Patent Publication Number: US-2021172430-A1

Title: Miniature blower

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This non-provisional application claims priority under 35 U.S.C. § 119(a) to Patent Application No. 108144820 filed in Taiwan, R.O.C. on Dec. 6, 2019, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a miniature blower. In particular, to a thin, portable, and low noise miniature blower. 
     Related Art 
     Many blowers discharge out gas by vibration of components in the blowers during their operation process. Because of the rapid high-frequency vibration, the operation of this type of blowers is often accompanied by the noise of the air flow. Thus, due to noise caused by the physical phenomena, such blowers cannot achieve the purpose of being portable as well as quiet and comfortable. 
     SUMMARY 
     In general, one of the objects of present disclosure is to provide a miniature blower which can reduce the noise caused by the air flow generated by its operation. The miniature blower of the present disclosure may become much more silent. 
     To achieve the above mentioned purpose(s), a general embodiment of the present disclosure provides a miniature blower including a soft sheet, a nozzle plate, a chamber frame, an actuator body, an insulation frame, a conductive frame. The soft sheet has a central hole. The nozzle plate has a suspension portion disposed on the soft sheet, and the suspension portion has a hollow hole and is capable of bending and vibrating. A center point of the central hole of the soft sheet and a center point of the hollow hole of the suspension portion are on a same axis. The chamber frame is disposed on the nozzle plate. The actuator body is formed by sequentially stacking, from bottom to top, a piezoelectric carrier plate, an adjusting resonance plate, and a piezoelectric plate with each other. The actuator body is disposed on the chamber frame, and the piezoelectric carrier plate is used to be applied with a first voltage and a second voltage so as to drive the piezoelectric plate to bend and vibrate reciprocatingly. The first voltage and the second voltage are alternately applied to the piezoelectric carrier plate at a frequency. The insulation frame is disposed on the actuator body. The conductive frame is disposed on the insulation frame. When the piezoelectric carrier plate is applied with the first voltage and the conductive frame is applied with the second voltage, the piezoelectric plate bends and vibrates toward a first direction. When the piezoelectric carrier plate is applied with the second voltage and the conductive frame is applied with the first voltage, the piezoelectric plate bends and vibrates toward a second direction opposite to the first direction. A resonance chamber is formed among the actuator body, the chamber frame, and the suspension portion. Upon application of the first voltage and the second voltage alternately, the actuator body is driven and thus brings the nozzle plate to resonate, so that the suspension portion of the nozzle plate bends and vibrates reciprocatingly. Thus, the gas passes through the central hole of the soft sheet and the hollow hole of the suspension portion to the resonance chamber and then is discharged out, thereby achieving gas transmission. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus not limitative of the disclosure, wherein: 
         FIG. 1  illustrates a schematic exploded view of a miniature blower according to an exemplary embodiment of the present disclosure; 
         FIG. 2A  illustrates a schematic top view of the miniature blower according to the exemplary embodiment of the present disclosure; 
         FIG. 2B  illustrates a schematic bottom view of the miniature blower according to the exemplary embodiment of the present disclosure; and 
         FIG. 3A  to  FIG. 3D  illustrate schematic cross-sectional views showing the miniature blower at different operation steps. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of different embodiments of this disclosure are presented herein for purpose of illustration and description only, and it is not intended to limit the scope of the present disclosure. 
     Please refer to  FIG. 1  to  FIG. 3A . The present disclosure provides a miniature blower  10 , which includes a soft sheet  101 , a nozzle plate  102 , a chamber frame  103 , an actuator body  104 , an insulation frame  105 , and a conductive frame  106 . The soft sheet  101  is a thin noise-absorbing pad. The center portion of the soft sheet  101  has a central hole  101   b . The nozzle plate  102  has a suspension portion  102   a , and the soft sheet  101  is disposed on the nozzle plate  102 . The center portion of the suspension portion  102   a  has a hollow hole  102   b , and the suspension portion  102   a  is capable of bending and vibrating. The center point of the central hole  101   b  of the soft sheet  101  and the center point of the hollow hole  102   b  of the nozzle plate  102  are on the same axis. The chamber frame  103  is disposed on the nozzle plate  102 . The actuator body  104  is formed by sequentially stacking, from bottom to top, a piezoelectric carrier plate  104   a , an adjusting resonance plate  104   b , and a piezoelectric plate  104   c  with each other. The actuator body  104  is disposed on the chamber frame  103 . The piezoelectric carrier plate  104   a  is used to be applied with a first voltage and a second voltage so as to drive the piezoelectric plate  104   c  to bend and vibrate reciprocatingly. The first voltage and the second voltage are alternately applied to the piezoelectric carrier plate  104   a  at a certain frequency. The first voltage and the second voltage may be the positive electrode and the negative electrode of the same power system (not shown), respectively, but is not limited thereto. In some embodiments, the waveform of the power system of the first voltage or the second voltage can also be adjusted according to the design requirements (such as sine wave, pulse wave, square wave, sawtooth wave, etc.). In this embodiment, the first voltage is +5V square wave, and the second voltage is −5V square wave. The alternating frequency between the first voltage and the second voltage is 25 Hz-29 kHz, but is not limited thereto. In other embodiments of the present disclosure, the waveform of the power system, the voltage value, and the alternating frequency between the first voltage and the second voltage can also be adjusted according to design requirements. The insulation frame  105  is disposed on the actuator body  104 . The conductive frame  106  is disposed on the insulation frame  105 . 
     It should be noted that, in this embodiment, when the piezoelectric carrier plate  104   a  is applied with the first voltage and the conductive frame  106  is applied with the second voltage, the piezoelectric plate  104   c  bends and vibrates toward a first direction. While the piezoelectric carrier plate  104   a  is applied with the second voltage and the conductive frame  106  is applied with the first voltage, the piezoelectric plate  104   c  bends and vibrates toward a second direction opposite to the first direction. In this embodiment, the first direction may be upward, and the second direction opposite to the first direction may be downward, but is not limited thereto. In other embodiments of the present disclosure, the first direction and the second direction may refer to other pairs of relative directions, such as up and down, right and left, or back and forward. 
     It should be noted that, in this embodiment, a resonance chamber  107  is formed among the actuator body  104 , the chamber frame  103 , and the suspension portion  102   a . Upon the application of the first voltage and the second voltage alternately, the actuator body  104  is driven and thus brings the nozzle plate  102  to resonate. Accordingly, the suspension portion  102   a  of the nozzle plate  102  bends and vibrates reciprocatingly, by which the gas is pushed through the central hole  101   b  of the soft sheet  101  and the hollow hole  102   b  of the nozzle plate  102  to the resonance chamber  107  and then is discharged out, thereby achieving a gas transmission. 
     Please refer to  FIG. 2B  and  FIG. 3A . In this embodiment, the central hole  101   b  of the soft sheet  101  has a central hole diameter R 1 , and the hollow hole  102   b  of the nozzle plate  102  has a hollow hole diameter R 2 . The central hole diameter R 1  is less than the hollow hole diameter R 2 . It should be noted that, since  FIG. 2B  illustrates a schematic bottom view of the miniature blower according to the exemplary embodiment of the present disclosure, the periphery of the hollow hole  102   b  (i.e. the periphery that defines the hollow hole diameter R 2 ) should not be seen in  FIG. 2B  theoretically. However, the periphery of the hollow hole  102   b  is shown in a dotted line for the purpose of comparing the size between the hollow hole diameter R 2  and the central hole diameter R 1 , as shown in  FIG. 2B . More specifically, as shown in  FIG. 3A , assume there is an axis Y passing through the central hole  101   b . When the soft sheet  101  is assembled to the suspension portion  102   a , the soft sheet  101  is staked on the suspension portion  102   a  along the direction of the axis Y, and the central hole  101   b  of the soft sheet  101  aims at the hollow hole  102   b  of the suspension portion  102   a . In an embodiment, the axis Y is perpendicular to both the soft sheet  101  and the suspension portion  102   a , and thus penetrates the central hole  101   b  and the hollow hole  102   b  thereof, respectively. Therefore, after the soft sheet  101  and the suspension portion  102   a  are stacked with each other, the center point of the central hole  101   b  and the center point of the hollow hole  102   b  are on the same axis (i.e. the axis Y). In some embodiments, the central hole  101   b  is located at the center of the soft sheet  101 , and the hollow hole  102   b  is located at the center of the suspension portion  102   a . The center point of the central hole  101   b  and the center point of the hollow hole  102   b  are on the same axis. In some embodiments, the central hole  101   b  is not located at the center of the soft sheet  101 , but the hollow hole  102   b  is located at the center of the suspension portion  102   a . However, the center point of the central hole  101   b  and the center point of the hollow hole  102   b  are still on the same axis. In some embodiments, the central hole  101   b  is located at the center of the soft sheet  101 , but the hollow hole  102   b  is not located at the center of the suspension portion  102   a . However, the center point of the central hole  101   b  and the center point of the hollow hole  102   b  are still on the same axis. In some embodiments, the central hole  101   b  is not located at the center of the soft sheet  101 , and the hollow hole  102   b  is not located at the center of the suspension portion  102   a . However, the center point of the central hole  101   b  and the center point of the hollow hole  102   b  are still on the same axis. Moreover, the periphery of the central hole  101   b  is surrounded by a sidewall  101   c , and the periphery of the hollow hole  102   b  is surrounded by a sidewall  102   c . Since the hollow hole diameter R 2  is greater than the central hole diameter R 1 , the sidewall  101   c  extends toward the center point of the central hole  101   b  and covers a portion of the hollow hole  102   b . In some embodiments, the sidewall  101   c  is substantially parallel to the sidewall  102   c.    
     It should be noted that, in some other embodiments, as long as the hardness of the soft sheet  101  is less than the hardness of the suspension portion  102   a , it falls in the scope of the present disclosure. That is, the hardness of the soft sheet  101  being less than the hardness of the suspension  102   a  is within the scope of the present disclosure. 
     It should be noted that, in some other embodiments, as long as the flexural strength of the soft sheet  101  is greater than the flexural strength of the suspension portion  102   a , it falls in the scope of the present disclosure. That is, the flexural strength of the soft sheet  101  being greater than the flexural strength of the suspension portion  102   a  is within the scope of the present disclosure. 
     It should be noted that, in some other embodiments, as long as the elasticity of the soft sheet  101  is greater than the elasticity of the suspension portion  102   a , it falls in the scope of the present disclosure. That is, the elasticity of the soft sheet  101  being greater than the elasticity of the suspension portion  102   a  is within the scope of the present disclosure. 
     Moreover, it should be noted that, in this embodiment, the central hole  101   b  of the soft sheet  101  has a central hole diameter R 1 . The central hole diameter R 1  is between 0.1 and 0.14 mm. The hollow hole  102   b  of the nozzle plate  102  has a hollow hole diameter R 2 . The hollow hole diameter is between 0.4 mm and 2.0 mm. 
     It should be noted that, in this embodiment, the central hole  101   b  of the soft sheet  101  is a circle. The central hole  101   b  of the soft sheet  101  may be a square, a rhombus, or a parallelogram as well. The width of the central hole  101   b  is between 0.1 and 0.14 mm, but is not limited thereto. The shape and width of the central hole  101   b  of the soft sheet  101  may be changed according to actual design requirements. 
     Moreover, it should be noted that, in this embodiment, the hollow hole  102   b  of the nozzle plate  102  is a circle. The hollow hole  102   b  of the nozzle plate  102  may be a square, a rhombus, or a parallelogram as well. The width of the hollow hole  102   b  is between 0.4 mm and 2.0 mm, but is not limited thereto. The shape and width of the hollow hole  102   b  of the nozzle plate  102  can be changed according to actual design requirements. 
     Then, please refer to  FIG. 3B  to  FIG. 3D .  FIG. 3B  to  FIG. 3D  illustrate schematic cross-sectional views showing the miniature blower  10  at different operation steps. First, when the actuator body  104  is applied with the first voltage and the conductive frame  106  is applied with the second voltage, the actuator body  104  bends and vibrates toward a first direction. The actuator body  104  is formed by sequentially stacking, from bottom to top, a piezoelectric carrier plate  104   a , an adjusting resonance plate  104   b , and a piezoelectric plate  104   c  with each other. As shown in  FIG. 3B , when the actuator body  104  bends and vibrates toward a first direction, the internal pressure of the resonance chamber  107  becomes negative, so that the gas enters into the resonance chamber  107  through the central hole  101   b  of the soft sheet  101  and the hollow hole  102   b  of the nozzle plate  102 . 
     Afterwards, due to the sudden negative pressure in the resonance chamber  107 , the nozzle plate  102  is driven by the actuator body  104 , so that the nozzle plate  102  resonates with the actuator body  104  (as shown in  FIG. 3C ). When the actuator body  104  is applied with the second voltage and the conductive frame  106  is applied with the first voltage, the piezoelectric plate  104   c  bends and vibrates toward a second direction opposite to the first direction (as shown in  FIG. 3D ). At this moment, the internal pressure of the resonance chamber  107  becomes positive, so that the gas is discharged out from the resonance chamber  107  to a gas flow chamber  108  through the hollow hole  102   b  of the nozzle plate  102  and the central hole  101   b  of the soft sheet  101 . 
     When the piezoelectric carrier plate  104   a  of the actuator body  104  and the conductive frame  106  are respectively applied with the first voltage and the second voltage alternately at a high frequency, the gas is continuously drawn into the miniature blower and discharged out of the miniature blower through the hollow hole  102   b  of the nozzle plate  102  and the central hole  101   b  of the soft sheet  101 . Moreover, the discharged gas will follow Bernoulli&#39;s principle, so that the gas in the gas flow chamber  108  flows in the direction indicated by the arrow shown in the  FIG. 3D . 
     Moreover, comparing to the miniature blower without the soft sheet  101 , the flow rate of the miniature blower  10  in the present disclosure is raised from 150 ml/s to 200 ml/s, and the decibels of the noise caused by gas flow in physical phenomena is decreased from 50 dB (the decibel of the noise produced by the miniature blower without the soft sheet  101 ) to 30 dB or lower. 
     To sum up, the miniature blower of one or some embodiments of the present disclosure can effectively decrease the noise caused by the gas flow. By utilizing specific combination of the hardness, flexural strength, and/or elasticity between the soft sheet and the suspension portion, and the difference between the diameter of the central hole and the diameter of the hollow hole, a miniature blower which is silent and produces stronger Bernoulli effect can be obtained. Thus, the industrial value of the miniature blower is quite high. 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.