GB1017921A - Shaft seal - Google Patents

Abstract

1,017,921. Shaft seals. ENGLISH ELECTRIC CO. Ltd. May 2, 1962 [May 9, 1961], No. 16792/61. Heading F2B. Sealing means for a rotatable shaft 11 where it extends through a housing 10 containing fluid under pressure comprises supplying sealing oil under pressure between the opposing faces of two rings 14 and 15 urged towards one another by the pressure of the fluid in the housing and connected, in fluid-tight manner to the housing and to the shaft respectively, at least one of the rings being cooled by circulating coolant therethrough. The ring 14 is connected to the housing by bellows 17 and urged toward the ring 15 by gas supplied to the interior of the bellows from the housing through an aperture 18. Pressurized sealing oil is supplied at a constant rate to recesses 22 in the ring 14 via passages 20 and orifices 21. A circumferential groove 23 interposed between the recesses 22 and the interior of the ring 14 has bleed orifices 25 leading to drain to maintain the pressure in the groove 23 less than that in the recesses 22 and thus limit leakage of sealing oil radially inwardly; most of the sealing oil flowing radially outwardly to an external drain. As an alternative, the orifices 25 may be omitted the pressure in the groove 23 then being automatically controlled by the clearances between the rings 14 and 15. Any leakage of sealing oil to the interior of the rings 14 and 15 is drained through a pressurized drain 26. The ring 14 is cooled by circulating coolant through a chamber 32 via inlet and outlet apertures 33 and 34. In a modification, the bleed orifices 25 are arranged outside the groove 23 in closed recesses between the recesses 22.