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:
Aug. 23, 1994
Filed:
Jun. 22, 1992
James C Toboni, Bedford, NH (US);
Thomas J Black, Jr, Merrimack, NH (US);
Ferrofluidics Corporation, Nashua, NH (US);
Abstract
A ferrofluidic seal arrangement for sealing a high-speed rotary shaft which passes between an environment at atmospheric or high pressure and an environment at high-vacuum is provided, which is especially useful in a high-speed rotating anode apparatus for generating x-rays in a CAT Scan apparatus or the like. A differentially-pumped region between a multi-stage ferrofluidic seal and a single-stage seal insures that no seal bursting into the high-vacuum region occurs. Bearings supporting the shaft are arranged in a mechanically-stable arrangement but are isolated from the high-vacuum environment. Thus, neither the high-vacuum environment nor the differentially-pumped region need be continually mechanically pumped, and a relatively light-weight apparatus results. The apparatus is electrically grounded by transferring the charge on the anode through the high-speed shaft out of the vacuum environment and to a slower-rotating shaft via an electrically conductive, flexible drive belt, the slower shaft rotating at a speed at which grounding by conventional means is feasible.