Device for generating a cooling air flow in a preferential flow direction for cooling electrical components

Abstract

The device for generating a cooling air flow in a preferential flow direction for cooling electrical components, particularly LEDs, comprises a first and a second channel wall ( 34,36 ) having mutually confronting inner sides, and an oscillation drive means ( 42 ) for generating an oscillating movement of at least a partial region ( 38 ) of at least one of said channel walls ( 34,36 ) in the direction toward the other channel wall and away therefrom. The inner side of at least one of said two channel walls ( 34,36 ) has a surface structure ( 30 ) designed for anisotropic flow, which has a smaller flow resistance coefficient in the preferential flow direction ( 28 ) than in a direction extending at an angle to the preferential flow direction ( 28 ) and particularly in a direction extending opposite to the preferential flow direction ( 28 ).

1 . A device for generating a cooling air flow in a preferential flow direction for cooling electrical components, particularly LEDs, wherein said device comprises
 a first and a second channel wall having mutually confronting inner sides, and   an oscillation drive means for generating an oscillating movement of at least a partial region of at least one of said channel walls in the direction toward the other channel wall and away therefrom,   the inner side of at least one of said two channel walls having a surface structure designed for anisotropic flow, said surface structure having a smaller flow resistance coefficient in the preferential flow direction than in a direction extending at an angle to the preferential flow direction and particularly in a direction extending opposite to the preferential flow direction.   
     
     
         2 . The device of  claim 1 , wherein said surface structure designed for anisotropic flow comprises a plurality of protrusions extending from the channel wall, each of said protrusions having a front side facing in a direction oppositely to the preferential flow direction and a rear side facing in the preferential flow direction, and wherein the geometry of said front side of a protrusion is adapted to generate a higher flow resistance coefficient than the geometry of said rear side of the protrusion. 
     
     
         3 . The device of  claim 2 , wherein said front sides of the protrusions are formed by front flanks and the rear sides of the protrusions are formed by rear flanks, and wherein said rear flanks are steeper than said front flanks. 
     
     
         4 . The device of  claim 3 , wherein the protrusions extend substantially transversely to the preferential flow direction and form a sawtooth profile. 
     
     
         5 . The device of  claim 1 , wherein said two channel walls comprise an anisotropic surface structure on their mutually confronting inner sides. 
     
     
         6 . The device of  claim 1 , wherein both channel walls are movable in an oscillating manner in opposite senses. 
     
     
         7 . The device of  claim 1 , wherein the channel wall which is movable in an oscillating manner comprises, on its inner side, an anisotropic surface structure. 
     
     
         8 . The device of  claim 1 , wherein a third channel wall is provided, said third channel wall having an inner side facing toward the two other channel walls, the second channel wall being arranged between the first and the third channel wall and having two inner sides opposite to the third and respectively the first channel wall, said two inner sides being provided with an anisotropic surface structure, with either (i) the second channel wall or (ii) the first and third channel wall or (iii) all three channel walls being movable in an oscillating manner. 
     
     
         9 . The device of  claim 1 , wherein a third channel wall is provided, said third channel wall having an inner side facing toward the two other channel walls, the second channel wall being arranged between the first and the third channel wall and having two inner sides opposite to the third and respectively the first channel wall, said two inner sides being provided with an anisotropic surface structure, the inner faces of the first and the third channel wall being provided with a respective anisotropic surface structure, with either (i) the second channel wall or (ii) the first and third channel wall or (iii) all three channel walls being movable in an oscillating manner. 
     
     
         10 . The device of  claim 8 , wherein the preferential flow directions in the two intermediate spaces between the second channel wall and the first and respectively the third channel wall are identical or opposite to each other. 
     
     
         11 . The device of  claim 1 , wherein the oscillatable channel wall comprises a partial region formed as an oscillatable elastic membrane, said partial region being operatively connected to the oscillation drive unit. 
     
     
         12 . The device of  claim 11 , wherein the oscillatable channel wall comprises on at least one of its sides, externally of the membrane, the anisotropic surface structure. 
     
     
         13 . The device of  claim 11 , wherein the oscillation drive means generates a magnetic field and wherein the membrane comprises a magnetic material exposed to the magnetic field, the membrane being movable in an oscillating manner as a result of magnetic and eddy-current effects. 
     
     
         14 . The device of  claim 1 , wherein a cooling body is provided, said cooling body comprising a plurality of projecting, substantially parallel cooling plate elements, of which two adjacent cooling plate elements form the first and respectively the second channel wall. 
     
     
         15 . The device of  claim 1 , wherein a cooling body is provided, said cooling body comprising a plurality of projecting, substantially parallel cooling plate elements, of which two adjacent cooling plate elements form the first and respectively the third channel wall, the second channel wall being formed by a further cooling plate element arranged between said two other cooling plate elements. 
     
     
         16 . The device of  claim 9 , wherein the preferential flow directions in the two intermediate spaces between the second channel wall and the first and respectively the third channel wall are identical or opposite to each other. 
     
     
         17 . The device of  claim 12 , wherein the oscillation drive means generates a magnetic field and wherein the membrane comprises a magnetic material exposed to the magnetic field, the membrane being movable in an oscillating manner as a result of magnetic and eddy-current effects.