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Diaphragm air pump

Diaphragm air pump description/claims

The present application claims priority to Japanese Patent Application JP2007-152411 filed in the Japanese Patent Office on Jun. 8, 2007, the entire contents of which being incorporated herein by reference.

1. Field of the Invention

The present invention relates to a diaphragm air pump which vibrates a diaphragm in a reciprocating manner to obtain a pump action.

2. Description of the Related Art

The disclosure examines a method in which a piezoelectric air pump using a piezoelectric vibrator is used for cooling a heat generating source (for example, CPU) of a notebook PC, for example.

The piezoelectric vibrator has an amplitude of several tens to several hundreds μm order. As a piezoelectric vibrator vibrates in a variable volume chamber, the volume of the chamber is sufficiently reduced such that jet gas (air) can be transferred, and the heated air around the heat generating source is moved by the gas flow such that the heat generating source is cooled.

The piezoelectric vibrator is constructed by stacking a piezoelectric body on at least one of the top and bottom surfaces of a shim (conductive thin metal plate). The thickness of the piezoelectric vibrator can be reduced into less than 1 mm as a whole. Further, the variable volume chamber formed over and under the piezoelectric vibrator has such a small volume as to supply and discharge compressive air through the vibration of the piezoelectric vibrator. Therefore, the thickness of a piezoelectric gas jetting device can be significantly reduced in such a manner that the device is used for cooling such an apparatus as a notebook PC having a small space. Such a gas jetting device is disclosed in Japanese Patent Unexamined Publication No. 2005-256834 and U.S. Pat. Nos. 6,801,430 and 6,123,145.

In the piezoelectric air pump, a ring-shaped seal member formed of an elastic material is provided on the top and bottom surfaces of the piezoelectric vibrator, in order to secure an air-tight structure of the piezoelectric vibrator (diaphragm). That is, the ring-shaped seal member is interposed between the top periphery of the diaphragm and an upper housing and between the bottom periphery of the diaphragm and a lower housing, respectively. It has been considered to be essential that the ring-shaped seal member is provided on both the top and bottom surfaces of the diaphragm. However, according to the analysis of the present inventors, a diaphragm air pump in which liquid leak does not need to be considered may not have a ring-shaped seal member provided on both the top and bottom surfaces. By improving a seal structure, air seal can be realized by a single ring-shaped seal member.

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, and the variable volume chambers provided on the top and bottom of the diaphragm, respectively, can be air-sealed by one ring-shaped elastic seal member.

In the diaphragm air pump, 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.

The diaphragm may be a piezoelectric vibrator.

FIG. 1 is a perspective view of an embodiment in which a diaphragm according to the present invention is applied to a piezoelectric gas jet generating device;

FIG. 2 is an exploded perspective view of the embodiment; and

FIG. 3 is a partially expanded cross-sectional view of the embodiment.

• Provisional Patent
• Utility Patent

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