A rotary wing vehicle includes a body structure having an elongated tubular backbone or core, and a counter-rotating coaxial rotor system having rotors with each rotor having a separate motor to drive the rotors about a common rotor axis of rotation. The rotor system is used to move the rotary wing vehicle in directional flight.

Rotary wing vehicle

A flying object with tandem rotors, in particular a helicopter, has a main rotor and a tandem rotor each with propeller blades which are driven by a rotor shaft and which is hinge-mounted to this rotor shaft. The angle between the surface of rotation of the main rotor and the rotor shaft may vary. A swinging manner on an oscillatory shaft is essentially transverse to the rotor shaft of the main rotor and is directed transversally to the longitudinal axis of the vanes. The main rotor and the tandem rotor each have an auxiliary rotor connected respectively to the main rotor and tandem rotor by a mechanical link. The swinging motions of the auxiliary rotor controls the angle of incidence (A) of at least one of the propeller blades of the main rotor and tandem rotor. There is an acute angle of displacement when viewing the propeller blades relative to the vanes in a direction perpendicular to their respective rotational planes.

Flying object with tandem rotors

An ultralight helicopter has a pair of counter-rotating rotor assemblies which in combination yield zero net angular momentum when rotating at equal speeds. A single motor drives both rotors through a counter-rotating bevel gear set coupled to a pair of concentrically nested output shafts. In an alternative embodiment, the motor is coupled to the rotors through a hydraulic drive system which includes a hydraulic pump and at least one hydraulic motor driving each of the rotor assemblies. The pilot is advantageously suspended in a "hang-glider" type harness from a single hang point positioned proximate the center of lift of the helicopter. A control bar is fixedly mounted to the frame and is grasped by the pilot suspended in the harness. The pilot maneuvers the helicopter in both the pitch and roll directions by manipulating the control bar. The pilot shifts his own center of gravity relative to the center of gravity of the helicopter while grasping the control bar to thereby maneuver the helicopter.

Ultralight helicopter and control system

A compact, rugged, streamline, stiff, pitch control system is devised in a helicopter by concentrically nesting a cyclic pitch control tube and collective pitch control tube within the drive shaft and stationary mast of a helicopter rotor system. The collective pitch control tube terminates in an upper inclined flange which engages a stationary swashplate by means of a bearing member disposed in an inclined bearing raceway in the stationary swashplate. The stationary swashplate in turn is rotatably coupled through a universal joint to the cyclic pitch control tube. Relative rotation of the cyclic pitch control tube with respect to the collective pitch control tube adjusts the stationary swashplate to a selected inclination with respect to the longitudinal axis of the control tubes and of the helicopter mast. A rotating swashplate is rotatably coupled to the stationary swashplate and transmits the angular orientation of the stationary swashplate to the pitch case of each rotor blade as appropriate. The cyclic pitch control tube and collective pitch control tube are rotatably coupled to each other to permit relative angular rotation, but otherwise can be displaced vertically in the direction of the mast as a collective unit, thereby vertically displacing the stationary swashplate and hence the rotating swashplate to effect collective pitch control for all of the blades of the rotor system.

Collective and cyclic in-mast pitch control system for a helicopter

A rotor shaft for helicopters in which a main rotatable shaft is tubular and supports in its interior a shaft (25) which is angularly fixed relative to the helicopter body and disposed coaxially to said main shaft; a swivel plate assembly being coupled to said fixed inner shaft and being disposed, together with at least part of a plurality of kinematic linkages connecting said swivel plate to the rotor blades and a plurality of actuator means controlling the position of said swivel plate, inside the space lying between said main shaft and said inner shaft.

Rotor shaft with internal controls for helicopters

Two Z-crank mechanisms connect at different stations to a rotor swashplate so that translation of the mechanisms causes collective pitch variation of the blades and so that rotation of the mechanisms either together or separately causes cyclic pitch variations of the blades.

Harold Danford Ulisnik

Papers

Pitch control mechanism for bladed rotor