Heatsink assembly and luminaire

Abstract

According to certain embodiments, a heatsink assembly for a luminaire may include a shell and one or more lighting module holders. The shell may include a frame and one or more cross members that may be attached to the inner surface of the frame and that may form one or more openings proximate to the rear end of the frame. One or more lighting module holders may be configured to be held in the one or more openings. The one or more lighting module holders may contain a mounting region and a plurality of heatsink fins that are extended from one surface of the mounting region and positioned to extend from the corresponding opening. wherein the plurality of fins has a thickness, height and spacing that are configured to provide a predetermined and / or optimized minimum weight of the plurality of fins. A support ring is mounted on the top portions of the heatsink fins to provide support during operation. The mounting region is configured to receive a lighting module and a lower surface that is sized to correspond to and be larger than a corresponding one of the openings. In some embodiments, the lighting module holder forms a heat sink.

Description

[0001] HEATSINK ASSEMBLY AND LUMINAIRE

[0002] FIELD OF THE INVENTION

[0003] The disclosure relates to heatsinks that can be incorporated into a luminaire. More particularly, the disclosure relates to an efficient thin-finned heatsink assembly using a combined support ring to add structural support while reducing the weight of heatsinks.

[0004] DESCRIPTION OF THE RELATED ART

[0005] A luminaire includes a light engine and a driver. A light engine can include light emitting diodes (LEDs) and other optics. The driver includes electronic components that control the voltage and current to the LEDs. A portion of the electricity provided to the LEDs of the luminaire is converted to heat that is internal to the LED. To ensure an extended lifetime and desired luminous output of LED lighting devices, LEDs are typically mounted to a heatsink to transfer the heat generated from LEDs to its surroundings. In operation, the heatsink maintains the operating temperature of LED lighting devices below a critical temperature, at or above which the LED lighting devices may exhibit a reduced lifetime and / or degradation of optical performance. For outdoor applications, a lighter and more efficient heatsink is desired.

[0006] US 2020 / 232633 relates to a heatsink assembly for a luminaire may include a shell portion and one or more lighting module holders. The shell portion may include a frame and one or more cross members that may be attached to the inner surface of the frame and that may form one or more openings proximate to the rear end of the frame. The frame may be made of a material that has a lower thermal conductivity than that of the material of the one or more lighting module holders. The one or more lighting module holders may be configured to be held in the one or more openings. The one or more lighting module holders may contain a l anding pad and a plurality of inner fins that are connected to the lower surface and positioned to extend from the corresponding opening. The landing pad may have an upper surface that is configured to receive a lighting module and a lower surface that is sized to correspond to and be l arger than a corresponding one of the openings.

[0007] CN219083008 U relates to a heat sink with stable structure, comprising: fixed underframe, joint install in the radi ating main body of fixed underframe top surface, the radiating main body includes: a plurality of radiating fins which are arranged in parallel at intervals, wherein two adjacent radiating fins are fixedly connected through a buckling structure; further comprises: the heat dissipation device comprises a heat dissipation main body and a fixed baffle plate and reinforcing plates, wherein the fixed baffle plate is arranged at two ends of the heat di ssipation main body, the fixed baffle plate is arranged at the top of the fixed underframe, two sides of the reinforcing plates are respectively and fixedly cl amped with the top of each heat dissipation fin, and two ends of the reinforcing plates are respectively and fixedly clamped with the two fixed baffle plates.

[0008] It should be noted that the above information of the background is merely provided for clear and complete explanation of the disclosure and for easy understanding for those skilled in the art. No inference should be drawn that any of the above information is known to those skilled in the art.

[0009] SUMMARY

[0010] According to certain embodiments, a heatsink assembly for a luminaire includes: one or more light module holders including a mounting region and a plurality of fins (203) extending from the mounting region; and a support ring attached to the ends of the plurality of fins that is opposite to the mounting region; and a shell portion, which includes: a frame having an inner surface and an outer surface, and a front end and a rear end; and one or cross members that are attached to the inner surface of the frame and that form one or more openings proximate to the rear end of the frame, the one or more light modules holders configured to be held in one of the openings proximate to the rear end of the frame, wherein the mounting region is configured to face the front end of the frame and receive a lighting module.

[0011] According to certain embodiments, a plurality of chamfered slots is provided on a top surface of the support ring and disposed above the extended ends of the plurality of fins. The plurality of chamfered slot is configured to deflect water droplet onto the side surface of the plurality of fins for liquid cooling or is configured to block external heat.

[0012] According to certain embodiments, a method for assembling a luminaire is formed using 3D printing the heat assembly comprising: a shell and one or more lighting module holders. The shell may include a frame and one or more cross members that may be attached to the inner surface of the fram e and that m ay form one or more openings proxim ate to the rear end of the frame. One or more lighting module holders may be configured to be held in the one or more openings. The one or more lighting module holders may contain a mounting region and a plurality of heatsink fins that are extended from one surface of the mounting region and positioned to extend from the corresponding opening. The mounting region is configured to receive a lighting module when held in the one or more openings. A support ring is mounted on the top portions of the heatsink fins to provide structural support.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0015] Fig. l is a top view of a heat sink assembly in accordance with an embodiment of the disclosure;

[0016] Fig. 2 is a front view of a shell of the heat sink assembly in accordance with an embodiment of the disclosure;

[0017] Fig. 3 illustrates a heatsink fins with a support ring in accordance with an embodiment of the disclosure;

[0018] Fig. 4 illustrates a bottom view of the heatsink fins with a support ring in accordance with an embodiment of the disclosure;

[0019] Fig. 5 illustrates a lab test of the heatsink assembly in accordance with an embodiment of the disclosure;

[0020] Fig. 6 illustrates a rear view of a shell portion of the heat sink assembly and a light module holder in accordance with an embodiment of the disclosure;

[0021] Fig. 7 illustrates a front view of a shell portion of the heat sink assembly in accordance with an embodiment of the disclosure;

[0022] Fig. 8 illustrates a heat sink assembly with different types of support rings in accordance with an embodiment of the disclosure;

[0023] Fig. 9 illustrates a top view of the support ring retained on the heatsink tins in accordance with an embodiment of the disclosure; and

[0024] Fig. 10 illustrates a section view of the heatsink tins with a support ring in accordance with an embodiment of the disclosure.

[0025] DETAILED DESCRIPTION

[0026] In operation of a light emitting diode (LED) luminaire, it is essential to remove the heat generated by the LEDs of the luminaire through efficient thermal management as it affects the lifetime of the LEDs. Moreover, a lighter and more efficient heatsink matching the thermal performance of heat sink is desired to save manufacturing cost. The concern for a lighter heatsink is structural integrity of the heatsink fins during shipping and installation. Deterioration due to contact with water and exposure to sun is also a concern, especially because certain luminaires are rated to receive and drain water.

[0027] This document describes a heatsink assembly that is directed to solving the issue described above, and / or other issues.

[0028] Accordingly, in certain embodiments, a combined structural support heatsink ring and lighter heatsink fins can be incorporated into a heatsink assembly to have a benefit of significant size and weight reduction while providing rain cooling advantages and sunshade for outdoor application.

[0029] Referring to Fig. 1, there is illustrated a luminaire in accordance with an embodiment of the disclosure. The luminaire includes a shell 100, a lighting module holder 200 and a support ring 300. When one or more LED is energized, the LED module 200 forms the heat sink by drawing heat away from the one or more LED and past the heat through the rear end thereof.

[0030] Referring to Fig. 2, the shell 100 includes a frame 101 and one or more cross members 102, 103. The frame 101 has an outer surface 105 and inner surface 106, and a front end 107 and a rear end 108. The one or more cross members 102, 103 are attached to the inner surface 106 of the frame and form one or more openings HO a-l lO d proximate to the rear end 108 of the frame 101. It should be noted that the shell portion 100 contains two cross members 102, 103 that form four openings 110 a- 110 d for illustration purposes. However, the number of openings should not be limited to only four openings according to the teachings of this disclosure.

[0031] The one or more cross members 102, 103 can have an extendable portion 111 that extends from the surface facing the rear end of the frame, such as shown in Fig. 2. The extendable portion 111 may be of any shape, size, or parts. In some embodiments, the portion of the cross member extending from the surface facing the rear end of the frame contains a plurality of fins 112. Additionally, the one or more cross members 102, 103 can contain holes on the surface facing the front end 107 of the frame 101. These holes can be used to mount lighting modules to the one or more cross members 10.

[0032] Figs. 3 and 4 shows a heatsink assembly including a lighting module holder 200 having a mounting region 202 and a plurality of heatsink fins 203 extending from the light module holder 200 from one end, and a support ring 300 fixed at the other end. Fig. 3 illustrates an exploded view from the top, and FIG. 4 illustrates an exploded view from the bottom.

[0033] As shown in Figs. 3 and 4, the support ring 300 is attached to the opposite end of the mounting region 202 via screws 304. It should be noted that other technique such as a ring clamp, or any other method known to artisians can be used to establish a secure connection. The plurality of heatsink fins 203 extending from the light module holder 200 is further securely locked to the support ring 300 via corresponding slots 305 formed underneath the support ring 300. A upper surface 200a of the light module molder 200 when held in one of the openings 110 a-lOOd, the upper surface 200a faces the front end of the frame 1101 to receive one or more lighting modules (not shown). The support ring 300 interfaces the heatsink fins 203 around the top perimeter along with a central strip 306. Note that the slots 305 are 0.020 wider than the fins in order to provide adequate clearance for a trouble-free fit. The top of heatsink fins 203 are recessed to provide a perfectly flush fitting the support ring.

[0034] As shown, the central strip 306 serves to provide structural support, to keep the heatsink fins 203 from bowing in the middle. The screws 304 are secured to the portion of fins 203 via receiving holder provided at lateral ends of the corresponding fins 203. With fastening of support ring 300 onto the plurality of fins, as shown in Figs. 3 and 4, the support ring 300 strengthen the integrity of heat assembly to minimize damages to the plurality of heatsink fins 203 during shipping, handling, installing and outdoor application. In operation, the lighting module holder 200 forms the heat sink by drawing heat away from the lighting modules through the rear end of the shell 100. The heat can be removed from the heatsink assembly and dissipated via the heatsink fins 203 by a liquid coolant or air, such as forced air.

[0035] Some of the known heatsink is made of heatsink fins that are 0.080” thick. However, according to the teachings of present disclosure, one or more of the fin thickness, gap distance between the heatsink fins and fin height are selected to provide a predetermined weight of the heatsink fins. In particular to optimize weight reduction of the heatsink fins while maintaining thermal performance. For example, a fin thickness of 0.035” (57% reduction in thickness), a gap distance between the heatsink fins 230 of 0.55” with a height of 4.350” performed as efficiently as prior known heatsink fins while weighing about 40% less (from 9.35 lbs to 5.6 libs). Note that the perimeter of fins 203 where the support ring 300 interfaces with the top portion of the fins would be less than 4.350” to accommodate the support ring 300. According to the teachings of present disclosure, the support ring 300 is effective when it is centered more on the ratio of fin heights to thickness. For example, if the fin is 3” tall and 0.040 thickness of fins would be just as fragile to the 6” tall fin that is 0.080 thick. The 0.035” thickness is about as thin as one can tool the fins from manufacturing and design constraints.

[0036] Fig. 5 illustrates optimized testing outcome with adjusted fin thickness, height and fin spacing. As shown, the fragile nature of thinned heatsink fins 230 is addressed by the support ring 300 which provided substantial reinforcement to the thinned fin design where the heatsink can be prevented from damage or bent during shipping and handling or in outdoor use.

[0037] Fig. 6 illustrates a rear view of a shell portion of the heat sink assembly and a light module holder in accordance with an embodiment of the disclosure. As shown, the heatsink assembly may include one or more lighting module 201 < -201, which are configured to be held in the corresponding openings 110 7- 1 10 d of the shell 100. The lighting module are held in the opening of the shell 100 by screws or a press fit.

[0038] As shown, each lighting module 201 c / -20 k / contains a mounting region 202 and a plurality of heatsink fins 203. The plurality of heatsink fins 203 extends from the corresponding opening of the shell portion 100 and past the rear end 108 of the frame 101. It should be noted that although FIG. 6 shows that each fin is equal in dimension to an adjacent fin for illustrative purposes; however, the fins are not required to have the same dimensions.

[0039] Fig. 6 shows the shell portion 100 of the heat assembly with the lighting module holders 20 la-20 Id mounted in the shell portion 100. Note that lighting modules connects to the mounting region 202 of the lighting module holders 200 and shell 100 to form a heat sink assembly. As shown, the mounting region 202 is configured to face the front end 107 of the frame 101 and receive a lighting module. The mounting region 202 is provided with holes that allow the lighting module to be connected to the mounting region 202 via screws, a ring clamp, or any method to establish a secure connection. As shown, when the lighting module holder 200 is held in the corresponding opening of the shell 100, the lighting module holder 200 is thermally connected to the shell 100 and a heatsink is formed by the lighting module holder 200, the frame 101, the outer fins 112 of the frame 101, and the one or more cross members 102,103. Although Fig. 6 shows a plurality of outer fins 112 that are attached to the outer surface of the frame and that extend from the front end of the frame toward the rear end of the frame, it is not a requirement for the plurality of outer fins 112 to extend to an ending position that is beyond the rear end of the frame. It should be noted that the plurality of outer fins 112 may be of any length. Additionally, the frame 101 of the shell 100 can be many different shapes, for example, the frame may be annular and / or it may have an inner surface that is angled so that a circumference of the frame at the rear end is smaller than a circumference of the frame at the front end. Additionally, the frame 101 may contain an area formed by the inner surface between the front end and rear end of the frame that forms a bowl that is configured to receive a plurality of LED modules.

[0040] Each lighting module holder 201 a-20 k / may have a gasket 206 that is configured to provide a seal between the mounting region 202 and the corresponding openings 110 a-110 d of the shell 100. The seal can be used to create a waterproof bond between the shell portion and the one or more lighting module holders. The seal can be a ring, liquid seal, or any other object that can create a seal. If heat is dissipated via the fins by a liquid coolant, the seal can protect the electronics from the liquid coolant.

[0041] Fig. 7 illustrates a front view of a shell portion of the heat sink assembly in accordance with an embodiment of the disclosure. The lighting modules are connected to the mounting region 202 of the lighting module holders 200 such that the lighting module holders including the heatsink fins 230 retained by the support ring 300, and the shell 100 forms a heatsink assembly.

[0042] Fig. 8 illustrates a heat sink assembly with different types of support rings 300,400 in accordance with an embodiment of the disclosure. FIG. 9 illustrates a top view of the support ring 400 retained on the heatsink tins in accordance with an embodiment of the disclosure. The support ring 400 is designed to provide a cover from the sun and also direct rainwater towards the side of the heatsink fins to drastically improve the effectiveness of natural liquid cooling.

[0043] As shown in Fig. 9, the support ring 400 includes a plurality of chamfered slots 402 and supports the heatsink fins 230 in an identical manner as the support ring 300 as shown with reference to Figs. 1 through 7. Thus, for simplicity, the description of same components is omitted.

[0044] Fig. 10 illustrates a section view of the heatsink tins with a support ring 400 shown in Fig. 9 in accordance with an embodiment of the disclosure. As shown, the openings 404 of chamfered slots 402 are placed directly placed over the heatsink fins 230 direct water or rain droplets onto the sides of the heatsink fins, thereby adding the benefits of liquid cooling during operation. Further, the support ring 400 provided with chamfered slots 402 serves to block the sun thus cooling the heatsink fins exposed to sun and hot air. Many outdoor activities such as sports events are often conducted right at or after dusk. As such, the residual heat from the sunlight that are trapped in the luminaire can interfere and which in turn cause to not power on due to surpassing the thermal breakers that are often in the range of 105 Celsius. The ring 400 provided with chamfered slots 402 as shown in FIG.10 serves to provide sunshade.

[0045] As is apparent from the foregoing, the present disclosure has an advantage in that a lighter and efficient heatsink assembly can be implemented which provides manufacturing cost saving and weight saving thus not needing as robust of a mast-arm or pole. The fragile nature of thinned heatsink fins addressed with a combed support ring to add substantial support and rigidity so the heatsink can operate at acceptable level for shipping, handling and installing. The additional benefits of aqueducts and sunshade can be applied to many outdoor fixtures and dramatically lower temp-initial for long term reliability.

[0046] It should be noted that, in some embodiments, one or more of the components shown in the figures for a heatsink assembly for a LED luminaire may be formed by die casting. Die casting is a metal casting that is characterized by forcing molten metal under high pressure into a mold cavity. After the casting solidifies, it is then removed from the dies. For some embodiments, the shell portion is formed by die casting a material. In these embodiments, the shell portion can include the frame, one or more cross members, and the extendable portion of the one or more cross members. The shell portion can also include the plurality of outer fins that are attached to the outer surface of the frame and that extend from the front end of the frame toward the rear end of the frame. A die casting method allows flexibility in the shape of the mold. For example, using a die casting method, the frame of the shell can have a geometric shape, such as annular, rectangular, triangular, etc. or any organic shape. For some embodiments, the shell can be a geometric shape containing an annular frame that contains one or more cross members and a plurality of outer fins that are attached to the outer surface of the frame.

[0047] In some embodiments, one or more of the components shown in the figures for a heatsink assembly for a LED luminaire may be formed by cold forging. Cold forging is a metal shaping process by application of compressive force while the metal is below its recrystallization point. Recrystallization of a metal occurs when the metal is heated whereby deformed grains are replaced by a new set of grains that nucleate and grow until the original grains have been entirely consumed. The method of cold forging typically occurs at or near room temperature, and it does not require the metal to be heated. One benefit of cold forging is that it can produce very thin and tall shapes of metal that can be an integral part of the base structure with no air gaps. In some embodiments, the lighting module holders may be formed by cold forging. For these embodiments, the lighting module holder includes a landing pad and a plurality of inner fins. The method of cold forging, would result in thin, tall fins as shown in FIG. 2, to be used as the plurality of inner fins that are connected to the lower surface of the one or more lighting module holders. Tall, thin fins will remove the heat further away from the lighting module holders forming a more efficient heatsink.

[0048] In some embodiments, one or more of the components shown in the figures for a heatsink assembly for a LED luminaire may be formed by extrusion. Extrusion is a method where a metal is passed through a die of the desired cross section. Through compressive and shear stresses, this method gives the ability to create very complex cross-sections. In some embodiments, the shell portion of the heatsink can be comprised of an aluminum die casting alloy. Although aluminum and aluminum alloys are metals that have a high thermal conductivity, any other metal can be used for the heatsink or a portion of the heat sink. Some other metals that can be used for the heatsink are copper, brass, steel, bronze, etc. The intent is that the heatsink discussed herein can be formed with any metal of preference.

[0049] The above paragraphs detail die casting, cold forging, and extrusion. The intent is that any one of these three methods, or any other suitable method, can be used to form the entire heatsink or any part of the heatsink. For example, 3D printing technologies es can be implemented to reduce capex for tooling, reduce time to market, create value adds in the design process and greatly increase flexibility for part delivery. Additionally, in some embodiments, one or more parts of the heatsink can be formed using more than one method. For example, in one embodiment, the shell portion of the heatsink may contain a frame that is formed by a method of die casting and one or more cross members that are formed by a method of extrusion. The discussion herein applies to any combination of methods used to form any part of the heatsink.

[0050] While one or more embodiments of the disclosure have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

Claims

CLAIMS:

1. A heatsink assembly (10) for a luminaire comprising: one or more light module holders (200) including a mounting region (202) and a plurality of fins (203) extending from the mounting region (200); and a support ring (300) attached to perimeter ends of the plurality of fins (203) that is opposite to the mounting region (202); and a shell portion (100) including: a frame (101) having an inner surface (106) and an outer surface (105), and a front end (107) and a rear end (108); and one or more cross members (102, 103) that are attached to the inner surface (106) of the frame (101) and that form one or more openings (110 a-1 lOd) proximate to the rear end (108) of the frame (101), the one or more light modules holders (200) configured to be held in one or more of the openings (110 a-1 lOd) proximate to the rear end (108) of the frame (101), wherein the mounting region (202) is configured to face the front end (107) of the frame and receive a lighting module, and wherein one or more of the plurality of fins (203) has one or more of a thickness, height and spacing that is / are configured to provide a predetermined and / or optimized minimum weight of the plurality of fins (203).

2. The heatsink assembly of claim 1, wherein the material of the frame (101) has a lower thermal conductivity than that of the one or more light module holders.

3. The heatsink assembly of claim 1, wherein the support ring (300) further comprising a plurality of chamfered slots (402) on a top surface thereof and the plurality of chamfered slots is disposed above the extended ends of the plurality of fins (203).

4. The heatsink assembly of claim 3, wherein the plurality of chamfered slots (402) is configured to deflect water droplet onto the side surface of the plurality of fins (203) for liquid cooling or is configured to block external heat.

5. The heatsink assembly of claim 1, wherein the support ring further comprising a central strip (306), such that the support ring (300) interfaces a top perimeter of the plurality of fins (203) along with the central strip 306.

6. The heatsink assembly of claim 1, further comprising a plurality of outer fins (112) that are attached to the outer surface of the frame (101) and that extend from the front end (107) of the frame (101) towards a rear end (108) of the frame.

7. The heatsink assembly of claim 1, wherein the thickness of each of the plurality of fins (203) is about 0.035’70.889mm.

8. The heatsink assembly of claim 1, wherein a size of the lateral gap between the plurality of fins (203) is about 0.55’713.97mm.

9. The LED luminaire of claim 1, wherein the support ring (300) further comprising a plurality of chamfered slots (402) on a top surface thereof and the plurality of chamfered slots is disposed above the extended ends of the plurality of fins (203).

10. The LED luminaire of claim 1, wherein the frame (101) is annular.

11. The LED luminaire of claim 1, wherein the thickness of one of the plurality of fins (203) is about 0.035”.

12. A method of manufacturing a heat sink assembly, the method comprising:3D printing at least a portion of the heat sink assembly, wherein the heat sink assembly comprises: providing one or more light module holders (200) including a mounting region (202) and a plurality of fins (203) extending from the mounting region (200); and providing a support ring (300) attached to perimeter ends of the plurality of fins (203) that is opposite to the mounting region (202), providing a shell portion (100) including: providing a frame (101) having an inner surface (106) and an outer surface (105), and a front end (107) and a rear end (108); andproviding one or cross members (102, 103) that are attached to the inner surface (106) of the frame (101) and that form one or more openings (110 a-1 lOd) proximate to the rear end (108) of the frame (101), the one or more light module holders configured to be held in one of the openings (110 a-1 lOd) proximate to the rear end (108) of the frame (101), wherein the mounting region (202) is configured to face the front end (107) of the frame and receive a lighting module, and wherein one or more of the plurality of fins (203) has one or more of a thickness, height and spacing that is / are configured to provide a predetermined and / or optimized minimum weight of the plurality of fins (203).

13. The method of claim 12, further including the step of providing a plurality of chamfered slots (402) on a top surface of the support ring (300) and the plurality of chamfered slots is disposed above the extended ends of the plurality of fins (203).

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