BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an LED (Light Emitting Device) lamp module and, in particular, to an LED lamp module for a street light. 
     2. Description of Related Art 
     Traditional street lights are quite common to be used in city streets, highways, and tunnels. They not only beautify the city, but also significantly improve the traffic safety and public order. However, with the developments of the times and the LED street lights as new energy, replacing the traditional street lights with the LED ones, which extends the lifetime of the street lights and lowers energy consumption and carbon emissions, obviously becomes a main research topic worldwide at the current stage. 
     Therefore, related manufacturers have developed LED street lights having various shapes or meeting various specifications. However, the developed LED street lights are not compatible with the currently traditional street lights. Thus, the traditional replacement of the street light is mostly made by a complete replacement, which signifies the high cost of the LED street light and the large manpower and associated equipment for the replacement. Accordingly, people desiring the replacement may step back, which needs to be overcome. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a replacement LED lamp module for a street light, which can achieve the replacement of a lighting module without affecting the main structure of a traditional street light. 
     The present invention provides a replacement LED lamp module for a street light. The replacement LED lamp module comprises a heat dissipating cover, a driver, and an LED module. The heat dissipating cover has a receiving cavity and a receiving recess disposed inward of a bottom of the heat dissipating cover. The driver is installed in the receiving cavity. The LED module is disposed corresponding to the receiving recess and fixed to the heat dissipating cover. The LED module is electrically connected to the driver. 
     The present invention also has the following effects. Heat generated by the LED module is dissipated via a thermal module, which enhances heat dissipation efficiency and extends the lifetime of the lighting unit of the LED module. By means of a fixture module, the LED lamp module of the present invention can be directly combined with the upper cover of the traditional street light to considerably reduce the manpower and the cost of the associated equipment. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
         FIG. 1  is an assembled view of the replacement LED lamp module of the present invention; 
         FIG. 2  is an exploded view of the replacement LED lamp module of the present invention; 
         FIG. 3  shows partial exploded views of the heat dissipating cover, the thermal module, and the driver of the present invention; 
         FIG. 4  is a top view of the heat dissipating cover in combination with the thermal module of the present invention; 
         FIG. 5  is an assembled cross-sectional view of the present invention applied in a street light; 
         FIG. 6  is an assembled view of the present invention applied in a street light; 
         FIG. 7  is an operational view of the present invention applied in a street light; and 
         FIG. 8  is a cross-sectional view of the present invention according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description and technical details of the present invention will be explained below with reference to accompanying figures. However, the accompanying figures are only for reference and explanation, but not to limit the scope of the present invention. 
     Please refer to  FIGS. 1-4 . The present invention provides a replacement LED lamp module for a street light. The replacement LED lamp comprises a heat dissipating cover  10 , a driver  20 , and an LED module  30 . 
     The heat dissipating cover  10 , which is made of metal such as aluminum, comprises a base plate  11  having an oval-like shape and a surrounding plate  12  bending upward from an edge of the base plate  11 . A folding edge  13  is formed at an end portion of the surrounding plate  12  away from the base plate  11 . The shape of the heat dissipating cover  10  is similar to that of the translucent cover of the traditional street light. A receiving cavity  14  is surrounded and formed by the base plate  11  and the surrounding plate  12 . A round receiving recess  15  is recessed in a direction from the base plate  11  to the receiving cavity  14 . A first hole  16  having a capsule shape and a plurality of second holes  17  are formed on the base plate  11  in the receiving recess  15 . Also, a plurality of longitudinal cuts  18  are formed on the surrounding plate  12  such that the gas in the receiving cavity  14  and that out of the heat dissipating cover  10  can be exchanged for heat transfer. 
     The driver  20  has a main body  21  and a cable  22  electrically connected to the main body  21 . A connector  23  is disposed at an end of the cable  22 . The driver  20  is installed in the receiving cavity  14 . The connector  23  is disposed corresponding to the first hole  16 . 
     The LED module  30  is disposed corresponding to the receiving recess  15  and fixed to the heat dissipating cover  10  and is electrically connected to the driver  20 . In the current embodiment, the LED module  30  comprises a collar  31 , a lighting unit  32 , a lens  33 , a washer  34 , and a sealing ring  35 . The lighting unit  32 , which is composed of a substrate and a plurality of LEDs fixed on the substrate, is fixed to a lower surface of the base plate  11  and is electrically connected to the connector  23  of the driver  20  via a butting connector (not shown). The lens  33  is fixed to the collar  31  through the sealing ring  35 . The collar  31  presses the washer  34  to be attached to the lower surface of the base plate  11 . The collar  31  is fixed to the base plate  11  via fastening elements such as screws such that the lens  33  covers the lighting unit  32  hermetically. 
     Preferably, the replacement LED lamp module of the present invention further comprises a thermal module  40  which is disposed in the receiving cavity  14  and thermally connected to the heat dissipating cover  10 . The thermal module  40  comprises a thermal plate  41 , a heat pipe  42 , and a fixing plate  43 . A long slot  411  is formed in the middle of the thermal plate  41 . A slot hole  412  is formed on the right side of the long slot  411 . The heat pipe  42  roughly has a “C” shape, which comprises a flat evaporation segment  421  and a condensation segment  422  extending from the evaporation segment  421 . The fixing plate  43  has a screw hole  431  for screwing an end of the connector  23 . The thermal plate  41  is attached to an upper surface of the base plate  11 . The evaporation segment  421  of the heat pipe  42  is attached to the upper surface of the base plate  11  and formed inside the long slot  411 . The condensation segment  422  of the heat pipe  42  is attached circularly to the surrounding plate  12 . The fixing plate  43  is pressed to contact the evaporation segment  421  of the heat pipe  42  and the top of the thermal plate  41  to provide a screw connection for the collar  31 . 
     Preferably, the replacement LED lamp module of the present invention further comprises a fixture module  50  connected to an open end of the heat dissipating cover  10 . The fixture module  50  comprises a separation plate  51 , a sealing member  52 , and a frame  53 . The separation plate  51  caps the heat dissipating cover  10  and is attached to the folding edge  13 . The sealing member  52  clamps the folding edge  13  and an edge area of the separation plate  51 . The frame  53  is stacked on the sealing member  52 . By means of fastening elements such as screws passing through the folding edge  13 , the frame  53  and the heat dissipating cover  10  can be fixed to each other (as shown is  FIG. 1 ). 
     Please refer to  FIGS. 5-7 . The replacement LED lamp module of the present invention can be applied in a traditional street light  8  which has a upper cover  81 . Since the structure of the present invention can replace the lighting member and light shell of the traditional street light  8 , the fixture module  5  can be embedded in the upper cover  81  and can be combined by the clipping mechanism of the traditional street light  8 . 
     The power of the driver  20  comes from the street light  8 . After the electric characteristics of voltage/current of the power are modulated and rectified by the main body  21 , the power is provided for the lighting unit  32  of the LED module via the cable  22  and the connector  23 . 
     The heat generated by the lighting unit  32  is delivered to the evaporation segment  421  of the heat pipe  42  and the thermal plate  41  via the base plate  11 . Some of the heat is delivered and dissipated from the condensation segment  422  to the heat dissipating cover  10  by vapor-to-liquid phase heat transfer in the heat pipe  42 . Some of the heat is delivered and dissipated to the fixing plate  43  by thermal conduction via the thermal plate  41 . 
     Since the replacement LED lamp module of the present invention is specifically arranged according to the above-mentioned structure, when it is installed in the street light  8 , the illumination range provided by the LED module  30  is basically consistent with that provided by the street light  8 . 
     Please refer to  FIG. 8 . The replacement LED lamp module of the present invention can be implemented as the above embodiments. Besides, for a high power lighting unit (i.e., an electric power between 60 W and 80 W or between 100 W to 120 W), a heat dissipator  60  can be additionally installed to the current embodiment. The heat dissipator  60  is made of aluminum material by extrusion molding and has a substrate thermally contacted to the upper surface of the base plate  11  and has a plurality of fins extending upwards from the substrate. The fins are spacedly arranged for enhanced heat dissipation. 
     In summary, the replacement LED lamp module of the present invention can achieve the expected objective and overcome the disadvantages of the prior art. Also it is indeed novel, useful, and non-obvious to be patentable. Please examine the application carefully and grant it as a formal patent for protecting the rights of the inventor.
A replacement LED lamp module for a street light includes a heat dissipating cover ( 10), a driver ( 20), and an LED module ( 30). The heat dissipating cover ( 10) has a receiving cavity ( 14) and a receiving recess ( 15) disposed inward of a bottom of the heat dissipating cover ( 10). The driver ( 20) is installed in the receiving cavity ( 14). The LED module ( 30) is disposed corresponding to the receiving recess ( 15) and fixed to the heat dissipating cover ( 10); the LED module ( 30) is electrically connected to the driver ( 20). Thus, the replacement of the LED lamp module can be achieved without affecting the main structure of the conventional street light.