Centrifugal air blower
A centrifugal air blower includes a lower case. The lower case includes a land part near a tongue part joining a discharge passage of a passage section and a spiral start position of a spiral passage. The land part protrudes toward an upper case. The height position of the land part is substantially the same as the height position of lower ends of blades. The land part includes a first wall which is vertically formed along an inner circumferential wall of the discharge passage, a second wall which is vertically formed on an outer circumferential side of an insertion hole and on a radially inward side of the first wall, and a ceiling covering upper ends of the first and second walls.
1. A centrifugal air blower comprising:
a casing;
a fan housed in the casing and configured to take in an air in an axial direction and send the air in a radial direction; and
a drive source housed in the casing and configured to drive the fan,
wherein the casing includes:
an air intake port opened at one end of the casing in the axial direction;
an insertion hole, through which the fan is assembled and disassembled;
a flat part extending radially outwardly from a holder main body housing the drive source and connected to the casing to cover the insertion hole;
a spiral first passage section formed on an outer circumferential side of the fan;
a second passage section extending from a spiral end position of the first passage section to a discharge port; and
a tongue part formed at a joined portion where a spiral start position of the first passage section and the second passage section are joined together, and
wherein the centrifugal air blower further comprises a first wall and a second wall adjacent to the tongue part;
the first wall is vertically formed along an inner circumferential wall of the second passage section so as to extend toward a position closer to the one end of the casing than the flat part in the axial direction; and
the second wall is located radially inwardly of the first wall and vertically formed so as to face an outer circumferential surface of the drive source and extend toward a position closer to the one end of the casing than the flat part in the axial direction.
2. The centrifugal air blower according to claim 1 , wherein height positions of one end of the first wall and one end of the second wall in the axial direction are substantially same as a height position of another end of the fan in the axial direction.
3. The centrifugal air blower according to claim 2 , wherein a ceiling extending substantially perpendicularly to the axial direction is joined to the one end of the first wall and the one end of the second wall in the axial direction.
4. The centrifugal air blower according to claim 3 , wherein a land part having a U-shape in cross section comprises the first wall, the second wall, and the ceiling.