Patent Publication Number: US-2009237891-A1

Title: Heat sink equipped driving circuit module assembly for led lamp

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a driving circuit module assembly, and more particularly to a driving circuit module assembly for an LED lamp, which has a heat sink assembly to dissipate heat generated by a driving circuit module of the driving circuit module assembly. 
     2. Description of Related Art 
     The technology of LED has been rapidly developed in recent years from indicators to illumination applications. With the features of long-term reliability, environment friendliness and low power consumption, the LED is viewed as a promising alternative for future lighting products, such as LED lamp assembly. 
     A conventional LED lamp assembly comprises a LED lamp and a driving circuit module assembly electronically connecting with and supplying power to the LED lamp. When the LED lamp assembly operates, a large amount of heat is generated by LEDs of the LED lamp and the driving circuit module. The heat generated by the driving circuit module can adversely affect the operational stability thereof. 
     What is needed, therefore, is a driving circuit module which has a heat sink assembly to dissipate heat generated therefrom. 
     SUMMARY OF THE INVENTION 
     A driving circuit module assembly includes a driving circuit module and a heat sink assembly to receive and cool the driving circuit module. The heat sink assembly includes a hollow heat sink, a cover abutting against a top portion of heat sink, and a base abutting against a bottom portion of the heat sink. The hollow heat sink has a plurality of fins extending radially and outwardly from an outer surface of the heat sink, and a plurality of grooves in the outer surface of the heat sink. The driving circuit module is mounted on the base of the heat sink assembly and thermally connects therewith, whereby heat generated by the driving circuit module is transferred to the heat sink via the base and further to a surrounding air via the fins of the heat sink. A plurality of screws extends through the cover, the grooves of the heat sink and the base to threadedly engage with nuts, thereby assembling the driving circuit module assembly together. 
     Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an exploded view of a driving circuit module assembly in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is an inverted view of  FIG. 1 ; 
         FIG. 3  is an assembled view of the driving circuit module assembly of  FIG. 1 ; and 
         FIG. 4  is an inverted view of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-2 , a driving circuit module assembly includes a heat sink assembly  10  and a driving circuit module  20  received in the heat sink assembly  10 . 
     The heat sink assembly  10  includes a hollow, cylindrical heat sink  13 , a cover  15  covering a top of the heat sink  13 , and a base  11  attached to a bottom of the heat sink  13 . 
     The heat sink  13  is integrally formed by aluminum extrusion. The heat sink  13  comprises an annular sidewall  131  and a plurality of fins  133  radially and outwardly extending from an outer surface of the sidewall  131 . The fins  133  extend from a top to a bottom of the sidewall  131  and are spaced from each other. The sidewall  131  inwardly protrudes at an equal interval of distance to define corresponding grooves  135  at the outer surface thereof. In this embodiment, the number of the grooves  135  is six. 
     Referring to  FIGS. 3-4  also, the cover  15  is made of aluminum. The cover  15  comprises a circular bottom plate  151  received in the heat sink  13 , an annular connecting wall  153  extending upwardly and perpendicularly from an outer edge of the bottom plate  151 , and a flange  155  extending perpendicularly and outwardly from an upper edge of the connecting wall  153 . The flange  155  abuts against a top portion of the sidewall  131  of the heat sink  13 . A waterproof connector  157  is mounted on a centre of the bottom plate  151  for connecting with a mating connector (not shown) in electrical connection with LEDs of an LED lamp (not shown). 
     The base  11  is also made of aluminum and has a diameter larger than a bore diameter of the heat sink  13 . The base  11  abuts against a bottom portion of the heat sink  13 . A waterproof connector  111  is mounted on a centre of the base  11  for connecting with a mating connector (not shown) in electrical connection with a power source (not shown). 
     In assembling, the driving circuit module  20  is mounted on a top surface of the base  11  and thermally connects therewith. Six elongated screws  30  extend through the flange  155  of the cover  15 , the grooves  135  of the heat sink  13  and the base  11  to engage with six nuts  40  to assemble the driving circuit module assembly  10  together. A pair of gaskets  50  are sandwiched between the cover  15  and the heat sink  13 , and the base  11  and the heat sink  13 , whereby the cover  15 , the base  11  and the heat sink  13  are hermetically connected together. 
     In use, heat generated by the driving circuit module  20  is absorbed by the heat sink  13  via the base  11  and finally dispersed into ambient cool air via the fins  133 . Therefore, a temperature of the driving circuit module  20  can be kept below a set value so that the driving circuit module  20  can always work normally to drive the LEDs to lighten. 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.