This non-provisional application claims priority under 35 U.S.C. ยง 119(a) on Patent Application No(s). 097217359 filed in Taiwan, R.O.C. on Sep. 25, 2008, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a positioning structure, and more particularly to a fan positioning structure.
2. Related Art
With the progress of technologies and the rapid development of electronic industry, the operating speed of an electronic device such as a computer, a personal digital assistant (PDA), or a global positioning system (GPS) is greatly increased. However, due to the increasingly high operating speed, the electronic device generates more heat during operation. If the heat cannot be effectively released, once the maximum load of the electronic device is exceeded, the electronic device fails.
In order to solve the heat-dissipation problem of the electronic device, a heat-dissipation fan is commonly disposed on heat-generating elements (for example, chips, a central processing unit (CPU), or integrated circuits (ICs)) of the electronic device, such that the heat-dissipation fan operates to generate an air flow to enable the heat-generating elements to maintain their operational efficiencies within a certain temperature range. Meanwhile, considering the manufacturing cost of the heat-dissipation fan, currently, a heat-dissipation fan with a self-lubricating bearing is usually used.
In such a heat-dissipation fan with a self-lubricating bearing, the rotation of a fan rotor is supported by a rotating shaft pivoted in a sleeve bearing, and after the fan is assembled, a C-shaped snap ring is snapped at one end of the rotating shaft from a bottom portion of the bearing sleeve, so as to prevent the fan blades from detaching from the bearing during rotation due to the centrifugal force. Meanwhile, in order to prevent the fan blades from abrading the axle seat of the fan blades and the C-shaped snap ring at the end of the rotating shaft during operation, a gap needs to be maintained with respect to the upper and lower ends of the bearing. However, due to the gap, the rotating shaft cannot rest on a fixed support. After the fan operates for a long period of time, the friction force between the rotating shaft and the C-shaped snap ring may become too large, so that the C-shaped snap ring is easily worn out or even loosened due to elastic fatigue, and the rotating shaft cannot be fixed. As a result, the fan blades easily moves up and down, sways, and generates noises during rotation, thus reducing the service life of the heat-dissipation fan.
In addition, such a heat-dissipation fan may be applied in a portable electronic device such as a PDA. Since the portable electronic device is mainly characterized by a light weight, thin structure, and portability, the using status of the portable electronic device is frequently changed according to different operating environments. For example, the portable electronic device may be changed from a horizontal operation direction to a vertical operation direction, or horizontally inverted during operation. At this time, if the C-shaped snap ring is loosened, the fan blades may move up and down. In this case, not only large noises are generated, but also the electronic device even vibrates with the movement of the fan, thereby causing troubles for a user in operating the electronic device. What's worse, the consumers are likely to consider this problem as a product defect, which damages the reputation of the manufacturer.
Moreover, a frame of a conventional heat-dissipation fan includes a frame body, a motor seat, and a plurality of ribs. The frame body has a plurality of bumps. Two ends of each rib are connected to the motor seat and one of the bumps respectively. In order to prevent the bumps from blocking an air flow field generated when the fan operates, the bumps are often designed to have an area only slightly larger than that of the ribs, resulting in poor connection strength thereof. Meanwhile, each bump also has a tip. When the fan operates, the air flow passing through the bumps is affected by the tips, such that the air flow field may be separated and a turbulence phenomenon occurs. Due to the turbulence phenomenon, not only the air flow is influenced and the wind shear effect occurs, but also noises are generated by the air flow, and the heat-dissipation performance is deteriorated.
In view of the above problems, the present invention is a fan positioning structure, which is applicable to solve the problems that a C-shaped snap ring sleeved on a rotating shaft for stabilizing a rotation of the rotating shaft is deformed during the operation of a fan and meanwhile the rotating shaft moves up and down within a bearing and drives the fan to move within a frame of the fan, thereby preventing the rotating shaft or the bearing from being excessively abraded and further preventing the generation of noises.
The present invention provides a fan positioning structure, which comprises a base, a cover, and a fan. The base comprises a stopping portion. The cover is fitted to the base, and comprises a stopper corresponding to the stopping portion of the base. The fan is rotatably disposed between the base and the cover, and comprises a rotating shaft penetrating the fan. One end of the rotating shaft presses against the stopping portion of the base, and the other end of the rotating shaft bears against the stopper of the cover, such that the fan is confined to rotating between the base and the cover.
In addition, the present invention further provides a fan positioning structure, which comprises a base, a cover, and a fan. The base comprises a stopping portion. The cover is fitted to the base, and comprises a stopper corresponding to the stopping portion of the base. The fan is rotatably disposed between the base and the cover, and comprises an urging portion and a rotating shaft. The urging portion and the rotating shaft are disposed on two opposite sides of the fan. The urging portion bears against the stopper of the cover, and one end of the rotating shaft contrary to the fan presses against the stopping portion of the base, such that the fan is confined to rotating between the base and the cover.
In the fan positioning structure of the present invention, the rotating shaft or the urging portion disposed at the fan presses against the stopper disposed on the cover, such that the fan is confined between the base and the cover. Therefore, the fan cannot move in an axial direction of the rotating shaft between the base and the cover during operation, thereby avoiding the abrading phenomenon between the rotating shaft and the bearing, and effectively solving the noise generation problem caused by the movement of the fan between the base and the cover.
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus is not limitative of the present invention, and wherein:
The fan positioning structure of the present invention is applicable to heat-dissipation structures of electronic devices such as a display card chipset, a memory module, a mobile phone, a PDA, and a hard-disk digital video camera. The above illustration is merely taken as examples, and the present invention is not limited thereto.
Meanwhile, if the fan positioning structure according to the first embodiment of the present invention is inverted, for example, horizontally inverted, as shown in
Moreover, referring to
Therefore, the fan positioning structure of the present invention is applicable to both fans for generating a vertical air flow and fans for generating a horizontal air flow.
In the fan positioning structure of the present invention, by disposing the rotating shaft of the fan or by combining the rotating shaft with the urging portion, two ends of the fan respectively press against the stopping portion of the base and bear against the stopper of the cover, such that the fan is confined to rotating between the base and the cover. Thus, the reciprocating movement of the fan in the axial direction of the rotating shaft between the base and the cover can be avoided without disposing any C-shaped snap ring, and the abrasion between the rotating shaft and the bearing is reduced, so as to enable the rotating shaft to stably rotate within the bearing, thereby solving the noise generation problem when the fan rotates.
Meanwhile, the wave-shaped connecting rib disposed on the cover generates a fluent pneumatics effect, thereby effectively reducing the turbulence phenomenon, wind shear effect, and noises.
Number | Date | Country | Kind |
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097217359 | Sep 2008 | TW | national |