Abstract: A two-bladed aircraft rotor is disclosed having blades mounted for freedom of blade motions, at least in the flapping sense and in the pitch-change sense, with the blades driven by flexible bellows.

Abstract: A bladed aircraft rotor is disclosed having blades mounted by means of flexible devices providing freedom for blade motions, at least in the flapping sense and in the pitch-change sense, without employment of flapping or pitch bearings or pivots, the rotor also being provided with a central bearingless joint for transmitting thrust forces while providing freedom for angular movement of the rotor as a whole about a center point on the axis of rotation. A constant velocity torque-transmitting system is also provided.

Abstract: A plenum for a circulation control rotor aircraft which surrounds the rotor drive shaft (18) and is so constructed that the top (32), outer (38) and bottom (36) walls through compressed air is admitted are fixed to aircraft structure and the inner wall (34) through which air passes to rotor blades (14) rotates with the drive shaft and rotor blades.

Abstract: A rotatable bladed device for vehicles, such as especially a helicopter rotor, which has its blade pitch controlled by a setup which includes a swash plate setup controlled by a set of hydraulic actuators and the particular swash plate setup position and attitude in turn controls the blade pitch by a plurality of rods pivoted together at one end at one particular point movable longitudinally of the rotor axis, one of which rods has its other end pivoted at a point on the pitch arm by which it controls pitch and another of which rods is also pivoted at a point fixed by the rotational position at any particular time of the rotor hub.

Abstract: A helicopter rotor system using composite flexbeams for connecting a rotor blade to the rotor hub, each flexbeam being of C-section and having a web section made up of 0.degree. and .+-.45.degree. plies and top and bottom flanges made up of low angle plies in the direction of their length with their ends being connected by an arc of plies so that the top and bottom flange plies are continuous with an attachment fitting encased at the ends of the flexbeams.

Abstract: In a helicopter rotor, a blade control linkage is externally supported on the rotor hub and connected to the root end of a torque tube to provide torsion inputs to the blade by twisting the flexible spar member, which is enveloped by the torque tube and joined to the torque tube at a predetermined blade radial location. The linkage forms a parallelogram with the torque tube, and short vertical ball joint mounted links incline in two directions to accommodate blade lead/lag and flapping motions without introducing pitch coupling.

Abstract: A composite bearingless helicopter rotor system utilizes one single and only flexible strap as at least the principal wing support, and also preferably has also a blade pitch shaft. The line of shear centers of the flexible strap, the line of shear centers of the blade pitch shaft, and the pitch axis each lie somewhere along the one straight line, or substantially so.The cross section of the flexible strap may vary but in each case it is one which is asymmetrical relative to a line through its center of gravity and parallel to the axis of rotation of a rotor, and in each case the line of shear centers of the flexible strap, the line of shear centers of the blade pitch shaft and the pitch axis all are spaced from the line of centers of gravity of the flexible strap. A number of examples of varying specific overall configurations of flex straps and blade pitch shaft will be found described and illustrated herein, of which an example is that in FIG.

Abstract: Each rotor blade is rigidly affixed to a pair of strap members which are also rigidly connected to a rotor hub. Each strap member is defined as an elongated open box beam of rectangular cross section. Each strap member has its open web located on the side of the rectangle opposite that of its associated strap member of a pair. A pitch shaft which is located intermediate the two strap members associated with the given rotor blade, is rigidly attached to that rotor blade, and is rotatably connected with respect to the rotor hub. In alternative configurations, the strap members are configured as various alternative solid or open web designs, but all are configured as pairs having a pitch shaft therebetween.