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: 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 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: 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.

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 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 are each formed such that 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 a blade inner diameter of inner circumferential ends of the blades at end portions of the blades that are close to a side plate in an axial direction are defined as a blade outer circumferential portion that is formed such that a vane thickness of each of the blades in decreased in the radial direction from an inner circumference toward the outer circumference.

Abstract: A multi-blade centrifugal air-sending device includes a fan 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 coupling the plurality of blades to each other, the plurality of blades being connected at respective first end portions on one side to the back plate, the rim being provided at respective second end portions of the plurality of blades on a side opposite to the one side where the respective first end portions are present; and a scroll casing having a spiral shape and including a facing side wall where an air inlet is provided and a peripheral wall, the scroll casing housing the fan such that the side wall faces the respective second end portions of the plurality of blades, the scroll casing being configured such that air is introduced through the air inlet and blown out to the outer peripheral side.

Abstract: A scroll casing has a scroll portion, a discharge portion provided with a discharge port, and a tongue portion. An extended plate has, in a cross section obtained by cutting in a thickness direction, a change point, at which an enlargement ratio of an area of the cross section is enlarged so as to be larger on a downstream side than that on an upstream side due to a change of inclination. In the extended plate, an angle ?1, and an angle ?2 satisfy a relationship of either 0??2<?1 or 0<?2??1. A distance L1 and a distance L2 satisfy a relationship of L2<L1.

Abstract: An air conditioning apparatus includes a centrifugal fan and a heat exchanger disposed in a position facing a discharge port of the centrifugal fan. The centrifugal fan includes: a fan, blades; and a scroll casing housing the fan, the scroll casing including a discharge portion, and a scroll portion including a side wall, a circumferential wall, and a tongue portion.

Abstract: An impeller connected to a motor having a drive shaft includes a back plate having a boss having a shaft hole through which the drive shaft is inserted, a ring-shaped rim provided to face the back plate, and a plurality of blades connected to the back plate and the rim and arranged along a circumferential direction of the back plate about the rotation shaft. The back plate includes a first surface portion on which the plurality of blades are formed, a second surface portion provided at a region between the boss and the first surface portion and depressed from the first surface portion in an axial direction of the rotation shaft, and a plurality of projections provided at the second surface portion and extending in the axial direction.