Vacuum pump

摘要

A vacuum pump has a pump case having a gas suction port at an upper surface thereof, a rotor shaft mounted in the pump case for undergoing rotation, and a rotor connected to the rotor shaft for rotation therewith. The rotor has inner and outer circumferential surfaces coated with a corrosion-resistant film treated by nonelectrolytic plating. Rotor blades are disposed in the pump case and are integrally connected to the outer circumferential surface of the rotor. Stator blades are integrally connected to the pump case so that the rotor blades and the stator blades are alternately positioned and arranged. A balancing body is disposed on the inner circumferential surface of the rotor for balancing the rotor during rotation thereof.