This invention relates to helicopter rotors and more particularly to rotor mounting involving a composite fiber-reinforced unitary yoke with resilient inplane restraints.

Soft inplane bearingless helicopter rotor

Wind generator apparatus employs an induction generator with a wind-driven rotor. Connection of the induction generator to AC power lines is controlled by apparatus that compares generator rpm and line frequency. The rotor blades have a pretwisted, varying-chord inboard portion and an untwisted, constant-chord outboard portion. The blades are self-starting, operate efficiently over a range of wind speeds with constant pitch maintained by a torsional biasing mechanism, and pitch up automatically when the normal rpm operating range is exceeded. An improved blade-supporting spar of low torsional stiffness has an I-beam configuration with filament-wound flanges. A pitch damper prevents torsional oscillations while permitting the blades to pitch up readily. The rotor, which includes a teetering hub, is free to weather-vane about the axis of a supporting tower, but a yaw damper limits angular velocity. A guy wire and gin pole arrangement stabilizes the tower and permits easy raising and lowering of the tower.

Wind-driven generator apparatus and method of making blade supports _therefor

A helicopter rotor hub assembly (10) in which a blade grip (30) extends inboard of a yoke (14) and transfers centrifugal forces to the yoke (14) through a spherical elastomeric bearing (38). Pitch change of the grip (30) and blade (32) is accommodated by the spherical elastomeric bearing (38) which also acts as the pivot point for lead-lag motion of the blade (32) and grip (30). A lead-lag damper (22) is located inboard of the elastomeric bearing (38) and is connected between one end of the grip (30) spaced away from the lead-lag pivot and the yoke (14) for damping the lead-lag motion between the grip (30) and yoke (14).

Soft inplane helicopter rotor

A rotor yoke (10) for coupling helicopter blades to a rotatable support mast (12) utilizes a novel laminated construction. Layers (30) of unidirectional fibers and layers (32) of bias ply fibers are arranged in alternating sequence to form an elongate loop structure. At least some of the bias ply layers (32) extend between the sides of the loop to form a transverse central section (20). Further, at least some of the bias ply layers (32) include gaps to provide flexure areas (24) in the sides of the yoke (10).

Laminated composite rotor yoke

A prop rotor hub includes a constant velocity joint in the same plane as a prop blade yoke. Torque is transmitted from a shaft to the blades through the CV joint, hub plates attached to the CV joint, and the yoke, which is attached to the hub plates. Providing all elements in a substantially planar arrangement results in a hub assembly which has significantly less height than a traditional design. The hub itself is in-plane with the yoke, resulting in a more efficient torque transmission from the mast to the rotor.

Prop rotor hub

An improved rotor for a helicopter comprises a yoke at the inner end of each arm engaging the rotor hub by way of a spherical abutment

Rene Louis Mouille

Papers

Rotor for rotating wing type aircraft

Rotor pour giravions

Rotor fuer drehfluegel-flugzeuge

Rotor fuer drehfluegelflugzeuge