... Roots Blower,1.the product line using clover-type impeller,spiral structure exhaust,exhaust pulse gently,less vibration and low noise.2 ... high-precision synchronous drive gear,imported bearings,equipment,long life,low noise.4.high precision rotor dynamic balance,dynamic balance through ... rigorous testing,high-speed operation of the force balance,low vibration.5.transmission medium is not oil.No oil ...