Patent Application
20070116573
1. Field of Invention
The invention relates to a fan and an impeller thereof and, in particular, to a fan and an impeller thereof having downward-shifted blades.
2. Related Art
With the high development of technologies, the requirements for the functions of the electronic products become more critical and complex. Accordingly, the number of electronic elements in the electronic product and the integration of the electronic elements are increased, which results in the growing demands for heat dissipation. In other words, the heat dissipation capability directly affects the reliability and lifetime of the electronic product.
Fan is commonly used as a heat dissipating device. In practice, the working area of the fan, which is the area that can provide proper airflow pressure and airflow quantity of the fan, is used to remove heat rather than the maximum airflow quantity or the maximum airflow pressure. If a user wants to enhance the performance of the fan in the working area, he or she must increase the rotation speed of the fan. However, this may cause louder noise and need increased power consumption.
With reference to
Therefore, it is an important subject of the invention to provide a fan and an impeller thereof that can enhance the performance of the working area without increasing the rotation speed of the fan and can prevent the blades from contacting the electronic product or other elements.
In view of the foregoing, the invention is to provide a fan and an impeller thereof that can enhance the performance of the working area without increasing the rotation speed of the fan and can prevent the blades from contacting the electronic product or other elements in an electronic system.
To achieve the above, an impeller of the invention includes a hub and a plurality of blades. The blades are disposed around the hub. Each blade has a leading edge with a predetermined distance below the top of the hub and a trailing edge protruding from the bottom of the hub.
To achieve the above, the invention also discloses a fan, which includes a fan frame, an impeller and a motor. In the invention, the fan frame includes a housing, a base and at least one supporting element. The base is connected to the housing by the supporting element. The impeller, which is disposed in the housing, includes a hub and a plurality of blades disposed around the hub. Each blade has a leading edge with a predetermined distance below the top of the hub and a trailing edge protruding from the bottom of the hub. The motor is disposed on the base and coupled to the impeller for driving it.
As mentioned above, each blade of the impeller has a leading edge with a predetermined distance below the top of the hub, so that when the fan is operated, a space formed among the housing, the blades and the hub can make airflow steadier to be expelled out of the blades. In this case, the airflow pressure and the airflow quantity in the working area are larger than those of the conventional fan. That is, the performance of the working area of the fan can be enhanced without increasing the rotation speed of the fan. Accordingly, the louder noise and the increased power consumption can be avoided, and the better heat dissipating effect can be achieved. Besides, since displaced downwardly, the blades of the impeller, which is raised due to the axial and centrifugal force, may not contact the electronic product or other elements, so as to prevent the malfunctions of the fan, such as being stuck.
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
With reference to
Each of the blades 22 has a leading edge 221 and a trailing edge 222. In this embodiment, the leading edge 221 and the trailing edge 222 are in parallel. The leading edge 221 has a predetermined distance h below the top 211 of the hub 21, and the trailing edge 222 protrudes from the bottom 212 of the hub 21. Accordingly, all of the blades 22 are moved downwardly. In the embodiment, the hub 21 and the blades 22 may be made of a plastic material, an acrylic material, a metal, or an alloy.
With reference to
The fan frame 31 has a housing 311, a base 312 and at least one supporting element 313. The supporting element 313 is, for example, a rib or a stationary blade, and the base 312 is connected to the housing 311 by the supporting element 313. In this case, the housing 311, base 312 and supporting element 313 are integrally formed, and the bottom 3131 of the supporting element 313 and the bottom 3111 of the housing 311 are placed at the same plane. Of course, the bottom 3131 of the supporting element 313 and the bottom 3111 of the housing 311 may be placed at different planes. For instance, the bottom 3131 of the supporting element 313 may be shifted toward the interior of the housing 311 as shown in
The impeller 32 is disposed in the housing 311 and supported by the base 312. In addition, the impeller 32 includes a hub 321 and a plurality of blades 322 disposed around the hub 321. The hub 321 and the blades 322 are integrally formed. Herein, the materials of the hub 321 and the blades 322 are not limited, and they may be made of a plastic material, an acrylic material, a metal, or an alloy. The motor 33 is disposed on the base 312 and coupled to the impeller 32 for driving it to rotate.
Each of the blades 322 has a leading edge 3221 and a trailing edge 3222. In this embodiment, the leading edge 3221 and the trailing edge 3222 are in parallel. The leading edge 3221 has a predetermined distance h below the top 3211 of the hub 321. In the embodiment, the predetermined distance h is preferably between 15% and 22.5% of the height H of the hub 321. In addition, the predetermined distance h is also preferably between approximately 8% and 12% of the height H′ of the housing 311. The trailing edge 3222 protrudes from the bottom 3212 of the hub 321. The protruding height of the trailing edge 3222 is approximately equal to the predetermined distance h, so that the blades 322 are substantially moved downwardly. Due to the provided distance h, the housing 311, the blades 322 and the hub 321 can define a space. When the fan 3 is operated, the flowing air becomes a steady airflow in this space. Accordingly, the performance of the working area of the fan 3 can be enhanced; that is, the airflow pressure and the airflow quantity in the working area become larger than those of the conventional fan.
To be noted, the blades of the impeller are unnecessary to have the leading edge 221 and the trailing edge 222 in parallel (as shown in
In summary, each blade of the impeller has a leading edge with a predetermined distance below the top of the hub, so that a space can be formed among the housing, the blades and the hub. When the fan is operated, the flowing air becomes a steady airflow in this space and is then blown out of the blades. In this case, the airflow pressure and the airflow quantity in the operating area are larger. That is, the performance of the working area of the fan can be enhanced without increasing the rotation speed of the fan. Accordingly, the louder noise and the increased power consumption can be avoided, and the better heat dissipating effect can be achieved Besides, since displaced downwardly, the blades of the impeller, which is raised due to the axial and centrifugal force, may not contact electronic product or other elements to avoid the malfunctions of the fan, such as being stuck.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 094140584 | Nov 2005 | TW | national |
