Roots blower

　　Roots blower is one of the types of positive displacement blower, have two three-blade impeller in the chassis and wallboard relative rotation in the sealed space, because of each impeller is involute, or epicycloid envelope for impeller processing line, three of each impeller blade is exactly the same, at the same time two impeller is exactly the same, thus greatly reduce the processing difficulty. Impeller when machining using CNC equipment, to ensure the two impellers. The condition of constant center distance, no matter what two impeller rotation to the position, can maintain a certain amount of minimum clearance, to ensure that the gas leak within the scope of the permit.