These blowers consist of a dynamically balanced impeller which revolves in a stator - cum - compression chamber having very fine clearances between them. The impeller is fitted directly on to the motor shaft. Both the suction and pressure openings are located on the outer periphery of the stator to reduce impedance to the air flow thereby developing vacuum and pressure. Since the impeller rotates with no cantact between itself and the casing, there is no wear and tear and requires no lubrication.
