| 摘要 |
609,926. Gas turbine plant; centrifugal compressors. LOMBARD, A. A. March 25, 1946, No. 9202. [Classes 110 (i) and 110 (iii)] An internal - combustion turbine engine of the kind in which air under pressure is delivered by a compressor to one or more combustion chambers from which the products of combustion flow to a turbine which is coaxial with and connected to the compressor by a driving shaft having at least one bearing between the compressor impeller and turbine rotor, is provided with an intermediate casing extending between the compressor and turbine, which casing houses a support for a bearing of the driving shaft between the compressor and turbine and accommodates an auxiliary compressor mounted on the driving shaft, the auxiliary compressor being arranged to deliver cooling air under pressure into the interior of the intermediate casing to flow past the bearing. The gas turbine plant shown has a main shaft 1 mounted in a front bearing 2, a centre bearing 4 between the compressor impeller 3 and turbine rotor 6 and a rear bearing 5. Extending between the compressor and turbine is an intermediate casing 8 which carries a housing 9 for the centre bearing and a casing 20 for an auxiliary compressor 22 mounted on the shaft 1. The auxiliary compressor 22 discharges through an outlet 21 into the front portion 11 of the space enclosed by the intermediate casing 8. The cooling air passes from the front portion 11 of the space enclosed by the intermediate casing to the main portion 12 past the centre bearing and thence through the rear bearing housing 7 and then over the front face of the turbine rotor 6 to a space 24 within the fixed inner shroud 18 of the fixed guide vanes 15. The pressure in the space 24 reduces the leakage of hot gases through the clearance between the shrouds 18 and 19. A number of ducts 26 may be used to take cooling air from the space 24 to the outer fixed shroud 17. The air intake 23 to the auxiliary compressor 22 passes radially inwards to the eye of the impeller. |
