公开(公告)号：US20210388847A1

公开(公告)日：2021-12-16

申请号：US17287826

申请日：2018-12-19

Applicant: Mitsubishi Electric Corporation

Inventor： Hiroyasu HAYASHI ,  Taxuva TERAMOTO ,  Kazuya MICHIKAMl ,  Ryo HORIE ,  Takahlro YAMATAN ,  Hiroshi TSUTSUMl

IPC: F04D29/42 ,  F24F7/007

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.