| 摘要 |
1511723 Axial-flow compressors ROLLSROYCE Ltd 14 April 1976 [1 May 1975] 18118/75 Heading F1C A mechanism for varying the angles of at least one row of stator vanes 10 of a compressor comprises an actuator 26 rigidly mounted on the compressor casing and driving a member, e.g. a nut 25 actuated via a rotary screw 24, along a straight line 27 which is tangential to a circle coaxial with the compressor casing, a first connection between a beam 20 and the member 25 which enables the beam to pivot relative to the member but constrains it to move with the member with a motion parallel to the straight line, and a second connection 30, 31 between the beam and the casing at a position on the beam remote from the first connection, the second connection enabling the beam to pivot and to move in the directions of its own length relative to the casing so as to accommodate the compound movement caused by the constraint of the first connection. Flexible links 15 connect the vanes 10 to a unison ring 14 via a ball joint 16, the unison ring being actuated by the beam 20 via a link 21 and ball joints 22, 23. The connection 30, 31 comprises a ball joint 30 which may be mounted on an offset pivot 31 as shown or on a sliding block or on a leaf-spring capable of flexing substantially longitudinally of the beam 20. A further beam 20 and actuator 26 may be located diametrically opposite those shown, both actuators being operated via a pair of flexible drives from a single air motor driven by air bled from the compressor. |
