Motor blower

PURPOSE:To improve fan efficiency by forming a smooth curved surface projecting toward a blade on the next stage on an end backside of the blade in a blower provided with an impeller having a sweep-back plural blade. CONSTITUTION:An impeller 19 is constituted with front and back shrouds 13, 15 and a sweep-back blade 14 crimped with a calking head 16. The blade 14 has a curved surface 20 formed toward an inlet 17 near an outlet 18, which is turned backward. When the impeller 19 is rotated, there is hardly produced such part as is low in air density, for the curved surface 20 present as above, near the blade back 14b. Thus, a vortex is prevented from arising in the interior of the impeller 19, an air current flows smoothly, and a fan efficiency can be improved consequently.