Airflow generator and heat dissipation device incorporating the same

Abstract

An airflow generator includes stacked airflow-generating units. Each airflow-generating unit includes a casing, first and second vibrating diaphragms received in the casing and spaced from each other, first and second driving members for driving the first and second vibrating diaphragms, and a nozzle connected to the casing. An inner space of the casing is divided into a first chamber formed between the first and second vibrating diaphragms, and a second chamber and a third chamber located at two opposite sides of the first chamber. The first driving member includes a first movable magnet attached to the first vibrating diaphragm, and a first stationary magnet received in the second chamber and attached to the casing. The second driving member includes a second movable magnet attached to the second vibrating diaphragm, and a second stationary magnet received in the third chamber and attached to the casing.

1 . An airflow generator, comprising:
 at least one airflow-generating unit, comprising:   a casing;   a first and a second vibrating diaphragms received in the casing and spaced from each other, an inner space of the casing being divided into a first chamber formed between the first and second vibrating diaphragms, and a second chamber and a third chamber located at two opposite sides of the first chamber, the second chamber and the third chamber being isolated from the first chamber by the first and second vibrating diaphragms, respectively;   a nozzle connected to a sidewall of the casing and located at a position corresponding to the first chamber, an air channel being defined in the nozzle and communicating the first chamber with an outer environment;   a first driving member adapted for driving the first vibrating diaphragm, the first driving member comprising a first movable magnet attached to the first vibrating diaphragm, and a first stationary magnet received in the second chamber and attached to the casing at a position corresponding to the first movable magnet; and   a second driving member adapted for driving the second vibrating diaphragm, the second driving member comprising a second movable magnet attached to the second vibrating diaphragm, and a second stationary magnet received in the third chamber and attached to the casing at a position corresponding to the second movable magnet;   wherein when the first and second driving members drive the first and second vibrating diaphragms to move towards each other, the first and second vibrating diaphragms compress the air inside the first chamber of the casing to move towards the air channel of the nozzle, thereby generating an airflow jetting to the outer environment through the nozzle.   
     
     
         2 . The airflow generator of  claim 1 , wherein one of the first movable magnet and the first stationary magnet of the first driving member is a permanent magnet, the other one of the first movable magnet and the first stationary magnet of the first driving member is an electromagnet, one of the second movable magnet and the second stationary magnet of the second driving member is a permanent magnet, the other one of the second movable magnet and the second stationary magnet of the second driving member is an electromagnet. 
     
     
         3 . The airflow generator of  claim 2 , wherein the first and second movable magnets are electromagnets, and the first and second stationary magnets are permanent magnets. 
     
     
         4 . The airflow generator of  claim 3 , wherein the first movable magnet comprises a movable iron core and a wire coil disposed around the iron core. 
     
     
         5 . The airflow generator of  claim 3 , wherein the second movable magnet comprises a movable iron core and a wire coil disposed around the iron core. 
     
     
         6 . The airflow generator of  claim 1 , wherein the first and second vibrating diaphragms are parallel to each other, the first vibrating diaphragm and the second vibrating diaphragm being spaced apart by a first distance, the first movable magnet and the first stationary magnet being spaced apart by a second distance, the second movable magnet and the second stationary magnet being spaced apart by a third distance, and both the second distance and the third distance being shorter than the first distance, respectively. 
     
     
         7 . The airflow generator of  claim 1 , wherein a first electromagnetic interference shielding layer and a second electromagnetic interference shielding layer are formed on the casing, and on the first and second vibrating diaphragms, the first electromagnetic interference shielding layer encircles the second chamber, and the second electromagnetic interference shielding layer encircles the third chamber. 
     
     
         8 . The airflow generator of  claim 1 , wherein the first and second movable magnets are attached to the middle portions of the first and second vibrating diaphragms, respectively. 
     
     
         9 . The airflow generator of  claim 1 , further comprising a shell, wherein the at least one airflow-generating unit is mounted in the shell. 
     
     
         10 . A heat dissipation device, comprising:
 a heat sink defining a plurality of air passages therein; and   an airflow generator disposed at a side of the heat sink, the airflow generator comprising:
 a plurality of airflow-generating units stacked together, each of the airflow-generating units comprising: 
 a casing; 
 a first and a second vibrating diaphragms received in the casing and spaced from each other, an inner space of the casing being divided into a first chamber formed between the first and second vibrating diaphragms, and a second chamber and a third chamber located at two opposite sides of the first chamber, the second chamber and the third chamber being isolated from the first chamber by the first and second vibrating diaphragms, respectively; 
 a nozzle connected to a sidewall of the casing and located at a position corresponding to the first chamber, an air channel being defined in the nozzle and communicating the first chamber with an outer environment; 
 a first driving member adapted for driving the first vibrating diaphragm, the first driving member comprising a first movable magnet attached to the first vibrating diaphragm, and a first stationary magnet received in the second chamber and attached to the casing at a position corresponding to the first movable magnet; and 
 a second driving member adapted for driving the second vibrating diaphragm, the second driving member comprising a second movable magnet attached to the second vibrating diaphragm, and a second stationary magnet received in the third chamber and attached to the casing at a position corresponding to the second movable magnet; 
 wherein when the first and second driving member drive the first and second vibrating diaphragms to move towards each other, the first and second vibrating diaphragms compress the air inside the first chamber of the casing to move towards the air channel of the nozzle, thereby generating an airflow jetting towards the air passages of the heat sink through the nozzle. 
   
     
     
         11 . The heat dissipation device of  claim 10 , wherein one of the first movable magnet and the first stationary magnet of the first driving member is a permanent magnet, the other one of the first movable magnet and the first stationary magnet of the first driving member is an electromagnet, one of the second movable magnet and the second stationary magnet of the second driving member is a permanent magnet, the other one of the second movable magnet and the second stationary magnet of the second driving member is an electromagnet. 
     
     
         12 . The heat dissipation device of  claim 11 , wherein the first and second movable magnets are electromagnets, and the first and second stationary magnets are permanent magnets. 
     
     
         13 . The heat dissipation device of  claim 12 , wherein the first movable magnet comprises a movable iron core and a wire coil disposed around the iron core. 
     
     
         14 . The heat dissipation device of  claim 12 , wherein the second movable magnet comprises a movable iron core and a wire coil disposed around the iron core. 
     
     
         15 . The heat dissipation device of  claim 10 , wherein the first and second vibrating diaphragms are parallel to each other, the first vibrating diaphragm and the second vibrating diaphragm being spaced apart by a first distance, the first movable magnet and the first stationary magnet being spaced apart by a second distance, the second movable magnet and the second stationary magnet being spaced apart by a third distance, and both the second distance and the third distance being shorter than the first distance, respectively. 
     
     
         16 . The heat dissipation device of  claim 10 , wherein a first electromagnetic interference shielding layer and a second electromagnetic interference shielding layer are formed on the casing, and on the first and second vibrating diaphragms, the first electromagnetic interference shielding layer encircles the second chamber, and the second electromagnetic interference shielding layer encircles the third chamber. 
     
     
         17 . The heat dissipation device of  claim 10 , wherein the first and second movable magnets are attached to the middle portions of the first and second vibrating diaphragms, respectively. 
     
     
         18 . The heat dissipation device of  claim 10 , wherein the airflow generator further comprises a shell, and the airflow-generating units being mounted in the shell. 
     
     
         19 . The heat dissipation device of  claim 10 , further comprising an additional airflow generator, wherein the additional airflow having a conformation the same as the airflow generator, the additional airflow generator being arranged at a side of the airflow generator opposite to the heat sink, with the nozzle of each airflow-generating unit thereof pointing in a direction opposite to the nozzle of each airflow-generating unit of the airflow generator.