Abstract:
A transmission system that is used in conjunction with a microturbine engine for propelling an aircraft body, such as a propeller-based fixed-wing aircraft or a rotor-based vertical lift aircraft, or for a wide variety of other applications. The output shaft of the microturbine engine preferably operates at a rotational speed in a range between 72,000 RPM and 150,000 RPM with an output power between 150 HP and 5 HP (and most preferably operates in an extended range between 50,000 RPM and 200,000 RPM with an output power between 200 HP and 5 HP). The transmission system includes a traction drive stage that provides a reduction ratio preferably having a value of at least 7, and most preferably greater than 9. The transmission system is of small-size preferably having a maximum diameter less than twelve inches. Preferably, the input stage of the transmission system is self-equilibrating such that first shaft can be supported without bearings and is operably coupled to the output shaft of the microturbine engine by an outside diameter piloted spline coupling mechanism. For vertical lift applications, a single traction stage along with a bevel gear assembly or other shaft transmission mechanism can be used to provide the necessary RPM reduction.
Abstract:
An aerial vehicle including a toroidal fuselage having a longitudinal axis, and a duct extending along the longitudinal axis between a leading edge and a trailing edge of the fuselage, first and second counter-rotating, variable pitch rotor assemblies coaxially mounted within the duct of the fuselage, and at least one canard wing secured to the toroidal fuselage and having a leading edge positioned out of the duct of the fuselage and axially forward of the leading edge of the fuselage, wherein at least a portion of the canard wing comprises a control surface having a variable angle of attack. The invention provides an aerial vehicle that can take-off and land vertically, hover for extended periods of time over a fixed spatial point, and operate in confined areas. The aerial vehicle also has the ability to transition between a hover and high speed forward flight.
Abstract:
A ring-wing aircraft suited particularly, although not exclusively, to use in micro-unmanned air vehicles (UAV's) with ring-wings. An aircraft (10) according to the invention comprises a ring-wing (11) defining a duct (16) with a longitudinally-extending central axis (31), propulsion element (15) located within the duct and moveable aerofoils (13, 18) for controlling the aircraft in flight, the ring-wing being truncated obliquely at one end, that end being the rear (11b) when in horizontal flight, to form a ring-wing with opposed sides of unequal length. This arrangement produces center of mass offset from the central axis of the ring-wing, the pendulum effect will ensure that the aircraft will roll so that its center of mass will always be at the lowest height possible when the aircraft is airborne. Therefore the aircraft has a preferred orientation, and the control surfaces can be oriented with respect to this preferred orientation. In addition, the oblique truncation at the rear keeps the center of mass towards the front of the aircraft thereby giving improved stability in all three axes.
Abstract:
An unmanned air vehicle (UAV) having a ducted fan configuration with a propeller mounted inside of an opening that extends longitudinally through a fuselage. A gyroscopic stabilization device is attached to the propeller shaft such that rotation of the propeller shaft also results in rotation of the gyroscopic stabilization device. The gyroscopic stabilization device has sufficient mass and rotates at a sufficient angular velocity such that the aircraft is gyroscopically stabilized during flight. In one embodiment, the gyroscopic stabilization device comprises a ring mounted to the outer tips of the propeller and in another embodiment is comprised of a disc.
Abstract:
A remotely-controlled unmanned mobile device (UMD) adapted to function as a robot scout to enter and reconnoiter the site of a disaster and to communicate to a rescue mission information regarding conditions prevailing at the site, making it possible for the mission to decide on rescue measures appropriate to these conditions. The UMD is operable in either of two modes. In its air-mobility mode the UMD is able to vertically take off and land, to fly to the site and then hover thereover. In its ground-mobility mode, the UMD can walk on legs over difficult terrain and through wrecked structures and ruins. The UMD is provided with condition-sensitive sensors for gathering data regarding conditions prevailing at the site, and position-sensitive sensors for avoiding obstacles in the path of the walking UMD, thereby assuring safe mobility. Other sensors govern geo-referenced navigation and flight control functions.
Abstract:
A radio controlled aerial disc capable of flight in any direction when airborne. The invention provides upper and lower body portions which form a disc shaped housing when connected. Within the housing there is a servo motor and drive assembly coupled to a quadripartite blade to provide lift and motion to the aerial disc. A servo control mechanism and a rear prop assembly are also components of the invention for controlling the movement of the aerial disc. A receiver mounted on the aerial disc provides a method of receiving signals from a remote transmitter to control the movement of the aerial disc.
Abstract:
A method for reducing a nose-up pitching moment in an unmanned aerial vehicle during forward flight. The unmanned aerial vehicle includes counter-rotating rotor assemblies that are mounted within a duct. Each rotor assembly includes a plurality of rotor blades. The method involves adjusting the rotor blades to have substantially zero pitch. Then rotating the rotor assemblies to produce a virtual plane across the duct. The virtual plane is operative for substantially deflecting air passing over the fuselage away from the duct. In one embodiment of the invention, the method involves the further step of obstructing at least a portion of the bottom of the duct to inhibit air that is flowing across the bottom of the duct from passing into the duct.
Abstract:
An unmanned aerial vehicle (UAV) has a toroidal fuselage and a rotor assembly having a pair of counter-rotating rotors secured in fixed coaxial combination with the toroidal fuselage to provide a vertical takeoff and landing (VTOL) capability for the UAV. One embodiment of the VTOL UAV is especially configured for ground surveillance missions by the inclusion of an externally mounted, remotely controllable stowable sensor subsystem that provides an azimuthal scanning capability and a predetermined elevation/depression scanning capability to accomplish the ground surveillance mission and a foldable landing gear subsystem to facilitate landing of the VTOL UAV at unprepared ground surveillance sites.
Abstract:
An unmanned aerial vehicle (UAV) having a toroidal fuselage and a rotor assembly including counter-rotating rotors coaxially mounted with respect to the toroidal fuselage incorporates ancillary aerodynamic structures aerodynamically configured and mounted in combination with the toroidal fuselage to provide a nose-down pitching moment to counteract the nose-up pitching moment generated by airflow over the toroidal fuselage during forward translational flight of the UAV. The ancillary aerodynamic structures have a cambered airfoil profile to provide high lifting forces. The ancillary aerodynamic structures may have centers of lift located significantly aft of the quarter-chord line of the airfoil, and are symmetrically mounted in combination with the lateral sides of the toroidal fuselage so that the centers of lift are located aftwardly of the fuselage axis of the toroidal fuselage in forward translational flight modes such that the ancillary aerodynamic structures generate a nose-down pitching moment to counteract the nose-up pitching moment due to airflow over the toroidal fuselage in forward translational flight. In a first embodiment, the ancillary aerodynamic structures are fixedly mounted in combination with the toroidal fuselage at a predetermined angle of incidence. In a second embodiment, the ancillary aerodynamic structures are rotatably mounted in combination with the toroidal fuselage to provide variable incidence ancillary aerodynamic structures for the UAV.
Abstract:
A rotor blade subassembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a flexbeam, an integrated torque tube/spar member, and an aerodynamic fairing or rotor blade. The flexbeam is a laminated composite structure that reacts centrifugal loads and a majority of the bending loads of the rotor assembly. The flexbeam has a spanwise predetermined linear twist so that the pretwisted flexbeam is unstrained during specified forward flight conditions. The integrated torque tube/spar member is formed as a continuous, filament wound tubular composite structure having high torsional and bending stiffness that provides a continuous torsional load path and facilitates load coupling between the rotor blade and the pretwisted flexbeam. The spar segment of the functions as the primary structural member of the rotor blade subassembly and, is operative to react all bending, torsional, shear, and centrifugal dynamic loads of the rotor assembly. The torque tube segment reacts all torsional loads and some of the bending loads of the rotor assembly. The rotor blade is fabricated from a high modulus composite material and has a high aerodynamic taper such that the tapered rotor blade has a low outboard mass, a high inboard stiffness, and a high chordwise frequency. The high chordwise frequency allows the rotor assembly to be operated over a weaker modal response zone. The tapered rotor blade includes a triangularly shaped trailing edge segment that is responsive to the aerodynamic pressures encountered during operation of the shrouded counter-rotating rotors.