GB876504A - Improvements in or relating to gas turbine engines - Google Patents

Abstract

876,504. Gas turbine engines; axial-flow compressors. ROLLS-ROYCE Ltd. April 25, 1960 [April 30, 1959; July 7, 1959], Nos. 14780/59 and 23272/59. Classes 110 (1) and 110(3). In a gas turbine engine, a compressor or turbine is provided with pivotally-mounted guide vanes and a vane operating device is disposed inwardly of the guide vanes, movement of the device effecting pivotal movement of the vanes. Means are disposed externally of the engine so as to effect movement of the vane operating device and a linkage is provided to connect the external means to the vane operating device, a portion of the linkage passing through a hollow vane-shape or strut which extends across the working fluid duct of the engine so that the linkage causes no obstruction to fluid flow through the engine. The invention is shown applied to a gas turbine jet engine of the by-pass type, the pivotally mounted vanes being the inlet guide vanes of the high pressure compressor. An actuating device such as an hydraulic or pneumatic ram is mounted externally of the engine and actuates a shaft 25 which extends radially of the engine across the working fluid passage through a hollow support strut 26. An extension 28 is secured to the radially inner end of the shaft and a lever arm 33 is secured to the extension; the lever arm carries a stub shaft 34 on which a roller 35 is rotatably mounted. The roller engages a slot 36 in a link 37, the link 37 being connected by bell-crank levers 40, 41 to links 42, 43 which are connected to further levers 44, 45. Each of the levers 40, 41, 44, 45 is splined on to a rod 47 being secured thereto by a bolt 48. Each rod 47 is rotatably mounted within fixed structure 51 axially of the engine, and each rod is provided with a radially-extending arm 52, the outer end of each arm engaging in a bush 53 which is rotatably mounted in a vane operating ring 54. The ring 54 is mounted for rotational movement within a channel section annular structure 55, 56 by means of rollers 58. Each inlet guide vane 65 is pivotally mounted on a spindle 63 which is formed with an actuating lever 62, the pin 61 of which engages within a bush 60 carried by the operating ring 54. In a second embodiment, the shaft 107 carries an arm 114 at its radially inner end, as in the first embodiment, the arm carrying a roller 115 which engages the forked end 116, 117 of a lever 118, 119 pivoted at its centre on a pin 125 which extends radially of the engine. The other end of the lever is formed with a pin 120 which engages a part-cylindrical bush 127 rotatably mounted in an insert 129 which is itself mounted in a frusto-conical operating ring 133. The ring is formed with a cylindrical extension 134 by which it is rotatably mounted in stator structure 136 by means of roller bearings 135. The operating ring 133 carries bushes 137 in each of which is journalled a pin 138 forming part of the operating crank arm 139.