being a point closest to the leading edge from among the points constituting the indentation. The blade has, at the indentation, a maximum thickness portion at which a thickness of the blade is maximum, and which is positioned radially inside of the apex.

Abstract: An axial fan includes a hub having a rotation shaft and configured to be driven to rotate and blades provided to the hub. The blades each have a front edge portion and a rear edge portion. A first blade section is a section of a portion between the front edge portion and the rear edge portion of each of the blades along a direction in which the blades rotate, and the first blade section is an area of each of the blades that is further inward than an outer periphery edge portion that is a most radially outer periphery in each of the blades. In the first blade section, the blades each have a projection portion and a first recess portion. The projection portion projects from a portion of a pressure surface of each of the blades. The first recess portion recedes from a portion of the pressure surface that is between the projection portion and the rear edge portion.

Abstract: An axial fan includes a hub and blades. The hub has a rotating shaft, and is configured to be driven to rotate. The blades are provided to the hub, and each have a front edge portion and a rear edge portion. In a state in which the blades rotate to generate an airflow, the front edge portion is placed most upstream in the airflow, and the rear edge portion is placed most downstream in the airflow. In a shape of the blades rotated and projected onto a meridian plane that covers shapes of the blades and a shape of the rotating shaft, the front edge portion has an outline represented by a front-edge projected portion having a first recess portion formed in a recessed shape that recedes upstream in the airflow, the rear edge portion has an outline represented by a rear-edge projected portion having a second recess portion formed in a recessed shape that recedes upstream in the airflow, and the first recess portion has at least a portion that is formed further radially inside than is the second recess portion.

Abstract: A propeller fan according to an embodiment of the present invention includes a shaft provided a rotation axis of the propeller fan, and a blade provided on an outer peripheral side of the shaft. The blade has a trailing edge on a rear side of the blade in a rotation direction of the propeller fan. The trailing edge includes a first trailing edge located on an innermost side of the trailing edge, and a second trailing edge adjacent to and outward of the first trailing edge. Where an innermost point of the first trailing edge is a first connection point, a connection point between the first trailing edge and the second trailing edge is a second connection point, and a straight line that extends through the rotation axis and the first connection point is a reference line, the second connection point is located forward of the reference line in the rotation direction, or located on the reference line, and the second trailing edge is located rearward of the second connection point in the rotation direction.

Abstract: A propeller fan includes a cylindrical shaft portion provided on a rotation axis of the propeller fan; a plurality of blades provided on an outer peripheral side of the shaft portion; a connection portion provided adjacent to the shaft portion and connecting two of the plurality of blades that are adjacent to each other in a circumferential direction of the propeller fan; a first rib provided on at least one of a pressure surface of each of the plurality of blades and a surface of part of the connection portion that is located on a downstream side in the flow of air, and a second rib provided on at least one of a negative-pressure surface of each of the plurality of blades and a surface of part of the connection portion that is located on an upstream side in the flow of air.

Abstract: An axial-flow fan includes an impeller including plural blades fixed to an outer peripheral portion of the hub and each surrounded by an inner peripheral edge, an outer peripheral edge, a leading edge, and a trailing edge. The leading edge is forward-curved in a rotational direction with an angle increasing to outer periphery of the impeller and runs toward an outer periphery up to point A, the trailing edge is forward-curved in the rotational direction and runs toward the outer periphery up to point D, recedes in the rotational direction of the impeller as the trailing edge runs toward the outer periphery up to point A? located closer to the outer periphery than point D is to the outer periphery, advances in the rotational direction of the impeller in a region between point A? and point B?, and reflexed at point D and point A?.

Abstract: In a propeller fan, an air-sending device and an air-conditioning apparatus, between a leading edge and trailing edge of each of blades, a starting point at which the first one of first maximum points is located is closer to the leading edge than a starting point at which the first one of second maximum points are located, distances L1 between minimum points and the first maximum points vary such that the distance L1 increases from the starting point at which the first one of the first maximum points is located, toward the trailing edge, and distances L2 between a connection point and the second maximum points vary in accordance with the position of each of the second maximum points such that the distance L2 increases from the starting point at which the first one of the second maximum points is located, toward the trailing edge.