Magnetic/centrifugal-fluid seal
US4304411A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1980 |
| Grant date | Dec 8, 1981 |
| Priority date | — |
| Expiry date | Apr 17, 2000 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16J15/43
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A magnetic/centrifugal-fluid seal comprising a rotating disk-like collar/vane surrounding a rotatable shaft journalled in a housing defined by close-fitting stationary members forming a cavity to accommodate the rotatable shaft and disk-like collar/vane. A magnetic fluid is retained in a close clearance magnetic gap region between the rotatable shaft and the stationary members and is magnetized by an external permanent magnet or electromagnet. At standstill or low-speed the magnetic fluid is retained by magnetic force in the close-clearance magnetic gap region formed by several sets of opposing pole-like teeth confronting the inner surfaces of the rotating disk-like collar/vane. By virtue of magnetic attraction the magnetic fluid can withstand a pressure drop between high and low pressure regions and thus effects a magnetic seal at standstill and low speeds. As the shaft rotates faster, the magnetic fluid is forced centrifugally from the magnetic seal region and becomes a rotating mass or pool of fluid at the circumferential rim of the disk-like collar/vane. The fluid then acts as a conventional centrifugal seal. When stopping or slowing down, a speed is reached where the magnetic/…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.