在大型汽轮机转子真空动平衡机室设计中选用了气冷式罗茨真空泵作为其主泵以大大加快抽空速度。气冷式罗茨真空泵由于其特殊结构，在携带一泵外冷却器后，可在极高的压差下连续工作而不会超温。这种泵还具备无油压缩的优点，可防止油蒸汽对被抽气体的污染，可广泛应用于各种真空作业上。本文介绍了这种泵的设计及其性能。 Air-cooled Roots vacuum pump was chosen as the main pump in the design of large-scale steam turbine rotor vacuum balancing machine room to greatly accelerate the evacuation speed. Air-cooled Roots vacuum pump due to its special structure, carrying a pump outside the cooler, the pressure can be a very high continuous work without over-temperature. This pump also has the advantages of oil-free compression, to prevent oil vapor on the body was pumping gas pollution, can be widely used in a variety of vacuum operations. This article describes the design of this pump and its performance.