Electric blower assembly

摘要

Electric blower assembly wherein air expelled by centrifugal force from impellers passes through volute chambers disposed peripherally with respect to said impellers and each defining a space which is increasingly larger as the distance from the impellers increases, whereby smooth air flow is produced in the volute chambers since the speed of air flow therethrough is lessened and pressure therein becomes static pressure. From the volute chambers air passes along inclined channels and then around a drive motor, whereby the drive motor is cooled. In entering at least part of each volute chamber air from the impellers comes into contact with a volute chamber wall extension which becomes gradually lower in a direction opposing that of impeller rotation whereby noise due to contact of a volute chamber wall by all portions of the air from the impeller does not occur simultaneously and a quieter blower assembly is provided.