GB1071987A - Improvements in and relating to oil seals for the propeller shaft of marine vessels - Google Patents

Abstract

1,071,987. Mechanical seals. R. YATES. Oct. 8, 1965, No. 42727/65. Heading F2B. An oil-sealing arrangement for a propeller shaft 10 where it extends between the, propeller boss 11 and a wear-ring 24 on the outer end of a stern tube 12 comprises a ring 19 of neoprene or other plastic material which rotates with the shaft and incorporates an anti-friction ring insert 23, preferably of hard bronze, on its sealing face, a housing 21 which tightly encircles the ring and a chamber 20a positioned between the propeller boss and the ring to which oil under pressure is supplied to retain the ring in sealing contact with the wear-ring irrespective of shaft expansion. As shown, two neoprene rings 18, 19 are gripped on to the shaft and initially distorted into engagement with the boss and wear-ring by a housing 21 formed by two parts drawn together by bolts. The oil under pressure is delivered from a tank 34 via a pipe 31 and ducting to the space between the rings. When shaft expansion occurs, the rings are further distorted to retain the seal. At the inner end of the stern tube a single neoprene ring 41 having a hard bronze insert 40 is clamped by a housing 42 into sealing contact with a wear-ring 39, sealing contact being maintained by the pressure of oil in a chamber 43 behind the ring. The oil pressure may be regulated by an adjustable spring-loaded valve 47a in the oil return pipe 47. In Fig. 5 (not shown), two neoprene rings instead of one are employed at the inner end of the stern tube. Only one ring may be employed at the outer end, the housing being bolted to the propeller boss.