FIELD OF THE INVENTION
- BACKGROUND OF THE INVENTION
The present invention generally relates to a fan assembly, and more particularly to a fan assembly that adopts a metal frame to reduce the thickness of an external frame and increase the diameter of the vane so as to improve the airflow and the heat dissipating effect.
The application of a fan becomes more popular since its invention and the advancement of electronic and network communications products, and an electric fan was invented. The functions and usages of a fan are planned to satisfy the increasingly sophisticated requirements of various different electronic and network communication products. As to present industrial servers, the height of the server is designed as 1U (where 1U=44.45 cm), but the processing speed of related electronic components and CPU in the server increases, and thus resulting a large amount of heat produced in such high-speed operations and working conditions. The large amount of heat so produced is cooled to a temperature lower than the maximum operating temperature by at least one fan, so that the server can maintain a normal operating environment.
In general, the specification of a fan used for servers is generally 40 cm×40 cm×20 cm, and the heat dissipation rate of this specification is preferably higher than those for other smaller fans such as the 30 cm×30 cm×10 cm and the 25 cm×25 cm×10 cm. In the meantime, the smaller is the design of the volume of the fan axle, the more difficult is the manufacture and the higher is the cost. Therefore, the 40 cm×40 cm×20 cm specification is widely used for the limited space in present servers due to the consideration of its cost, heat dissipation, and structure.
Referring to FIG. 1, a conventional prior fan (60 cm×60 cm×20 cm) comes with a vane 76 disposed in an accommodating space 74 of a general external frame 72. With the consideration of the strength of the structure, the fan 70 must have a thicker and a larger external frame, and thus the minimum thickness of one side of the external frame is 2˜3 cm, the external diameter of the vane 76 must fall into the range of 54˜56 cm, and the airflow produced after the rotation is very limited.
Further, the general external frame 72 has a screw hole 75 disposed at four corners separately, so that the fan can be fixed onto a casing 80 by securing a screw 77 into the screw hole 75. When the fan 70 is turned on to dissipate heat, the heat in the casing 80 can be discharged from the casing or external air can be blown directly into the casing to maintain the normal operation of electronic components in the casing 80.
However, the shortcomings of the foregoing fan 70 resides on its structure having a weight heavier than a general external frame 72, and thus the area of the air inlet or outlet is limited and larger airflow cannot be obtained. As a result, the maximum flow is restricted significantly.
- SUMMARY OF THE INVENTION
Further, the presently developed servers tend to have a flat design, and the space for installing a cooling fan in a server becomes smaller, and thus the fan installed in the server is smaller. It is an important subject for manufacturers in the related industry to maximize the airflow in the limited space for installing a small fan, and everyone is happy to see a design of an improved fan assembly that can effectively overcoming the foregoing shortcomings.
In view of the shortcomings of the prior-art, the inventor of the present invention conducted extensive researches and experiments and finally invented an improved fan assembly.
It is therefore a primary objective of the present invention to design and develop a fan assembly that comprises a metal frame, a vane, and a driving means; wherein the driving means is installed at the central position of the metal frame, and the vane is installed at an end of the driving means. With better tensile strength and structural strength of metal, the thickness of an external frame of a fan in accordance with the present invention can be made thinner than that of a general fan. Therefore, the airflow of such fan is larger than the airflow of a general fan and the invention provides a better heat dissipating effect for dissipating the produced heat more easily.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
FIG. 1 is a schematic view of a fan assembly of a prior art;
FIG. 2 is an exploded view of a fan assembly of the present invention;
FIG. 3 a schematic view of a fan assembly of a preferred embodiment of the present invention;
FIG. 4 is a perspective view of a fan assembly of a preferred embodiment of the present invention; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 5 is a schematic cross-sectional view of a fan assembly of a preferred embodiment of the present invention.
Referring to FIG. 2, a fan assembly in accordance with the present invention is illustrated. The fan assembly comprises a metal frame 20, a vane 40, and a driving means 60; wherein the vane 40 is installed at an end of the driving means 60, and the driving means is installed at the central position of the metal frame 20. With the tensile strength and structural strength of the metal, the thickness of the metal frame of a fan 1 in accordance with the present invention can be made thinner than a general fan, so that the external diameter of the vane 40 can be larger than a general vane. As a result, the airflow of the fan 1 is larger than that of a general fan, and the fan 1 of the invention can give a better heat dissipating effect.
Referring to FIG. 2 that illustrates a preferred embodiment, the metal frame 20 includes a protective grid 21 at an external edge, and the protective grid 21 is coupled closely with an end of the metal frame 20 so that foreign matters will not fall into the fan 1 easily. The protective grid 21 has a fixing member 210 disposed at a central position on the surface of the protective grid 21, and the fixing member 210 is connected to an end of the driving means 60 for supporting the driving means 60 to reduce vibrations produced during its rotation.
Further, the driving means 60 includes an axle 65 pivotally connected to another end of the fixing member 210, such that the driving means 60 can drive the axle 65 to rotate, and the vane 40 includes a groove 45 disposed thereon at a position facing the axle 65, and the groove 45 can be latched with another end of the axle 65. When the driving means 60 is operated to drive the axle 65, the vane 40 can be rotated.
Referring to FIG. 3, the vane 40 includes a wing nose 47 disposed at an end of the groove 45, and the design of the wing nose 47 is streamlined, so that the vane 40 is operated to guide the direction of the airflow, reduce the wind resistance, and improve the performance of the fan 1.
Referring to FIG. 2, the metal frame 20 of the invention comprises a plurality of lugs 23 disposed at the external periphery of the metal frame 20, and the position of the lug 23 varies according to the requirements of the design of the casing 80, and the casing 80 has a plurality of bores 235 disposed on one side of the casing 80 and the quantity of the bores 235 is equal to that of the lugs 23 for fixing the lugs 23 onto the cores 235 of the casing by a plurality of bolts 230 to reduce vibrations and noises.
Referring to FIG. 4 for another preferred embodiment, the metal frame 20 comprises a plurality of L-shape hook sections 25 disposed at the external periphery of the metal frame 20, and the position of the L-shape hook section 25 varies according to the requirements of the design of the casing 80. The casing 80 has a groove 250 disposed at a corresponding position of the metal frame 20 that fits the L-shape hook section 25, and the metal frame 20 can be rotated and embedded into the groove 250, and the fan 1 can be fixed into the casing to reduce vibrations and noises produced during the operation of the fan 1.
In the foregoing preferred embodiments, the thickness of the metal frame 20 of the fan 1 is thinner than a general plastic frame, and the minimum thickness of a side of the metal frame 20 can be reduced to 1 cm (while the minimum thickness of a side of a plastic frame is 2˜3 cm.) When the thickness of the metal frame 20 is reduced, the external diameter of the vane 40 can be increased to 58 cm without changing its structural strength, and thus enhancing the airflow during the operation of the fan 1 and improving the performance of the fan 1.
In the foregoing preferred embodiments, the metal frame 20 and the casing 80 can be coupled integrally. Referring to FIG. 5, the metal frame 20 can be cast directly onto the surface of the casing 80 and integrally coupled with the casing 80 by a mold design due to the tensile strength of the metal. Therefore, the metal frame 20 can firmly support the fan 1, and the metal frame 20 together with the casing 80 can absorb the vibration and noise produced during the operation of the fan 1.
In the foregoing preferred embodiments, the vane 40 of the fan 1 is made by metal, since metals have better thermal conductivity (the coefficient of thermal conductivity is 0.94 W/MK for copper, 0.05 W/MK for stainless steel, and 0.034 W/MK for plastics) that can easily reduce the heat produced by the operation of the vane 40, and the heat can be dissipated from the surface quickly. In general, the plastic material of a plastic vane will be worn out or deformed by the heat accumulated for some time. Unlike the plastic vane, the life of a metal vane 40 is much longer.
Since the present servers tend to have a flat design, the space for installing a cooling fan in a server becomes smaller, and the size of the fan has to be smaller. The fan 1 used for network servers according to the foregoing preferred embodiments seems to be unable to increase the length of the vane 40 of fan 1 in a substantial amount, but several fans 1 can be serially installed into the server to increase the airflow for cooling and circulation, and thus greatly improving the heat dissipating effect.
While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.