| 摘要 |
<p>A bleed valve 60 for regulating air flow through a bleed hole 88 in a gas turbine engine compressor casing 49 to control surge, comprises a piston 62 and a static structure 70 defining first, second and third chambers 82, 84, 86. The piston 62 includes first and second end plates 90, 64, and a spindle 66 which extends through a flange 74 of the static structure 70. Air from the compressor can pass into the first chamber 82 via pressure balancing apertures in the form of radial slots 108 (which replace prior art holes 106) in end plate 64, and into the third chamber 86 via a passageway 100 in the spindle 66. Valve 116 responsive to a predetermined pressure in the compressor controls movement of the piston between bleed hole open and closed positions. Wall 68 may alternatively sealingly engage the outer surface of wall 72. A method of operating a gas turbine engine with the bleed valve is also disclosed.</p> |
