Abstract: In an electric blower, exhaust air discharged radially from a centrifugal fan is redirected to a motor drive section by a diffuser and a fan cover. The air passes from a ventilation opening on a motor frame and through a bracket to cool the motor drive section. A portion of the air from the centrifugal fan is bled off through exhaust openings without passing over the motor, whereby this portion remains cooler and cleaner than the air that passes over the motor. Air flows up a wand and then passes over the motor to cool the motor. This air passes through filters before being discharged. The portion of air that is bled off passes along a parallel path in the wand to agitate dirt, and to maintain the wand relatively cool. In one embodiment, some of the bled-off portion is discharged directly without passing along the wand.

Abstract: An electric fan comprises: a radial impeller for expelling the air trapped therein out of the impeller; a diffuser having a multiplicity of air passages separated by air guides, the air passages adapted to receive the air expelled from the impeller; a fan case for covering the impeller and the air guides; at least one throughhole which is formed in the fan case for each of the air passages; and a silencer equipped with a multiplicity of silencer cavities each having a predetermined volume and communicating with a corresponding one of the air passages, the silencer covering the fan case. The silencer is provided either on top of or beneath the fan case. Because the volumes of these silencer cavities may be chosen arbitrarily such that the silencer cavities may absorb noise caused by the interference between the impeller and the air passages, even audible noise may be suppressed sufficiently.