US 12,241,477 B2
Multi-blade centrifugal air-sending device
Hiroyasu Hayashi, Tokyo (JP); Takuya Teramoto, Tokyo (JP); Katsuhiro Fujiki, Tokyo (JP); and Wahei Shingu, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 18/043,917
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Oct. 23, 2020, PCT No. PCT/JP2020/039898
§ 371(c)(1), (2) Date Mar. 3, 2023,
PCT Pub. No. WO2022/085175, PCT Pub. Date Apr. 28, 2022.
Prior Publication US 2024/0026899 A1, Jan. 25, 2024
Int. Cl. F04D 29/30 (2006.01); F04D 17/08 (2006.01); F04D 29/28 (2006.01); F04D 29/42 (2006.01)
CPC F04D 29/4226 (2013.01) [F04D 17/08 (2013.01); F04D 29/281 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A multi-blade centrifugal air-sending device comprising:
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 a side of the rim and blown out to an outer peripheral side,
wherein each of the blades includes a sirocco blade portion constituted by a forward blade, and a turbo blade portion constituted by a rearward blade and connected to an inner peripheral side of the sirocco blade portion,
wherein the impeller is constituted by a metal,
wherein each of the blades has a wall thickness constant from a side of the back plate to the side of the rim in an axial direction of a rotational axis of the impeller and each of the blades from the side of the back plate to the side of the rim extends toward an inner side further than an inner peripheral end of the rim in a radial direction of the rotational axis,
wherein, when viewed in an axial direction of a rotational axis of the impeller, a portion of each of the blades covered by the rim is constituted by the sirocco blade portion and a portion of the turbo blade portion, and
wherein a chord length of the sirocco blade portion is larger than a chord length of the portion of the turbo blade portion.