GB1104326A - Improvements in or relating to breathing means for high speed turbo-units - Google Patents

Abstract

1,104,326. Bearings; lubricating. WESTLAND AIRCRAFT Ltd. 17 Aug., 1966 [18 Aug., 1965], No. 35516/65. Heading F2A. [Also in Division F1] Bearings for a high speed turbo-unit are enclosed in a space which also contains lubrieating means, has a shaft passing therethrough, and is sealed except for at least one breather opening arranged to maintain the pressure in the space substantially at ambient pressure without permitting the leakage of lubricant from the space. In an embodiment, two spacedapart ball-bearings 5, Fig. 1, support a shaft 4 having a turbine 2 at one end thereof and a compressor 3 at the other end. The bearings are mounted in a carrier 6 which is supported in an outer shell 7. A cylindrical-shaped member 8b divides the annular space between the carrier 6 and the shell 7 into an oil-sump 8 and an annular space 8a, Fig. 2. Lubricant is conveyed from the sump 8 to the shaft 4 by means of wicks 9. An impeller 17 is provided at each end of the shaft 4 to draw oil-mist through the bearings 5 from a bearing chamber formed between the carrier 6, the shaft 4 and the bearings 5. The oil-mist is returned to this chamber via grooves 20 in annular members 19, ports 21, the annular space 8a and via ports 8c in the carrier 6. Labyrinth seals 18 are provided between sleeves 16 attached to the shaft 4 and the annular members 19 and a breather-tube 22 is provided to prevent oil from escaping through the seals. The tube 22 connects the bearing chamber with ambient pressure by passing through the carrier 6, the cylindrical-shaped member 8b and the outer shell 7 and is secured to the latter by means of bolts 25 and a support 24. A filter unit 27 is mounted on the tube 22 and serves to separate oil from the mist, the oil draining back into the bearing chamber. The shaft is provided with a V-shaped groove 30 which prevents oil from being centrifuged into the breather tube 22.