Cryopump
US5343709A · kind A · utility
Inventor
Key dates
| Filing date | Jul 20, 1993 |
| Grant date | Sep 6, 1994 |
| Priority date | — |
| Expiry date | Jul 20, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S417/901
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A cryopump includes a housing in which is mounted a cooling head having a first, 80.degree. K. cooling stage and a second, 20.degree. K. cooling stage. A shield mounted on the cooling head surrounds the two stages, and a cooling surface within the housing and within the shield surrounds the second stage. The housing and the shield include corresponding inlet openings for admitting gases, and a diaphragm protects the cooling surface from heat radiation entering the inlet openings. The diaphragm is closer to the cooling surface than is the shield, creating a transfer opening that permits free access of gases into the volume within the shield. The cooling head can be rotated by an adjustment motor to displace the shield inlet opening with respect to the housing inlet opening to control the suction capacity of the pump for process gases without the need for an additional reduction valve, while maintaining the capacity for processing water vapor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.