A linear actuator is provided. The linear actuator comprises: a body; a shaft adapted to move linearly relative to the body; a driver adapted to drive the linear movement of the shaft; and a shape memory alloy component configured to compensate for thermal expansion or contraction of the linear actuator due to a change in temperature thereof.

A linear actuator is provided. The linear actuator comprises: a body; a shaft adapted to move linearly relative to the body; a driver adapted to drive the linear movement of the shaft; and a shape memory alloy component configured to compensate for thermal expansion or contraction of the linear actuator due to a change in temperature thereof.

A rotor assembly for an aircraft operable to generate a variable thrust output at a constant rotational speed. The rotor assembly includes a mast rotatable at the constant speed about a mast axis. A rotor hub is coupled to and rotatable with the mast. The rotor hub includes a plurality of spindle grips extending generally radially outwardly. Each of the spindle grips is coupled to one of a plurality of rotor blades and is operable to rotate therewith about a pitch change axis. A collective pitch control mechanism is coupled to and rotatable with the rotor hub. The collective pitch control mechanism is operably associated with each spindle grip such that actuation of the collective pitch control mechanism rotates each spindle grip about the respective pitch change axis to collectively control the pitch of the rotor blades, thereby generating the variable thrust output.

Embodiments are directed to a rotor system for an aircraft comprising a gearbox configured to receive torque from a drive train, a mast having a first end and a second end, wherein the first end is attached to the gearbox and the mast configured to rotate in response to the torque from the drive train, a rotor hub attached to the second end of the mast, a first light transceiver mounted adjacent to the first end of the mast, wherein the first light transceiver is does not rotate relative to the mast, and a second light transceiver mounted adjacent to the second end of the mast, wherein the second light transceiver rotates with the mast.

Embodiments are directed to a rotor system for an aircraft comprising a gearbox configured to receive torque from a drive train, a mast having a first end and a second end, wherein the first end is attached to the gearbox and the mast configured to rotate in response to the torque from the drive train, a rotor hub attached to the second end of the mast, a first light transceiver mounted adjacent to the first end of the mast, wherein the first light transceiver is does not rotate relative to the mast, and a second light transceiver mounted adjacent to the second end of the mast, wherein the second light transceiver rotates with the mast.

A cyclic pitch angle adjustment apparatus for a rotor or propeller, to a rotor with such a cyclic pitch angle adjustment apparatus, and to a rotorcraft with such a rotor. The cyclic pitch angle adjustment apparatus may include levers that rotate rotor blades around associated pitch axes rods that mechanically link the levers with a bearing such that the rods are movable relative to the central point, the bearing being attached to a central rod that is movable and adapted for adjusting the cyclic pitch angle of the rotor blades from one pitch angle in one position to another pitch angle in another position.

A high-speed vertical take-off and landing aircraft has a lifting structure, a first rotor with a first and second blade, a second rotor with a first and second blade, an auxiliary propulsion unit for providing forward thrust, and a control system for controlling the pitch of each of the rotor blades. The aircraft has a first, rotor-only, flight mode for hovering and low speed maneuvering. It also has a second flight mode where the rotors are held in at fixed azimuth angles and forward thrust is provided by the auxiliary propulsion unit. Three axis control is provided during the second flight mode by adjusting the attack angles of the fixed rotor blades. Between these two flight modes, there is an intermediate flight mode covering a fully controlled transition between the first two flight modes.

A high-speed vertical take-off and landing aircraft has a lifting structure, a first rotor with a first and second blade, a second rotor with a first and second blade, an auxiliary propulsion unit for providing forward thrust, and a control system for controlling the pitch of each of the rotor blades. The aircraft has a first, rotor-only, flight mode for hovering and low speed maneuvering. It also has a second flight mode where the rotors are held in at fixed azimuth angles and forward thrust is provided by the auxiliary propulsion unit. Three axis control is provided during the second flight mode by adjusting the attack angles of the fixed rotor blades. Between these two flight modes, there is an intermediate flight mode covering a fully controlled transition between the first two flight modes.

An anti-torque rotor is described comprising: a mast rotatable about a first axis; a plurality of blades rotatable about respective second axes; an element slidable along the first axis with respect to the mast, rotating integrally with the mast and operatively connected to the blades; a control rod slidable along axis; a first bearing with a first ring rotating integrally with element, a second ring radially internal to the first ring with respect to the first axis and a plurality of first rolling bodies; a third ring sliding integrally with the control rod along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a standard configuration, in which it prevents the relative rotation of the second and third rings and movable from the standard configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.

An anti-torque rotor is described comprising: a mast rotatable about a first axis; a plurality of blades rotatable about respective second axes; an element slidable along the first axis with respect to the mast, rotating integrally with the mast and operatively connected to the blades; a control rod slidable along axis; a first bearing with a first ring rotating integrally with element, a second ring radially internal to the first ring with respect to the first axis and a plurality of first rolling bodies; a third ring sliding integrally with the control rod along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a standard configuration, in which it prevents the relative rotation of the second and third rings and movable from the standard configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.