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 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: 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 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 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.

Abstract: An impeller includes: a main plate to be rotated; an annular side plate having a suction port for air; and blades in a circumferential direction. Each of the blades has: an inner peripheral end; an outer peripheral end; a sirocco blade portion that includes the outer peripheral end, and forms a forward-swept blade; and a turbo blade portion that includes the inner peripheral end and forms a swept-back blade. The blade has an end portion facing the suction port and a base portion connected to the main plate, and the end portion has a smaller thickness than that of the base portion in the sirocco blade portion. The end portion of the blade has a blade shape, and in the end portion having the blade shape, a first blade thickness of an inner circumferential side of the impeller is greater than a second blade thickness of the outer circumferential side.

Abstract: A 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. In the circumferential wall, at a first end between the circumferential wall and the tongue portion, and at a second end between the circumferential wall and the discharge portion, a distance between an axis of the rotational shaft and the circumferential wall is equal to a distance between the axis of the rotational shaft and a standard circumferential wall, and is greater than or equal to the distance between the first end and the second end of the circumferential wall, the circumferential wall including a plurality of extended portions between the first end and the second end of the circumferential wall.

Abstract: An impeller includes a main plate, an annular side plate and blades. The blades each have: an inner circumferential end; an outer circumferential end; a sirocco blade portion formed as a forward-swept blade portion, and having an outlet angle that is greater than 90 degrees; and a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end. The blades include a first blade portion and a second blade portion that are provided on respective sides of the main plate. The impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inlet-blade distance is a distance between any adjacent two of the blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion.

Abstract: A centrifugal fan includes: an impeller having a back plate; and a scroll casing including a peripheral wall 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 distance between the f

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 centrifugal blower includes a fan including a main plate having a disk-shape, and a plurality of blades, and a scroll casing configured to accommodate the fan. The scroll casing includes a discharge portion and a scroll portion including a side wall, a circumferential wall, and a tongue portion. The circumferential wall includes a curved circumferential wall and a flat circumferential wall. In comparison with a centrifugal blower including a standard circumferential wall having a logarithmic spiral shape in cross-section perpendicular to a rotational shaft of the fan, in the curved circumferential wall, at a first end being a boundary between the circumferential wall and the tongue portion and at a second end being a boundary between the circumferential wall and the discharge portion, a distance L1 between an axis of the rotational shaft and the circumferential wall is equal to a distance L2 between the axis of the rotational shaft and the standard circumferential wall.

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.