| 摘要 |
1,201,949. Elastic-fluid turbines; axial-flow compressors. UNITED AIRCRAFT CORP. Oct.27, 1967 [Oct.31, 1966], No.49028/67. Headings F1C and F1T. A adjustable-pitch aerofoil stator vane unit for a turbine or compressor comprises a stator vane 24, Fig. 2; a platform 60, Figs. 2 and 4, having at least one circular portion, a platform 30, Figs. 2 and 3, at the other end of the vane having a circular portion 32; a housing 68 having an opening at least partly circular in shape to recive the platform 60; a seal ring 88 between the housing 68 and the platform 60; a housing 38 having a circular recess 36 to receive the circular portion 32 of the platform 30; a journal 42 extending from the platform 30 and journalled in a bearing 44 having a spherical surface to allow relative tilting between the bearing housing 48 and the vane 24; and actuating means 110 connected to the platform 60 for adjusting the vane. A small clearance between each platform and its neighbour permits the adjustment. In the embodiment shown, the vane 24 is a turbine stator vane in a gas turbine engine, and coolant, which may be compressor discharge air, enters a pivot bearing 82 via a passage 92 and flows through an annular chamber 100 between a bearing bush 82 and the outer pivot spindle 86 of the vane and thence through a passage 103 and an annular chamber 104 to enter the hollow interior the the vane. The coolant then flows out of the vane through the hollow journal 42 to an annular chamber 54 and thence via a passage 56 and a chamber 58 to join the combustion gases. Since the coolant is at a higher pressure than the combustion gases, its presence in the chamber 58 minimizes leakage of combustion gases between the platform 30 and the recess 36. Seal ring 88 is urged into sealing contact with the platform 60 and the housing 68 by coolant pressure communicated via a passage 114, a chamber 116 and a gap 118. |
