GB579586A - Improvements in or relating to helicopters - Google Patents

Abstract

579,586. Helicopter rotors. FAIREY AVIATION CO., Ltd., and FORSYTH, A. G. Aug. 31, 1944, No. 16586. [Class 4]. A helicopter rotor is driven by internal-combustion engineunits mounted at the outer ends of arms carried by the rotor head, and the rotor blades are mounted on tubular shafts surrounding the arms, .the inner ends of the shafts being mounted in sockets in the rotor head by means of bearings which allow pitch change movement of the blades and at the same time take up loading due to the centrifugal force on the blades. By this means the centrifugal force on the engine units is transmitted to the rotor head independently of the blades and change of pitch may be effected without undue effort. In one form, Fig. 1, a rotor shaft a is mounted in bearings (not shown) and carries keys b engaging slots in the heads d of arms e on which engine units f are mounted. The keys and slots are formed with spherical surfaces so that the rotor may tilt about the centre c. The outer surfaces of heads d abut the spherical inner surface of a hollow rotor head g which is formed with sockets h for rotor blades carried by tubular shafts m surrounding the arms e. The shafts m are rotatable in the sockets h by means of thrust bearings k, and bearings n are provided between the shafts and arms e. In another form, Fig. 2 (not shown), the shaft a is fixed and the heads d of arms e are mounted on the shaft by means of a spherical ball-race to allow tilting of the rotor. In a further form, Fig. 3 (not shown), the heads d and rotor head g are mounted on a fixed rotor shaft a by means of a sleeve and ball bearings, tilting of the rotor being allowed by a universal mounting of the shaft.