Evacuating apparatus
US5709537A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C2240/402
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An evacuating apparatus includes a first pump section disposed on a suction opening side, a second pump section for exhausting a smaller amount of gas than the first pump section, the second pump being disposed in an exhaust opening side, a plurality of rotors accommodated in a housing, bearings for supporting rotation of the rotors, a suction opening for drawing fluid and a first exhaust opening thereof both formed on the housing, and a plurality of motors for driving the rotors. In the apparatus, the first pump section is a pump of positive displacement type formed by utilizing a volume change of a space defined by the rotors and the housing, and the second pump section is a viscous-type pump formed by utilizing a relatively moving surface formed in a small gap defined between the rotors and the housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.