Piezoelectric micro blower

Abstract

A piezoelectric micro blower includes a blower body that includes a first wall and a second wall. An opening is provided at a portion of the first wall that faces an area of the approximate center of a driver of the piezoelectric micro blower. An opening is provided at a portion of the second wall. A central space that is in communication with the openings is provided between the first and second walls. Inlet passages through which the central space is in communication with the outside are provided between the first and second walls. Bottleneck portions are provided at regions at which the inlet passages are connected to the central space. The driver vibrates when a voltage is applied to a piezoelectric element. The first wall vibrates in a corresponding manner as the driver vibrates.

1 . A piezoelectric micro blower comprising:
 a blower body;   a driver including a peripheral portion that is fixed to the blower body and a piezoelectric element; and   a blower chamber provided between the blower body and the driver; wherein   the piezoelectric element is arranged to receive a voltage to cause the driver to vibrate due to bending in order to transport a compressible fluid;   the blower body includes a first wall arranged such that the blower chamber is provided between the driver and the first wall;   the first wall includes a first opening arranged such that an inside of the blower chamber is in communication with an outside of the blower chamber through the first opening;   a second wall is provided at a side opposite to the blower chamber with the first wall being provided between the second wall and the blower chamber, the second wall being spaced at a distance from the first wall;   the second wall includes a second opening;   a central space is provided between the first wall and the second wall, includes an open area that is greater than an area of the first opening and the second opening but less than an area of the blower chamber, and is in communication with the first opening and the second opening;   an inlet passage is provided and includes an outer end that is in communication with an outside of the piezoelectric micro blower and an inner end that is connected to the central space; and   a bottleneck portion including a passage area that is less than that of the inlet passage is provided in the inlet passage.   
     
     
         2 . The piezoelectric micro blower according to  claim 1 , wherein the first opening is provided at a portion of the first wall that faces an area of an approximate center of the driver. 
     
     
         3 . The piezoelectric micro blower according to  claim 1 , wherein the second opening is provided at a portion of the second wall that faces the first opening. 
     
     
         4 . The piezoelectric micro blower according to  claim 1  wherein the bottleneck portion is provided at a region at which the inlet passage is connected to the central space. 
     
     
         5 . The piezoelectric micro blower according to  claim 1 , wherein the passage area of the bottleneck portion gradually decreases in a direction of a flow from the inlet passage to the central space. 
     
     
         6 . The piezoelectric micro blower according to  claim 1 , wherein the open area of the central space is arranged such that the facing portion of the first wall vibrates as the driver vibrates. 
     
     
         7 . The piezoelectric micro blower according to  claim 1 , wherein the inlet passage includes a plurality of passages extending in radial directions from the central space.