Air flow generating device

Abstract

An air flow generating device includes an enclosing wall, a frame sheet, a cover film, and a vibrating part. The frame sheet is disposed inside an air flow passage formed by the enclosing wall and closely contacts the air flow passage by its periphery. The cover film includes a central connection portion fixed to a central portion of the frame sheet, and a plurality of movable cover portions connected to the central connection portion. The cover film is between the frame sheet and an outlet of the air flow passage. The movable cover portions selectively cover a plurality of through holes of the frame sheet. The vibrating part is fixed on the frame sheet. When the vibrating part vibrates, the central portion and the central connection portion move together with the vibrating part so that the movable cover portions seal the through holes or move relative to the through holes.

What is claimed is: 
     
         1 . An air flow generating device, comprising:
 an enclosing wall forming an air flow passage, the air flow passage having an inlet and an outlet;   a frame sheet disposed in the air flow passage and having a plurality of first through holes, a periphery of the frame sheet closely contacting the enclosing wall, the frame sheet partitioning the air flow passage into a first air cavity connecting with the outlet, and a second air cavity connecting with the inlet;   a first cover film comprising a first central connection portion and a plurality of first movable cover portions connected to the first central connection portion, the first cover film being located between the frame sheet and the outlet, the first central connection portion being fixed on a central portion of the frame sheet, the first movable cover portions selectively covering the first through holes; and   a vibrating part fixedly connected to the frame sheet and being capable of repetitively moving;   
       wherein, when the vibrating part moves in a first direction toward the first air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the first direction, so that the first movable cover portions seal the first through holes, push air in the first air cavity out through the outlet, and draw in external air from the inlet, and 
       when the vibrating part moves in a second direction opposite to the first direction toward the second air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the second direction, so that the first movable cover portion lift in the first direction relative to the first through holes so as to make at least a portion of the external air enter the first air cavity from the second air cavity. 
     
     
         2 . The air flow generating device of  claim 1 , wherein the periphery of the frame sheet is fixedly connected to the enclosing wall. 
     
     
         3 . The air flow generating device of  claim 1 , further comprising a lower support fixedly connected to the enclosing wall and located at the inlet, wherein the vibrating part comprises a magnet and an electromagnet, the magnet is fixedly connected to the central portion of the frame sheet, and the electromagnet is disposed on the lower support opposite to the magnet. 
     
     
         4 . The air flow generating device of  claim 3 , further comprising a lower spring disposed between the frame sheet and the lower support, wherein when the vibrating part vibrates, the lower spring is elastically deformable. 
     
     
         5 . The air flow generating device of  claim 4 , further comprising an upper support and an upper spring, wherein the upper support is fixedly connected to the enclosing wall and located at the outlet, the upper spring is disposed between the frame sheet and the upper support, and when the vibrating part vibrates, the upper spring is elastically deformable. 
     
     
         6 . The air flow generating device of  claim 1 , further comprising a lower support and a second cover film, wherein the lower support is fixedly connected to the enclosing wall and located at the inlet, the lower support has a plurality of second through holes, the second cover film includes a second central connection portion and a plurality of second movable cover portions connected to the second central connection portion, the second cover film is located between the lower support and the frame sheet, the second central connection portion is fixed on a central portion of the lower support, the second movable cover portions selectively cover the second through holes, when the vibrating part moves in the first direction toward the first air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the first direction, so that the second movable cover portions lift in the first direction relative to the second through holes to draw the external air into the second air cavity, and when the vibrating part moves in the second direction toward the second air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the second direction, so that the second movable cover portions seal the second through holes so as to make the external air drawn into the second air cavity be pushed into the first air cavity. 
     
     
         7 . The air flow generating device of  claim 6 , wherein the lower support is a membrane. 
     
     
         8 . The air flow generating device of  claim 1 , further comprising an upper support and a third cover film, wherein the upper support is fixedly connected to the enclosing wall and located at the outlet, the upper support has a plurality of third through holes, the third cover film comprises a third central connection portion and a plurality of third movable cover portions connected to the third central connection portion, the upper support is located between the third cover film and the first cover film, the third central connection portion is fixed on a central portion of the upper support, the third movable cover portions selectively cover the third through holes, when the vibrating part moves in the first direction toward the first air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the first direction, so that the third movable cover portions lift in the first direction relative to the third through holes so as to make the air in the first air cavity be pushed out through the outlet, and when the vibrating part moves in the second direction, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the second direction, so that the third movable cover portions seal the third through holes so as to make the external air drawn into the second air cavity be drawn into the first air cavity. 
     
     
         9 . The air flow generating device of  claim 8 , wherein the upper support is a membrane. 
     
     
         10 . The air flow generating device of  claim 8 , further comprising a lower support and a second cover film, wherein the lower support fixedly connected to the enclosing wall and located at the inlet, the lower support has a plurality of second through holes, the second cover film comprises a second central connection portion and a plurality second movable cover portions connected to the second central connection portion, the second cover film is located between the lower support and the frame sheet, the second central connection portion is fixed on a central portion of the lower support, the second movable cover portions selectively cover the second through holes, when the vibrating part moves in the first direction toward the first air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the first direction, so that the second movable cover portions lift in the first direction lift relative to the second through holes to draw the external air into the second air cavity, and when the vibrating part moves in the second direction toward the second air cavity, the first central connection portion of the first cover film and at least the central portion of the frame sheet move in the second direction, so that the second movable cover portions seal the second through holes so as to make the external air drawn into the second air cavity be pushed into first air cavity. 
     
     
         11 . The air flow generating device of  claim 10 , further comprising an upper spring and a lower spring, wherein the upper spring is disposed between the frame sheet and the upper support, the lower spring is disposed between the frame sheet and the lower support, and when the vibrating part vibrates, the upper spring and the lower spring are elastically deformable. 
     
     
         12 . The air flow generating device of  claim 1 , wherein the vibrating part is fixedly connected to a central portion of the frame sheet. 
     
     
         13 . The air flow generating device of  claim 1 , wherein each first movable cover portion is formed in a circular sector form, and the first movable cover portions are disposed radially relative to the first central connection portion. 
     
     
         14 . The air flow generating device of  claim 1 , wherein the first movable cover portions correspond to the first through holes respectively. 
     
     
         15 . The air flow generating device of  claim 14 , wherein the profile of each first movable cover portion is larger than the profile of the corresponding first through hole.