| 摘要 |
<p>934,363. Axial-flow compressors. ROLLSROYCE Ltd. Sept. 20, 1961 [Sept. 26, 1960], No. 33011/60. Addition to 869,576. Class 110 (1). A compressor for a gas-turbine engine comprises a compressor casing with an apertured portion through which air, compressed by the compressor, is bled, a valve bond encircling the casing and mounted for partial radial movement with respect to the casing and positionable in at least one position in addition to the positions at which the apertured portion is fully opened and fully closed, and means for progressively moving the valve band into and retaining it in each of these positions. A flat strip 32, Fig. 2, which encircles a casing 14 of a compressor 10, Fig. 1, is guided between radial flanges 17, 18 circumferentially spaced on the casing 14. The strip 32 is urged against lips 20, 21 by leaf springs 33 also arranged circumferentially but riveted to blade platforms 22. When the strip is in the position shown in Fig. 2, air compressed in the compressor passes through apertures (not shown) between the stator blades, through openings between casing portions 23, 24 and to the atmosphere through the gaps between the flanges 17 and between the flanges 18. The ends of the strip 32 are welded to straps, one of which has fingers 36, 37, Fig. 5, mounted on a pin 49, and the other has a portion 38 mounted on a pin 46, each pin 46 and 49 being carried by a slide 42 or 43 of inverted channel cross-section. A piston 52 of a ram 50 may be forced to the right against the action of a spring 57 by the pressure of air bled from the compressor through a conduit 53 fitted with a control valve 55. A lever 56 controls the pressure exerted on the piston 52 and thereby the extent to which the latter is forced to the right, which movement causes the piston-rod 60 to operate through linkages 65 to 68, Fig. 5, to force the two slides apart and thereby draw-in the strip 32 around the compressor casing 14. Thus the strip 32 may assume any position between its fully opened position and the position (dotted lines in Fig. 2) at which it fully closes the apertured portion of the casing 14. The ram 50 may additionally effect movement of inlet guide vanes of a highpressure compressor (not shown), or the guide vanes may be independently operated by means acting in synchronism with the ram. Specification 903,236 also is referred to.</p> |
