The working principle of Roots vacuum pump is based on its unique dual-rotor design. The two rotors rotate synchronously and in opposite directions in the pump housing, always maintaining a certain gap without contact. The carefully designed protrusions and grooves on the rotor continuously change the spatial volume as the rotor rotates, realizing the suction and compression of gas. During the rotation of the rotor, the gas is tightly enclosed in the chamber formed by the rotor and the pump housing. After being squeezed, it is discharged in an orderly manner from the exhaust port. This process continuously forms a vacuum in the pump chamber.
The rotor of the Roots vacuum pump is usually an "8"-shaped cross-section, installed on parallel shafts, and rotates in opposite directions at equal angular speeds through gear transmission. When the rotor rotates in the direction of the arrow, the pumped gas enters the space formed by the rotor, pump housing and end cover from the suction port. As the rotor continues to rotate, the inhaled gas is enclosed in the space. When the rotor rotates to the exhaust port position, the higher pressure gas recoils into this part of the space and is then discharged.
The characteristics of Roots vacuum pumps include high speed (up to 3450-4100 rpm) and high pumping rate (30-10000 liters/second), but its ultimate vacuum is low, and it usually requires a fore pump to improve the vacuum. In addition, Roots pumps are suitable for handling scenes with low exhaust pressure and are widely used in the fields of petroleum, chemical industry, plastics, pesticides, turbine rotor dynamic balancing, aerospace, etc.
