GB826899A - Fluid seals for relatively rotating parts - Google Patents

Abstract

826,899. Stuffing-box substitutes. MAGNETIC SEAL CORPORATION. March 18, 1958, No. 8653/58. Class 122 (5). A rotary shaft seal comprises two sealing rings 14 and 31 urged into facial sealing contact by magnetic means, one ring 14 being fixed to the shaft 10 for rotation therewith and the other ring 31 being non-rotatably and axiallymovably mounted in the shaft housing 11 and sealed thereto by a metal seal, such as a metal bellows 37. The ring 14 is a permanent magnet and is secured between sleeves 17 and 18 to the shaft 10, the sleeves and the shaft being of non-magnetic material, for instance, a stainless steel alloy. The ring 31 is of material magnetically attracted to the ring 14 so that a sealing face 34 of an insert 32, which may be of carbon, in the ring 31 contacts a sealing face 15 of the ring 14 to prevent escape of fluid in chamber 12. The bellows 37 is welded at one end to the ring 31 and at the other end to a flange 24 secured to the housing 11 by screws 26 and sealed thereto by a metal gasket 27. A sleeve 29 secured between the flange 24 and the housing 11 extends around the bellows 37 and has projections 36 that engage in recesses 35 in the ring 31 and hold the latter against rotation whilst permitting axial movement. The magnetic sealing contact pressure is augmented by the differential pressure across the ring 31 due to the sealed fluid pressure. In a modification, Fig. 5, a non-rotatable ring 52 having a carbon insert 54 in sealing contact with a magnetic ring 51 secured to the shaft 50 is slidably sealed to the shaft housing 56 by a number of metal piston-rings 58.