| 摘要 |
1,200,348. Elastic - fluid turbines; axial-flow compressors. UNITED AIRCRAFT CORP. Oct. 27, 1967 [Oct. 31, 1966], No.48979/67. Headings F1C and F1T. An adjustable aerofoil stator vane 24 for a turbine or compressor comprises generally circular end portions 36, 68 enclosed by housings 40,72 a journal 34 extending from the end portion 36 and journalled in a bearing 60 having a spherical surface to allow for tilting produced by thermal distortion and a spherical journal 86 connected to the end portion 68 and to an actuating lever 90 through splines 84, 88 and journalled in a bearing surface 94 in the outer casing 22 of the machine. In the embodiment shown, the machine is a turbine incorporated in a gas turbine engine, and air bled from the compressor of the engine is introduced into the hollow vane 24 to cool it, entering through the hollow journal 34 and passing through holes 32 in an inner cam 30 to scrub along the interior of the vane. The cooling air then passes through passages 78, annular chamber 80 and one or more discharge passages 82 and then flows along the interior of the outer casing 22 to cool it. Seal ring 42 is urged into sealing contact with the housing 40 by the pressure of the cooling air, transmitted via a passage 44. Seal ring 74 is urged into sealing contact with the housing 72 by combustion gas pressure, to which it is exposed through holes (not shown) in the end portion 68. Housing 40 is retained relative to vane 24 by a retainer ring 50 and is pressed into sealing engagement with the end portion 36 by the combustion gases acting on the outside of the housing in opposition to the lower pressure of the cooling air acting on the interior of the housing via a passage 46 and an annular chamber 48. Because a portion only of the external surface area of the housing 72 is exposed to the combustion gas pressure, there is a net force urging the housing and the end portion 68 towards the outer casing 22 with arcuate flanges 76 in sealing contact with the outer casing. The flanges 76 of the row of housings 72 abut to form a pair of seal rings. Similarly, flanges 56 extending from the housings 40 form a seal ring which is urged by combustion gas pressure into sealing contact with a diaphragm 58. |
