摘要:
A transmission fluid circuit includes a transmission, a cooler, and a valve. The valve includes a housing, a spool and an actuator. The spool is movable inside the housing between a first position and a second position. The actuator includes a smart material configured to be activated in response to the temperature of the fluid exhibiting at least a first temperature such that the actuator is in a first state. The smart material is configured to be deactivated in response to the fluid being a sufficient number of degrees less than the first temperature such that the actuator is in a second state. The fluid flows from the housing to the transmission and from the transmission the cavity when the spool is in the first position. The fluid flows from the housing to the cooler and from the cooler to the transmission when the spool is in the second position.
摘要:
An exhaust gas recirculation system adapted for use by an internal combustion engine, and for selectively diverting a recirculated portion of the engine exhaust away from the EGR cooler, includes a by-pass conduit and/or feed line shiftable between open and closed conditions, and an active material actuator.
摘要:
Malfunction or failure of mechanical, electrical and electro-mechanical equipment, for example equipment used in manufacturing operations, is often preceded by an increase in the operating temperature of at least some portion of the equipment. A temperature-sensitive, active material-containing actuator is pre-selected to operate at a pre-determined temperature indicative of impending equipment failure and placed in thermal contact with the equipment. If the equipment achieves the pre-selected temperature the actuator signals this by displaying a flag or providing some other passive visual indication. Alternatively, or additionally, the actuator may issue an electrically-powered alert including visual or audible alerts or a wireless communication. Selected actuators are based on smart materials including shape memory alloys (SMA), shape memory polymers (SMP) and paraffin wax, all of which may be adapted to operate over a temperature range sufficient to encompass the expected range of pre-determined temperatures.
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 thermal conduction element may be in direct contact with the SMA material, where the thermal conduction element is configured to receive thermal energy from the hot region and to transfer a portion of the received thermal energy to the SMA material through conduction.
摘要:
A method of reducing an initial stress on a cable includes stretching the cable to a first length to thereby define the initial stress. The cable has a central longitudinal axis, and includes a plurality of wires each twisted around the axis and formed from a shape memory alloy transitionable in response to a signal between a first state wherein each of the wires has a first temperature-dependent length, and a second state wherein each of the wires has a second temperature-dependent length that is less than the first. After stretching, the method includes activating the alloy by exposing the alloy to the signal such that the alloy transitions from the first to the second temperature-dependent state. Concurrent to activating, the method includes elongating the cable to a second length that is greater than the first to define a second stress on the cable that is less than the first.
摘要:
In an embodiment, a device comprises an active material. Activation of the active material causes deformation within the device to conform to and/or retain an object without engaging the object below a surface of the object. In another embodiment, contact with an object causes deformation within the device to conform to and/or retain the object. In yet another embodiment, an object holder can comprise: a recess, a cover disposed over the recess, and a switch configured to cause the active material to retain a deformed shape in the recess. The cover comprises an active material. The active material is configured to deform into the recess when contacted with an object.
摘要:
A mechanical implement adapted for use in an autonomously functioning device, such as a robot arm, and including an active material, such as shape memory polymer, element that when activated and/or deactivated is operable to modify the mechanical impedance of a joint or link in the device.
摘要:
An apparatus for and method of displacing a body, such as a projectile, piston, or the distal edge of a sunshade cover or energy absorbing honeycomb matrix, utilizing momentum generated by the rapid actuation of an active material element, such as a Martensitic shape memory alloy wire.
摘要:
A heat engine system configured for converting thermal energy to mechanical energy includes a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a heat sink having a second temperature that is lower than the first temperature. The heat engine is configured for converting thermal energy to mechanical energy and includes an 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 heat source and the heat sink. The heat engine system also includes a start-up mechanism configured for inducing initial movement of the element in a desired operational direction to thereby start the heat engine.
摘要:
A pinch-protection mechanism adapted for use with a closure panel and method for use of the same, said mechanism comprising at least one structural component defining an adjustable edge section manipulable between first and second configurations and an active material element coupled to the component, such that the change causes or enables the edge section to be manipulated to one of said first and second configurations, and manipulating the edge section between said first and second configurations eliminates, warns of, or mitigates a pinch condition.