| 摘要 |
<p>A vacuum pump (1) for pumping gas from a pump inlet (21) to a pump outlet, comprising a rotor and a stator body (3) in which the rotor is adapted for rotation and including at least two molecular drag stages each comprising adjacent stationary and rotating Holweck cylinders (13,14,16,17) attached to the stator body (3) and the rotor respectively and with a threaded upstanding helical flange positioned therebetween which is attached either to the stationary or to the rotating cylinder wherein the molecular drag stage (14,20) closest to the pump inlet (21) has the threaded flange (20) on its rotating cylinder (15) and the subsequent molecular drag stage or stages has the threaded flange on the stationary cylinder (13,14). <IMAGE></p> |
