US 11,808,270 B2
Impeller, multi-blade air-sending device, and air-conditioning apparatus
Takuya Teramoto, Tokyo (JP); Hiroyasu Hayashi, Tokyo (JP); Ryo Horie, Tokyo (JP); Kazuya Michikami, Tokyo (JP); Takahiro Yamatani, Tokyo (JP); and Hiroshi Tsutsumi, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/438,553
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Apr. 25, 2019, PCT No. PCT/JP2019/017548
§ 371(c)(1), (2) Date Sep. 13, 2021,
PCT Pub. No. WO2020/217367, PCT Pub. Date Oct. 29, 2020.
Prior Publication US 2022/0145893 A1, May 12, 2022
Int. Cl. F04D 17/16 (2006.01); F04D 29/28 (2006.01); F04D 29/30 (2006.01); F04D 29/42 (2006.01); F04D 29/44 (2006.01); F04D 29/60 (2006.01); F04D 29/68 (2006.01)
CPC F04D 17/162 (2013.01) [F04D 29/282 (2013.01); F04D 29/30 (2013.01); F04D 29/424 (2013.01); F04D 29/44 (2013.01); F04D 29/60 (2013.01); F04D 29/68 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A multi-blade air-sending device comprising:
an impeller comprising
a backing plate configured to be driven by rotating,
an annular 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, one end of each of the plurality of blades being connected with the backing plate, an other end of each of the plurality of blades being connected with the rim; and
a scroll casing housing the impeller and having a peripheral wall formed into a volute shape and a side wall having a bellmouth forming an air inlet communicating with a space formed by the backing plate and the plurality of blades,
each of the plurality of blades having
an inner circumferential end located closer to the rotation axis in a radial direction around the rotation axis,
an outer circumferential end located closer to an outer circumference than the inner circumferential end in the radial direction,
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,
the plurality of blades being formed such that a blade length,
decreases from the backing plate toward the rim,
a ratio of the turbo blade portion in the radial direction to a total length of a corresponding blade in the radial direction being larger than a ratio of the sirocco blade portion in the radial direction to the total length of the corresponding blade in the radial direction,
wherein an inside diameter of the bellmouth is smaller than a blade inside diameter formed by the inner circumferential end of each of the plurality of blades in the second region.