Patent Application
20080049398
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms first body 125 and second body 130 are employed to differentiate between sources of heat and sinks for transported heat. For example, the first body 125 may be a heat load while the second body may be a cold source. In an alternate prophetic example, the first body 125 may be a cold load and the second body 130 may be a heat source.
The thermal connector 105 is configured to contact the first body 125 to form a thermal connection. In the depicted prophetic example, a second thermal connector 105b contacts the first body 125 while a first and third thermal connector 105a, 105c are separated from the first body 125.
In a certain embodiment, the thermal connector 105 contacts the first body 125 at a contact surface such as the contact surface 135 shown for the third thermal connector 105c. An additional contact surface (not shown) may also be disposed on the third thermal connector 105c such that the contact surface of the third thermal connector 105c and the contact surface 135 of the first body 125 form a thermal connection.
The contact surface 135 may improve the heat transfer between the third thermal connector 105c and the first body 125. In one embodiment, the contact area 135 may be a polished metal surface. Alternatively, the contact area 135 may comprise interlocking protrusions. In one embodiment, a viscous thermal conductor is applied between the contact surface of the thermal connection 105 and the contact surface of the first body 125 to improve heat transfer.
The thermal link 115 is in thermal communication with the thermal connector 105. In addition, the thermal link 115 is configured to transport heat. The thermal link 115 may be configured as a flexible member. In the depicted system 100, a first and third thermal links 105a, 105c are depicted as flexed into a significant arc while the second thermal link 105b is flexed into a slight arc. The thermal link 115 may flex to maintain the thermal connection with the thermal connector 105 when the thermal connector 115 contacts the first body 125 and when the thermal connector 105 is separated from the first body 125.
In the depicted prophetic example, each thermal connector 105 has a unique surface area that is configured to contact the first body 125. In addition, each thermal connector 105/thermal link 115 pair may be configured to transport heat at a unique rate. Thus the rate of heat transport may be varied by the selection of thermal connectors 105 that contact the first body 125.
The actuator 110 motivates the thermal connector 105 to contact the first body 125. Each actuator 110 is shown mounted to the second body 130 using a corresponding actuator mount 120. Alternatively, each actuator 110 may be positioned within the system 100 using one or more fasteners, mounting fixtures, braces, struts, and the like as is well known to those skilled in the art.
Each actuator 110 may be connected to a controller as will be described hereafter. For simplicity the connection to the controller is not shown. The actuator 110 motivates thermal connector 105 under the control of the controller. In the depicted embodiment, the system 100 transfers heat between the first body 125 and second body 130 through the second thermal connector 105b and the second thermal link 110b. In a prophetic example, the system 100 may increase heat transfer by motivating one or more additional thermal connectors 105 such as the first and third thermal connectors 105a, 105c to contact the first body 125. The system 100 modifies the heat transfer by motivating the thermal connectors 105 to contact with and separate from the first body 125.
The thermal connector 105 is configured to contact the first body 125 to form a thermal connection and to separate from the first body 125 to break the thermal connection. The thermal link 115 is in thermal communication with the thermal connector 105. In one embodiment, the thermal link 115 is in thermal communication through a solderless thermal link connection produced by Space Dynamics Laboratory of North Logan, Utah. The thermal link 115 may be held in physical communication with the thermal connector 105 by a fastener. Alternatively, the thermal link 115 may be adhesively bonded to the thermal connector 105. In a certain embodiment, the thermal link 115 is soldered to the thermal connector 105. The thermal link 115 may also be pressed in physical communication with the thermal connector 105 to create the thermal communication.
In one embodiment, the area of physical communication between the thermal link 115 and the thermal connector 105 is the range of between ten percent to ninety-five percent (10% -95%) of the surface area of the thermal connector 105. In a certain embodiment, the thermal link 115 is in physical communication with a conducting slug and the slug is physically connected to the thermal connector 105.
In one embodiment, the thermal link 115 is in thermal communication with the second body 130. The thermal link 115 may be held by a fastener, adhesively bonded, soldered, and/or pressed into thermal communication with the second body 130.
The thermal link 115 is configured to transport heat. In one embodiment, the thermal link 115 is a passive heat conductor that conducts heat between the thermal connector 105 and the second body 130. In an alternate embodiment, the thermal link 115 includes an active heat transport device such as a cryogen line, a heat pump line, or the like. A cryogen-based thermal link 115 will be described hereafter.
In one embodiment, the thermal link 115 is configured as a plurality of foil conductive layers. The conductive layers may comprise copper, aluminum, or the like. For example, the thermal link 115 may comprise a plurality of aluminum foil ribbon layers pressed at the ends of the ribbons into aluminum end blocks. In an alternative embodiment, the thermal link 115 is configured as a conductive braid such as a braid of copper wires, aluminum wires, or the like.
In one embodiment, the second body 130 is configured as a cold source. The second body 130 may be configured to radiate heat. In a certain embodiment, the second body 130 is configured to conduct heat to and/or from a third body such as a fuselage. Alternatively, the second body 130 may be cooled by a heat pump, a cryogen, or the like.
The actuator 110 motivates the thermal connector 105 to contact the first body 125. The actuator 110 may apply a force in response to heat. In one embodiment, the actuator 110 is a wax actuator as will be described hereafter. Alternatively, the actuator 110 may comprise a structural member that changes shape when heated. The structural member may exert a force as the structural member changes shape in response to the heat. In a prophetic example, the actuator 110 may comprise curved structural member that straightens in response to heat. Heating the structural member generates a force as the structural member straightens.
The actuator 110 may motivate the thermal connector 105 to contact to the first body 125 by applying a force in the range of zero point four newtons (0.4 N) to two thousand five hundred newtons (2,500 N) to the thermal connector 115, with the force directed toward the first body 125.
The actuator 110 may latch with the thermal connector 105 in contact with the first body 125. For example, a second actuator 110b may latch the second thermal connector 105b in contact with the first body 125 as shown in
The apparatus 200 allows one or more thermal connectors 105 to be positioned in contact with the first body 125. In addition, one or more thermal connectors 105 may be separated from the first body 125. The apparatus 200 may vary the heat that is transported to and/or from the first body 125 by varying the number and selection of thermal connectors 105 that are positioned in contact with the first body 125. Thus the system 100 may transfer minimal heat through the thermal connectors 105 when each thermal connector 105 is separated from the first body 125 while the system may transfer maximum heat when each thermal connector 105 is in contact with the first body 125.
The wires 330 may form an electric circuit that carries electric current between the wax actuator 300 and a controller. The wires 330 may carry the electric current to a heating element disposed in the base 325. Alternatively, the wires 330 may carry the electric current to a heating element disposed in the body 315. The heating element is in communication with a reservoir of a thermal expansive substance such as wax that expands when heated. The actuator 300 is referred to as a wax actuator 300, although alternative thermal expansive substances may be employed.
When the electric current flows through the heating element, the heating element may emit heat that heats the thermal expansive substance. The heated thermal expansive substance may expand, pushing against a piston (not shown) disposed within the body 315. The piston may be physically connected to the plunger 320. The heated thermal expansive substance may push against the piston, motivating the plunger 320.
The piston may motivate the plunger 320 to an extended position wherein the tip of the plunger 320 is a maximum distance from the body 315. In an alternate embodiment, the piston may motivate the plunger 320 to a retracted position wherein the tip of the plunger 320 is a minimum distance from the body 315. In one embodiment, the heated thermal expansive substance motivating the piston moves the plunger from the retracted position to the extended position over a time interval in the range of fifteen to two hundred seconds (15-200 s). Similarly, the heated thermal expansive substance motivating the piston may move the plunger from the extended position to a retracted position over a time interval in the range of one to two hundred seconds (1-200 s).
The wax actuator 300 may be configured to operate in a reduced pressure environment. In one embodiment, the wax actuator 300 is configured to operate in environmental pressures in the range of one hundred and one Kilopascals to zero point zero zero one micropascals (101 KPa -0.0001 μPa). In a specific embodiment, the wax actuator 300 is configured to operate in a vacuum in the range of one micropascal to zero point zero one micropascals (1 μPa -0.001 μPa).
In one embodiment, the wax actuator 300 consumes in the range of five to fifty watts (5-50 W). In addition, the wax actuator 300 may operate at between three and forty-eight volts (3-48V). In a certain embodiment, the wax actuator 300 consumes twenty watts (20 W) at twenty-eight volts (28 V).
In one embodiment, the wax actuator 300 may latch the plunger 320 in an extended position. Alternatively, the wax actuator 300 may be configured to latch the plunger 320 in a retracted position. The wax actuator 300 may consume no power with the plunger 320 latched.
In one embodiment, the controller 405 controls the wax actuator 300, motivating the plunger 320 to extend and retract. In a certain embodiment, the controller 405 switches an electrical current to flow through the wires 330 of the cable to the wax actuator 300. Alternatively, the controller 405 may communicate a signal to the wax actuator 300 and the signal may activate the flow of an electrical current through the wax actuator 300.
In one embodiment, the controller 405 directs the wax actuator 300 to latch the plunger in the extended position and/or in the retracted position. The controller 405 may also direct the wax actuator to unlatch the plunger 320. In an alternate embodiment, the wax actuator 300 may automatically latch the plunger 320 in the extended position when the plunger 320 reaches the extended position. Similarly, the wax actuator 300 may automatically latch the plunger 320 in the retracted position when the plunger 320 reaches the retracted position.
In one embodiment, the wax actuator 300 unlatches the plunger 320 in response to the controller 405 directing the wax actuator 300 to retract the plunger 320. Similarly, the wax actuator 300 may unlatch the plunger 320 in response to the controller 405 directing the wax actuator 300 to extend the plunger 320.
The actuator 110, thermal connector 105, and first body 125 of
In one embodiment, the actuator 110 motivates the thermal connector 105 to contact the first body 125. The thermal connector 105 cooled by the cryogen and in contact with the first body 125 may conduct heat from the first body 125 to cool the first body 125. In addition, the actuator 110 may motivate the thermal connector 105 to separate from the first body 125. The separated thermal connector 105 does not conduct heat from the first body 125 and so does not cool the first body.
The actuator 110, thermal connector 105, first body 125, actuator mount 120, thermal link 115, and second body 130 of
In one embodiment, the actuator 110 motivates the thermal connector 105 to contact the first body 125. Heat may flow from the second body 130 through the thermal link 115 and the thermal connector 105 to the first body 125, cooling the second body 130. The system 600 supports modifying the thermal connection between the second body heat source and the first body cold sink.
A plurality of thermal connectors 105 are disposed on opposite sides of the first body 125. Each thermal connector 105 is in thermal communication with a thermal link 115, and each thermal link 115 is in thermal communication with a second body 130a, 130b. In addition, each thermal connector 105 is in physical communication with an actuator 110 and each actuator 110 is mounted through an actuator mount 120 to a second body 130a, 130b.
Each actuator 110 is configured to motivate a thermal connector 105 along a shared axis with an opposing thermal connector 105. As shown, a first thermal connector 105a is configured to be motivated by a first actuator 110a along an axis shared with a third thermal connector 105c motivated by a third actuator 110c. A second thermal connector 105b is also shown configured to be motivated by a second actuator 110a along an axis shared with a fourth thermal connector 105d motivated by a fourth actuator 110d.
In one embodiment, the controller 405 may direct actuators 110 to motivate opposing pairs of thermal connectors 105 to contact the first body 125. In a prophetic example, the controller 405 may direct the first and third actuators 110a, 110c to motivate the first and third thermal connectors 105a, 105c to contact the first body 125 at substantially the same time. In addition, controller 405 may direct the first and third actuators 110a, 110c to motivate the first and third thermal connectors 105a, 105c with substantially equivalent force. Thus the first and third thermal connectors 105a, 105c may together apply a net force of zero newtons (0 N) to the first body 125.
Similarly, the controller 405 may direct the second and fourth actuators 110b, 110d to motivate the second and fourth thermal connectors 105b, 105d to contact the first body 125 at substantially the same time and with substantially the same force. Thus the system 600 may modify the thermal connections to the first body 125 while applying a net zero force to the first body 125.
The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
The method 800 begins and the actuator 110 motivates 805 the thermal connector 105. The actuator 110 may be the wax actuator 300 of
In one embodiment, a plurality of actuators 110 motivate a plurality of thermal connectors 105. The controller 405 may specify the number of actuators 110 to motivate in order to transport a specified quantity of heat. In a prophetic example, the controller 405 may need to transfer four hundred joules per minute (400 J/min) of heat from the first body 125. In addition, each thermal connector 105 may be configured to transport two hundred joules per minute (200 J/min) of heat through thermal links 115 to the second body 130. The controller 405 may direct two (2) actuators 110 to motivate two thermal connectors 105 to contact the first body 125 in order to transport the needed quantity of heat.
In an alternate embodiment, the controller 405 may direct each actuator 110 to motivate a corresponding thermal connector 105 in response to feedback one or more sensors disposed on the first body 125. In a prophetic example, the first body 125 may have an operational temperature of minus sixty degrees Celsius (−60° C.). A thermocouple sensor disposed on the first body 125 may report that the temperature of the first body 125 is minus forty degrees Celsius (−40° C.). As a result, the controller 405 may direct the first actuator 110a to motivate the first thermal connector 105a. If the temperature of the first body 125 does not reach minus sixty degrees Celsius (−60° C.), the controller 405 may also direct the second actuator 110b to motivate the second thermal connector 105b to further reduce the temperature of the first body 125.
The thermal connector 105 contacts 810 the first body 125 to form a thermal connection between the thermal connector 105 the first body 125. In one embodiment, the plurality of thermal connectors 105 contact one or more first bodies 125.
In one embodiment, the actuator 110 latches 815 with the thermal connector 105 in contact with the first body 125. The latched actuator 110 may consume no power. In addition, the latched actuator 110 may prevent the thermal connector 105 from separating from the first body 125 and breaking the thermal connection between the first body 125 and the thermal connector 105.
The thermal link 115 transports 820 heat through the thermal connection. In one embodiment, the thermal link 115 transports 820 heat between the first body 125 and the second body 130. Alternatively, the thermal link 115 may comprise a cryogen that cools the thermal connector 105 by transporting 820 heat from the thermal connector 105. The method 800 supports controlling the flow of heat from and/or to the first body 125 controlling the thermal connectors 105 that are motivated 805 to contact 810 the first body 125.
The method 900 begins and in one embodiment, the actuator 110 unlatches 905 to allow the thermal connector 105 move away from the first body 125. The controller 405 may direct the actuator 110 to unlatch 905.
In one embodiment, the actuator 110 motivates 910 the thermal connector 105 to separate from the first body 125. In an alternate embodiment, a spring motivates the thermal connector 105 to separate from the first body 125. In a certain embodiment, the actuator 110 is the wax actuator 300 and may motivate 910 the thermal connector 105 by melting the thermal expansive substance. The controller 405 may direct the actuator 110 to motivate 910 the thermal connector 105.
In one embodiment, the actuator 110 latches 915 with the thermal connector 105 separated from the first body 125 and the method 900 terminates. The controller 405 may direct the actuator 110 to latch 915. The method 900 separates the thermal connector 105 from the first body 125 to break the thermal connection between the first body 125 and the thermal connector 105, regulating heat transport from and/or to the first body 125.
The embodiment of the present invention modifies a thermal connection. In addition, the embodiment of the present invention may modify the transport of heat to maintain a specified temperature range and/or rate of heat transport. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
