WO2012011050A2

WO2012011050A2 - Mounting device with cooling subassembly and luminaire using same

Info

Publication number: WO2012011050A2
Application number: PCT/IB2011/053210
Authority: WO
Inventors: John Andre Adams; Travis James Reinert
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2010-07-23
Filing date: 2011-07-19
Publication date: 2012-01-26
Also published as: TW201221850A; WO2012011050A3

Abstract

A mounting device (10) with cooling subassembly (12) and luminaire (14) using the same are disclosed. In one embodiment of the mounting device (10), a mounting surface (40) is adapted to accept heat - generating electronic components, such as LED chip packages (22). A cooling subassembly (12) is coupled in thermal contact to the mounting surface (40). Multiple U-shaped air passageways (128,136) are provided by the cooling subassembly (12) and each of the U-shaped air passageways (128) includes a radial air inlet passageway (140) in communication with a common central air passageway (142) in communication with a radial air outlet passageway (144). Each radial inlet passageway (140) contacts an inlet heatsink (74,84) and each radial outlet passageway contacts a finned heat exchanger (106,112) in thermal contact with the mounting surface by way of at least one heat pipe (88-98). A fan (118) located within the cooling subassembly directs air flow through the U-shaped air passageways.

Description

MOUNTING DEVICE WITH COOLING SUBASSEMBLY

AND LUMINAIRE USING SAME

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates, in general, to mounting devices for heat dissipation and management and, in particular, to mounting devices having cooling subassemblies for use with electronic components such as light emitting diodes (LED) and luminaires using the same.

BACKGROUND OF THE INVENTION

[0002] Without limiting the scope of the present invention, its background will be described with reference to LEDs utilized in the creation of artificial light or illumination and luminaires using the same, as an example. Thermal considerations play a large role in the design of LEDs and luminaires using LEDs. Heat must be managed and dissipated or symptoms of heat stress occur as LED heat escalates. Such symptoms include an increased load on LED-related driver components, optical wavelength shifting and color changes, lens yellowing, loss of efficiency and diminishing of light output, and damage to the LED junction, among others. As today's luminaires have numerous LED lights within a tight, defined space, heat cannot efficiently be dissipate from the circuit board copper alone. Essentially, to maintain peak LED performance in a modern luminaire, a cooling subassembly is required to dissipate heat when thermal energy generated exceeds thermal energy dissipated. These thermal challenges may be difficult to meet in demanding, high temperature environments including ambient outdoor environments.

SUMMARY OF THE INVENTION

[0003] It would be advantageous to achieve a mounting device with cooling subassembly and a luminaire using the same. It would also be desirable to enable thermal challenges to be realized by managing and dissipating heat in a variety of demanding environments. To better address one or more of these concerns, in one aspect of the invention, one embodiment of a mounting device with cooling subassembly is presented that includes a mounting surface adapted to accept heat-generating electronic components, such as LED chip packages. A cooling subassembly is coupled in thermal contact to the mounting surface .

[0004] Multiple U-shaped air passageways are provided within the cooling subassembly and each of the U-shaped air passageways includes a radial air inlet passageway in communication with a common axial air passageway in communication with a radial air outlet passageway. The radial inlet passageway contacts an inlet heatsink and the radial outlet passageway contacts a finned heat exchanger in thermal contact with the mounting surface by way of at least one heat pipe. A fan located within the cooling subassembly directs air flow through the plurality of U-shaped air passageways such that dual action component cooling is furnished whereby inlet air contacts cooling devices twice to provide thermal mitigation and heat management before the air exists the mounting device with the cooling subassembly.

[0005] Additionally, to better address one or more of the aforementioned concerns, in one aspect of the invention, one embodiment of a luminaire incorporating the mounting device with cooling subassembly is presented that may provide a complete lighting fixture for various applications. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment ( s ) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:

[0007] Figure 1 is a perspective illustration of one embodiment of a luminaire incorporating a mounting device with cooling subassembly in accordance with an embodiment of the invention;

[0008] Figure 2 is a perspective illustration of the luminaire depicted in figure 1, with a partial cut-away to better reveal internal components;

[0009] Figure 3 is front perspective view of one embodiment of the mounting device of figures 1 and 2;

[0010] Figure 4 a rear perspective view of the mounting device of figure 3;

[0011] Figure 5 is a front cross-sectional perspective view of the mounting device of figure 3;

[0012] Figure 6 is a side cross-sectional view of the mounting device of figure 3;

[0013] Figure 7 is a top cross-sectional view of an upper cooling device layer of the mounting device of figure 3; and [0014] Figure 8 is a top cross-sectional view of a lower cooling device layer of the mounting device of figure 3.

DETAILED DESCRIPTION OF THE INVENTION

[0015] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.

[0016] Referring initially to figures 1 and 2, therein is depicted one embodiment of a mounting device 10 with a cooling subassembly 12 located within a luminaire 14 according to the teachings presented herein. A housing 16 having vents 18 is adapted to accommodate the mounting device 10 and LED chip packages, collectively numbered 20, mounted thereto with corresponding optical arrangements, collectively numbered 22. As will be discussed in more detail hereinbelow, the mounting device 10 incorporates the cooling subassembly 12 to absorb and dissipate heat produced by the LED chip packages 20.

[0017] As depicted, in order to further enhance the quality of the white light generated by the LED chip packages 20, four LED chips including one red LED chip (R) , one green chip (G) , one blue LED chip (B) , and one white LED chip (W) are utilized. It is contemplated, however, that as LED chip design advances, different numbers of LED chips and/or different color LED chips may be used in the array to optimize the quality of the light generated by the LED chip packages 22. By way of example, in one embodiment, four LED chips including one red LED chip (R) , one green chip (G) , one blue LED chip (B) , and one amber LED chip (A) are utilized. By way of further example, in another embodiment, four LED chips including one red LED chip (R) , two green chips (Gl, G2), and one blue LED chip (B) are utilized. It is further contemplated that both low-power and high-power LED chips may be used in the LED chip packages 22.

[0018] The housing 16 is fitted in place by a yoke 24 swivelly connected to a support structure 26. An electronics subassembly (not shown) may be located throughout the housing 16, yoke 24, and support structure 26 provides motorized movement and electronics to the luminaire 14. The electronics subassembly may include multiple on-board processors providing diagnostic and self-calibration functions as well as internal test routines and software update capabilities. The luminaire 14 may also include any other required electronics such as connection to power. As illustrated, zoom and finishing lenses 30 are included for adding end effects.

[0019] Figures 3 through 5 depict the mounting device 10 with cooling subassembly 12 in further detail. A cold plate or mounting surface 40 has two sides, an upper side 42 and a lower side 44. LED chip package mounting seats 46 through 58 are disposed on the upper side 42. The LED chip package mounting seats are a specific, non-limiting example of electronic component mounting seats. As shown, there is one LED chip package mounting seat 46 centrally located along a central axis (66) of the mounting surface 40. Six LED chip package mounting seats 48 through 58 are disposed radially therearound. Brackets, collectively numbered 60, extend from the mounting surface 40 for securing the mounting device 10 to the housing 16. The cooling subassembly 12 is attached to the lower side 44 of the mounting surface 40 and includes an upper end 62, a lower end 64, and a central axis (66) 66 therethrough. The upper end 62 of the cooling subassembly 12 is coupled in thermal contact to the lower side 44 of the mounting surface 40. The cooling subassembly 12 furnishes two cooling device layers, an upper cooling device layer 68 and a lower cooling device layer 70, which manage and dissipate heat.

[0020] With respect to the upper cooling device layer 68, a thermal conductive member 72 is centrally interposed between the mounting surface 40 under the LED chip package mounting seat 46 and a central inlet heatsink 74. Radially located inlet heatsinks 76 through 86 are respectively located in thermal contact with the six radially or exteriorly positioned chip package mounting seats 48 through 58. The heatsinks 74 through 86 are the cooling devices of the upper cooling device layer 68. Heat pipes 88-98 are radially positioned under the LED chip package mounting seats 48 through 58 and provide for thermal conductivity therewith. In the illustrated embodiment, the heat pipes 88 through 98 are substantially L-shaped and extend radially and then axially along the periphery of the mounting device 10 in order to traverse the upper cooling device layer 68 and enter the lower cooling device layer 70. The heat pipes 88 through 98 may be clustered, such as the clusterings of groups of three. As one will appreciate, the number, size, and clustering of the heat pipes will depend on the application. As shown, in one implementation, there is a one-to-one correspondence between the LED chip package mounting seats 48 through 58 and the radially located inlet heatsinks 76 through 86 whereby each of the radially located inlet heatsinks 76 through 86 is associated with one of the LED chip package mounting seats 48 through 58 and the corresponding heat pipes 88 through 98. In this implementation, the heatsinks are adapted to establish thermal conductivity with the LED chip package mounting seats directly or by way of the heat pipes.

[0021] A partition 100 is located between the upper cooling device layer 68 and the lower cooling device layer 70. The partition supports the radially located inlet heatsinks 76 through 86 and includes an axial or central air passageway 102 therethrough for providing for airflow from the upper cooling device layer 68 to the lower cooling device layer 70. The axial air passageway 102 is aligned with the central axis (66) 66 of the cooling subassembly 12. Finned heat exchangers 104 through 114, which are the cooling devices of the lower cooling device layer 70, are located beneath the partition 100 and secured thereto. As shown, the finned heat exchangers 104 through 114 extend radially and intersect the heat pipes 88 through 98 such that the heat pipes 88-98 traverse the interiors of the finned heat exchangers 104 through 114. The heat pipes 88 through 98 furnish thermal contact between the mounting surface 40 and the finned heat exchangers 104 through 114. A base plate 116, which may have sides, supports the finned heat exchangers 104 through 114 from beneath. An impeller or fan 118 having vanes, collectively numbered 120, rotatably coupled to a motor 122 is secured to the base plate 116. The vanes 120 may be substantially axially aligned and circumferentially located such that the space between the impellers defines a displacement chamber 124 that is located in fluid or air communication with the finned heat exchangers 104 through 114 at an eye 126 of the fan 118. [0022] It should be appreciated that although the mounting device 10 is depicted as being substantially hexagonal with a central heatsink and six-periphery cooling devices, other shapes and numbers of cooling devices are with the teachings presented herein. By way of example, the cooling devices of the upper cooling device layer are not limited to heatsinks and the cooling devices of the lower cooling device layer are not limited to finned heat exchanger or even heat exchangers. The selection of the number, type, and arrangement of cooling devices will vary by the demands of the particular application and intended range of environments in which the mounting device will be employed. By way of another example, the mounting seats may accommodate any type of electronic component; not only LED chip packages.

[0023] Figures 6 through 8 depict the thermal conductivity and airflow of the mounting device 10 with cooling subassembly 12 in further detail. As shown, U-shaped air passageways 128 through 138 are located within the cooling subassembly 12. With respect to U-shaped air passageways 128, 136 as an example of each of the U-shaped air passageways 128 through 138, the U- shaped air passageways 128, 136 include radial air inlet passageways 140 in communication with an axial air passageway 142 in communication with radial air outlet passageways 144. The radial air inlet passageways 140 are proximate to the upper end 62 of the cooling subassembly 12, near the mounting surface 40. The radial air inlet passageways 140 pass through the cooling device of the upper cooling device layer 68, namely the radial inlet heatsinks 78, 84 and the central inlet heatsink 74 (as shown in figure 6) . [0024] The axial air passageway 142 connects the upper cooling device layer 68 to the lower cooling device layer 70 and the displacement chamber 124 wherein the fan 118 is located. As depicted, a single or common axial air passageway 142 is generally shared by each of the U-shaped air passageways 128 through 138. The radial air outlet passageways 144 are proximate to the lower end 64 of the cooling subassembly 12. The radial air outlet passageways 144 pass through the cooling device of the lower cooling device layer 70 which is the finned heat exchangers 106, 112 (as shown in figure 6) . The fan 18 located at the lower end 64 of the cooling subassembly 12 at an intersection of the axial air passageway 142 and the radial air outlet passageways of each of the U-shaped air passageways 128 through 138 causes air to circulate through the cooling subassembly 12.

[0025] In particular, air circulates through airflow cooling passageways 146 that include all of the U-shaped passageways 128 through 138 and, in particular, inlet through the heatsinks 74 through 86, passage through the axial air passageway 142, passage through the displacement chamber 124, and outlet through the finned heat exchangers 104 through 114. In operation, the velocity achieved by the fan 118 transfers into pressure when the movement of the air is generally confined to the displacement chamber 124, as shown by arrow 148. Air is accepted into the displacement chamber 124 from the upper cooling device layer 68 at the eye 126 and then the vanes 120 push the air radially through the fined heat exchangers 104 through 114. In this way, the mounting device 10 with the cooling subassembly 112 provides dual action component cooling whereby inlet air contacts cooling devices twice to provide thermal mitigation and heat management before the air exists the mounting device 10 with the cooling subassembly.

[0026] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.

Claims

What is claimed is:

1. A mounting device comprising:

a mounting surface having first and second sides, a plurality of electronic component mounting seats disposed on the first side for contact with a plurality of heat-generating electronic components;

a cooling subassembly including an upper end, a lower end, and central axis therethrough, the upper end of the cooling subassembly coupled in thermal contact to the second side of the mounting surface;

a plurality of U-shaped air passageways located within the cooling subassembly, each of the plurality of U-shaped air passageways including a radial air inlet passageway in communication with an axial air passageway in communication with a radial air outlet passageway;

the radial air inlet passageway of each of the plurality of U-shaped air passageways being proximate to the upper end, the radial air inlet passageway passing through a first cooling device being located in thermal contact with the mounting surface;

the axial air passageway being aligned with the central axis;

the radial air outlet passageway of each of the plurality of U-shaped air passageways being proximate to the lower end, the radial air outlet passageway passing through a second cooling device being located in thermal contact with the mounting surface; and a fan located at the lower end of the cooling subassembly at an intersection of the axial air passageway and the radial air outlet passageway of each of the plurality of U-shaped air passageways, the fan for directing air flow through the plurality of U-shaped air passageways.

2. The mounting device as recited in claim 1, wherein the heat-generating electronic components comprise LED chip packages .

3. The mounting device as recited in claim 1, wherein the first cooling device comprises a radial inlet heatsink.

4. The mounting device as recited in claim 1, wherein the first cooling device comprises a central inlet heatsink.

5. The mounting device as recited in claim 1, wherein the second cooling device comprises a finned heat exchanger.

6. The mounting device as recited in claim 1, wherein the second cooling device is located in thermal contact with the mounting surface by way of a thermal heat pipe therebetween.

7. The mounting device as recited in claim 1, wherein the cooling assembly further comprises a base plate at the lower end .

8. A mounting device comprising:

a mounting surface having a plurality of electronic component mounting seats disposed thereon for contacting with a plurality of heat-generating electronic components;

a first cooling device layer coupled to the mounting surface opposite to the plurality of electronic component mounting seats, the first cooling device layer including a plurality of heatsinks disposed in thermal contact with the plurality of electronic component mounting seats, the plurality of heatsinks being arranged one per electronic component mounting seat;

a second cooling device layer coupled to the first cooling device layer, the second cooling device layer including a plurality of heat exchangers disposed radially about a fan to define a displacement chamber thereabout;

a plurality of heat pipes traversing the first cooling device layer, the plurality of heat pipes providing thermal contact between the mounting surface and the plurality of heat exchangers ;

a central airflow passageway formed between the first cooling device layer and the second cooling device layer, the fan adapted to cause air to circulate through an airflow cooling passageway including inlet through the plurality of heatsinks, passage through the central airflow passageway, passage through the displacement chamber, and outlet through the plurality of heat exchangers.

9. The mounting device as recited in claim 8, further comprising a partition located between the first cooling device layer and the second cooling device layer, the partition including the central air passageway therethrough.

10. The mounting device as recited in claim 8, wherein the second cooling device layer further comprises a base plate opposite to the mounting surface.

11. The mounting device as recited in claim 8, wherein the plurality of electronic component mounting seats further comprises seven mounting seats adapted to seat seven LED chip packages .

12. The mounting device as recited in claim 11, wherein the seven LED chips packages further comprise an arrangement of six LED chip packages radially positioned vanes around one centered LED chip package .

13. The mounting device as recited in claim 8, wherein the fan further comprises radially positioned rotatably coupled to a motor .

14. A mounting device comprising:

a mounting surface having a plurality of electronic component mounting seats disposed thereon for contact with a plurality of heat-generating electronic components;

a first cooling device layer coupled to the mounting surface opposite to the plurality of electronic component mounting seats, the first cooling device layer including a first cooling means disposed in thermal contact with the plurality of electronic component mounting seats;

a second cooling device layer coupled to the first cooling device layer, the second cooling device layer including a second cooling means disposed radially about a fan to define a displacement chamber thereabout;

a plurality of heat pipes traversing the first cooling device layer, the plurality of heat pipes providing thermal contact between the mounting surface and the second cooling means;

a central airflow passageway formed between the first cooling device layer and the second cooling device layer, the fan adapted to cause air to circulate through an airflow cooling passageway including inlet through the first cooling device layer, passage through the central airflow passageway, passage through the displacement chamber, and outlet through the second cooling device layer.

15. The mounting device as recited in claim 14, wherein the heat-generating electronic components comprise LED chip packages .

16. The mounting device as recited in claim 14, wherein the fan further comprises radially positioned vanes rotatably coupled to a motor.

17. The mounting device as recited in claim 14, wherein the heat pipes are substantially L-shaped and extend radially along the mounting surface and then axially along the first and second cooling device layers.

18. A luminaire comprising:

a mounting surface having first and second sides, a plurality of electronic component mounting seats disposed on the first side;

the axial air passageway being aligned with the central axis;

the radial air outlet passageway of each of the plurality of U-shaped air passageways being proximate to the lower end, the radial air outlet passageway passing through a second cooling device being located in thermal contact with the mounting surface;

a fan located at the lower end of the cooling subassembly at an intersection of the axial air passageway and the radial air outlet passageway of each of the plurality of U-shaped air passageways, the fan for directing air flow through the plurality of U-shaped air passageways; a plurality of light emitting diode chip packages mounted to the electronic component mounting seats, the plurality of light emitting diode chip packages providing a plurality of sources of light;

a respective plurality of optical arrangements superposed over the plurality of light emitting diode chip packages; and

a housing adapted to accommodate the mounting surface, cooling subassembly, and the plurality of optical arrangements.

19. The luminaire as recited in claim 18, wherein the mounting surface further comprises brackets extending therefrom for securing the mounting device to the housing.

20. The luminaire as recited in claim 18, further comprising zoom and finishing lenses located at the end of the hous ing .