摘要:
An exhaust system configured for converting thermal energy to mechanical energy includes a source of thermal energy provided by a temperature difference between an exhaust gas having a first temperature and a heat sink having a second temperature that is lower than the first temperature. The exhaust system also includes a conduit configured for conveying the exhaust gas, a heat engine disposed in thermal relationship with the conduit and configured for converting thermal energy to mechanical energy, and a member disposed in contact with the conduit and configured for conducting thermal energy from the conduit to the heat engine. The heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to the temperature difference between the exhaust gas and the heat sink.
摘要:
A cable adapted for use as an actuator, adaptive structural member, or damper, includes a plurality of longitudinally inter-engaged and cooperatively functioning shape memory alloy wires.
摘要:
A releasable connection connects a first component to a second component. The second component includes and is manufactured from a Shape Memory Polymer (SMP), and defines a pocket. The first component includes a portion disposed within the pocket. The pocket is deformed from an initial shape permitting insertion of the portion into the pocket to assembly the releasable connection into a connected shape wherein the pocket is deformed to secure the first component relative to the second component. The pocket is transformed from the initial shape into the connected shape by heating the SMP material of the second component to a switching temperature. Re-heating the SMP second component to the switching temperature returns the pocket back to the initial shape from the connected shape to disassembly the releasable connection.
摘要:
A door system includes a structural member and a door that is movably mounted with respect to the structural member for movement between an open position and a closed position. A spring is mounted with respect to the structural member or the door and being sufficiently positioned to bias the door toward its open position when the door is in its closed position. Active material based actuators may selectively compress the spring prior to door closure to minimize door closing effort.
摘要:
A vehicle includes a fluid mixing system. The fluid mixing system includes a fluid and a heat engine. 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 includes a shape-memory alloy disposed in heat exchange contact with each of the first fluid region and the second fluid region. The heat engine is operable to mix the fluid between the first fluid region and the second fluid region in response to a change in the crystallographic phase of the shape-memory alloy to reduce the difference in the composition of the fluid bath between the first fluid region and the second fluid region.
摘要:
A method of controlling an energy harvesting system that converts excess thermal energy into mechanical energy and includes a Shape Memory Alloy (SMA) member, includes obtaining current operational parameters of the energy harvesting system, such as a maximum temperature, a minimum temperature and a cycle frequency of the SMA member. The current operational parameters are compared to a target operating condition of the energy harvesting system to determine if the current operational parameters are within a pre-defined range of the target operating condition. If the current operational parameters are not within the pre-defined range of the target operating condition, then a heat transfer rate to, a heat transfer rate from or a cycle frequency of the SMA member is adjusted to maintain operation of the energy harvesting system within the pre-defined range of the target operating condition to maximize efficiency of the energy harvesting system.
摘要:
A cable adapted for use as an actuator, adaptive structural member, or damper, includes a plurality of longitudinally inter-engaged and cooperatively functioning shape memory alloy wires.
摘要:
A servo system includes pressurized fluid, and one or more fluid control devices (FCD) such as a valve or actuator, with at least one FCD having an element with a variable property that varies in response to a stimulus. The FCD controls a flow rate or pressure transmission of the fluid within the servo system. The element may include an active return spring having a variable stiffness. The servo system may operate as an interlock system for a transmission. A method for moving an output load using a servo system includes providing a first FCD with an active element, connecting an output load to a second FCD, activating the active element with a stimulus to vary a property of the active element, transmitting a force from the pressurized fluid to the second FCD, and moving the output load from a first position to a second position in response to the force.
摘要:
A device is provided that may be adapted to control or monitor the pressure level of a fluid system. The device includes a member composed of a shape memory alloy in a superelastic state. The member is configured to undergo a phase change from a high modulus Austenitic phase to a low modulus Martensitic phase and stretch in response to an activation stress. In one embodiment, the member defines two ends such that one end of the member is operatively connected to a fixed point. Another end of the member is operatively connected to a movable element. As the member stretches in response to the activation stress, the movable element is translated relative to the fixed point. In another embodiment, the member includes two plates with respective holes that are selectively aligned when the first and second plates stretch or deform in response to the activation stress.
摘要:
A system for and method of providing overload protection for an active material actuator, includes a magnetically functioning mechanism comprising, for example, one or more permanent or electromagnets, and/or magnetorheological fluid, and configured to produce a holding force less than the capacity of the actuator, and more preferably, a modifiable holding force responsive to load influencing conditions.