The Boeing Company

A Dean Jacot

Dan John Clingman

Robert T Ruggeri

David C Cunningham

L Porter Davis

Brian J Hamilton

A preferred rotary actuator includes an actuator assembly having a torque tube formed of a shape memory alloy (SMA), a superelastic NiTinol return spring associated with the torque tube and adapted to bias the torque tube toward an initial position, and a torque tube heating element, especially a thermoelectric device, for switching the SMA to cause rotation to an object connected to the actuator or to generate a torque upon that object. The torque tube () includes a proximal end () and a distal end (). The return spring and torque tube are connected at their ends, with the torque tube being pretwisted while in a martensitic state relative to the spring. Activation of the heating element causes the torque tube to enter an austenitic state in which it returns to its previous untwisted configuration. Removal of heat allows the torque tube to return to a martensitic state, when the return spring retwists the torque tube. A unique locking assemblyis used with the preferred actuator assembly. A helicopter blade twist rotation system for a rotorcraft bladehaving a blade rootand a tipincludes a SMA rotary actuatorlocated within the blade near the blade root, and a passive torque tube () located within the blade and having a proximal end connected to the rotary actuator and a distal end connected to the blade near to the blade tip.

Shape memory alloy device and control method

A single crystal piezo (SCP) apparatus and method of forming same. The apparatus is ideally suited for actuator and energy harvesting applications. The apparatus includes an SCP layer bonded to a surface of a flexible metal layer while the metal layer is held flattened within a press or other tool. Once the bonding process is complete, the metal layer imparts a compressive strain to the SCP layer bonded thereto. A layer of uniaxial graphite may also be bonded to the SCP layer to eliminate the poison's ratio tension that would otherwise be created in the SCP layer.

Single crystal piezo (SCP) apparatus and method of forming same

A preferred rotary actuator includes an actuator assembly having a torque tube formed of a shape memory alloy (SMA), a superelastic NiTinol return spring associated with the torque tube and adapted to bias the torque tube toward an initial position, and a torque tube heating element, especially a thermoelectric device, for switching the SMA to cause rotation to an object connected to the actuator or to generate a torque upon that object. The torque tube ( ) includes a proximal end ( ) and a distal end ( ). The return spring and torque tube are connected at their ends, with the torque tube being pretwisted while in a martensitic state relative to the spring. Activation of the heating element causes the torque tube to enter an austenitic state in which it returns to its previous untwisted configuration. Removal of heat allows the torque tube to return to a martensitic state, when the return spring retwists the torque tube. A unique locking assembly is used with the preferred actuator assembly. A helicopter blade twist rotation system for a rotorcraft blade having a blade root and a tip includes a SMA rotary actuator located within the blade near the blade root, and a passive torque tube ( ) located within the blade and having a proximal end connected to the rotary actuator and a distal end connected to the blade near to the blade tip.

A dual mode vibration isolator for reducing transmission of vibrations between a forward body and an aft body includes a mounting member positioned between the forward and aft bodies, a plurality of magnetic actuators each having an armature fixed to the forward body and a stator mounted on the mounting member, and a plurality of linear actuators pivotally connected between the aft body and the mounting member. The magnetic actuators support the forward body relative to the mounting member by magnetically supporting the armatures between paired stator cores in each stator. The magnetic actuators are controlled, preferably through local flux feedback loops, to permit the stators to vibrate relative to the armature without transmitting forces to the armatures, thus isolating the vibration of the aft body and mounting member from the forward body. The linear actuators extend and contract to reposition the forward body and mounting member relative to the aft body. In addition, the linear actuators provide supplemental vibration isolation through a followup isolation loop that detects variation of the armatures from a predetermined null position between the paired stator cores. The followup isolation loop moves the mounting member relative to the aft body to restore the armatures to their null positions. The assistance provided by the linear actuators enables the use of small-size magnetic actuators for a given force requirement. A method for isolating vibration from transmission between two bodies also is disclosed.

Growing community of inventors

Kent, WA, United States of America

A Dean Jacot