A rotorcraft aircraft design incorporates double swept forward and aft rotor blades to configured to provide efficient hover and efficient cruise at Mach number of 0.65-0.7 without varying a diameter of the rotor. The aircraft design combines the benefits of helicopters and fixed-wing aircraft, enabling vertical takeoff and landing (VTOL) capabilities while also achieving improved forward flight speed and reduced noise emissions.
B64C 27/28 - Compound rotorcraft, i.e. aircraft using in flight the features of both aeroplane and rotorcraft with forward-propulsion propellers pivotable to act as lifting rotors
A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.
B64C 29/00 - Aircraft capable of landing or taking-off vertically, e.g. vertical take-off and landing [VTOL] aircraft
B64F 5/00 - Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided forHandling, transporting, testing or inspecting aircraft components, not otherwise provided for
An up-down flapping wingtip is provided for a ground effect vehicle. The wingtip is positionable at an anhedral angle to control the wingtip clearance from ground. Variable wingtip clearance reduces the risk of damage due to collision with the ground or water, thereby permitting more efficient flight at lower altitude with an equivalent safety. The wingtip is positioned by a wingtip flap and an actuator. The wingtip anhedral angle is controlled by a flight control system. A sensor is included for determining whether an object lies in the path of the wingtip. The sensor communicates with the flight control system in order to vary the flapping angle of the wingtip to increase clearance from the ground or water, thus avoiding impact with the object. The wingtip anhedral angle is reduced to increase the wingspan for flight out of ground effect.
A tiltrotor aircraft comprising a wing carrying an engine on each wing half, and a fuselage-mounted third engine with a transmission system configured to drive each of the tilting rotors from the third engine. The engines may be any powerplant, including fore example, a reciprocating engine, a turbine engine, or an electric motor. The third engine is preferably controlled for best efficiency and best safety in engine failure cases.
A tiltrotor aircraft comprising a wing carrying an engine on each wing half, and a fuselage-mounted third engine with a transmission system configured to drive each of the tilting rotors from the third engine. The engines may be any powerplant, including fore example, a reciprocating engine, a turbine engine, or an electric motor. The third engine is preferably controlled for best efficiency and best safety in engine failure cases.
An aircraft uses trajectory-based control algorithms for blade pitch (or twist). This approach greatly enhances the ability of the actuator to accurately achieve the desired blade pitch and to track the commanded pitch position. An actuator includes an electronic rotor blade controller that converts communicated or desired changes in pitch (or similar parameter) to actual physical effects that match the desired changes as closely as possible. The controller preferably includes a motor drive circuit, such as an h-bridge, a communication circuit for connection to external commands, and a processor with associated enabling circuitry (e.g. memory, I/O) to coordinate and implement the control.
B64C 27/605 - Transmitting means, e.g. interrelated with initiating means or means acting on blades mechanical including swash plate, spider or cam mechanisms
An aircraft uses trajectory-based control algorithms for blade pitch (or twist). This approach greatly enhances the ability of the actuator to accurately achieve the desired blade pitch and to track the commanded pitch position. An actuator includes an electronic rotor blade controller that converts communicated or desired changes in pitch (or similar parameter) to actual physical effects that match the desired changes as closely as possible. The controller preferably includes a motor drive circuit, such as an h-bridge, a communication circuit for connection to external commands, and a processor with associated enabling circuitry (e.g. memory, I/O) to coordinate and implement the control.
B64C 27/57 - Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement characterised by the control initiating means, e.g. manually actuated automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust
A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.
B64C 29/00 - Aircraft capable of landing or taking-off vertically, e.g. vertical take-off and landing [VTOL] aircraft
B64F 5/00 - Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided forHandling, transporting, testing or inspecting aircraft components, not otherwise provided for
A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.
B64C 29/00 - Aircraft capable of landing or taking-off vertically, e.g. vertical take-off and landing [VTOL] aircraft
B64F 5/00 - Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided forHandling, transporting, testing or inspecting aircraft components, not otherwise provided for
Devices and systems of the inventive concept provide an aircraft flap system is deflected to achieve minimum drag in cruise, maximum coefficient of lift (CL) at low speed, and minimum download in hover. It does so by opening a gap or slot between an aircrafts wing body and an associated trailing flap during hover flight, while providing a continuous aerodynamic contour under other conditions.
Devices and systems of the inventive concept provide a durable, all-weather manned or unmanned aircraft that is capable of vertical flight and provides improved stability upon payload launch or delivery. The payload bay is positioned along the central axis of the aircraft and proximal to the aircrafts center of gravity. Control and fuel systems are positioned fore and aft of the payload bay, respectively. The payload bay is configured to store and deliver a wide variety of payload types. The aircraft also includes features that reduce vibration, prolong the interval between necessary maintenance, and permit all-weather operation.
B64C 25/10 - Undercarriages non-fixed, e.g. jettisonable retractable, foldable, or the like
B64D 7/00 - Arrangement of military equipment, e.g. armaments, armament accessories or military shielding, in aircraftAdaptations of armament mountings for aircraft
B64D 27/02 - Aircraft characterised by the type or position of power plants
12.
Use of individual blade control on a propeller or rotor in axial flight for the purpose of aerodynamic braking and power response modulation
Systems and methods are contemplated for favorably improving flight dynamics of aircraft, including enhanced aerodynamic braking and improved flight maneuverability. Air braking systems selectively position a first set of blades at a negative thrust pitch to product a net negative thrust across first and second sets of blades, while balancing torque of the drive shafts to zero. First and second sets of IBC blades can be driven by the same shaft or torque-linked shafts. Flight maneuver systems operate a powerplant at a high power mode, and dissipate the energy from the high power output by positioning a first set of IBC blades at a low efficiency pitch while maintaining constant thrust. As increased or rapid flight maneuverability is required, the first set of blades is positioned toward a high efficiency pitch to instantly increase thrust to the aircraft without requiring a related increase in energy output from the powerplant.
B64C 27/80 - Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement for differential adjustment of blade pitch between two or more lifting rotors
B64C 29/00 - Aircraft capable of landing or taking-off vertically, e.g. vertical take-off and landing [VTOL] aircraft
Systems and methods are contemplated for favorably improving flight dynamics of aircraft, including enhanced aerodynamic braking and improved flight maneuverability. Air braking systems selectively position a first set of blades at a negative thrust pitch to product a net negative thrust across first and second sets of blades, while balancing torque of the drive shafts to zero. First and second sets of IBC blades can be driven by the same shaft or torque-linked shafts. Flight maneuver systems operate a powerplant at a high power mode, and dissipate the energy from the high power output by positioning a first set of IBC blades at a low efficiency pitch while maintaining constant thrust. As increased or rapid flight maneuverability is required, the first set of blades is positioned toward a high efficiency pitch to instantly increase thrust to the aircraft without requiring a related increase in energy output from the powerplant.
Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45' diameter) footprint.
Methods of manufacturing and operating a solar powered aircraft having segmented wings that can be reconfigured during flight to optimize collection of solar energy are described. The aircraft have rigid construction that is resistant to inclement weather and is configured to rely on free flight control at high altitude and under conventional conditions, thereby providing flight duration in excess of 2 months. The aircraft is particularly suitable for use as part of a telecommunications network.
G05D 1/00 - Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
B64C 39/02 - Aircraft not otherwise provided for characterised by special use
B64F 5/00 - Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided forHandling, transporting, testing or inspecting aircraft components, not otherwise provided for
Methods of manufacturing and operating a solar powered aircraft having segmented wings that can be reconfigured during flight to optimize collection of solar energy are described. The aircraft have rigid construction that is resistant to inclement weather and is configured to rely on free flight control at high altitude and under conventional conditions, thereby providing flight duration in excess of 2 months. The aircraft is particularly suitable for use as part of a telecommunications network.
B64F 5/00 - Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided forHandling, transporting, testing or inspecting aircraft components, not otherwise provided for
B64C 3/38 - Adjustment of complete wings or parts thereof
B64C 13/50 - Transmitting means with power amplification using electrical energy
B64D 41/00 - Power installations for auxiliary purposes
B64D 27/24 - Aircraft characterised by the type or position of power plants using steam or spring force
A solar powered aircraft having segmented wings that can be reconfigured during flight to optimize collection of solar energy are described. The aircraft have rigid construction that is resistant to inclement weather and is configured to rely on free flight control at high altitude and under conventional conditions, thereby providing flight duration in excess of 2 months. The aircraft is particularly suitable for use as part of a telecommunications network. A telecommunications network incorporating such aircraft is also discussed.
A solar powered aircraft having segmented wings that can be reconfigured during flight to optimize collection of solar energy are described. The aircraft have rigid construction that is resistant to inclement weather and is configured to rely on free flight control at high altitude and under conventional conditions, thereby providing flight duration in excess of 2 months. The aircraft is particularly suitable for use as part of a telecommunications network. A telecommunications network incorporating such aircraft is also discussed.
A harmonic drive has an outer gear, an elliptical follower hub, and an outer chain coupled to the follower hub, and having teeth that mate with the outer gear. Preferred embodiments further include an inner chain disposed such that the follower hub is functionally interposed between the inner and outer chains.
F16H 25/06 - Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying rotary motion with intermediate members guided along tracks on both rotary members
A tiltrotor aircraft having a fixed wing and tilting rotors has a rotor blade with a shaped tip portion that provides improved hover performance. The shaped tip portion preferably has a terminal anhedral of at least 20° with respect to its stacking line, and the blade has an overall twist from root to tip of at least 20°, and a thickness ratio between 19% and 30% at a radial station of 10%. These features advantageously conspire to provide a hover figure of merit of at least 0.84 and a cruise propulsive efficiency of at least 0.85. A controller preferably limits the rotor speed in sustained airplane-mode forward flight cruise of at most 40% of a hover maximum rotor speed, and alternatively or additionally limits a rotor edgewise advance ratio to at most 0.20.
An electric linear actuator is disposed to pitch a blade of a hingeless, swashplateless rotor in rotary motion. This actuator can be equipped with an electric motor advantageously made fault tolerant by winding the motor for at least 4, 5, 6, 8, or even 12 phases. Rotational motion of the electric motor is preferably converted to a translatory linear actuator output motion using a planetary roller screw coupling the rotation of the motor with pitch of the blade. The output link of the actuator can be advantageously coupled to the planetary roller screw using an internal spherical joint providing an isolated load path through the actuator. It is contemplated that a preferred rotorcraft having an electric blade pitch actuator might also be equipped with a controller that could provide the vehicle with individual blade control, in which the pitch of any rotor blade can be controlled independently of the others.
B64C 9/00 - Adjustable control surfaces or members, e.g. rudders
B64C 27/39 - Rotors having articulated joints with individually articulated blades, i.e. with flapping or drag hinges
B64C 27/68 - Transmitting means, e.g. interrelated with initiating means or means acting on blades using electrical energy, e.g. having electrical power amplification
22.
SWASHPLATELESS ROTORCRAFT WITH FAULT TOLERANT LINEAR ELECTRIC ACTUATOR
An electric linear actuator is disposed to pitch a blade of a hingeless, swashplateless rotor in rotary motion. This actuator can be equipped with an electric motor advantageously made fault tolerant by winding the motor for at least 4, 5, 6, 8, or even 12 phases. Rotational motion of the electric motor is preferably converted to a translatory linear actuator output motion using a planetary roller screw coupling the rotation of the motor with pitch of the blade. The output link of the actuator can be advantageously coupled to the planetary roller screw using an internal spherical joint providing an isolated load path through the actuator. It is contemplated that a preferred rotorcraft having an electric blade pitch actuator might also be equipped with a controller that could provide the vehicle with individual blade control, in which the pitch of any rotor blade can be controlled independently of the others.
B64C 27/68 - Transmitting means, e.g. interrelated with initiating means or means acting on blades using electrical energy, e.g. having electrical power amplification
Systems and methods are provided in which an electrical control system independently effects acceleration of both driven and driving elements of a clutch to engage each other. In preferred embodiments the clutch is not a friction clutch, but a dog clutch, and forms part of a drive drain of a rotorcraft. A second clutch can be used, along with a mechanical interlock to prevent simultaneous engagement of the clutches. Speeds of the driven and driving elements can be sensed, and altered using at least one of a rotor, a brake, a generator, an electric motor, and a combustion motor. In rotorcraft embodiments, the gearbox can have a neutral condition in which no power is transmitted from the engine to the rotor.
B64C 27/28 - Compound rotorcraft, i.e. aircraft using in flight the features of both aeroplane and rotorcraft with forward-propulsion propellers pivotable to act as lifting rotors
Substantial reduction in aircraft stowage space can be achieved by stacking aircraft using minimal or no folding of parts of the aircraft. This results in reduced complexity and reduced cost compared to other aircraft compact stowage schemes including for example fully folding an aircraft. Landing gear variable height, length, or orientation can be used to orient all or a portion of the aircraft for stowage. Alternately or in combination with such orientation by landing gear, other portions of the aircraft including tilting rotors and tilting nacelles can be oriented to achieve a geometric configuration conducive to compact stowage. In preferred embodiments, aircraft are moved relative to each other so that a portion of one aircraft is offset relative to a corresponding portion of the other. In especially preferred configurations, a portion of the first aircraft will overlap or lie on top of without touching a portion of the second aircraft.
An aircraft is equipped with hingeless rotors on tilting nacelles, and the tilt angles of the nacelles are controlled using either or both of an actuator and a mast moment generated by a hingeless rotor. An aircraft with two or more rotors on tilting nacelles can achieve control of yaw orientation by differential tilt of its nacelles or masts. Hingeless rotors can be manipulated to control a tilt angle of a mast by changing the rotor blade pitch to produce a mast moment. The rotor and nacelle tilt of a tiltrotor rotorcraft can be controlled and effected in order to manipulate the yaw orientation and flight mode of a rotorcraft such as a tiltrotor. The use of mast moment to control nacelle tilt angle can reduce tilt actuator loads and allows for the control of nacelle tilt even in the event of an actuator failure.
An aircraft is equipped with hingeless rotors on tilting nacelles, and the tilt angles of the nacelles are controlled using either or both of an actuator and a mast moment generated by a hingeless rotor. An aircraft with two or more rotors on tilting nacelles can achieve control of yaw orientation by differential tilt of its nacelles or masts. Hingeless rotors can be manipulated to control a tilt angle of a mast by changing the rotor blade pitch to produce a mast moment. The rotor and nacelle tilt of a tiltrotor rotorcraft can be controlled and effected in order to manipulate the yaw orientation and flight mode of a rotorcraft such as a tiltrotor. The use of mast moment to control nacelle tilt angle can reduce tilt actuator loads and allows for the control of nacelle tilt even in the event of an actuator failure.
A spar of a rotor blade having moderate depth transitions to a relatively much deeper shank over a relatively short distance. This rapid transition enables a low-weight blade root that is structurally efficient, offers a high moment capability, and enables high Mach number axial flow. A transition could advantageously reduce section depth by at least 15%, 20%, 30%, or even 40% over at most 5%, 6%, 10%, or 12% of a total length of the rotor blade. Such a transition could advantageously be accomplished using a cuff, which has interfaces with each of the spar and the shank. The rotor blade shank has a generally circular cross-section which allows for a rotary attachment to a hub, where the attachment may advantageously comprise a mechanical or elastomeric bearing. Preferred embodiments have a spar with a generally rectangular cross-section.
Systems and methods are provided in which an electrical control system independently effects acceleration of both driven and driving elements of a clutch to engage each other. In preferred embodiments the clutch is not a friction clutch, but a dog clutch, and forms part of a drive drain of a rotorcraft. A second clutch can be used, along with a mechanical interlock to prevent simultaneous engagement of the clutches. Speeds of the driven and driving elements can be sensed, and altered using at least one of a rotor, a brake, a generator, an electric motor, and a combustion motor. In rotorcraft embodiments, the gearbox can have a neutral condition in which no power is transmitted from the engine to the rotor.
A gearbox comprising a gearset is able to transmit high output torques at high numerical reduction ratios at a power-to-weight ratio higher than previously attainable with existing designs. A distributor gear is disposed relative to a spur gear in order to produce automatic torque balancing. The distributor gear can be advantageously configured as an input floatring gear, for which support in all directions is provided by gear tooth mesh forces rather than bearings. Automatic torque balancing is achieved by configuring the distributor gear with first and second rows of helical teeth on the external circumference, and with a set of double helical teeth disposed on the internal circumference of the distributor gear. This allows for the placement of up to 50 or more planet gears in a countershaft arrangement with one end having helical teeth and the other end having spur teeth.
F16H 3/08 - Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously- meshing gears, that can be disengaged from their shafts
F16H 1/32 - Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
Systems and methods are provided in which an electrical control system independently effects acceleration of both driven and driving elements of a clutch to engage each other. In preferred embodiments the clutch is not a friction clutch, but a dog clutch, and forms part of a drive drain of a rotorcraft. A second clutch can be used, along with a mechanical interlock to prevent simultaneous engagement of the clutches. Speeds of the driven and driving elements can be sensed, and altered using at least one of a rotor, a brake, a generator, an electric motor, and a combustion motor. In rotorcraft embodiments, the gearbox can have a neutral condition in which no power is transmitted from the engine to the rotor
B64C 27/28 - Compound rotorcraft, i.e. aircraft using in flight the features of both aeroplane and rotorcraft with forward-propulsion propellers pivotable to act as lifting rotors
A gearbox comprising a gearset is able to transmit high output torques at high numerical reduction ratios at a power-to-weight ratio higher than previously attainable with existing designs. A distributor gear is disposed relative to a spur gear in order to produce automatic torque balancing. The distributor gear can be advantageously configured as an input floatring gear, for which support in all directions is provided by gear tooth mesh forces rather than bearings. Automatic torque balancing is achieved by configuring the distributor gear with first and second rows of helical teeth on the external circumference, and with a set of double helical teeth disposed on the internal circumference of the distributor gear. This allows for the placement of up to 50 or more planet gears in a countershaft arrangement with one end having helical teeth and the other end having spur teeth.
A spar of a rotor blade having moderate depth transitions to a relatively much deeper shank over a relatively short distance. This rapid transition enables a low-weight blade root that is structurally efficient, offers a high moment capability, and enables high Mach number axial flow. A transition could advantageously reduce section depth by at least 15%, 20%, 30%, or even 40% over at most 5%, 6%, 10%, or 12% of a total length of the rotor blade. Such a transition could advantageously be accomplished using a cuff, which has interfaces with each of the spar and the shank. The rotor blade shank has a generally circular cross-section which allows for a rotary attachment to a hub, where the attachment may advantageously comprise a mechanical or elastomeric bearing. Preferred embodiments have a spar with a generally rectangular cross-section.
Electrically controlled and/or actuated landing gear mechanisms are presented that allow for adjustment of aircraft attitude on the ground as well as for retraction and extension of the landing gear in a single unit. Most preferably, the electric actuator is positioned within the diameter of the strut to thereby form a compact and load bearing structure.
Contemplated gearboxes provide first and second power-balanced paths in which a speed changer is configured to operate with only one path. Most preferably, the gearbox includes a friction clutch and a sprag clutch arranged such that, together with a layshaft and spur-gear differential, gear shifting can be done while transmitting power.
B64D 35/04 - Transmitting power from power plants to propellers or rotorsArrangements of transmissions characterised by the transmission driving a plurality of propellers or rotors
B64D 35/08 - Transmitting power from power plants to propellers or rotorsArrangements of transmissions characterised by the transmission being driven by a plurality of power plants
F16H 37/06 - Combinations of mechanical gearings, not provided for in groups comprising essentially only toothed or friction gearings with a plurality of driving or driven shaftsCombinations of mechanical gearings, not provided for in groups comprising essentially only toothed or friction gearings with arrangements for dividing torque between two or more intermediate shafts
Contemplated couplings include an intermediate shaft internal and coaxial to a driver and a driven shaft, wherein the intermediate shaft moves a plurality of teethed rollers that engage with corresponding splined inner surfaces of the driver and the driven shaft. Such devices allow separation of the shafts under load using substantially reduced force and will typically have a friction coefficient virtual &mgr; of less than 0.05.
B64D 35/00 - Transmitting power from power plants to propellers or rotorsArrangements of transmissions
B64D 35/08 - Transmitting power from power plants to propellers or rotorsArrangements of transmissions characterised by the transmission being driven by a plurality of power plants
F16D 11/04 - Clutches in which the members have interengaging parts disengaged by a contact of a part mounted on the clutch with a stationarily-mounted member with clutching members movable only axially
F16D 11/10 - Clutches in which the members have interengaging parts actuated by moving a non-rotating part axially with clutching members movable only axially
B64C 27/22 - Compound rotorcraft, i.e. aircraft using in flight the features of both aeroplane and rotorcraft
B64C 27/26 - Compound rotorcraft, i.e. aircraft using in flight the features of both aeroplane and rotorcraft characterised by provision of fixed wings
Contemplated gearboxes combine a high numerical reduction ratio with the capability of transmitting power at a superior power to weight ratio using a compound star planetary gearbox configuration (110) that is radially expanded using hollow driveshafts (140) to link the planet gears. In most preferred compound planetary gear arrangements, planets of different diameter are torsionally connected to each other, or mesh with each other. Input and output gears counter rotate while the planets rotate in bearings (149) anchored to a static casing (115).
F16H 15/48 - Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by friction between rotary members with members having orbital motion
F16H 13/06 - Gearing for conveying rotary motion with constant gear ratio by friction between rotary members with members having orbital motion
Contemplated gearboxes combine a high numerical reduction ratio with the capability of transmitting power at a superior power-to-weight ratio using a compound star planetary gearbox configuration that is radially expanded using hollow driveshafts to link the planet gears. In most preferred compound planetary gear arrangements, planets of different diameter are torsionally connected to each other, or mesh with each other. Input and output gears counter-rotate while the planets rotate in bearings anchored to a static casing.
Electrically controlled and/or actuated landing gear mechanisms are presented that allow for adjustment of aircraft attitude on the ground as well as for retraction and extension of the landing gear in a single unit. Most preferably, the electric actuator is positioned within the diameter of the strut to thereby form a compact and load bearing structure.
patents
