Patent Application
20090303717
1. Field of the Invention
The present invention relates to an LED lamp assembly for a lighting purpose, and more particularly relates to an improved LED lamp assembly having a good heat dissipation capability and large illumination area.
2. Description of Related Art
An LED lamp assembly is a type of solid-state lighting that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different semiconductors, 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 assembly is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
Known implementations of LED modules in an LED lamp assembly make use of a plurality of individual LEDs to generate light that is sufficient and of satisfactory spatial distribution. The large number of LEDs leads to a more expensive module and one with greater power consumption. The greater power usage leads to greater heat output, which, if not adequately addressed at additional expense, impacts the LED lamp assembly reliability.
Besides, since the LEDs are generally arranged on a printed circuit board which has a flattened surface, the LEDs acting as a light source and arranged in this way usually are failed to provide a three-dimensional lamplight for a condition that needs even and large-scale light.
What is needed, therefore, is an improved LED lamp assembly which can overcome the above problems.
An LED lamp assembly includes a first heat sink, a plurality of second heat sinks secured to a periphery of the first heat sink, a plurality of LED modules respectively attached to the second heat sinks and a plurality of heat pipes interconnecting the first heat sink and the second heat sinks. The first heat sink comprises a heat conducting body defining a through hole therein and a plurality of first fins around the heat conducting body. The second heat sinks each comprise a plurality of second fins facing the first fins of the first heat sink. The heat pipes each comprise an evaporating section attached to a corresponding second heat sink and a condensing section extending into the through hole of the heat conducting body of the first heat sink and attached to the heat conducting body. The LED modules face outward toward different radial directions of the first heat sink, whereby the LED lamp assembly can cover a large range of illumination. Heat generated by the LED modules is dissipated by the second heat sinks directly and the first heat sink via the heat pipes.
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:
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.
Referring to
The LED lamp assembly further comprises a top cover 60 covering a top of the first heat sink 20. The LED lamp assembly can be held at a predetermined position by a supporting post 10 engaging with the first heat sink 20. In this embodiment, the supporting post 10 extends upwardly to support the first heat sink 20 on a top thereof. The supporting post 10 comprises a cylindrical lamp holder 12, which supports the first heat sink 20 on a top thereof. The lamp holder 12 has three engaging portions 14 extending outwardly along a circumferential sidewall thereof. The engaging portions 14 are evenly located around the circumferential sidewall of the lamp holder 12 of the supporting post 10 and each are provided with a locking hole 140 therein.
As shown in
As shown in
Each group of the heat pipes 40 has two heat pipes 40 and each heat pipe 40 comprises an evaporating section 42, a condensing section 44 parallel to the evaporating section 42 and a connecting section 46 interconnecting the evaporating section 42 and the condensing section 44. The evaporating section 42 has a length longer than that of the condensing section 44. The three groups of the heat pipes 40 are evenly fixed to the first heat sink 20 along the circumferential direction of the heat conducting body 22 of the first heat sink 20 by soldering, wherein each of the evaporating sections 42 of the heat pipes 40 is accommodated in the groove 322 of the heat conducting plate 32 of the second heat sink 30, each of the connecting sections 46 of the heat pipes 40 is located adjacent to a top face of the heat conducting body 22 of the first heat sink 20 (illustrated in
The LED modules 50 are attached to the another outer sides 320 of the heat conducting plates 32 of the second heat sinks 30, respectively. Each of the LED modules 50 comprises two LED assemblies 52, a frame 54 and a cover 56. Each LED assembly 52 has a rectangular printed circuit board 520 and a plurality of LEDs 522 arranged on a side along an elongated direction of the printed circuit board 520. The LED assembly 52 is attached to the corresponding another outer side 320 of the heat conducting plate 32 of the second heat sink 30 along the axis of the first heat sink 20 with an opposite side of the printed circuit board 520 of the LED assembly 52 contacting the corresponding another outer side 320 of the heat conducting plate 32 of the second heat sink 30. The printed circuit boards 520 of the LED assemblies 52 are located corresponding to the grooves 322 of the heat conducting plate 32 of the second heat sink 30 for ensuring that heat generated by the LEDs 522 can be quickly conducted to the evaporating sections 42 of the heat pipes 40 received in the grooves 322.
The frame 54 has a rectangular, ring-like shape and includes a plurality of through orifices 5420 located corresponding to the fixing holes (not labeled) of the fixing ears 327 of the second heat sink 30. The cover 56 is made of transparent/translucent plastic or glass and in the form of a rectangular hood. The cover 56 is mounted in the frame 54. Screws (not shown) are used to extend through the through orifices 5420 of the frame 54 to screw into the locking holes of the fixing ears 327 of the second heat sink 30 to thereby secure the cover 56 to the another outer side 320 of the heat conducting plate 32 of the second heat sink 30.
In use of the LED lamp assembly, the three second heat sinks 30 are assembled to the circumference of the first heat sink 20 by the three groups of the heat pipes 40 being respectively connected with the second heat sinks 30 and the first heat sink 20. The LED modules 50 are attached to the another outer sides 320 of the second heat sinks 30. At this embodiment, the LED assemblies 52 face outwardly from the first heat sink 20 along three equidistantly, radially outward directions. As the LED assemblies 52 are disposed surrounding the first heat sink 20, every sides of the LED lamp assembly are sufficiently illuminated, whereby the LED lamp assembly can provide a large illumination area. When the LEDs 522 of the LED assemblies 52 are activated to lighten, the heat generated from the LEDs 522 is conducted to the heat conducting plates 32 of the second heat sinks 30 via the printed circuit boards 520 of the LED assemblies 52. Since the heat pipes 40 connect the second heat sinks 30 and the first heat sink 20, the heat can be not only dissipated by the second heat sinks 30, but also dissipated by the first heat sink 20. A part of the heat is dispersed to the ambient cool air via the second fins 34 of the second heat sinks 30. Remaining part of the heat is transmitted to the first heat sink 20 via the heat pipes 40, whereby the heat which originally should be concentrated in the second heat sink 30 is partly transferred to the first heat sink 20 and is dispersed to surrounding environment by cool air which flows through the first fins 24 of the first heat sink 20.
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.
