Patent ID: 8152488

Claim:
A blower for a vacuum cleaner or the like, comprising: a housing; an electric motor accommodated within the housing and having a stator and a rotor; an impeller fixed to the rotor for rotation therewith; a diffuser located at a first end of the housing and located between the impeller and the housing; and a cover, fixed to the first end of the housing and covering the diffuser and impeller, the cover having an aperture forming an inlet port for the impeller; wherein the diffuser has a plate like portion which extends adjacent a rear surface of the impeller and having on one side thereof at a peripheral edge, a plurality of diffuser vanes extending perpendicularly from the plate like portion and extending along respective curves from adjacent a peripheral edge of the impeller to a peripheral edge of the diffuser and having therebetween a plurality of passageways and having on a second surface thereof a plurality of return guide vanes extending perpendicularly from the plate like portion and following respective curves from the peripheral edge of the diffuser to a radially intermediate location and forming a second plurality of passageways therebetween for leading air from the periphery of the diffuser, inwardly towards and into the housing to cool the motor; and wherein the diffuser vanes form an angle A with the peripheral edge of the impeller and an inner side of the return guide vanes form an angle B with the outer edge of the diffuser such that the angle A is in the range of 4° to 6° and the angle B is in the range of 6° to 20°.