GB736017A - Improvements in or relating to gas turbine engines - Google Patents

Abstract

736,017. Gas turbine plant. BRISTOL AEROPLANE CO., Ltd. July 24, 1953 [Aug. 5, 1952], No. 19721/52. Class 110(3). A gas turbine engine comprises in axial sequence a compressor 1, combustion equipment 5 housed between inner and outer air casings 3, 4, and a turbine 6, the compressor and the turbine rotor being mounted on a shaft 9 journalled in bearings. In the Complete drawing, labyrinth or like seals 15, 16 are disposed around the shaft between the compressor rotor 1 and the adjacent bearing 12, and between the turbine rotor 6 and the adjacent bearing 13, respectively, and partition means 17, 18 extend from the stationary members of the seals to the inner air casing 3. A second partition means 60 extends between second labyrinth seals 19, 20 arranged around the shaft between the first-mentioned seals 15, 16 and the bearings 12, 13 adjacent thereto, the partition 60 forming inner and outer chambers 25, 26 within the air casing. Third partition means 61 in sealing connection with the shaft forms within the inner chamber 25 one, or more, innermost chamber, or chambers, 31 which contains the bearings 12, 13. Liquid lubricant is supplied to the bearings from a pump 40 and conduit 41, and a lubricant scavenge pump 44 communicates by conduit 43 with the innermost chamber 31. Air under pressure is supplied to the inner chamber 25 through the duct 46, the temperature of the air being less than that of the air discharged from the compressor and the pressure being greater than that in the innermost chamber. The outer chamber 26 is vented to atmosphere through the hollow vane 47. In the Provisional drawing, the shaft is mounted in three bearings 12, 13, 14. The first partition means are 17, 18 as before, but the second partition means extending between the labyrinth seals 19, 20 comprises the part 21, 22, 23, 24 and forms inner and outer chambers 25, 26. In this embodiment there are two innermost chambers 31, 36, chamber 31 being formed by the partition 32, 33, 34 and housing the bearings 12, 13, and chamber 36 being formed by a partition 37 and housing the bearing 14. Oil supply and return means and air supply to the inner chamber 25 are similar to those shown in the Complete drawing. Fourth partition means 52 in the Complete drawing, and 52 and 50 in the Provisional drawing, which extend from the second labyrinth seals 20, 19 or from the second partition means 60 or 21, 22, 23, 24 respectively, constitute with the first partition means 18 or 18, 17 respectively, chambers which are separately vented thorugh passages 53 or 53, 51 respectively. Fifth partition means 55 extend between the inner air casing 3 and the labyrinth seal 16 adjacent the turbine rotor, and the chamber formed between the partitions 18, 55 communicates with the air duct through openings 54, the air discharging through openings 56 across the upstream face of the rotor.