US 12,320,363 B2
Centrifugal air-sending device and air-conditioning apparatus
Takuya Teramoto, Tokyo (JP); Hiroyasu Hayashi, Tokyo (JP); Ryo Horie, Tokyo (JP); Yoshitaka Akari, Saitama (JP); Takashi Yamaguchi, Tokyo (JP); Kazuya Michikami, Tokyo (JP); Takahiro Yamatani, Tokyo (JP); Masahiko Takagi, Tokyo (JP); Kazuki Watanabe, Tokyo (JP); and Hidetoshi Seki, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 18/044,091
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Oct. 22, 2020, PCT No. PCT/JP2020/039665
§ 371(c)(1), (2) Date Mar. 6, 2023,
PCT Pub. No. WO2022/085143, PCT Pub. Date Apr. 28, 2022.
Prior Publication US 2023/0323892 A1, Oct. 12, 2023
Int. Cl. F04D 29/30 (2006.01); F04D 17/08 (2006.01); F04D 29/42 (2006.01); F04D 29/58 (2006.01); F24F 1/0022 (2019.01)
CPC F04D 29/30 (2013.01) [F04D 17/08 (2013.01); F04D 29/4206 (2013.01); F04D 29/582 (2013.01); F24F 1/0022 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A centrifugal air-sending device comprising:
an impeller that has a main plate that is to be driven to rotate, a side plate that is ring-shaped and located such that the side plate faces the main plate, and a plurality of blades that each have one end connected to the main plate and an other end connected to the side plate and are arranged in a circumferential direction centered on a rotation axis of the main plate that is virtual; and
a scroll casing that houses the impeller and has a circumferential wall that is scroll-shaped and a side wall that has a bell mouth that forms a suction port that communicates with a space defined by the main plate and the plurality of blades,
the plurality of blades each having
an inner circumferential end that is closer to the rotation axis than is an outer circumferential end in a radial direction centered on the rotation axis,
the outer circumferential end that is closer to an outer circumference than is the inner circumferential end in the radial direction,
a sirocco vane portion that includes the outer circumferential end and forms a forward-curved blade at which an outlet angle is formed larger than 90 degrees,
a turbo vane portion that includes the inner circumferential end and forms a backward-curved blade,
a first region that is located closer to the main plate than is an intermediate position between the main plate and the side plate in an axial direction of the rotation axis, and
a second region that is located closer to the side plate than is the first region,
the plurality of blades each having a vane length in the first region that is greater than a vane length in the second region,
the plurality of blades being each formed such that a proportion for which the turbo vane portion accounts is higher in the radial direction than a proportion for which the sirocco vane portion accounts in the first region and the second region,
in a case in which portions of the plurality of blades that are located closer to the outer circumference than is a blade inner diameter of the respective inner circumferential ends of the plurality of blades at end portions of the plurality of blades that are close to the side plate in the axial direction are defined as a blade outer circumferential portion, the blade outer circumferential portion is formed such that a vane thickness of each of the plurality of blades is decreased in the radial direction from an inner circumference toward the outer circumference.