Patent Publication Number: US-8974193-B2

Title: Synthetic jet equipment

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Taiwan Patent Application No. 101119481, filed on May 31, 2012, the entirety of which is incorporated by reference herein in its entirety. 
     TECHNICAL FIELD 
     The disclosure relates to synthetic jet equipment, and relates to heat dissipation in synthetic jet equipment. 
     BACKGROUND 
     The synthetic jet can provide turbulent flow for heat dissipation, which has better convectional efficiency when compared to a laminar flow. The conventional synthetic jet actuator comprises a chamber, a diaphragm, and an outlet. When the diaphragm moves upward and compresses the chamber during vibration, air is ejected through the outlet from the chamber and forms the synthetic jet. When the diaphragm moves downward, air is drawn into the chamber. With repeated vibrations, the actuator can eject incontinuous synthetic jet. However, since the outlet of the conventional synthetic jet actuator is also usually used as an intake, the ejected air may be drawn back into the chamber, such that the heat transfer efficiency may be hampered. 
     Additionally, the conventional synthetic jet actuator may be combined with a cooler (such as fins), to form a heat dissipation mechanism. Though conventional synthetic jet actuators can eject air to dissipate heat via fins, some of the heated air will be drawn back into the chamber, thus, causing temperatures inside of the chamber to rise, thus, decreasing heat dissipation efficiency. 
     SUMMARY 
     The disclosure provides a synthetic jet equipment, comprising a base, a frame fixed to the base, a first member, a pump diaphragm, a second member, and a valve diaphragm. The pump diaphragm connects the first member to the frame, and the valve diaphragm connects the second member to the frame. The base, the frame, the first member, the pump diaphragm, the second member, and the valve diaphragm define a chamber forming an intake and an outlet. When the first member moves in a first direction, the second member moves in a second direction opposite to the first direction, and the external air flows into the chamber through the inlet. When the first member moves in the second direction, the second member moves in the first direction, such that the air is exhausted from the chamber through the outlet 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a perspective diagram showing a synthetic jet equipment according to an embodiment of the disclosure; 
         FIG. 2  is a sectional view of a synthetic jet equipment according to an embodiment of the disclosure; 
         FIG. 3  is a sectional view showing of a synthetic jet equipment in an inspiratory state according to an embodiment of the disclosure; 
         FIG. 4  is a sectional view showing of a synthetic jet equipment in an aspiratory state according to an embodiment of the disclosure; 
         FIG. 5  is a perspective diagram showing a synthetic jet equipment according to another embodiment of the disclosure; 
         FIG. 6  is a sectional view of a synthetic jet equipment according to another embodiment of the disclosure; and 
         FIG. 7  is a sectional view of a synthetic jet equipment according to another embodiment of the disclosure; 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Referring to  FIG. 1  and  FIG. 2 , an embodiment of the disclosure provides a synthetic jet equipment  10  comprising a base  15 , a frame  20 , a holder  21 , a first member  41 , a pump diaphragm  42 , a second member  51 , a valve diaphragm  52 , a magnetic unit  60 , and a heat exchanger  70 . As shown in  FIG. 1  and  FIG. 2 , the heat exchanger  70  is disposed below the base  15 , and the second member  51 , the frame  20 , the magnetic unit  60  in the frame  20 , and the first member  41  are disposed above the base  15 . A fixed member  25  is disposed on the base  15 , and the valve diaphragm  52  connects the fixed member  25  to an edge of the second member  51 . The frame  20 , the second member  51 , and the base  15  are separated from each other and between a bottom edge of the frame  20  and the second member  51 , the base  15  form a gap for drawing air into the frame  20 . The holder  21  is fixed to the heat exchanger  70  (as shown in  FIG. 1  and  FIG. 5 ) and extended through the frame  20  to fix the magnetic unit  60  in the frame  20 . Thus, the magnetic unit  60  can be positioned between the first member  41  and the second member  51 . In some embodiments, the magnetic unit  60  may be a permanent magnet with N and S poles. 
     As shown in  FIG. 2 , the pump diaphragm  42  surrounds the first member  41  and connects the first member  41  with an upper edge of the frame  20 . A first coil  43  is disposed in the first member  41  and surrounds an edge of the magnetic unit  60 , such as the edge of the N pole. The first coil  43  may be disposed on a first surface  40  of the first member  41 . In some embodiments, the first coil  43  and the first member  41  may be integrally formed in one piece. A through hole  54  is formed at the center of the second member  51 , and the valve diaphragm  52  connects the second member  51  to the fixed member  25 . A second coil  53  is disposed in the second member  51  and surrounds an edge of the magnetic unit  60 , such as the edge of the S pole. The second coil  53  may be disposed on a second surface  50  of the second member  51 . In some embodiments, the second coil  53  and the second member  51  may be integrally formed in one piece. The wires extended from the first coil  43  and the second coil  53  can be guided along the holder  21  to an external power source. 
     The frame  20 , the first member  41 , the second member  51 , the pump diaphragm  42 , and the valve diaphragm  52  define a chamber  30  therebetween, wherein an intake  31  is formed between the frame  20  and the second member  51 , and an outlet  32  is formed on the base  15 . A first flow channel  73  is formed between the base  15  and the second member  51  to communicate the through hole  54  to the outlet  32 . 
     As shown in  FIG. 1  and  FIG. 2 , the heat exchanger  70  connects to the base  15  and forms a plurality of fins  77  surrounding the base  15 . The heat exchanger  70  is positioned under the base  15 . The base  15  has a circular structure, wherein the fins  77  are radically disposed under the base  15 . The fins  77  are equidistant annularity arrangement. During usage, the bottom of the heat exchanger  70  may connect to a heat source, such as an LED, and the heat can be dissipated by the fins  77  surrounding the heat exchanger  70 . In some embodiments, the base  15  and the heat exchanger  70  may be integrally formed in one piece. 
     The mechanism of the magnetic unit  60 , the first member  41 , the first coil  43 , the second member  51 , and the second coil  53  in  FIG. 3  will be described below. When an alternating current is applied to the first coil  43  and the second coil  53 , the magnetic field caused by the current can influence the magnetic unit  60  by a magnetic force (Lorentz force) upward or downward. When the current direction of the first coil  43  is as shown in  FIG. 3 , the first coil  43  and the magnetic unit  60  produce a repulsion force (first magnetic force) therebetween, such that the pump diaphragm  42  and the first member  41  move in a first direction A1, and air is drawn into the chamber  30  through the intake  31 , as the arrow S 1  indicates in  FIG. 3 . 
     Similarly, when the current direction applied to the second coil  53  is as shown in  FIG. 3 , the second coil  53  and the magnetic unit  60  generate a repulsion force (second magnetic force) therebetween, such that the valve diaphragm  52  and the second member  51  move in a second direction A2. When the second member  51  moves in the second direction A2, the outlet  32  of the base  15  can be closed. When the first member  41  moves in the first direction A1, and the second member  51  moves in the second direction A2, air can be drawn into the chamber  30  through the intake  31 , such that the synthetic jet equipment  10  is in an inspiratory state. 
     As shown in  FIG. 4 , when the phase of the alternative current changes, the current directions of the first coil  43  and the second coil  53  are reversed, and the first coil  43  and the magnetic unit  60  may have an attraction force (third magnetic force) therebetween. Thus, the pump diaphragm  42  and the first member  41  may move in the second direction A2. Similarly, when the current direction of the second coil  53  reverses as shown in  FIG. 4 , the second coil  53  and the magnetic unit  60  produce an attraction force (fourth magnetic force) therebetween, and the valve diaphragm  52  and the second member  51  move in the first direction A1. 
     When the pump diaphragm  42  and the first member  41  move in the second direction A2, the chamber  30  is compressed, and air in the chamber  30  is ejected through the through hole  54  of the center of the second member  51 , the first flow channel  73 , and the outlet  32 , so as to form a synthetic jet. The synthetic jet may be guided through a second flow channel  75  in the base  15  to the heat exchanger  70  for heat exchange, as the arrow S 2  indicates in  FIG. 4 , wherein the second flow channel  75  extends through the base  15 . 
     As shown in  FIG. 4 , when the second member  51  moves in the first direction A1, the intake  31  is closed, such that air in the chamber  30  is ejected through the through hole  54  of a center of the second member  51 , a first flow channel  73 , the outlet  32 , and the second flow channel  75 , and the synthetic jet equipment  10  is in an aspiratory state. In other words, when the first member  41  and the second member  51  move in the second direction A2 and the first direction A1 respectively, air in the chamber  30  can be ejected to produce the synthetic jet without external air flowing into the chamber  30 . 
     Referring to  FIG. 5  and  FIG. 6 , another embodiment of the disclosure provides a synthetic jet equipment  10  similar to the aforesaid embodiments ( FIGS. 1-3 ). The differences between the present embodiment from the  FIGS. 1-3  is that the base  15  of  FIGS. 5 and 6  has the same height with the heat exchanger  70 , wherein the base  15  and the heat exchanger  70  can be integrally formed in one piece. In  FIG. 6 , the second flow channel  75  is disposed in the base  15 , and a nozzle  71  is formed on a side of the second flow channel  75 . The synthetic jet from the outlet  32  can be horizontally ejected and guided through the second flow channel  75  and the nozzle  71  to dissipate heat via the fins  77  surrounding the heat exchanger  70 . As shown in  FIG. 5  and  FIG. 6 , the fins  77  are radically arranged surround and under the base  15  and separated from each other by the same distance. Here, the second flow channel  75  is not extended through the base  15 . 
     In this embodiment, the first member  41 , the first coil  43 , the pump diaphragm  42 , the second member  51 , the second coil  53 , the valve diaphragm  52 , and the magnetic unit  60  have the same mechanism as  FIGS. 1-3 . In some embodiments, an alternating current with a frequency may be applied to the first coil  43  and the second coil  53 , such that the pump diaphragm  42 , the valve diaphragm  52 , the first member  41 , and the second member  51  can periodically vibrate. Furthermore, the first coil  43  and the second coil  53  may be respectively connected to an independently driven circuit to control the motions of the first member  41  and the second member  51 . 
     Referring to  FIG. 7 , in another embodiment of the synthetic jet equipment  10 , a first magnet  46  and a second magnet  56  are respectively fixed to the first member  41  and the second member  51 , and a coil unit  61  is fixed to the holder  21 , wherein the coil unit  61  is disposed between the first magnet  46  and the second magnet  56 . When an alternating current is applied to the coil unit  61 , the current induces an magnetic field influencing the first magnet  46  and the second magnet  56  by an attractive force or repulsive force, to drive the first magnet  46  and the second magnet  56  moving upward (first direction A1) or downward (second direction A2). Thus, the pump diaphragm  42 , the valve diaphragm  52 , the first member  41 , and the second member  51  can produce periodic vibrations to generate a synthetic jet. 
     The disclosure provides a synthetic jet equipment having an intake and an outlet, preventing external air from drawing back into the chamber after heat exchange. Compared to the conventional synthetic jet actuator, the disclosure can always eject cold air and improve the efficiency of heat exchange. 
     While the disclosure has been described by way of example and in terms of the preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.