GB624494A - Improvements in or relating to compressors - Google Patents

Abstract

624,494. Axial-flow compressors. BRISTOL AEROPLANE CO., Ltd., MARCHANT, F. C. I., and ROBINSON, S. June 16, 1947, No. 15809. [Class 110(i)] Balancing end-thrust; multi-stage compressors.-The compressed fluid is applied to a face of the rotor to produce an axial thrust opposing the end thrust; in a multistage compressor plant the applied fluid is derived from another of the compressors. In the arrangement shown, a low-pressure turbine-type compressor 6 on a shaft 8 feeds a similar high-presure compressor 7, driven by a tubular shaft 9, through an annular duct 10 of which the walls are connected by radial arms and which carries diaphragms 14, 15. The diaphragm 14 carries a bearing for the shaft 8 and encloses with the low-pressure rotor a space which communicates with the duct 10 only through a labyrinth packing. The diaphragm 15 ends in a labyrinth packing surrounding a bearing 17 by which the high-pressure rotor is supported, and forms with the end of this rotor a chamber 27 which communicates with the duct 10 through a narrow gap; a similar chamber 39 at the other end of the rotor communicates with the outlet duct of the compressor only through a labyrinth packing, and a lower pressure is maintained in this chamber than that in the chamber 27, for example, by connection to an intermediate stage of the compressor 6, so that there is a resultant thrust to the right. This thrust may be given the required value by selecting the diameter of the inner wall 25 of the chamber 27, which is integral with a plate fixed to the end of the rotor, to determine the effective diameter of this plate.