摘要:
An apparatus for and method of conditioning a thermally activated shape memory alloy wire for use in an application, wherein the apparatus includes an adjustable hard-stop and the preferred method includes pre-determining a minimum activating current, allowable strain, and a loading magnitude and form based on the wire configuration and application, and further includes applying a double-exponential model to determine a final recoverable strain over fewer cycles.
摘要:
An energy harvesting system in thermal communication with a hot region and a cold region includes a hot end heat engine in thermal communication with the hot region, a cold end heat engine in thermal communication with the cold region, and an intermediate heat engine disposed between the hot end heat engine and the cold end heat engine. The hot end heat engine includes a hot end shape memory alloy (SMA) element, the cold end heat engine includes a cold end SMA element disposed, and the intermediate heat engine includes an intermediate SMA element. A hot side of the intermediate SMA element is in thermal communication with a cold side of the hot end SMA element. A cold side of the intermediate SMA element is in thermal communication with a hot side of the cold end SMA element.
摘要:
A shape memory alloy (SMA) heat engine includes a first rotatable pulley, a second rotatable pulley, and an SMA material disposed about the first and second rotatable pulleys and between a hot region and a cold region. A method of starting and operating the SMA heat engine includes detecting a thermal energy gradient between the hot region and the cold region using a controller, decoupling an electrical generator from one of the first and second rotatable pulleys, monitoring a speed of the SMA material about the first and second rotatable pulleys, and re-engaging the driven component if the monitored speed of the SMA material exceeds a threshold. The SMA material may selectively change crystallographic phase between martensite and austenite and between the hot region and the cold region to convert the thermal gradient into mechanical energy.
摘要:
An energy harvesting system for converting thermal energy to mechanical energy includes a heat engine that operates using a shape memory alloy active material. The shape memory alloy member may be in thermal communication with a hot region at a first temperature and a cold region at a second temperature lower than the first temperature. The shape memory alloy material may be configured to selectively change crystallographic phase between martensite to austenite and thereby one of contract and expand in response to the first and second temperatures. A driven component, such as an electric generator, may be selectively coupled with the heat engine through a coupling device, which may be controlled via a controller.
摘要:
An overheating protection system adapted for use with a shape memory alloy actuator element, includes at least one switching shape memory alloy element presenting a slower activation period than that of the actuator element, and configured to selectively prevent activation of the actuator element, when the actuator element is actually or predicted to be experiencing overheating; and a circuit comprising the system, wherein the switching element and/or a circuit implement functions to modify activation of the actuator element.
摘要:
An energy harvesting system includes a heat engine and a component configured to be driven by operation of the heat engine. The heat engine includes a first member, a second member, a shape memory alloy material, and a tensioner. The second member is spaced from the first member. The shape memory alloy material operatively interconnects the first member and the second member. The shape memory alloy material is configured to selectively change crystallographic phase from martensite to austenite and thereby contract in response to exposure to a first temperature. The shape memory alloy material is also configured to selectively change crystallographic phase from austenite to martensite and thereby expand in response to exposure to a second temperature. The tensioner is configured to apply tension to the shape memory alloy material as the shape memory alloy material selectively expands and contracts such that the shape memory alloy material is taut.
摘要:
A vehicle includes an energy harvesting system. The energy harvesting system includes a fluid, a heat engine, and a component. The fluid has a first fluid region at a first temperature and a second fluid region at a second temperature that is different from the first temperature. The heat engine is configured for converting thermal energy to mechanical energy and includes a shape-memory alloy disposed in contact with each of the first fluid region and the second fluid region. The component is driven by the heat engine in response to the temperature difference.
摘要:
A recliner adjustment system and method utilizing active material based actuation is adapted for use with a recliner defining an engaging surface and operable to adjust the angle of inclination of the surface, and includes a locking mechanism configured to selectively prevent the surface from pivoting, an unlocking actuator including at least one active material element configured to release the mechanism when activated or deactivated, a signal source operable to generate and deliver to the element an activation signal, and more preferably, a second adjusting actuator including a second active material element configured to rotationally displace the surface, so as to adjust the angle, when activated or deactivated and the mechanism has been released.
摘要:
An active material actuator adapted for use in a circuit includes an active material member, and a piezoelectric or piezoresistive element or otherwise force sensing device, wherein the element or device is communicatively coupled to the member and operable to vary the current within the circuit when the member is caused to achieve a predetermined stress, such that, in one aspect, the element presents an overload protection mechanism.
摘要:
A center console comprising a manipulable structural component, such as a pivotal lid, sliding armrest, tambour door, or pivotal cup holder, and at least one active material actuator including an active material element operable to undergo a reversible change, drivenly coupled to the component, and configured to autonomously cause and/or enable the component to be manipulated as a result of the change.