Messerschmitt-boelkow-blohm Gesellschaft MIT Beschraenkter Haftung

Messerschmitt-bolkow-blohm Gesellschaft MIT Beschrankter Haftung

Messerschmitt-bolkow-blohm Gmbh

Messerschmitt-boelkow-blohm Gmbh

Alois Schwarz

Karlheinz Mautz

Michael Stephan

Emil Weiland

Hubert Frommlet

Karl-Heinz Mautz

Alexander Schroder

The blade angle of the blades is adjustable in a rotor for a rotary wing craft by a lever mechanism (13, 14 or 41, 42) secured to the radially inner end of an extension bushing (7; 7.1) or shaft (43). The extension bushing (7; 7.1) or shaft (43) is connected with its radially outer lever (15 or 44) to the blade root (2) or a blade root mounting (39, 50) of a rotor blade in an angular position adjustable manner for adjusting the tracking of the blades. The bushing (7; 7.1) or shaft (43) is adjustable in its angular position relative to the blade root (2) by adjustment screws cooperating with a free end of the lever (15 or 44) which reaches into a gap between two of such adjustment screws (16 or 45) cooperating with counter nuts (17 or 46). By adjusting the angular position of the bushing or shaft with the screws it is possible to assure a uniform tracking among all the blades of a multiblade rotor. Such uniform tracking is desirable if the blades of a rotor are to rotate in the same plane.

Apparatus for adjusting the tracking of the blades in a rotor,

The blades or wings of a rotor for example of a rotary wing aircraft, are nnected to the rotor head in a hingeless and bearingless manner by a blade neck section, which is flexible relative to torsion loads, flapping movements and lead-lag movements. The blade angle adjustments are made by a torsion stiff control rod bridging the flexible blade neck section. The control rod is flexible relative to flapping and lead-lag movements. The radially outer end of the control rod is rigidly connected to the respective wing. The radially inner end of the control rod is connected to the rotor head in such a manner that the control rod is movable substantially in the direction of its own longitudinal axis.

Rotor having a hingeless and bearingless blade connection

The blade angle of the blades of a rotary wing aircraft is adjusted by a control rod (5) inside the hollow rotor head operating a control shaft (8) extending radially out of the rotor head in axial alignment with the blade angle adjustment axis. The adjustment movement of the shaft (8) is transmitted to the respective blade (3.3) by a yoke (11, 12) and a torsion-stiff sleeve (7) which bridge the blade root (3.1) and the torsion yielding blade neck (3.2) respectively. The blade root (3.1) is connected to the rotor hub (1) by a forked member (2) through which a portion (11) of the yoke extends for connection to the control shaft.

Rotor structure for a rotary wing aircraft

The rotor blades of a rotary wing aircraft are mounted at their blade roots pon a rotor head formed as an integral body of composite fiber material shaped to define a plurality of bifurcated rotor blade support arms between which the blade roots are mounted. Each of the blades is formed, at least in the region of the blade roots, with a laminated configuration including at least two layers formed with a fiber loop having a unidirectional fiber orientation extending longitudinally of the rotor blade and about a load-bearing connection between the blade root and the rotor head. An intermediate layer having a crosswise fiber orientation is provided between each of the at least two layers of the blade root which integrally joins the two layers and the fiber loop is enclosed by support members at its longitudinal edges at the inside and outside thereof at least in the region of the load-bearing connection.

Rotor mounting assembly for rotary wing aircraft

The wings of a rotary wing aircraft comprise, for example, four wing blades orming two pairs of wing blades whereby the blades of a pair are located diametrically opposite each other. The blades of a pair are connected to each other by a spar extending from wing blade to wing blade. The spar is operatively secured to the rotor head. Each spar has between the rotor head and the respective wing blade a zone with a torsion yieldability larger than in the spar outside said zone. A beam stiff against bending, bridges the zone, referred to as a torque soft zone, from the wing blade toward the rotor head except for a small flexible section between the rotor head and the radially inner end of the beam. The flexible section permits the blade flapping movements and the blade lead-lag movements.

In a rotor for a rotary wing aircraft, an integral central headpiece supps the rotor blades. The headpiece consists of two plates interconnected by a centrally arranged distance member. Each plate has a similar star-shape with at least four angularly spaced point-like arms. Each plate is formed of a number of superposed layers with each layer containing continuous loops extending in the direction of the point-like arms. At least one loop extends from one point-like arm into another diametrically opposite point-like arm. Others of the loops, located in the other point-like arms, extend radially outwardly from the loop extending through the two point-like arms. The headpiece consisting of the plates and distance member, is a unitary or integral structure.

Headpiece support for rotor of a rotary wing aircraft

The present four-blade rotor is made up of two blade pairs, each blade pair aving two rotor blades arranged diametrically opposite one another. The blades of each blade pair are coupled to each other by means of a coupling loop for taking up centrifugal forces produced by the rotation of the blades. The present rotor system also has a centering device including a centering body and tension straps for each coupling loop. The tension straps connect the respective loop end to the centering body whereby the two coupling loops may be centered in the rotor head practically without play and without substantially limiting the free movement of the coupling loops.

Four-blade rotor, especially for helicopters

The mounting assembly of a rotary wing aircraft is formed to include a ceal headpiece which operates to support the rotor blades of the aircraft, which blades are mounted to extend radially outwardly from the central headpiece. The headpiece includes rotor mounting supports having a bifurcated configuration consisting of two arms each having a flat, generally planar shape which extend at a right angle relative to the plane of the rotor. The headpiece may be formed of a pair of generally congruent plate members with an intermediate spacer member located therebetween, with the plate members and the spacer member being integrally joined together in a unitary structure made of composite fiber material.

The present four-blade rotor structure comprises two pairs of rotor blades. iametrically opposite each other located blades form a pair and the blades of a pair are connected to each other by coupling belts which are tension resistant and torsionally yielding. One coupling belt extends substantially horizontally whereas the other extends substantially vertically. The coupling belts are centered in the rotor head by respective centering bodies. The centering bodies are connected to their respective belt by bearing elements capable of taking up pressure loads while simultaneously permitting a blade angle adjustment. In a modification the bearings may be slide bearings.

The present hingeless rotor structure, especially for rotary wing aircraft, omprises at least one pair of rotor blades, whereby the blades of a pair are arranged diametrically opposite each other. The blades are secured to a rotor head for proper blade angle adjustment. Each blade has its root or radially inner end secured in a blade root sleeve which in turn is held in a respective blade angle bearing bushing. The blades of a pair are interconnected by a tension resistant, torsionally yielding member. One bearing which is pressure loadable in the direction of the longitudinal blade axis is provided for each blade pair between one of the respective blade root sleeves and the corresponding blade angle bearing bushing. The tension resistant, torsionally yielding member is capable of a certain stretching or elongation during operation. In order to compensate for such an elongation, the tension resistant, torsionally yielding members are installed in such a manner that in the rest or non-rotating condition of the blades, the center is radially displaced from the axis of rotation of the rotor head toward the respective pressure loadable bearing by one half of the length of said elongation.

Rotor structure, especially for hingeless rotary wing aircraft

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.

Bearing seal and lubricating device

A rotor for a rotary wing aircraft includes a rotor head and an even number of rotor blades arranged in pairs about the rotor head. The rotor blades of each pair are located diametrically opposite each other and each blade has a root end positioned radially inwardly toward the head. Bearings carried by the rotor head pivotally support each of the rotor blades. A torsionally elastic connection member extends between and connects the roots of a pair of rotor blades, and the connection member is mounted at its longitudinal center in the rotor head for pivotal movement about its longitudinal axis.

Rotor for a rotary wing aircraft

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.

Apparatus for connecting a rotor blade to a rotor hub

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. The adjustment capability permits sufficient adjustment of the blade with respect to the hub to ensure desired balance between the several blades of a given rotor.

Growing community of inventors

Putzbrunn, Germany

Alois Schwarz