The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 08, 1981
Filed:
Apr. 17, 1980
Donald F Wilcock, Schenectady, NY (US);
Martin W Eusepi, Rexford, NY (US);
Mechanical Technology Incorporated, Latham, NY (US);
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/gravitational forces again dominate over the centrifugal forces and the magnetic fluid returns to the magnetic seal region.