Abstract: A flexible blade neck of a helicopter rotor blade is bridged by a torsion gid sleeve for the blade angle adjustments. The radially outer end of the blade neck and sleeve are rigidly connected to the wing section of the blade. The radially inner end of the blade neck forms a blade root which is secure to the rotor head or hub. Additionally, the radially inner ends of the blade root and of the sleeve are interconnected by a ball and socket arrangement permitting a universal movement between the sleeve and the blade neck, thereby decoupling sleeve movements from the blade neck and vice versa.

Abstract: The wing blades of a helicopter rotor each are connected to the rotor hub a connection, e.g. a spar being .fwdarw..rarw. including a hinge which is at least fictitious to permit lead-lag movements of the blades <yielding relative to torsion to permit the blade angle adjustment>. A rod, which is stiff in the lead-lag direction and yielding against torsion, is connected in parallel to the connection between the blade root and the rotor hub. One connection of the rod is rigid, for example the connection to the blade root. The other connection of the rod is elastically yielding substantially only in the plane of the rotor whereby a substantial damping of blade movements in the lead-lag direction is accomplished.

Abstract: The wing blades of a hingeless and bearingless multiblade rotor are connected to a substantially rigid rotor hub by spar sections elastically twistable and bendable in the flapping direction and in the lead-lag direction. The mounting positions on the periphery of the rotor hub for connection of the spar sections of the respective blades are off-set relative to the angular position of the corresponding blades to which they are connected. Further, the mounting positions for the spar sections of each rotor blade are situated on the periphery of the half side or far side of the rotor hub, facing away from the respective rotor blade.

Abstract: A bearing seal for the outer and inner blade angle bearings of a rotor hub of a rotary wing aircraft comprises a lubricating oil chamber interconnecting the inner and outer bearings and extending coaxially therebetween. The bearings are provided with sealing rings at their faces opposite the lubricating oil chamber. A shielding member is positioned in front of the face of the outer blade angle bearing facing the lubricating oil chamber. A receptacle is arranged as part of the chamber and positioned in operative relationship with the deflector member for entrapping particles contained in the lubricating oil and separated therefrom by the effect of centrifugal forces as the oil migrates from the inner blade angle bearing toward the outer bearing.

Abstract: A rotor blade is connected to a rotor hub, for example, in a helicopter, by t least one pair of damping elements and by a blade connector bolt. The damping elements comprise metal discs and layers of elastomeric material arranged in sandwich fashion. The damping elements are arranged symmetrically relative to the rotor blade, as well as to the blade connector bolt. Furthermore, the damping elements are connected in a force transmitting manner to the rotor blade on the one hand and to the rotor hub on the other hand.

Abstract: One of two races of a roller bearing is equipped with a sliding ring exteng thereabout, with a melting ring formed of material having a melting point higher than the normal operating temperature of the bearing being interposed between the one race and the sliding ring. Malfunction of the bearing such as might occur by seizure of the bearing rollers will cause at least partial melting of the melting ring whereupon the one race is placed in relative sliding engagement through the melting ring with the sliding ring.

Abstract: Resilient drive means for a helicopter rotor blade. The rotor blade is pivotally supported on a stub shaft which is in turn supported on the rotor hub. First means are fixed to the rotor blade and second means fixed to the stub shaft with resilient and adjustable means positioned therebetween for controlling the angular relationship between the rotor blade and the stub shaft. In this embodiment, said first means comprise a shoulder which projects from the rotor blade and the second means comprise a rectangular hollow frame which is fixed to the stub shaft. The shoulder projects into the hollow frame. Threaded means acting through resilient means holds the first and second means in selected pivotal adjustment with respect to each other but the resilient component thereof permits sufficient slight lead lag movement therebetween as to effect damping of the lead lag mode of the rotorblade.