Abstract: A centrifugal air-sending device includes an impeller that includes blades and a scroll casing that includes a bell mouth. Each of the blades is formed such that a vane length of the blade decreases from a portion of the blade close to a main plate toward a portion of the blade close to a side plate. Each of the blades includes a first vane portion that includes an outer circumferential end and that is connected to the side plate, and a second vane portion that includes an inner circumferential end, a turbo vane that forms a backward-curved blade, and a portion close to the main plate in an axial direction of a rotation axis that protrudes further inward than the bell mouth. The blades are formed such that a blade outer diameter is larger than an inner diameter of the bell mouth.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: In a centrifugal air-sending device, a first area portion has a first vertex that is an intersection point of a curve line formed by a tongue portion and a bisector of a first connection straight line connecting a winding start portion and an end of a discharge portion. A second area portion has a second vertex that is an intersection point of the curve line formed by the tongue portion and a bisector of a second connection straight line connecting the winding start portion and the end of the discharge portion. When a virtual straight line connecting a rotational axis and the first vertex is defined as a first straight line, and a virtual straight line connecting the rotational axis and the second vertex is defined as a second straight line, the second straight line is longer than the first straight line.

Abstract: An air-conditioning apparatus includes: a centrifugal air-sending device including a fan and a scroll casing having a tongue portion and a discharge portion, and a housing having a housing suction port and a discharge portion. A trailing edge of a blade located closest to a wall portion of the housing is a first trailing edge portion, and a leading edge of a blade located closest to the tongue portion is a first leading edge portion. In a first region, a boundary portion located closest to the tongue portion is located between first and second straight lines. The first straight line passes through a rotation axis of the fan and the first trailing edge portion, the second straight line is parallel to the first straight line and passes through the first leading edge portion, and the first region forms part of the housing suction port close to the tongue portion.

Abstract: A centrifugal fan includes a fan configured to be driven to rotate, and a scroll casing housing the fan. The scroll casing includes a peripheral wall having a volute shape having an inner end of a spiral thereof at a boundary with a tongue portion of the scroll casing. When a portion at the peripheral wall at which a distance between the peripheral wall and a rotation shaft of the fan is minimum is defined as a closest portion, the peripheral wall includes a narrowed portion at which the distance between the peripheral wall and the rotation shaft is reduced from the inner end toward the closest portion in a rotation direction of the fan, and an expanded portion that is formed between the narrowed portion and the closest portion and at which the distance between the peripheral wall and the rotation shaft is increased.

Abstract: An air sending device is provided with a cross flow fan including an impeller in which a plurality of blades is arranged annularly. Each of the blades includes a pressure surface, a suction surface, an inner peripheral end face, and an outer peripheral end face. The pressure surface of the blade satisfies the following relationship: a curvature of a second pressure-surface side curved surface>a curvature of a third pressure-surface side curved surface>a curvature of a first pressure-surface side curved surface. When a first, a second, and a third pressure-surface side area of a surface of part of a pressure surface side of the blade are projected on a chord line connecting the inner and outer peripheral end of the blade, a length of the third pressure-surface side area>a length of the first pressure-surface side area>a length of the second pressure-surface side area.

Abstract: A centrifugal fan includes: an impeller having a back plate; and a scroll casing including a peripheral wall having a volute shape, a first side wall facing a virtual extension of the back plate and an inner end portion of the volute shape of the scroll casing, an expanded portion, and a first edge end portion being an end of a first edge defining the discharge port, of the first side wall, are arranged in a named order in the rotation direction, the first edge end portion being farther from the rotation shaft than an other end of the first edge and distance L1?distance LM>distance LS is satisfied where LS is a distance between the first side wall at the inner end portion of the volute shape and the virtual extension of the back plate, LM is a distance between the first side wall at the expanded portion and the virtual extension of the back plate, the expanded portion being a portion at which the distance between the first side wall and the virtual extension of the back plate is larger than LS, and L1 is a

Abstract: An indoor unit includes: a casing that has an air outlet and an air inlet, and inside which an air passage is formed; a cross flow fan disposed in the air passage and configured to blow out, through the air outlet, air sucked in from the air inlet; a stabilizer configured to stabilize vortex of air caused by circulation of air and generated inside the cross flow fan upon rotation thereof; and a guide wall having a surface defining an outlet side air passage being a part of the air passage, the part being in downstream of the cross flow fan, wherein the stabilizer has a first surface that defines a surface opposite to the guide wall in the outlet side air passage, and a part of the outlet side air passage is formed such that a distance in a vertical direction from the first surface to the guide wall gradually decreases toward the downstream.

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: A scroll casing accommodates a cross-flow fan, thereby forming an airflow passage, and includes a scroll section having, as an upstream end, an approach point at which the scroll section most closely approaches the fan. A region between the upstream end of the scroll section and a downstream end is divided into three regions in the flow direction of airflow. In the three regions, the distance between the center of rotation of the fan and the scroll section increases at different change rates from the upstream end to the downstream end as the scroll section is viewed at a section perpendicular to an axis of rotation of the fan. Where the three regions are a first region, a second region, and a third region in this order from an upstream side in the flow direction of the airflow, the change rate of the second region is the smallest.

Abstract: A turbo fan includes a main plate and a plurality of blade portions. The plurality of blade portions include a plurality of first blade portions and a plurality of second blade portions. In a case where, in each of the plurality of first blade portions, a length of a virtual straight line connecting a first inner peripheral end part and a first outer peripheral end part is defined as a first chord length, and in each of the plurality of second blade portions, a length of a virtual straight line connecting a second inner peripheral end part and a second outer peripheral end part is defined as a second chord length, the first chord length and the second chord length are not equal to each other at positions separated by a same distance from the main plate in the axial direction of the rotary shaft.

Abstract: A multi-blade centrifugal air-sending device includes an impeller including a back plate having a disk shape, a plurality of blades arranged at a peripheral portion of the back plate in a circumferential direction, and a rim having an annular shape and disposed to face the back plate, the rim fixing the plurality of blades; and a scroll casing having a spiral shape and housing the impeller, the scroll casing being configured such that air is introduced from the side of the rim and blown out to the outer peripheral side. The impeller is constituted by a metal. Each of the blades has a wall thickness constant from the side of the back plate to the side of the rim and extends toward the inner side further than an inner peripheral end of the rim.

Abstract: In an axial flow fan, a plurality of blades are rotated about a rotation axis of the plurality of blades to generate an air current. Each of the plurality of blades includes a leading edge portion on a forward side in a rotation direction, and a trailing edge portion on a rearward side in the rotation direction. At the trailing edge portion of the blade, a first recessed portion is formed such that the first recessed portion is recessed toward the leading edge portion. At the leading edge portion of the blade, the second recessed portion is recessed toward the trailing edge portion. Ranges of the first recessed portion and the second recessed portion in a radial direction overlap with each other or completely coincide with each other.

Abstract: A centrifugal air-sending device has blades that each have a vane length in a first region that is greater than a vane length in a second region and have a portion at which a proportion for which a turbo vane portion accounts is higher in a radial direction than a proportion for which a sirocco vane portion accounts in the first region and the second region. The blades that are located closer to an outer circumference than is an inner circumferential side end portion of a bell mouth that is located closest to an inner circumference in the radial direction is defined as a blade outer circumferential portion that is formed such that the proportion for which the sirocco vane portion accounts is higher in the radial direction than or equal to the proportion for which the turbo vane portion accounts in the first region and the second region.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: A centrifugal air blower includes a fan; and a scroll casing. The scroll casing includes: a sidewall covering the fan from an axial direction of a rotation axis, the sidewall having a suction opening for sucking air; a discharge opening; a tongue portion for guiding the airflow to the discharge opening; a peripheral wall surrounding the fan from a radial direction of the rotation axis; and a bell mouth formed along the suction opening of the sidewall. The bell mouth includes upstream and downstream ends, with the upstream end being an end portion on an upstream side in a direction of flow of the air passing through the suction opening, and the downstream end being an end portion on a downstream side in the direction of flow of the air.

Abstract: An air-conditioning apparatus includes: a centrifugal air-sending device including a fan and a scroll casing having a tongue portion and a discharge portion, and a housing having a housing suction port and a discharge portion. A trailing edge of a blade located closest to a wall portion of the housing is a first trailing edge portion, and a leading edge of a blade located closest to the tongue portion is a first leading edge portion. In a first region, a boundary portion located closest to the tongue portion is located between first and second straight lines. The first straight line passes through a rotation axis of the fan and the first trailing edge portion, the second straight line is parallel to the first straight line and passes through the first leading edge portion, and the first region forms part of the housing suction port close to the tongue portion.

Abstract: An indoor unit includes: a main body having an opening near an air-conditioning target space and attached to an installation section; a panel having an air inlet through which air is suctioned and an air outlet through which the suctioned air is discharged, and covering the opening of the main body; a fan provided to the main body and generating flow of air that is suctioned from the air inlet of the panel and blown out from the air outlet of the panel; a bell mouth provided upstream of the fan in the main body and guiding the air suctioned from the air inlet toward the fan; and an electric component box provided upstream of the bell mouth in the main body, to thereby define an air-flowing space between the electric component box and the bell mouth, and accommodating a control unit that controls operation of the fan.

Abstract: An impeller includes a backing plate, a rim disposed so as to face the backing plate, and a plurality of blades arranged in a circumferential direction around a virtual rotation axis of the backing plate. Each of the plurality of blades has an inner circumferential end, an outer circumferential end a sirocco blade portion being forward-swept and including the outer circumferential end and having a blade outlet angle of larger than 90 degrees, and a turbo blade portion being swept-back and including the inner circumferential end, a first region located closer to the backing plate than a middle point in an axial direction of the rotation axis, and a second region located closer to the rim than the first region. Each of the plurality of blades is formed such that a blade length in the first region is longer than a blade length in the second region.