GB818487A - Helicopter - Google Patents

Abstract

818,487. Helicopters. UNITED AIRCRAFT CORPORATION. May 28, 1957 [June, 1, 1956], No. 16886/57. Class 4. [Also in Group XXVI] A helicopter rotor is driven through a master gear journalled for rotation about the rotor axis and meshing with a plurality of pinions each driven by a turbine supplied with fluid under pressure. Fig. 3 shows a gas turbine 78 driving a compressor 88 with an air intake 90, delivering compressed air to a manifold 74 through a flexible joint 91 and a heat exchanger 94 in the exhaust duct 92 of turbine 78. Manifold 74 is fed by two such gas turbine and compressor units, and feeds four turbines 72 (two shown), each having optional fuel injection at 85 and ignition at 87. A valve 105 may be opened to by-pass the turbines 72. Each turbine shaft 71 has a pinion 70 driving a gear 68 integral with a gear 66 and rotatably mounted on a shaft 56 fixed to a plate 54 rigid with the rotor pylon 20. Each gear 66 meshes with a central gear 64 journalled on the pylon 20 and integral with a sun gear 52. Four planet gears 48 (two shown) journalled in the rotor hub 39 mesh with the sun gear 52 and a ring gear 50 secured to the shafts 56. The five blades 28 (two shown) are connected to the hub through pitch change bearings 38, flapping and drag hinges 34, 36, and folding hinges 32, conventional cyclic and collective pitch controls being used. The exhaust of each turbine 72 may be led to atmosphere through a duct 73 and valve 61, or to atmosphere through valve 179, duct 77, and a heat exchanger 81 in the turbine inlet duct, or may be led through a duct 75 a valve 63, and through the interior of the pylon 20 to a distributer 67 feeding nozzles 95 through flexible couplings 108. Each nozzle 95 discharges into a throat 89 in a blade so that the flow entrains ambient air. The mixture is ducted along the hollow blade, and may be used for de-icing, or burnt with more fuel from nozzles in the blades for extra power. The turbines 78 are mounted on stub wings on the fuselage. An anti-torque tail rotor is driven by a take-off shaft 104 and bevel gear 102 meshing with gear 64, or by an auxiliary turbine fed with compressed air, or by an independent power unit.