| 摘要 |
<p>The integrally constructed vacuum pump has a multiplicity of different types of pump stages (5, 6, 7) which are arranged in a casing (4) along a single shaft (1) from the inlet port side to the outlet port side. The pump comprises a spiral molecular pump stage (5) having a high compression ratio, a radial compressor stage (6) which operates in the viscous flow range, and a peripheral pump stage (7) or screw pump stage (19) which both operate optimally close to the shut-off point. The peripheral pump (7) or screw pump (19), which forms the last pump stage, may have a rotary section with a reduced diameter, owing to the pump type used. This reduces the friction loss and thus the power required to operate the pump, leading to increased pump efficiency. <IMAGE></p> |
