Performance of Screw Rotor of Claw Vacuum Pump:A Simulation Study

The distributions of the velocity and pressure fields, in operation of the claw-type vacuum pump with a pair of intermeshing spiral and/or cylindrical rotors, were mathematically modeled and numerically simulated with software COMSOL Multiphysics.The influence of the spiral angle on the properties of the rotor, including the suction and exhaust efficiency, bearing capacity and stability was investigated.The simulated results show that the spiral angle has a major impact.To be specific, as the spiral angle increases, the suction and exhaust efficiency decrease and both the bearing capacity and stability change in an increase-decrease manner.When it comes to stability, the claw type vacuum pump with spiral rotors outperforms that with cylindrical rotors, in spite of the fact that the latter has a higher pumping efficiency.