GB919231A - Multiple-engine aircraft power plant - Google Patents

Abstract

919,231. Turbines. DE HAVILLAND ENGINE CO. Ltd. Feb. 19, 1960 [Feb. 20, 1959], No. 5989/59. Class 110 (3). [Also in Group XXXIII] An aircraft power plant includes at least two gas turbine engines 11 mounted in parallel with one another, each including an annular shaped air intake 12, a compressor 13 and a turbine 15, each output shaft of which extends rearwardly away from compressor 13, transmission mechanism 16 connecting each output shaft to a common reduction gear-box 21 disposed downstream of the engine compressors and serving to couple the two turbines, a final drive shaft, in a casing 23, from the gear-box 21 to a propeller or rotor and ducting 22 defining paths for the turbine exhaust gases, which ducting 22 is displaced laterally from the final drive-shaft, so that the shaft is not subjected directly to the heat of the gases. Fig. 1 is a plan view of this arrangement, which incorporates a second reduction gear-box 24, connected between the final drive-shaft of gear-box 21 and the propeller shaft 26. Gear-box 21 is situated partly above and between the engines 11, so that, when viewed from the front, Fig. 3, not shown, the axes of the engines 11 and the final drive-shaft are at the vertices of an isosceles triangle. Also the propeller blades swept area includes both air intakes 12, which are substantially unobstructed by the gear-box 24. Freewheel devices 30, 31 enable either engine to drive the propeller should the other engine fail, but the device 31 may also be set so that the engine attached thereto, in Fig. 4, may overrun the gearing. This engine also drives, by a shaft 32, the gearing 33, which is used to drive shafts 35 connected to auxiliary apparatus and which has a freewheel device 34 enabling it to overrun the shaft 32. The gearing 33 may also be driven through shaft 36 from the gearing 16, which provides the input from the engines 11 to the gear box 21, and incorporates another freewheel device 38. The power plant may be installed in an inclined attitude to drive a helicopter rotor through an angled gear-box, Fig. 5, not shown. In a modification, Fig. 6, not shown, comprising two power plant/propeller combinations, as described above, there is a coupling between the front or rear gear-boxes of each pair of engines, so that if one, two or three engines should fail, the remaining engine(s) will still be able to provide a balanced output to the two propeller shafts.