GB719763A - Improvements in or relating to gas turbine jet propulsion engines - Google Patents

Abstract

719,763. Gas turbine, jet-propulsion engines; axial-flow compressors. COLVIN, R. H. Dec. 1, 1952 [Dec. 7, 1951], No. 30382/52. Classes 110(1) and 110(3) [Also in Groups XXXIII and XXXIV] In a gas turbine, jet propulsion engine comprising an axial flow compressor, a combustion chamber, and an axial-flow turbine the rotor 19, Fig. 1, surrounds the stator 16 and is enclosed in an outer shell 17 the space 34 between the shell and the rotor being filled with gas under pressure so as to counterbalance a large proportion of the centrifugal force tending to rupture the rotor. The outer shell is connected to the stator by webs 18 and the stator is secured to an aircraft 11 by webs 12, 13, 14. A cylinder 24, which may be spaced from the rotor to pass cooling air, forms the outer wall of the combustion chamber and is connected to the stator by webs 25. The rotor is supported in the outer shell by sealing devices 38, 45 supplied with oil under constant pressure by a feed line 61 through a non- return valve 64. A seal is also provided at 39. A compressed air connection 35 leads from the comoressor outlet to connections 36. 36a, to the space 34 on either side of fins 40, 41 provided to counterbalance the forward thrust on the rotor. An outlet port 43 forms a vent for the space between the blades. The fins and vent can be omitted if the rotor diameter is increased towards the rear end. A balance connection 62 ensures equal pressures on either side of the seal 45. Each supporting seal comprises an annular ring 46. Fig. 2. secured to the rotor 19 and located between flanges 47, 48 on the outer shell 17. The space between the ring 46 and the outer shell and its flanges is filled with oil retained therein by seals 49, 50. The space is divided centrally by an annular member 51 with a V shaped trough co-operating with a V shaped portion 52 of ring 46 to form an oil channel. Channels are also formed between opposing flanges 53. 54 and oil passages 55. 56 are provided in the ring 46. If the axis of the rotor moves relatively to the outer shell a localized pressure build-up is produced in the oil to restore equilibrium. Radial longitudinally extending fins provided in the oil space prevent swirling and release of localized pressure. Starting is effected bv a compressed air feed 28 to the combustion chamber. In addition thin cylindrical members 65, 66, Fig. 4, and a thin cylindrical member 67 aligned therewith may be associated respectively with rotor blades 31a, 31b and stator blades 30b. A ring 68 fed with compressed air by radially arranged pipes 69 is provided with outlet passages whereby air impinges on the parts of rotor blades 31 n between the member 66 and the rotor 19 to assist in starting. During operation the compressed air supply may be cut off and an atmosphere air inlet valve 70 may be opened to supply cooling air. In a modification. Fig. 5, an aircraft 72 is encircled by an annular wing 71 secured thereto by struts 73 and enclosing the engine.