The present disclosure relates generally to synthetic jet ejectors, and more particularly to systems and methods for integrating components into synthetic jet ejectors.
A variety of thermal management devices are known to the art, including conventional fan based systems, piezoelectric systems, and synthetic jet ejectors. The latter type of system has emerged as a highly efficient and versatile solution, especially in applications where thermal management is required at the local level.
Various examples of synthetic jet ejectors are known to the art. Earlier examples are described in U.S. Pat. No. 5,758,823 (Glezer et al.), entitled “Synthetic Jet Actuator and Applications Thereof”; U.S. Pat. No. 5,894,990 (Glezer et al.), entitled “Synthetic Jet Actuator and Applications Thereof”; U.S. Pat. No. 5,988,522 (Glezer et al.), entitled Synthetic Jet Actuators for Modifying the Direction of Fluid Flows“; U.S. Pat. No. 6,056,204 (Glezer et al.), entitled “Synthetic Jet Actuators for Mixing Applications”; U.S. Pat. No. 6,123,145 (Glezer et al.), entitled Synthetic Jet Actuators for Cooling Heated Bodies and Environments”; and U.S. Pat. No. 6,588,497 (Glezer et al.), entitled “System and Method for Thermal Management by Synthetic Jet Ejector Channel Cooling Techniques.
Further advances have been made in the art of synthetic jet ejectors, both with respect to synthetic jet ejector technology in general and with respect to the applications of this technology. Some examples of these advances are described in U.S. 20100263838 (Mahalingam et al.), entitled “Synthetic Jet Ejector for Augmentation of Pumped Liquid Loop Cooling and Enhancement of Pool and Flow Boiling”; U.S. 20100039012 (Grimm), entitled “Advanced Synjet Cooler Design For LED Light Modules”; U.S. 20100033071 (Heffington et al.), entitled “Thermal management of LED Illumination Devices”; U.S. 20090141065 (Darbin et al.), entitled “Method and Apparatus for Controlling Diaphragm Displacement in Synthetic Jet Actuators”; U.S. 20090109625 (Booth et al.), entitled Light Fixture with Multiple LEDs and Synthetic Jet Thermal Management System“; U.S. 20090084866 (Grimm et al.), entitled Vibration Balanced Synthetic Jet Ejector”; U.S. 20080295997 (Heffington et al.), entitled Synthetic Jet Ejector with Viewing Window and Temporal Aliasing“; U.S. 20080219007 (Heffington et al.), entitled “Thermal Management System for LED Array”; U.S. 20080151541 (Heffington et al.), entitled “Thermal Management System for LED Array”; U.S. 20080043061 (Glezer et al.), entitled “Methods for Reducing the Non-Linear Behavior of Actuators Used for Synthetic Jets”; U.S. 20080009187 (Grimm et al.), entitled “Moldable Housing design for Synthetic Jet Ejector”; U.S. 20080006393 (Grimm), entitled Vibration Isolation System for Synthetic Jet Devices“; U.S. 20070272393 (Reichenbach), entitled “Electronics Package for Synthetic Jet Ejectors”; U.S. 20070141453 (Mahalingam et al.), entitled “Thermal Management of Batteries using Synthetic Jets”; U.S. 20070096118 (Mahalingam et al.), entitled “Synthetic Jet Cooling System for LED Module”; U.S. 20070081027 (Beltran et al.), entitled “Acoustic Resonator for Synthetic Jet Generation for Thermal Management”; U.S. 20070023169 (Mahalingam et al.), entitled “Synthetic Jet Ejector for Augmentation of Pumped Liquid Loop Cooling and Enhancement of Pool and Flow Boiling”; U.S. 20070119573 (Mahalingam et al.), entitled “Synthetic Jet Ejector for the Thermal Management of PCI Cards”; U.S. 20070119575 (Glezer et al.), entitled “Synthetic Jet Heat Pipe Thermal Management System”; U.S. 20070127210 (Mahalingam et al.), entitled “Thermal Management System for Distributed Heat Sources”; U.S. 20070141453 (Mahalingam et al.), entitled “Thermal Management of Batteries using Synthetic Jets”; U.S. Pat. No. 7,252,140 (Glezer et al.), entitled “Apparatus and Method for Enhanced Heat Transfer”; U.S. Pat. No. 7,606,029 (Mahalingam et al.), entitled “Thermal Management System for Distributed Heat Sources”; U.S. Pat. No. 7,607,470 (Glezer et al.), entitled “Synthetic Jet Heat Pipe Thermal Management System”; U.S. Pat. No. 7,760,499 (Darbin et al.), entitled “Thermal Management System for Card Cages”; U.S. Pat. No. 7,768,779 (Heffington et al.), entitled “Synthetic Jet Ejector with Viewing Window and Temporal Aliasing”; U.S. Pat. No. 7,784,972 (Heffington et al.), entitled “Thermal Management System for LED Array”; and U.S. Pat. No. 7,819,556 (Heffington et al.), entitled “Thermal Management System for LED Array”.
In one aspect, a method is provided for forming tinsel on a synthetic jet actuator. The method comprises (a) providing a synthetic jet actuator assembly comprising a coil, driver electronics, and a surround; and (b) completing an electrical circuit between the coil and the driver electronics by depositing a conductive ink across the surround.
In another aspect, a synthetic jet actuator is provided which comprises (a) a coil, driver electronics, and a surround; and (b) a conductive ink which extends across the surround and which forms an electrical circuit between the coil and the driver electronics.
In a further aspect, a synthetic jet actuator is provided which comprises (a) a diaphragm equipped with a surround; (b) a voice coil having first and second terminal portions; (c) a pot structure having first and second portions which are electrically isolated from each other; (d) a first portion of tinsel having a first end which is in electrical communication with said first terminal portion of said voice coil, and a second end which is in electrical communication with said first portion of said pot structure; and (e) a second portion of tinsel having a first end which is in electrical communication with said second terminal portion of said voice coil, and a second end which is in electrical communication with said second portion of said pot structure.
In still another aspect, a synthetic jet actuator is provided which comprises (a) a diaphragm equipped with a surround; (b) a voice coil having first and second terminal portions; (c) a pot structure having first and second passageways defined therein; (d) a first portion of tinsel which extends through said first passage way and which is in electrical communication with said first terminal portion of said voice coil; and (e) a second portion of tinsel which extends through said second passage way and which is in electrical communication with said second terminal portion of said voice coil.
In another aspect, a synthetic jet actuator is provided which comprises (a) a diaphragm equipped with a surround; (b) a voice coil having first and second terminal portions; (c) a pot structure having first and second passageways defined therein; (d) a first conductive element which extends through said first passage way and which is in electrical communication with said first terminal portion of said voice coil; and (e) a second portion of tinsel which extends through said second passage way and which is in electrical communication with said second terminal portion of said voice coil.
In a further aspect, a synthetic jet actuator is provided which comprises (a) a diaphragm equipped with a surround; and (b) a plurality of electrically conductive elements integrated with said surround.
The devices and methodologies disclosed herein utilize synthetic jet actuators or synthetic jet ejectors. Prior to describing these devices and methodologies, a brief explanation of a typical synthetic jet ejector, and the manner in which it operates to create a synthetic jet, may be useful.
The formation of a synthetic jet may be appreciated with respect to
The movement of the flexible diaphragm 111 may be controlled by any suitable control system 117. For example, the diaphragm may be moved by a voice coil actuator. The diaphragm 111 may also be equipped with a metal layer, and a metal electrode may be disposed adjacent to, but spaced from, the metal layer so that the diaphragm 111 can be moved via an electrical bias imposed between the electrode and the metal layer. Moreover, the generation of the electrical bias can be controlled by any suitable device, for example but not limited to, a computer, logic processor, or signal generator. The control system 117 can cause the diaphragm 111 to move periodically or to modulate in time-harmonic motion, thus forcing fluid in and out of the orifice 113.
Alternatively, a piezoelectric actuator could be attached to the diaphragm 111. The control system would, in that case, cause the piezoelectric actuator to vibrate and thereby move the diaphragm 111 in time-harmonic motion. The method of causing the diaphragm 111 to modulate is not particularly limited to any particular means or structure.
The operation of the synthetic jet ejector 101 will now be described with reference to
The devices and methodologies described above represent notable improvements in synthetic jet technology. However, a number of problems still exist in the art. In particular, many synthetic jet ejectors require the use of tinsel wires or flexible circuit connections between the coil terminals of a moving synthetic jet actuator. These types of connections are prone to breaking or wear, present manufacturing difficulties, and also create surfaces that other components may become caught on or entangled with.
It has now been found that some of the foregoing problems may be overcome through embodiments described herein which avoid the need for tinsel wires or a flexible circuit connection between the coil terminals of a moving coil actuator. This may be accomplished, for example, by utilizing Polymer Thick Film (PTF) conductive inks that may be printed on three-dimensional surfaces using inkjet deposition technologies.
It has further been found that some of the foregoing problems may be overcome by soldering the tinsel leads coming from the diaphragm to the pot magnet structure. The pot magnet structure is preferably in two semicircular halves that do not have electrical contact with each other, thus eliminating contact with the surround.
It has also been found that some of the foregoing problems may be overcome by routing tinsel leads coming from the diaphragm through via holes in the pot structure or frame before reaching the diametric location of the surround, or by using other tinsel routing methodologies as described herein.
Various printable conductive inks may be utilized to form the printed interconnect 209. Preferably, the printable conductive ink is a polymer thick film (PTF) based ink, though conductive inks based on fired high solids compositions or nanoparticles may also be utilized. These inks allow circuits to be drawn or printed on a variety of substrate materials, including polyester or paper, and may contain conductive ingredients or fillers such as powdered or flaked silver, carbon or graphite. These inks may be deposited using inkjet material deposition techniques, which may utilize a print head equipped with piezoelectric crystals.
By utilizing terminal pins 207 inserted into the plastic bobbin 203 and actuator basket 205, the PTF conductive ink 209 can be printed in a trace or plane shape that extends across the roll of the surround 211 and connects the voice coil 213 to the driver board electronics 215. This conductive ink 209 may be bonded to the surround 211 of the actuator 201, thus ensuring that the electrical connection travels in unison with the surround 211 and cannot contact any other parts to cause acoustic artifacts.
The surround 211 can be shaped to minimize bending in any region and to provide high reliability in a dynamic flex environment. Since the surface where the printing of the conductive ink 209 is deposited is on the outside of the synthetic jet actuator 201, this step may be performed after the complete synthetic jet actuator assembly is assembled and (if applicable) ultrasonically welded together. This method is also compatible with automated assembly techniques, since it does not require a tinsel wire or flexible circuit to be carefully woven through the support structure of the synthetic jet actuator.
First and second portions of tinsel 319 are arranged such that one end of each portion of tinsel 319 is attached to one of the semicircular halves of the pot 315 by way of a solder joint 321, and the other end of each portion of tinsel 319 is attached to a lead on the coil 307. Positive and negative electrical leads 323 are attached to one of the semicircular halves of the pot 315 by way of a solder joint 321. This arrangement eliminates any contact between the tinsel 319 and the surround 305.
The passageways 425 are preferably large enough to provide clearance so that the tinsel 419 or wires do not come into contact with the moving parts of the synthetic jet actuator 401. Also, it is preferable that the travel path of the diaphragm 403 be uniform (normal to the voice coil 407). This wire routing method will help improve reliability as well as acoustics due to tinsel noise. As with the previous embodiment, this arrangement may be used to eliminate any contact between the tinsel 419 and the surround 405.
In a preferred embodiment of this approach, the carbon nanotube coating 719 on the actuator diaphragm 703 is a thin, preferably elastomeric layer that connects the center of the actuator 701 to the edge of the basket 715 along the surface of the diaphragm 703. This provides an electrical connection between the voice coil 707 and a power source, without interfering with the internal geometry or volume of the synthetic jet actuator 701. By contrast, the corresponding conventional synthetic jet actuator 702 depicted in
It will be appreciated that the synthetic jet actuator 801 of
The diaphragm 903 and surround material 905 are coated (e.g., through vapor deposition, sputtering, plating, or otherwise depositing metal or other conductive materials) with a patterned conductive structure to provide a current path to and from the wires of the voice coil 907. Preferably, electrical connections are made to the metallic coating through the use of a suitable adhesive, by soldering, or the like. The metal coating may be implemented in various shapes and patterns as necessary to achieve the desired electrical and mechanical properties and a suitable lifetime. The electrical contact may be made by pressing, press fitting, crimping, clamping, or through the use of other suitable means.
In a preferred embodiment, an insulating diaphragm 903 is utilized which is coated on one, and preferably on both, sides to provide a current path to and from the voice coil 907. The connection may be made by crimping the top and bottom of the diaphragm 903 to the voice coil former 909. In some embodiments, the entire diaphragm 903 may be made of a material that can be doped, irradiated or otherwise treated so as to change its properties from conductive to non-conductive (or from non-conductive to conductive) to provide two distinct current paths to the voice coil 907.
The foregoing methods may also be combined with other methods, such as the use of tinsel wires, to achieve desired electrical and mechanical properties and a suitable lifetime. Moreover, to aid in current routing, the voice coil 907 may be coated or patterned using methodologies such as those described above.
It is typically necessary to connect the moving voice coil of a synthetic jet actuator to a fixed point for external electrical power to drive the coil. The wires used for this connection are specially designed for long flexure life. The synthetic jet actuator 1001 of
The diaphragm 1005, which is driven by the motion of the voice coil 1003, often is made with reinforcing ribs or rings molded into it to give more uniform motion, to prevent buckling, and to add strength. By molding the rings as spirals from the coil connection points near the center to the outer rim of the diaphragm 1005, the strength benefits can be obtained. Moreover, by routing the tinsel 1007 along the spirals (e.g., next to the ridge of the spirals or between these ridges), the tinsel 1007 is flexed only a very small amount, and uniformly along the entire path from the voice coil 1003 to the fixed termination point. Hence, instead of having the end-to-end displacement of the tinsel 1007 occur over approximately one radial length, it can occur over 2π× the radial length or longer if the spiral makes several revolutions between the center and the outer perimeter of the diaphragm 1005.
Several variations are possible with the foregoing embodiment. Typically, at least two tinsels will be required to connect the voice coil to an external power source. In some embodiments, a single spiral may be provided in the diaphragm with both tinsels run adjacent to each other, and with the tinsels electrically insulated from each other. In other embodiments, a separate spiral may be provided for each tinsel. The tinsel may be disposed on the top or bottom surface of the diaphragm, or both. One or more tabs may be provided on the rim of the diaphragm to make electrical connections to the tinsel.
In some embodiments of the devices and methodologies described herein, the voice coils utilized may be powered through electrical induction. In accordance with such methods, electrical power is delivered to the voice coil without tinsels (e.g., wirelessly) by using an electric inductance effect. An external coil is used to emit the AC magnetic field, which in turn is picked up by the voice coil or a secondary pick up coil to power the voice coil.
The above description of the present invention is illustrative, and is not intended to be limiting. It will thus be appreciated that various additions, substitutions and modifications may be made to the above described embodiments without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed in reference to the appended claims.
This application claims the benefit of U.S. Provisional Application No. 61/487,277, filed May 18, 2011, incorporated herein by reference in its entirety.
Number | Date | Country | |
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61487277 | May 2011 | US |