Bi-directional rotary shape memory alloy element actuator assemblies, and systems and methods including the same

Patent metadata

Field	Value
Publication number	US-9897078-B2
Application number	US-201615163011-A
Country	US
Kind code	B2
Filing date	May 24, 2016
Priority date	May 24, 2016
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Rotary actuator assemblies, wind tunnels including the same, and associated methods are disclosed. A rotary actuator assembly includes a rotary element and a rotary actuator with a shape memory alloy element. The rotary actuator is configured to generate a first torque and a second torque in opposing rotary directions to rotate the rotary element. A rotary actuator assembly further includes an assist magnetic element and a receiver magnetic element configured to generate a magnetic force therebetween. Wind tunnels include an aerodynamic model with a rotary actuator assembly to rotate a portion of the aerodynamic model with respect to an airstream in a chamber. A method of rotating a rotary element includes modulating a temperature of a shape memory alloy element and applying a supplemental torque to the rotary element with an assist magnetic element and a receiver magnetic element.

First claim

The invention claimed is:

1. A wind tunnel for testing an aerodynamic model, the wind tunnel comprising:
a chamber extending in a longitudinal direction;
an airstream source configured to generate an airstream in the chamber with an airstream flow direction generally parallel to the longitudinal direction; and
an aerodynamic model positioned in the chamber to receive an aerodynamic load force from the airstream;
wherein the aerodynamic model includes an actuator assembly configured to rotate a portion of the aerodynamic model with respect to the airstream flow direction to test an aerodynamic property of the aerodynamic model, wherein the actuator assembly includes:
an actuator mount;
a rotary actuator coupled to the actuator mount and configured to generate a first torque in a first rotary direction and a second torque in a second rotary direction that is opposite the first rotary direction;
a rotary element coupled to the rotary actuator, wherein the rotary element has an angular position in an angular range of motion, and further wherein the rotary element is configured to:
(i) rotate with respect to the actuator mount in the first rotary direction responsive to receipt of the first torque from the rotary actuator; and
(ii) rotate with respect to the actuator mount in the second rotary direction responsive to receipt of the second torque from the rotary actuator;
an assist magnetic element mounted on the actuator mount;
a receiver magnetic element mounted on the rotary element; and
a thermal control unit configured to regulate a temperature of at least a portion of the rotary actuator;
wherein the rotary actuator includes a shape memory alloy element configured to generate the first torque and the second torque responsive to the thermal control unit regulating a temperature of the shape memory alloy element; and wherein the assist magnetic element and the receiver magnetic element are configured to generate a magnetic force therebetween when the angular position of the rotary element is in a magnetic assist portion of the angular range of motion, wherein the magnetic assist portion is a subset of the angular range of motion.

2. The wind tunnel of claim 1 , wherein the angular range of motion includes a neutral position in which the rotary element is generally parallel to the airstream flow direction, wherein the aerodynamic load force applies a load torque in the second rotary direction when the rotary element is rotated in the first rotary direction relative to the neutral position, wherein the aerodynamic load force applies the load torque in the first rotary direction when the rotary element is rotated in the second rotary direction relative to the neutral position, and wherein the shape memory alloy element is configured to generate at least one of the first torque and the second torque to at least one of balance the load torque and oppose the load torque.

3. The wind tunnel of claim 1 , wherein the rotary element is a control surface of a model aircraft, wherein the control surface rotates in the first rotary direction when the thermal control unit increases the temperature of the shape memory alloy element, wherein the control surface rotates in the second rotary direction when the thermal control unit decreases the temperature of the shape memory alloy element, and wherein the magnetic force between the assist magnetic element and the receiver magnetic element opposes the load torque in the first rotary direction when the angular position of the rotary element is in the magnetic assist portion of the angular range of motion.

4. A bi-directional rotary shape memory alloy element actuator assembly, the actuator assembly comprising:
an actuator mount;
a rotary actuator coupled to the actuator mount and configured to generate a first torque in a first rotary direction and a second torque in a second rotary direction that is opposite the first rotary direction;
a rotary element coupled to the rotary actuator, wherein the rotary element has an angular position in an angular range of motion, and further wherein the rotary element is configured to:
(i) rotate with respect to the actuator mount in the first rotary direction responsive to receipt of the first torque from the rotary actuator; and
(ii) rotate with respect to the actuator mount in the second rotary direction responsive to receipt of the second torque from the rotary actuator;
an assist magnetic element mounted to the actuator mount;
a receiver magnetic element mounted on the rotary element; and
a thermal control unit configured to regulate a temperature of at least a portion of the rotary actuator;
wherein the rotary actuator includes a shape memory alloy element configured to generate the first torque and the second torque responsive to the thermal control unit regulating a temperature of the shape memory alloy element; and wherein the assist magnetic element and the receiver magnetic element are configured to generate a magnetic force therebetween when the angular position of the rotary element is in a magnetic assist portion of the angular range of motion, wherein the magnetic assist portion is a subset of the angular range of motion.

5. The actuator assembly of claim 4 , wherein the shape memory alloy element is configured to exhibit a two-way shape memory effect.

6. The actuator assembly of claim 4 , wherein the rotary actuator includes a single shape memory alloy element configured to generate both the first torque and the second torque.

7. The actuator assembly of claim 4 , wherein the shape memory alloy element is configured to transform from a martensite state to an austenite state responsive to the thermal control unit increasing the temperature of the shape memory alloy element, wherein the shape memory alloy element is configured to transform from the austenite state to the martensite state responsive to the thermal control unit decreasing the temperature of the shape memory alloy element, wherein the rotary actuator is configured to apply the first torque to the rotary element in the first rotary direction when the shape memory alloy element transforms from the martensite state to the austenite state, wherein the rotary actuator is configured to apply the second torque to the rotary element in the second rotary direction when the shape memory alloy element transforms from the austenite state to the martensite state, wherein a first magnitude of the first torque is greater than a second magnitude of the second torque, wherein the magnetic force is configured to apply a supplemental torque to the rotary element in the second rotary direction, wherein the supplemental torque and the second torque are applied simultaneously to rotate the rotary element in the second rotary direction, and wherein the supplemental torque is applied to the rotary element only when the angular position of the rotary element is in the magnetic assist portion of the angular range of motion.

8. The actuator assembly of claim 7 , wherein the actuator assembly utilizes only the shape memory alloy element, the assist magnetic element, and the receiver magnetic element to generate the first torque, the second torque, and the supplemental torque.

9. The actuator assembly of claim 4 , wherein the rotary element is configured to rotate in the first rotary direction when the only torsional force applied to the rotary element is the first torque applied by the rotary actuator, and wherein the rotary element is configured to rotate in the second rotary direction when the only torsional force applied to the rotary element is the second torque applied by the rotary actuator.

10. The actuator assembly of claim 4 , wherein the rotary actuator includes a shape memory all

Assignees

• Boeing Co

Inventors

• Nicholson Douglas E
• Bass Micheal
• Mabe James Henry

Classifications

• G01M9/08

  Aerodynamic models · CPC title

• G01M9/02

  Wind tunnels · CPC title

• G01M9/062

  Wind tunnel balances; Holding devices combined with measuring arrangements · CPC title

• F03G7/06146

  Torque tubes or torsion bars · CPC title

• F03G7/065 Primary

  using a shape memory element · CPC title