U.S. patent application number 10/670680 was filed with the patent office on 2005-03-24 for shaftless cooling fans.
Invention is credited to Park, Hee-Keun.
Application Number | 20050063842 10/670680 |
Document ID | / |
Family ID | 34313862 |
Filed Date | 2005-03-24 |
United States Patent
Application |
20050063842 |
Kind Code |
A1 |
Park, Hee-Keun |
March 24, 2005 |
Shaftless cooling fans
Abstract
A shaftless cooling fan is comprised of a fan body pivotally
mounted on a fan base through a configured shaft. The fan base
further comprises a plurality of vents, an electrical device for
driving the fan body, a recess in its top and bottom ends for
positioning a shaft end respectively, and a plurality of
electromagnets surrounding the recess in the bottom end. The fan
body is rotatably positioned in the fan base by placing the shaft
ends in respective recesses, and there is also a plurality of
permanent magnets aligned surrounding the lower shaft end, in which
every permanent magnet is comprised of a magnetic N-zone, an
S-zone, and a Neutral zone, and repeatedly structured. Every
electromagnet is controlled by the electrical device to form
magnetic zones corresponding to the N-zone, S-zone, and Neutral
zone of each the permanent magnet, such that each permanent magnet
is driven to rotate the fan body by changing the magnetic zones in
each electromagnet.
Inventors: |
Park, Hee-Keun; (Taipei,
TW) |
Correspondence
Address: |
SUPREME PATENT SERVICES
POST OFFICE BOX 2339
SARATOGA
CA
95070
US
|
Family ID: |
34313862 |
Appl. No.: |
10/670680 |
Filed: |
September 24, 2003 |
Current U.S.
Class: |
417/423.1 |
Current CPC
Class: |
F04D 25/066
20130101 |
Class at
Publication: |
417/423.1 |
International
Class: |
F04B 035/04 |
Claims
What is claimed is:
1. A shaftless cooling fan, comprised of a fan body having a
configured shaft rotatably jointed to a fan base, said shaft being
extended radially to form a plurality of fan leaves, said fan base
being a square hollow casing having at least an opening penetrating
the casing itself in its top end and lateral wall, and an
electrical device for driving said fan body, in which: a recess for
positioning a shaft end is formed at respective corresponding
positions of the lower surface of a top end and the upper surface
of a bottom end in said fan base; the electrical device is extended
to the upper surface of the bottom end of the fan base to form a
plurality of electromagnets, which is aligned surrounding said
recess in the upper surface of the bottom end of said fan base;
said shaft having a plurality of permanent magnets in its bottom
face is tapered at both ends for mating with the recesses of said
fan base so that each shaft end can be rotatably fitted in each
recess; and a magnetic N-zone, an S-zone, and a Neutral zone are
arranged repeatedly and rotationally in every permanent magnet, and
the magnetic zones of each electromagnet are controlled
correspondingly to that of each said permanent magnet.
2. The shaftless cooling fan according to claim 1, in which each
shaft end is substantially point-contacted with each recess.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to cooling fans, more
specifically, it relates to a shaftless cooling fan, in which an
electromagnet is applied to interact with a permanent magnet in a
fan body so as to rotate the fan body without needing any
conductive contact or a shaft, thus to reduce the frictional
resistance of the cooling fan.
BACKGROUND OF THE INVENTION
[0002] As the higher the operating speed of a computer is raised,
the more the heat is generated in that computer, therefore, a
delicate design of heat dissipation of computer is considered a
very important factor to engineers.
[0003] For cooling the environment of computer in order to operate
normally, one or more cooling fans are usually arranged in a
computer for maintaining inside temperature under workable
conditions. The cooling fan is generally comprised of a fan body
pivotally jointed to a fan base through a shaft, where the shaft is
rotatably fixed in the fan base by means of bearings or some other
lubricating devices and electrically connected with an electrical
device for driving the fan body.
[0004] In the foregoing fan structure, since the electrical
connection for driving the fan body to rotate is made through the
shaft, therefore the conventional jointing manner of the shaft with
the fan base cannot be waived, and accordingly, nor can the
frictional resistance be thoroughly eliminated. Moreover, just as
the frictional resistance to a generic micro-mechanism, the heat
generated from the frictional resistance is of equal importance to
a notebook computer, which requires a high efficiency of heat
dissipation. And a final point to be emphasized is the assembling
accuracy of the conventional fan structure. An assembling of low
precision could result in an unsmooth rotation, vibration, or even
impairment to the fan structure.
SUMMARY OF THE INVENTION
[0005] The primary objective of this invention is to provide a
shaftless cooling fan for the purpose of improving the conventional
fan structure.
[0006] In order to realize abovesaid objective, the shaftless
cooling fan of this invention is comprised of a fan body pivotally
mounted on a fan base through a configured shaft. The fan base has
a plurality of vents, an electrical device for driving the fan
body, a recess in its top and bottom ends for positioning a shaft
end respectively, and a plurality of electromagnets surrounding the
recess in the bottom end. The fan body is rotatably positioned in
the fan base by placing the shaft ends in respective recesses, and
there is also a plurality of permanent magnets aligned surrounding
the lower shaft end. Every permanent magnet is comprised of a
magnetic N-zone, an S-zone, and a Neutral zone, and repeated to
form an annular structure. Every electromagnet is controlled by the
electrical device to form magnetic zones corresponding to the
N-zone, S-zone, and Neutral zone of each the permanent magnet. By
arrangement in this way, each permanent magnet is driven to rotate
the fan body by changing the magnetic zones in each
electromagnet.
[0007] The merits of the shaftless cooling fan of this invention
might be summarized as follows:
[0008] 1. Since the shaft ends are rotatably point-contacted with
the recesses without electrical connection, therefore the
frictional resistance of shaft can be significantly reduced;
[0009] 2. As the frictional resistance is reduced as described, the
driving power required and heat generated can be accordingly
lowered;
[0010] 3. The rotation speed of the cooling fan can be raised
accordingly because of the reduced frictional resistance;
[0011] 4. The rotatable jointing of the shaft to the recess,
requires no high-precise assembling so that cost saving is
possible; and
[0012] 5. The rotatable jointing of the shaft to the recess in the
manner of point-contact may simplify the assembling process.
[0013] For more detailed information regarding advantages or
features of this invention, at least an example of preferred
embodiment will be fully described below with reference to the
annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The related drawings in connection with the detailed
description of this invention to be made later are described
briefly as follows, in which:
[0015] FIG. 1 is a three dimensional view showing the structure of
a shaftless cooling fan of this invention;
[0016] FIG. 2 is a cutaway sectional view of the shaftless cooling
fan of this invention;
[0017] FIG. 3 shows a schematic distribution diagram of magnetic
poles of a permanent magnet and electromagnet in the shaftless
cooling fan of this invention;
[0018] FIG. 4A is a schematic distribution diagram of magnetic
poles showing the interactive force between the permanent magnet
and the electromagnet in the shaftless cooling fan of this
invention;
[0019] FIG. 4B is a schematic view showing thee force exerted upon
a magnetic N-zone of the permanent magnet in the shaftless cooling
fan of this invention;
[0020] FIG. 4C is a schematic view showing the force exerted upon a
magnetic S-zone of the permanent magnet in the shaftless cooling
fan of this invention;
[0021] FIG. 5A is a schematic view showing an initial state of the
shaftless cooling fan of this invention;
[0022] FIG. 5B is a schematic view showing another initial state of
the shaftless cooling fan of this invention; and
[0023] FIG. 5C is a schematic view showing yet another initial
state of the shaftless cooling fan of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A preferred embodiment of shaftless cooling fan of this
invention is mainly comprised of a fan body (1) installed on a fan
base (2) as shown in FIGS. 1 and 2.
[0025] The fan base (2) is substantially a square hollow casing
having at least an opening formed in its top end and side wall,
respectively. A recess (21) for positioning a shaft end is formed
at respective corresponding positions of the lower surface of a top
end and the upper surface of a bottom end in the fan base (2).
Also, an electrical device (not shown) for driving the fan body (1)
is arranged in the fan base (2) and extended to the upper surface
of the bottom end of the fan base (2) to form a plurality of
electromagnets (22), which is aligned surrounding the recess
(21).
[0026] The fan body (1) is composed of a configured shaft (11) and
a plurality of fan leaves (12) outwardly extended therefrom, in
which the top and the bottom end of the configured shaft (11) are
tapered into respective sharp ends (13) for being accommodated in
the recess (21) individually to have the configured shaft (11)
rotatably located in the fan base (2). In addition, a plurality of
permanent magnets (14) is disposed surrounding the sharp ends (13)
on the bottom face of the configured shaft
[0027] The contact face of the sharp end (13) of the configured
shaft (11) in contact with the respective recess (21) is deemed as
a point-contact.
[0028] FIG. 3 shows a schematic distribution diagram of magnetic
poles of a permanent magnet and electromagnet in the shaftless
cooling fan of this invention.
[0029] As shown in FIG. 3, the magnetic poles of the permanent
magnets (14) on the bottom face of the configured shaft (11) are
spaced equally and aligned annularly in a same circumferential
direction to form intermittently inserted magnetic N-zones (14a),
S-zones (14b), and Neutral zones (14c). Further, the electromagnets
(22) in the fan base (2) are controlled by an electrical device for
defining a plurality of annularly aligned magnetic zones (22a), in
which each magnetic zone (22a) is annularly and repeatedly
controlled to create a magnetic N-zone, an S-zone, and a Neutral
zone cyclically, and is controlled by a clock to produce a Neutral
zone, an S-zone, then an N-zone sequentially and rotationally. By
the foregoing arrangement and the commutation of each magnetic zone
(22a) of the electromagnets (22), every permanent magnet (14) on
the bottom end of the configured shaft (11) is either repulsed or
attracted to hence drive the configured shaft (11), and accordingly
the fan body (1), to rotate.
[0030] Referring to FIGS. 4A, 4B, and 4C and observing all the
permanent magnets (14) and electromagnets (22) in an imaginary
straight line, the periodicaly and cyclically appeared N-zones
(14a), S-zones (14b), and Neutral zones (14c) of the permanent
magnets (14) are assumedly zigzag aligned against that of the
electromagnets (22) in an initial state. Therefore, every N-zone
(14a) of the permanent magnet (14) is repulsed theoretically by the
corresponding N-zones (22a) of the electromagnets (22) such that a
resultant force is consequently formed to drive the shaft (11) to
rotate in a direction shown in FIG. 4B. Similarly, every S-zone
(14b) of the permanent magnet (14) is repulsed theoretically by the
corresponding S-zones (22a) of the electromagnets (22) such that a
resultant force is consequently formed to drive the shaft (11) to
rotate in a direction shown in FIG. 4C. Hence, the shaft (11) will
rotate in a direction depending upon the total resultant force that
exerts on the permanent magnets (14).
[0031] Then, after a short time is elapsed, the order of the
magnetic zones (22a) of each electromagnet (22) is changed
rotationally by way of: the original N-zone (22a) into a Neutral
zone (22a), the original S-zone (22a) into an N-zone (22a), and the
original Neutral zone (22a) into an S-zone (22a), so that the shaft
(21) will rotate in the same direction. Therefore, under a proper
means for controlling the magnetic zones of each electromagnet (22)
in the order of a Neutral zone, an S-zone, then an N-zone, the
shaft (11) could be kept in continuous rotation.
[0032] As indicated in FIGS. 5A, 5B, and 5C, an initializing
process is indispensable at the first place for starting a
shaftless cooling fan of this invention for controlling the
alignment of the magnetic zones (22a) of each electromagnet (22) in
the order of a Neutral zone, then an S-zone, and followed by an
N-zone, and holding that order for an optimum time period. As a
result, in the initial state, an attractive force and a repulsive
force from an S-zone (22a) of each electromagnet (22) are applied
on every N-zone (14a) and S-zone (14b) of each permanent magnet
(14), respectively, hence each N-zone (14a) of every permanent
magnet (14) will be positioned right above an S-zone (22a) of each
electromagnet (22). Then, the initializing process is going to
dispense an N-Zone and a Neutral zone to two immediate neighboring
magnetic zones (22a) of The S-zone (22a) in each electromagnet
(22), then change the magnetic zones sequentially in the order of a
Neutral zone, an S-zone, then an N-zone, so that the configured
shaft (11) is driven to rotate continuously in the state as
above-mentioned.
[0033] In the above described, at least one preferred embodiment
has been described in detail with reference to the drawings
annexed, and it is apparent that numerous changes or modifications
may be made without departing from the true spirit and scope
thereof, as set forth in the claims below.
* * * * *