GB1412124A - Rotating machines - Google Patents

Abstract

1412124 Bearings NORMALAIR-GARRETT (HOLDINGS) Ltd 9 Jan 1973 [7 Feb 1972] 5628/72 Heading F2A [Also in Division F1] A machine such as a turbo-compressor having a rotatable member 12 extending through a sealed lubrication chamber defined in part by wall members 24, 25 comprises static pressure chambers 27, 28 outboard of said wall members, a centrifugal pump 32, ducts 35 directed towards the rotatable member outboard of said pressure chambers, and inner and outer seals associated with the rotatable member, said ducts 35 being adapted to convey pressurized fluid to bleed paths through said outer seals at least to said pressure chambers. The lubrication chamber comprises a lubricant reservoir 19 and wicks 20 which convey lubricant to bearing races 13. Impellers 22 mounted on the member 12 draw a lubricant mist through the bearings and return it by way of a passage 26 to the region of the member 12 between-the bearings. Leakage of lubricant from the lubrication chamber is prevented by maintaining a pressure gradient across the inner seals 23, the higher pressure being in the static pressure chambers. Pressurized air is supplied to the chambers from the turbine inlet by way of the passages 37, 36, the ducts 35, and the bleed paths through the seals on the walls 30. The pressure gradient is maintained at a suitable value under system changes through the centrifugal pump 32, which tends to draw air from within the lubrication chamber towards the chamber 28 by way of bores in the member 12. The two chambers 27, 28 are interconnected by a duct 31.