| 摘要 |
<p>The object of the invention is a volumetric pump comprising a rotor turning in a stator with a given clearance, used for the pumping of a gas or a gas mixture of given molecular mass, characterised in that it comprises means for injecting into the said clearance a gas of higher molecular mass than that of the pumped gas or gas mixture. Applications to vane pumps, Roots pumps, double cylindrical or conical screw pumps, etc. <IMAGE></p> |
