Stator vane assembly for axial flow compressors

摘要

845,325. Axial-flow compressor stator casings. GENERAL ELECTRIC CO. Nov. 29, 1957 [Dec. 18, 1956], No. 37271/57. Classes 110 (1) and 110 (3). In a stator assembly of a multi-stage axialflow compressor comprising a casing and a plurality of stator vanes mounted on support rings spaced inwardly from the casing, the space between the casing and the support rings is subdivided into a separate compartment for each row of blades, and the support rings are urged radially inwardly by the pressure of working fluid bled from the stages corresponding to the respective blade rows. The compressor shown comprises a casing 20 formed in two halves, the flanges 10 of which are secured together by bolts 12. The casing parts are formed with internal, annular ribs 22 of T-section and with ribs 44. The stator vanes 58 are mounted in support rings 60 which are also formed of two semi-circular parts, two rows of vanes being mounted in each ring, and the support rings are located within the casing 20 by means of the ribs 22. Each support ring 60 is formed at its ends with annular axially-projecting flanges 64 and at its mid-portion with an annular, radially-projecting rib 90. Upon assembly, the flanges 64 of the support rings engage the T- section ribs 22 of the casing 20 as shown in Fig. 6 and the ribs 90 bear axially against the sides of the ribs 44 as shown in Fig. 7. The support ring 82 at the downstream end of the compressor is not provided with an intermediate rib and the two rows of stator vanes carried thereby are spaced closely together axially, as a row of rotor vanes is not disposed therebetween. The flanges 64 of the downstream end support ring 82 are so dimensioned that no radial clearance is provided between the flanges and the recesses in the T-section rib 22 and in the casing flange 56. Annular spaces 110 are provided between the casing 20, vane support rings 60 and the ribs 22, and 44 and openings 120 are provided in the support rings 60 at the downstream end of each of these spaces so that air under pressure flows from the compressor working passage into the spaces and so exerts a radially inward force on the support rings. The support rings 60 are prevented from circumferential movement by means of strips which bear against the ends of the semi-circular halves of the rings and are received in recesses in the casing flanges 10.