Mechanical pump assembly for pumping a secondary vacuum, and a leak detection installation using such an assembly
US5116196A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1990 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Jul 10, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M3/202
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A mechanical pump assembly (20) for pumping a secondary vacuum, the assembly comprising two pumping stages, the first stage having a suction inlet (9) and the second stage having a suction orifice (10), said inlet and said orifice both opening out to the outside, both stages having a common delivery outlet (4), the pump assembly being characterized in that both of said pumping stages are of the Holweck drum type, said first stage having a compression ratio of about 50 for a gas such as helium and of about 30,000 for air, the pumping speed of the first stage being about 4 l/s for air and about 2.5 l/s for said gas, and in that said second stage has a pumping speed of about 3.5 l/s for air and of about 2 l/s for said gas, the nominal speed of rotation of said mechanical pump assembly being about 27,000 rpm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.