Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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).
Abstract:
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 μ of less than 0.05.
Abstract:
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.