Multi-stage vacuum pump
US5478210A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1994 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Oct 21, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K16/00
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A vacuum pump includes a plurality of rotors accommodated in a housing, a plurality of bearings for supporting the shafts of the rotors, respectively, a fluid-suction opening and a fluid-discharge opening formed in the housing, and a motor for driving at least one of the rotors. The pump has a first pump structure section for suction and discharge of gas, the pressure of which is in a viscous flow region, by utilizing change in volume of a space formed by the rotors and the housing. A second pump structure section is provided for transporting gas, a pressure of which is in an intermediate flow region, and gas, the pressure of which is lower than a pressure of the intermediate flow region, by utilizing movement of the space from a suction side to a discharge side of the second pump structure section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.