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US 11,815,096 B2Granted
Pump unit
AssigneePfeiffer Vacuum GmbH
InventorsEric Mandallaz, Thibaut Bourrilhon, Christophe Santi
Life of this patent
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Abstract
A pump unit includes a rough-vacuum pump and a Roots vacuum pump connected in series and upstream of the rough-vacuum pump in the direction of flow of the pumped gases. The Roots vacuum pump has three pumping stages in which the rotors are designed to be driven simultaneously in rotation by a motor of the Roots vacuum pump. A ratio of the flow rate generated by the first pumping stage of the rough-vacuum pump in the direction of flow of the pumped gases over the flow rate generated by the last pumping stage of the rough-vacuum pump is less than or equal to four.
Claims14
A pump unit comprising:
- a rough-vacuum pump;
- and
- a Roots vacuum pump connected in series with and upstream of the rough-vacuum pump in a direction of flow of pumped gases,
- wherein the Roots vacuum pump has three pumping stages in which the rotors are configured to be driven simultaneously in rotation by a motor of the Roots vacuum pump, and
- wherein a ratio of a flow rate generated by a first pumping stage of the rough-vacuum pump in the direction of flow of the pumped gases over a flow rate generated by a last pumping stage of the rough-vacuum pump is less than or equal to four.
2 more elements
Dependencies are inferred from the claim text.