Diaphragm air pump

Abstract

A diaphragm air pump includes a diaphragm; and upper and lower housings that interpose the diaphragm such that a variable volume chamber is formed over and under the diaphragm. The diaphragm air pump vibrates the diaphragm to obtain a pump operation, a circular concave portion into which the diaphragm that is circular in plan view is fitted is formed in any one of the upper and lower housings, a ring-shaped groove for housing a seal member is formed in the other, the ring-shaped groove having inner and outer diameters which are set across the circular concave portion, and a ring-shaped elastic seal member which is compressively deformed across the periphery of the diaphragm by the upper and lower housings is housed in the ring-shaped groove.

1 . A diaphragm air pump comprising:
 a diaphragm; and   upper and lower housings that interpose the diaphragm such that a variable volume chamber is formed over and under the diaphragm,   wherein the diaphragm air pump vibrates the diaphragm to obtain a pump operation, a circular concave portion into which the diaphragm that is circular in plan view is fitted is formed in any one of the upper and lower housings, a ring-shaped groove for housing a seal member is formed in the other, the ring-shaped groove having inner and outer diameters which are set across the circular concave portion, and a ring-shaped elastic seal member which is compressively deformed across the periphery of the diaphragm by the upper and lower housings is housed in the ring-shaped groove.   
   
   
       2 . The diaphragm air pump according to  claim 1 ,
 wherein the diaphragm comprises a piezoelectric vibrator.   
   
   
       3 . The diaphragm air pump according to  claim 2 ,
 wherein the piezoelectric vibrator comprises a unimorph-type piezoelectric vibrator in which a piezoelectric body is stacked on a shim formed of a conductive metal thin plate.   
   
   
       4 . The diaphragm air pump according to  claim 3 ,
 wherein the shim of the piezoelectric vibrator has a larger diameter than the piezoelectric body, and the circular concave portion of the lower housing is composed of a large-diameter stepped portion into which the shim is fitted and a small-diameter stepped portion in which the piezoelectric body is housed in a non-contact manner.   
   
   
       5 . The diaphragm air pump according to  claim 1 ,
 wherein the cross-sectional shape of the ring-shaped elastic seal member in a free state is rectangular.   
   
   
       6 . The diaphragm air pump according to  claim 1 ,
 wherein the cross-sectional shape of the ring-shaped elastic seal member in a free state is circular.   
   
   
       7 . The diaphragm air pump according to  claim 1 ,
 wherein the cross-sectional shape of the ring-shaped elastic seal member in a free state is elliptical oval.   
   
   
       8 . The diaphragm air pump according to  claim 1 ,
 wherein the cross-sectional shape of the ring-shaped elastic seal member in a free state is oval.