摘要 |
<p>Vacuum pumping apparatus includes a non-scroll type auxiliary pump and a scroll pump disposed in a single housing. The auxiliary pump and the scroll pump are connected in series and are driven by a common motor. Typically, the auxiliary pump has a relatively high pumping speed and the scroll pump has a relatively high compression ratio. The auxiliary pump may be a regenerative blower, a roots-type blower or a screw-type blower. When a co-rotating scroll pump is utilized, a regenerative blower may be formed at or near the outer periphery of a disk on which the non-orbiting scroll blade is mounted. In another configuration, first and second scroll pumps are disposed within a housing. The scroll blade sets of the first and second scroll pumps have different orbiting radii. Scroll pump leakage may be reduced by forming a closed-loop seal around the inlet region of the scroll pump and connecting the inlet region to an intermediate pressure. Scroll pump leakage and contamination may be reduced in a scroll pump structure wherein the drive components and the orbiting scroll blade are located on opposite sides of the non-orbiting scroll blade.</p> |