Rotating seal
AssigneeGroupement pour les Activities Atomiques et Advancees "GAAA"
InventorJean Martin
Life of this patent
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Abstract
Rotating seal sealing by viscous effect, intalled on a rotating shaft crossing through a bore separating, from the outside medium, an enclosure containing a fluid kept under pressure, comprising at its center two threads having an unequal length and having reverse pitches, separated by a groove and two lip seals for a rotating shaft of the conventional type on either side of the threads. The gap between the two lip seals is fed with viscous fluid by two tanks, one of which is at the pressure of the fluid for which sealing is to be provided. Application to the passing of shafts rotating at a high speed for all types of enclosures containing a gas or a liquid under pressure which can reach several tens of bars.
Claims18
In a seal assembly for a rotating shaft effecting sealing by viscous effect, and having a rotating shaft extending through a bore formed in a wall separating, from the outside medium, an enclosure coontaining a fluid kept under high pressure, said assembly comprising, at the level of the bore, a sleeve mounted within said bore and surrounding said shaft and defining with said shaft opposed continuous cylindrical faces, first and second threads within one of said faces separated at their center by a groove and limited at their periphery by first and second lip seals for said rotating shaft, of the conventional type, two tanks of viscous liquid, cooling means, means for balancing the pressures between said viscous liquid and said high pressure fluid, the improvement wherein said threads have unequal lengths and are cut on one of the continuous cylindrical faces in opposite pitches such that each of said threads tend to drive said viscous liquid towards its periphery in the direction of the lip seals.
Dependencies are inferred from the claim text.