US20090071624A1

US20090071624A1 - Heat sink

Info

Publication number: US20090071624A1
Application number: US11/857,401
Authority: US
Inventors: Wen-Xiang Zhang; Guang Yu; Shi-Song Zheng
Original assignee: Fuzhun Precision Industry Shenzhen Co Ltd; Foxconn Technology Co Ltd
Current assignee: Fuzhun Precision Industry Shenzhen Co Ltd; Foxconn Technology Co Ltd
Priority date: 2007-09-18
Filing date: 2007-09-18
Publication date: 2009-03-19

Abstract

A heat sink adapted for removing heat from a plurality of LEDs, includes a heat-conducting member, a plurality of conducting arms extending radially and outwardly from a periphery of the heat-conducting member and a plurality of outer fins perpendicularly extending from at least a lateral side of each of the conductive arms. The outer fins are spaced from and surround the heat-conducting member. Outer faces of outermost ones of the outer fins are used for thermal connection with the LEDs, whereby heat generated by the LEDs is absorbed by the heat sink. A plurality of spaces is defined between the outer fins, the heat-conducting member and the conducting arms and through bottom and top of the heat sink, whereby the heat absorbed by the heat sink can be easily dissipated to surrounding atmosphere along a vertical direction.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to heat sinks, and particularly to a heat sink for removing heat from electronic components such as LED components.
2. Description of related art
Electronic component includes numerous circuits operating at high speed and generating substantive heat. In many applications, it is desirable to employ a heat sink to remove heat from heat-generating electronic components, for example, LED components in an LED lamp, to assure that the components function properly and reliably.
An LED lamp is a type of solid-state lighting device that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for converting electricity into light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different types of semiconductor, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
An LED lamp generally has a limited space therein and requires a plurality of LEDs. Most of the LEDs are driven at the same time, which results in a quick rise in temperature of the LED lamp. Since the limited space in the LED lamp, the heat sink has a restricted heat dissipating area and is unable to remove heat from the LEDs effectively. Operation of the conventional LED lamps thus has a problem of instability because of the rapid buildup of heat.
What is needed, therefore, is a heat sink has a greater heat-transfer capability in a limited space.

SUMMARY OF THE INVENTION

A heat sink adapted for removing heat from a plurality of heat-generating components, such as LEDs, includes a cylindrical heat-conducting member, a plurality of conducting arms extending radially and outwardly from a periphery of the heat-conducting member and a plurality of outer fins perpendicularly extending from two lateral sides of each of the conductive arms. The outer fins are spaced from and surround the heat-conducting member. The outer fins has an outermost one which has an outer, flat surface adapted for thermally connecting with the heat-generating components, whereby heat generated by the heat-generating components is absorbed and dissipated to surrounding air by the heat sink.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present heat sink 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 LED lamp. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric view of a heat sink in accordance with a preferred embodiment of the present invention; and

FIG. 2 is a top view of the heat sink of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2, a heat sink is disclosed for removing heat from heat-generating electronic components (not shown) such as LEDs in an LED lamp.
The heat sink is integrally formed of a one-piece metal with good heat conductivity, such as aluminum or copper. The heat sink has a heat-conductive member at a center thereof. In this embodiment, the heat-conductive member is an elongated cylinder 10 with a through hole (not labeled) defined therein. The cylinder 10 has a plurality of inner fins 12 extending inwardly from an inner wall thereof. The inner fins 12 are centrosymmetric relative to a central axis of the cylinder 10 and each have a thickness gradually decreasing inwardly. The heat sink has a plurality of conducting arms 14 extending radially and outwardly from an outer wall of the cylinder 10. The conducting arms 14 are identical to each other and centrosymmetric relative to the central axis of the cylinder 10. A quantity of the conducting arms 14 can be different in an alternative embodiment. In this embodiment, the quantity of the conducting arms 14 is designed to be six. A plurality of pairs of outer fins 140 are formed on two opposite lateral sides of each of the conducting arms 14. Each pair of the outer fins 140 extend respectively and perpendicularly from the two opposite lateral sides of a corresponding conducting arm 14 and are symmetrical to each other relative to the corresponding conducting arm 14. Lengths of the outer fins 140 at a lateral side of each of the conducting arms 14 increase along a direction from the cylinder 10 to a distal end of the corresponding conducting arm 14. The distal end of the conducting arm 14 terminates at an inner face of an outermost one of the outer fins 140. An outer face of each outermost outer fin 140 is flat and used for thermally contacting with the LEDs.
Heat generated by the LEDs is first received by the outermost ones of the outer fins 140. Then the heat is transferred to inner ones of the outer fins 140 and the elongated cylinder 10 and the inner fins 12 via the conducting arms 14. The heat is dissipated to a plurality of spaces (not labeled) between the conducting arms 14, the outer fins 140, the elongated cylinder 10 and the inner fins 12, wherein the spaces extend vertically through the heat sink. Air in the spaces and heated by the heat from the LEDs flows upwardly beyond a top of the heat sink, whereby cool air enters into the spaces from a bottom of the heat sink. Therefore, the heat is taken away from the heat sink to the surrounding air so that the heat generated by the LEDs can be effectively dissipated.
It is believed that the present invention and its 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.

Claims

1. A heat sink adapted for removing heat from LEDs of an LED lamp, the heat sink comprising:

a heat-conducting member; and

a plurality of outer fins being spaced from and surrounding the heat-conductive member, the outer fins having outermost ones forming outer contacting faces adapted for contacting with the LEDs.

2. The heat sink of claim 1, wherein each of the contacting faces of the outermost ones of the outer fins is flat.

3. The heat sink of claim 1, wherein the heat-conducting member is a cylinder with a through hole defined therein.

4. The heat sink of claim 3, wherein the cylinder has a plurality of inner fins extending inwardly from an inner wall thereof.

5. The heat sink of claim 4, wherein a thickness of each of the inner fins decreases gradually from the inner wall of the cylinder to a distal end of the each of the inner fins.

6. The heat sink of claim 1, wherein a plurality of conducting arms extend outwardly from an outer wall of the cylinder, and the outer fins extend from two lateral sides of each of the conducting arms.

7. The heat sink of claim 6, wherein the conducting arms radially and evenly extend from the outer wall of the cylinder.

8. The heat sink of claim 7, wherein the conducting arms are centrosymmetric relative to a central axis of the cylinder.

9. The heat sink of claim 8, wherein the outer fins are perpendicular to a corresponding conducting arm from which the outer fins are extended, and the outer fins which extend from the corresponding conducting arm are divided into a plurality of pairs each being symmetrical to the corresponding conducting arm.

10. The heat sink of claim 6, wherein lengths of the outer fins extending from each of the conducting arms are gradually increased along a direction from the heat-conducting member to a distal end of a corresponding conducting arm.

11. The heat sink of claim 10, wherein the distal end of the corresponding conducting arm terminates at an inner face of a corresponding outermost one of corresponding outer fins, the inner face being opposite to the contacting face of the corresponding outermost one of the corresponding outer fins.

12. A heat sink adapted for removing heat from a plurality of heat-generating components comprising:

a heat-conducting member;

a plurality of conducting arms extending radially and outwardly from a periphery of the heat-conducting member; and

a plurality of outer fins perpendicularly extending from at least a lateral side of the conductive arm, the outer fins spaced from and surrounding the heat-conducting member;

wherein outer faces of outermost ones of the outer fins are adapted for contacting with the heat-generating components.

13. The heat sink of claim 12, wherein the heat-conducting member is a cylinder with a through hole defined therein, a plurality of inner fins extending inwardly from an inner wall of the cylinder.

14. The heat sink of claim 13, wherein the inner fins are centrosymmetric relative to a central axis of the cylinder and thicknesses of the inner fins decrease inwardly.

15. The heat sink of claim 12, wherein the conducting arms are centrosymmetric relative to a central axis of the cylinder, the outer fins are formed at two lateral sides of each of the conductive arms.

16. The heat sink of claim 15, wherein lengths of the outer fins are increased outwardly from the cylinder to distal ends of the conducting arms.

17. The heat sink of claim 16, wherein each distal end of the conducting arms terminates at an inner face of an outermost one of corresponding outer fins, and an outer face of the outermost one of the corresponding outer fins is flat adapted for contacting with the electronic components.

18. A heat sink adapted for cooling LEDs, comprising:

a tube-shaped heat conductive member;

a plurality of arms extending outwardly from an outer side of the heat conductive member;

a plurality of outer fins connected to outer ends of the arms, respectively, each outer fin having a flat outer surface adapted for thermally connecting with the LEDs;

wherein a plurality of spaces is defined between the heat conductive member, the arms and the outer fins and extends through top and bottom of the heat sink.

19. The heat sink of claim 18 further comprising a plurality of additional outer fins extending from the arms and located between the outer fins and the heat conductive member.

20. The heat sink of claim 19 further comprising a plurality of inner fins extending inwardly from an inner side of the heat conductive member.