Title:
Propeller structure of a fan
Kind Code:
A1


Abstract:
A propeller structure of a fan, including a base section and multiple vanes. The base section has a base section surface and each vane has a vane surface for contacting with airflow. The propeller has multiple recesses distributed over the base section surface of the base section and the vane surfaces of the vanes. The recesses are formed on the base section surface and the vane surfaces for reducing the flow resistance between the airflow and the base section surface and the vane surfaces of propeller and the noise produced when the propeller rotates.



Inventors:
Chen, Cheng-kang (Chung-Ho City, TW)
Application Number:
10/916511
Publication Date:
02/16/2006
Filing Date:
08/12/2004
Primary Class:
International Classes:
B63H1/28
View Patent Images:
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Primary Examiner:
VERDIER, CHRISTOPHER M
Attorney, Agent or Firm:
ROSENBERG, KLEIN & LEE (ELLICOTT CITY, MD, US)
Claims:
What is claimed is:

1. A propeller structure of a fan, comprising a base section and multiple vanes, the base section having a base section surface and each vane having a vane surface for contacting with airflow, said propeller structure being characterized in that the propeller has multiple recesses distributed over the vane surfaces of the vanes, the recesses being formed on the vane surfaces for reducing the flow resistance between the airflow and the vane surfaces of the propeller and the noise produced when the propeller rotates.

2. The propeller structure as claimed in claim 1, wherein the recesses formed on the vane surfaces are concave faces.

3. A propeller structure of a fan, comprising a base section and multiple vanes, the base section having a base section surface and each vane having a vane surface for contacting with airflow, said propeller structure being characterized in that the propeller has multiple recesses distributed over the base section surface of the base section and the vane surfaces of the vanes, the recesses being formed on the base section surface and the vane surfaces for reducing the flow resistance between the airflow and the base section surface and the vane surfaces of propeller and the noise produced when the propeller rotates.

4. The propeller structure as claimed in claim 3, wherein the recesses formed on the base section surface and the vane surfaces are concave faces.

Description:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to an improved propeller structure of a fan, and more particularly a propeller structure in which multiple recesses are formed on the base section surface and the vane surfaces for reducing the flow resistance between the airflow and the base section surface and the vane surfaces produced when the propeller rotates. In addition, the noise produced when the propeller rotates can be also reduced.

2. Description of the Prior Art

Referring to FIGS. 7 and 8, the propeller 20 of a conventional fan includes a base section 21 and several vanes 22. The base section 21 has a base section surface 23 and each vane 22 has a vane surface 24. The base section surface 23 and the vane surfaces 24 are all polished for reducing the flow resistance against the propeller 20. However, when the propeller 20 rotates, a parallel flow layer 25 is produced between the base section surface 23 and the vane surfaces 24 and the ambient airflow. The parallel flow layer 25 cannot attach to the base section surface 23 and the vane surfaces 24 so that a frictional resistance exists between the base section surface 23 and the vane surfaces 24 and the airflow. In addition, due to the frictional resistance between the base section surface 23 and the vane surfaces 24 and the airflow, a noise will be produced.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide an improved propeller structure of a fan. Multiple recesses are formed on the base section surface and the vane surfaces of the propeller. When the propeller rotates, a turbulence layer will be produced. The turbulence layer is easier to attach to the base section surface and the vane surfaces to form a thin air film for spacing the airflow from the base section surface and the vane surfaces so as to reduce the frictional effect between the airflow and the base section surface and the vane surfaces. Therefore, the flow resistance between the airflow and the base section surface and the vane surfaces produced when the propeller rotates can be reduced.

It is a further object of the present invention to provide the above propeller structure of the fan. By means of the recesses formed on the base section surface and the vane surfaces of the propeller, the flow resistance between the propeller and the airflow can be reduced so that the noise produced when the propeller rotates can be reduced.

According to the above objects, the propeller structure of the fan of the present invention includes a base section and multiple vanes. The base section has a base section surface and each vane has a vane surface for contacting with airflow. The propeller has multiple recesses distributed over the vane surfaces of the vanes. The recesses are formed on the vane surfaces for reducing the flow resistance between the airflow and the vane surfaces of the propeller and the noise produced when the propeller rotates.

In the above propeller structure, the recesses formed on the vane surfaces are concave faces.

Still according to the above objects, the propeller structure of the fan of the present invention includes a base section and multiple vanes. The base section has a base section surface and each vane has a vane surface for contacting with airflow. The propeller has multiple recesses distributed over the base section surface of the base section and the vane surfaces of the vanes. The recesses are formed on the base section surface and the vane surfaces for reducing the flow resistance between the airflow and the base section surface and the vane surfaces of propeller and the noise produced when the propeller rotates.

In the above propeller structure, the recesses formed on the base section surface and the vane surfaces are concave faces.

The present invention can be best understood through the following description and accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a side view of the present invention;

FIG. 4 is a perspective view of the present invention mounted in a fan;

FIG. 5 shows the airflow produced when the present invention is rotated;

FIG. 6 is a perspective view of another embodiment of the present invention;

FIG. 7 is a perspective view of a conventional fan; and

FIG. 8 shows the airflow produced when the conventional fan is rotated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 to 6. The propeller structure 10 of the fan of the present invention includes a base section 11 and multiple vanes 12. The base section 11 has a base section surface 13 and each vane 11 has a vane surface 14 for contacting with the airflow.

The present invention is characterized in that the propeller 10 has multiple recesses 15 distributed over the vane surfaces 14 of the vanes 12 and the base section surface 13 of the base section 11. (The vane surfaces 14 include two main upwind faces.) The recesses 15 are formed on the base section surface 13 and the vane surfaces 14 for reducing the flow resistance between the airflow and the base section surface 13 and the vane surfaces 14 produced when the propeller 10 rotates. Also, the recesses 15 serve to reduce the noise produced when the propeller 10 rotates.

In a preferred embodiment, the recesses 15 formed on the base section surface 13 and the vane surfaces 14 are concave faces.

When the propeller 10 rotates, due to the recesses 15 formed on the base section surface 13 and the vane surfaces 14, a turbulence layer 16 will be produced, which is not easy to separate from the base section surface 13 and the vane surfaces 14. That is, the turbulence layer 16 is easier to attach to the base section surface 13 and the vane surfaces 14 to form a thin air film for spacing the airflow from the base section surface 13 and the vane surfaces 14 so as to reduce the frictional effect between the airflow and the base section surface 13 and the vane surfaces 14. Therefore, the flow resistance between the airflow and the base section surface 13 and the vane surfaces 14 produced when the propeller 10 rotates can be reduced. In addition, the noise produced when the propeller 10 rotates can be reduced.

According to the above arrangement, the propeller structure of the fan of the present invention has the following advantages:

1. When the propeller rotates, due to the recesses formed on the base section surface and the vane surfaces, a turbulence layer will be produced. The turbulence layer is easier to attach to the base section surface and the vane surfaces to form a thin air film for spacing the airflow from the base section surface and the vane surfaces so as to reduce the frictional effect between the airflow and the base section surface and the vane surfaces. Therefore, the flow resistance between the airflow and the base section surface and the vane surfaces produced when the propeller rotates can be reduced.

2. By means of the recesses formed on the base section surface and the vane surfaces of the propeller of the present invention, the flow resistance between the propeller and the airflow can be reduced so that the noise produced when the propeller rotates can be reduced.

The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.