GB1266254A - - Google Patents

Abstract

1,266,254. Turbines. GENERAL MOTORS CORP. March 12, 1970 [July 25, 1969], No. 11951/70. Heading FIT. A variable area stator vane assembly, e.g. for a gas turbine, comprises non-adjustable stator vanes 10 secured between outer and inner annular shroud rings 7, 8 and adjustable throttling members 42 disposed between adjacent vanes 10. Each member 42 has radial extensions 46, the radially inner of which is secured to a crank arm 47 fixed to a shaft 48 which extends through a reinforcing spine 32 within an adjacent vane 10 The radially outer extension 46 is attached to an actuating arm 50 which is also secured to shaft 48. All the arms 50 are coupled to a unison ring 51, rotation of which causes rotation of shafts 48 with consequential movement of extensions 46 and members 42 in a generally upstream or downstream direction so as to vary the effective flow area between vanes 10. Each member 42 may be rotatable relative to extensions 46, e.g. so that it can automatically align itself with the flow therepast. The inner shroud ring 8 includes upstream and downstream flanged rings 18, 19 bolted to a combustion chamber wall 20 and porous facing rings 22, 23 secured to the rings 18, 19 by spring clips 24. Similar porous facing rings 12, 14 form part of the outer shroud ring 7. Cooling air is introduced behind the porous facings through holes 61, 62, some exhausting through the facings into the working fluid and the remainder flowing into the interiors of vanes 10, the walls of which may also be porous. In a modification, Fig. 6 (not shown), shafts 48 and cranks 47 are eliminated and the movement of each throttling member 42 is a swinging movement about a fixed pivot (57) on the inner shroud ring 8.