Patent Grant
7165939
The present invention relates in general to a fan shaft structure, and more particular, to a fan shaft structure suitable for a ceramic fan shaft, which is provided for combining firmly the fan shaft with the fan blade and preventing the combination from separation caused by long-term utilization.
Referring to
However, this shaft structure, attaining engagement by means of the annular groove portion 100a and the knurl 102a, is suitable only for fan shaft made of metal material. It is pretty difficult to apply this art in manufacturing the ceramic fan shaft. Moreover, because the twill of the knurl 102a is shallow, the combination is not firm enough and therefore quite probable to separate. Consequently, the useful lifetime of the fan using this prior art is comparatively shorter.
The present invention provides a shaft structure which is not only able to firmly combine one end of the fan shaft with the fan blade but also suitable for a ceramic fan shaft manufacturing. It resolves the longstanding problems like difficulty to manufacture the ceramic fan shaft, inferior engagement between the fan shaft and the fan blade, and other drawbacks. It successfully extends the useful lifetime of the cooling fan.
The shaft structure provided by the present invention includes an annular groove portion, an end head adjacent to the groove portion, and several teeth equally cut from the surface of the shaft. The present invention enables the center part of the fan blade to enwrap the insert part of the fan shaft, and firmly engage with the fan shaft. It is, therefore, not only able to enhance the robustness of the combination but also successful in preserving the adhesion effect between the fan shaft and the fan blade.
These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of preferred embodiments.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
These as well as other features of the present invention will become more apparent upon reference to the drawings therein:
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Referring to
Because the end portion 10 of the fan shaft 1 is utilized together with the fan blade 2 for insert molding, it can be defined as an “insert part.” The insert part 10 includes an annular groove portion 100 cut around close to the top of the fan shaft 1, an end head 101 adjacent to the annular groove portion 100, and several teeth 102 equally cut from the surface of the fan shaft 1. Between each two teeth 102 is a gap 103 which links to the annular groove portion 100. The cutting of the annular groove portion 100 around the surface of the fan shaft 1 produces the end head 101 on the top of the fan shaft 1. The top surface of the end head 101 is the end surface of the fan shaft 1. The gaps 103 are cut from the end head 101. The contour of the end head 101 constitutes the teeth 102.
When utilizing this shaft structure to fabricate the fan rotor by insert molding, because the fan blade 2 is made of moldable plastic, the plastic resin is injected or squeezed into the annular groove portion 100 and the gaps 103, and solidifies therein. The fan blade 2 is, therefore, so firmly engaged with the teeth 102 that the destruction of their adhesion caused by rotational torque can be prevented. At the same time, the annular groove portion 100 is helpful to bear the axial opposite force that the fan shaft 1 imposes upon the fan blade 2 while the fan producing airflow. By means of both the axial and radial engagement, the present invention resolve the separation problems caused by long-term rotational motion or incidental impact of other external forces. The present invention provides a shaft structure which enables a ceramic fan shaft to firmly engage with the fan blade 2. The center part 20 of the fan blade 2 enwraps the insert part of the fan shaft 1. Because the teeth 102 provide better engagement and spaces that the plastic resin may flow into and stick thereon, the robustness of the combination is enhanced. The lifetime of the fan thus successfully extends.
Referring to
Referring to
Referring to
Consequently, the shaft structure in accordance with the present invention at least has the following merits. First, it is suitable for the fan shaft 1 made of ceramic material. Second, it strengthens the engagement effect between the fan shaft 1 and the fan blade 2, enhances the robustness of the combination, possesses the ability to bear the axial external force, and therefore extends the useful lifetime of the cooling fan.
While an illustrative and presently preferred embodiment of the invention has been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 92215688 U | Aug 2003 | TW | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5281099 | Hunter et al. | Jan 1994 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20050047920 A1 | Mar 2005 | US |
