The impellor is mounted directly on the motor shaft for contact free compression. Maximum operational reliability and service life, even at high differential pressure, is ensured by the arrangement of the bearings outside the compression chamber. The gas is taken through the inlet silencer (1). As the gas enters the side channel (2), the rotating impellor (3) imparts velocity to the gas in the direction of rotation. Centrifugal force in the impellor blades accelerates the gas outward and the pressure increases. Every rotation adds kinetic energy , resulting in further increase of pressure along the side channel . The side channel narrows at the rotor, sweeping the gas off the impellor blades and discharging it through the outlet silencer(4).