Compared with the two clover leaf blower type, gas pulsation is small, too small vibration, low noise. Between the impeller and the housing bore oval face, face and fans around the impeller fan cover between the two shafts and fan impeller always keep a small gap from the fan inlet rim housing wall in synchronous wind driven gear delivered to the discharge side. Fan cavity does not need oil, simple structure, stable operation, stable performance, adapt to a variety of purposes, has been applied to a wide range of fields. Clover Roots blower is a positive displacement blower, air volume delivered is proportional to the number of revolutions, clover type impeller rotates once every two impellers by three times the suction and discharge. Three cattle Machinery Co., Ltd. Shandong