Heat dissipation apparatus incorporating airflow generator

Abstract

A heat dissipation apparatus includes a heat sink defining a plurality of air passages therein, and an airflow generator arranged on the heat sink and including a plurality of airflow-generating units. Each airflow-generating unit includes a casing, and a vibration diaphragm and a driving member arranged in the casing. The vibration diaphragm divides an inner space of the casing into first and second chamber isolated from each other. The second chamber communicates with the exterior via an orifice defined in a bottom wall of the casing. The driving member is capable of vibrating the vibration diaphragm when alternating voltage is applied thereto. When the driving member vibrates the vibration diaphragm towards the bottom wall of the casing, the vibration diaphragm compresses the air inside the second chamber of the casing towards the orifice, generating airflow from the orifice to the air passages of the heat sink.

1 . An airflow generator, comprising:
 at least one airflow-generating unit, comprising:
 a casing defining an inner space therein, the casing comprising a bottom wall defining an orifice therein; 
 a vibration diaphragm arranged in the casing, the vibration diaphragm dividing the inner space of the casing into a first chamber and a second chamber isolated from each other, the second chamber communicating with an exterior of the casing via the orifice of the bottom wall of the casing; and 
 a driving member received in the casing, capable of vibrating the vibration diaphragm in directions substantially perpendicular to the vibration diaphragm when alternating voltage is applied to the driving member, wherein when the driving member vibrates the vibration diaphragm towards the bottom wall of the casing, the vibration diaphragm compresses the air inside the second chamber of the casing and drives the air towards the orifice, generating an airflow from the orifice to the exterior of the casing. 
   
     
     
         2 . The airflow generator of  claim 1 , wherein the driving member comprises a piezoelectric element attached to the vibration diaphragm. 
     
     
         3 . The airflow generator of  claim 1 , wherein the driving member comprises a movable magnet attached to the vibration diaphragm, and a stationary magnet attached to a top wall of the casing facing the vibration diaphragm, one of the movable magnet and the stationary magnet is a permanent magnet, and the other one of the movable magnet and the stationary magnet is an electromagnet. 
     
     
         4 . The airflow generator of  claim 3 , wherein the movable magnet is an electromagnet, and the stationary magnet is a permanent magnet. 
     
     
         5 . The airflow generator of  claim 4 , wherein the movable magnet comprises a movable iron core attached to the vibration diaphragm and a wire coil disposed around the iron core. 
     
     
         6 . The airflow generator of  claim 1 , further comprising a cover, in which the at least one airflow-generating unit is mounted. 
     
     
         7 . The airflow generator of  claim 1 , wherein the airflow generator comprises a plurality of the airflow-generating units, and the bottom walls of the casings of the airflow-generating units are integrally formed together as a single body of material. 
     
     
         8 . A heat dissipation apparatus, comprising:
 a heat sink defining a plurality of air passages therein; and   an airflow generator arranged on the heat sink, the airflow generator comprising a plurality of airflow-generating units arranged in an array, each of the airflow-generating units comprising:
 a casing comprising a bottom wall adjacent to the heat sink; 
 a vibration diaphragm arranged in the casing, the vibration diaphragm dividing an inner space of the casing into a first chamber and a second chamber isolated from each other, the second chamber being located nearer to the heat sink and communicating with an exterior of the casing via an orifice defined in the bottom wall; and 
 a driving member received in the casing, capable of vibrating the vibration diaphragm in directions substantially perpendicular to the vibration diaphragm when alternating voltage is applied to the driving member, wherein when the driving member vibrates the vibration diaphragm towards the bottom wall of the casing, the vibration diaphragm compresses the air inside the second chamber of the casing and drives the air towards the orifice, generating an airflow from the orifice to at least one of the air passages of the heat sink. 
   
     
     
         9 . The heat dissipation apparatus of  claim 8 , wherein the driving member comprises a piezoelectric element attached to the vibration diaphragm. 
     
     
         10 . The heat dissipation apparatus of  claim 8 , wherein the driving member comprises a movable magnet attached to the vibration diaphragm, and a stationary magnet attached to a wall of the casing facing the vibration diaphragm, one of the movable magnet and the stationary magnet is a permanent magnet, and the other one of the movable magnet and the stationary magnet is an electromagnet. 
     
     
         11 . The heat dissipation apparatus of  claim 10 , wherein the movable magnet is an electromagnet, and the stationary magnet is a permanent magnet. 
     
     
         12 . The heat dissipation apparatus of  claim 11 , wherein the movable magnet comprises a movable iron core attached to the vibration diaphragm and a wire coil disposed around the iron core. 
     
     
         13 . The heat dissipation apparatus of  claim 8 , further comprising a cover, in which the airflow-generating units are mounted. 
     
     
         14 . The heat dissipation apparatus of  claim 13 , wherein the cover comprises a top plate and a sidewall extending down from a peripheral edge of the top plate. 
     
     
         15 . The heat dissipation apparatus of  claim 14 , wherein the heat sink comprises a base and a plurality of spaced fins formed on the base, and the air passages are defined between adjacent fins. 
     
     
         16 . The heat dissipation apparatus of  claim 15 , wherein the heat sink comprises a plurality of mounting portions, the cover has a plurality of fixing portions corresponding to the mounting portions of the heat sink, and the mounting portions of the heat sink are spaced from the fixing portions of the cover by a plurality of supporting posts disposed therebetween. 
     
     
         17 . The heat dissipation apparatus of  claim 8 , wherein the bottom walls of the casings of the airflow-generating units are integrally formed as a single piece. 
     
     
         18 . An airflow generator, comprising:
 a shell comprising a base plate and a cover connected to the base plate, the cover and the base plate cooperatively defining a cavity therebetween, the base plate defining a plurality of orifices therein; and   a plurality of airflow-generating units arranged in the cavity and located corresponding to the orifices of the base plate, each of the airflow-generating units comprising:
 a casing defining an inner space therein; 
 a vibration diaphragm arranged in the casing, the vibration diaphragm dividing the inner space of the casing into a first chamber and a second chamber isolated from each other, the second chamber being located adjacent to the base plate and communicating with an exterior of the casing via a corresponding orifice of the base plate; and 
 a driving member received in the casing, capable of vibrating the vibration diaphragm in directions substantially perpendicular to the vibration diaphragm when alternating voltage is applied to the driving member, wherein when the driving member vibrates the vibration diaphragm towards the bottom wall of the casing, the vibration diaphragm compresses the air inside the second chamber of the casing and drives the air towards the corresponding orifice, generating an airflow from the corresponding orifice to the exterior of the casing. 
   
     
     
         19 . The airflow generator of  claim 18 , wherein the driving member comprises a piezoelectric element attached to the vibration diaphragm. 
     
     
         20 . The airflow generator of  claim 18 , wherein the driving member comprises a movable magnet attached to the vibration diaphragm, and a stationary magnet attached to a wall of the casing facing the vibration diaphragm, one of the movable magnet and the stationary magnet is a permanent magnet, and the other one of the movable magnet and the stationary magnet is an electromagnet.