U.S. patent application number 14/093380 was filed with the patent office on 2015-06-04 for blade structure of axial fan.
This patent application is currently assigned to Applied Thermal/Fluid Analysis Center Limited Liability Company. The applicant listed for this patent is Applied Thermal/Fluid Analysis Center Limited Liability Company. Invention is credited to Yih-Wei Tzeng.
Application Number | 20150152879 14/093380 |
Document ID | / |
Family ID | 53264962 |
Filed Date | 2015-06-04 |
United States Patent
Application |
20150152879 |
Kind Code |
A1 |
Tzeng; Yih-Wei |
June 4, 2015 |
BLADE STRUCTURE OF AXIAL FAN
Abstract
A blade structure of an axial fan is disclosed. The blade
structure includes a hub and a plural of fan blades. The fan blades
are disposed equidistantly on a periphery of the hub along a
rotating direction of the hub. Each fan blade includes a first
blade and a second blade. The first blade has a first leading edge
and a first trailing edge, and the second blade having a second
leading edge and a second trailing edge. A line connecting the
first leading edge and the first trailing edge of each fan blade is
a first chord line. The second leading edge is located at a line
extended along the first chord line, and the separation between the
first blade and the second blade is smaller than a distance of
adjacent fan blades on the periphery of the hub.
Inventors: |
Tzeng; Yih-Wei; (Taipei
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Thermal/Fluid Analysis Center Limited Liability
Company |
Taipei City |
|
TW |
|
|
Assignee: |
Applied Thermal/Fluid Analysis
Center Limited Liability Company
Taipei City
TW
|
Family ID: |
53264962 |
Appl. No.: |
14/093380 |
Filed: |
November 29, 2013 |
Current U.S.
Class: |
416/203 ;
416/223R |
Current CPC
Class: |
F04D 29/384 20130101;
F04D 19/002 20130101 |
International
Class: |
F04D 29/38 20060101
F04D029/38 |
Claims
1. A blade structure of an axial fan, comprising: a hub; and a
plural of fan blades disposed equidistantly on a periphery of the
hub along a rotating direction of the hub, and each fan blade
including a first blade and a second blade arranged at intervals,
the first blade having a first leading edge and a first trailing
edge, the second blade having a second leading edge and a second
trailing edge; wherein, a line connecting the first leading edge
and the first trailing edge of each fan blade is a first chord
line, the second leading edge is located at a line extended along
the first chord line, and a separation between the first blade and
the second blade is smaller than a distance of adjacent fan blades
on the periphery of the hub.
2. The structure according to claim 1, wherein the separation
between the first blade and the second blade is smaller than the
one third of the length of the first chord line.
3. The structure according to claim 1, wherein the second trailing
edge is located at a line extended along the first chord line.
4. The structure according to claim 1, wherein a surface area of
the first blade and a surface area of the second blade are
equal.
5. The structure according to claim 1, wherein a surface area of
the first blade and a surface area of the second blade are
unequal.
6. The structure according to claim 1, wherein a shape of the first
blade and a shape of the second blade are the same.
7. The structure according to claim 1, wherein a shape of the first
blade and a shape of the second blade are not the same.
8. The structure according to claim 1, wherein a cross sectional
area of the first blade and a cross sectional area the second blade
at the corresponding position are the same.
9. The structure according to claim 1, wherein a cross sectional
area of the first blade and a cross sectional area the second blade
at the corresponding position are not the same.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to an axial fan and,
in particular to a blade structure of an axial fan with high
working efficiency.
[0003] 2. Description of Related Art
[0004] Axial machine plays an important role in human industry.
Fans, blowers, bumps, and propellers, for example, are used of
axial blades for driving or transmitting fluid. Therefore, it is
very important to improve the performance of axial machines for
working efficiency and energy savings, and it's also a target for
the industry continues to pursue.
[0005] Take fans for an instance, an axial fan usually includes a
motor, a hub and a plural of blades. The hub is rotated by the
driving of the motor, and fluid is flown by the push of the blades.
To improve the characteristic of static pressure and air flow rate
(P-Q curve) of the axial fan for pushing the fluid, a best
performance is achieved through adjusting the size and angle of the
blades. However, a limited success is achieved up to now.
[0006] Thus, how to improve the working efficiency of blades
without increasing the product cost for getting a greater air
volume and a higher air pressure are important issues in the
industry.
[0007] In view of the above drawbacks, the Inventor proposes the
present invention based on his expert knowledge and elaborate
researches in order to solve the problems of prior art.
SUMMARY OF THE INVENTION
[0008] Accordingly, an object of the present invention is to
provide a blade structure of an axial fan to improve the
characteristic of the static pressure and air flow rate (P-Q curve)
of the axial fan for pushing the fluid. Thus a higher air pressure
and a greater air volume are achieved for improving the working
efficiency.
[0009] In order to achieve the object mentioned above, the present
invention provides a blade structure of an axial fan including a
hub and a plural of fan blades. The fan blades are disposed
equidistantly on a periphery of the hub along a rotating direction
of the hub. Each fan blade includes a first blade and a second
blade. The first blade has a first leading edge and a first
trailing edge, and the second blade having a second leading edge
and a second trailing edge. A line connecting the first leading
edge and the first trailing edge of each fan blade is a first chord
line. The second leading edge is located at a line extended along
the first chord line, and a separation between the first blade and
the second blade is smaller than a distance of adjacent fan blades
on the periphery of the hub.
[0010] Comparing to the prior art, each fan blade of the blade
structure of an axial fan of the present invention includes of a
plural of blades (at least one first blade and a second blade).
Moreover, because there is a separation between the blades, and the
second leading edge is located at a line extended along the line
between the first leading edge and the first trailing edge (the
first chord line). Therefore, the flow above the surface of the
first blade could be maintained and the momentum of the boundary
layer can be reinforced at the downstream. Therefore, a separation
phenomenon will be delayed or minimized, and the thickness of the
boundary layer of fluid will be reduced. Thus, the P-Q curve and
consumption efficiency of axial machines will be enhanced.
Moreover, the present invention also has characteristics of low
cost and easy implement. BRIEF DESCRIPTION OF DRAWING
[0011] The features of the invention believed to be novel are set
forth with particularity in the appended claims. The invention
itself, however, may be best understood by reference to the
following detailed description of the invention, which describes a
number of exemplary embodiments of the invention, taken in
conjunction with the accompanying drawings, in which:
[0012] FIG. 1 is a perspective schematic view of a blade structure
of an axial fan of the present invention;
[0013] FIG. 2 is a top view of a blade structure of an axial fan of
the present invention;
[0014] FIG. 3 is a side view of a blade structure of an axial fan
of the present invention;
[0015] FIG. 4 is a cross sectional view of a blade structure of an
axial fan of the present invention;
[0016] FIG. 5 is a flowing schematic view of a blade structure of
an axial fan of the present invention;
[0017] FIG. 6 is a P-Q curve of a blade structure of an axial fan
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] In cooperation with attached drawings, the technical
contents and detailed description of the invention are described
thereinafter according to a number of preferable embodiments, being
not used to limit its executing scope. Any equivalent variation and
modification made according to appended claims is all covered by
the claims claimed by the present invention.
[0019] Please refer to FIG. 1 and FIG. 2, they depict a perspective
schematic view and a top view of a blade structure of an axial fan
of the present invention. The present invention provides a blade
structure of an axial fan including a hub 10 and a plural of fan
blades 20. The fan blades 20 are combined on the hub 10. The hub 10
is driven to rotate with the fan blades 20 to push surrounding
fluid flowing.
[0020] The hub 19 is a cylinder including a top plate 11 and a side
plate 12 extended from a periphery of the top plate 11, and the
side plate 12 encloses one side of the top plate 11 for forming a
peripheral surface 101 of the hub 10. In practice, the top plate 11
and the side plate 12 could be, but not limited to, integrally
formed of the hub 10. The fan blades 20 are disposed equidistantly
on a periphery of the hub 10 along a rotating direction of the hub
10. Each fan blade 20 includes a first blade 21 and a second blade
22 arranged at intervals. The first blade 21 has a first leading
edge 211 and a first trailing edge 212, and the second blade 22 has
a second leading edge 221 and a second trailing edge 222.
[0021] In an embodiment of the present invention, each fan blade 20
includes two blades (a first blade 21 and a second blade 22),
however, the quantity of blades of the fan blade 20 is not limited.
For instance, each fan blade 20 can include three blades.
[0022] With further referring to FIG. 3 and FIG. 4, they depict a
side view and a cross sectional view of a blade structure of an
axial fan of the present invention. In each fan blade 20, a line
connecting the first leading edge 211 and the first trailing edge
212 is a first chord line 213. The second leading edge 221 is
located at a line extended along the first chord line 213.
Furthermore, the separation 210 between the first blade 21 and the
second blade 22 is shorter than a g distance 200 of adjacent fan
blades 20 on the periphery 101 of the hub 10.
[0023] In the present embodiment, the first blade 21 and the second
blade 22 of the present invention could be provided in any proper
shape of blades. A surface area of the first blade 21 and a surface
area of the second blade 22 could be equal or unequal. Besides, a
shape of the first blade 21 and a shape of the second blade 22
could the same or not the same. Moreover, a cross sectional area of
the first blade 21 and a cross sectional area the second blade 22
at the corresponding position could be the same or not the
same.
[0024] Preferably, the separation 210 between the first blade 21
and the second blade 22 is smaller than the one third of the length
of the first chord line 213, and the second trailing edge 222 is
located at a line 2130 extended along the first chord line 213, but
not limited to.
[0025] Please also refer to FIG. 5, it depicts a flowing schematic
view of a blade structure of an axial fan of the present invention.
When the fan blades 20 rotate, the fluid will be conducted into the
fan blade 20. Firstly, the fluid flows through the first blade 21,
and then flows to the second blade 22 along the surface of the
first blade 21. As the separation 210 is existed between the first
blade 21 and the second blade 22, and the second leading edge 221
of the second blade 22 is located at the line 2130 extended along
the first chord line 213. Thus the flow formed above the surface of
the first blade 21 will be maintained in the separation 210 and
being reconstructed. Therefore, a separation phenomenon will be
delayed or minimized, and the thickness of the boundary layer of
fluid will be reduced.
[0026] Flowing through the first blade 21, a vortex could be
eliminated by the disposing of the first blade 21 and the second
blade 22. In the present invention, the separation phenomenon
occurred between the fluid and the fan blades 20 could be avoided
or minimized when the fluid flow through the fan blades 20 by the
deposition of the corresponding location of the first blade 21 and
the second blade 22. Therefore, the flow above the surface of the
first blade 21 could be maintained and the momentum of the boundary
layer can be reinforced at the downstream, and the resistance
between the fluid and the fan blades 20 will be reduced to get a
maximum efficiency.
[0027] With referring to FIG. 6, it depicts a P-Q curve of a blade
structure of an axial fan of the present invention. As shown in
FIG. 6, a P-Q curve 30 of the fan blade structure of an axial fan
of the present invention is higher than a P-Q curve 40 of a
traditional axial fan. Thus, the blade structure of an axial fan of
the present invention greatly enhances the mechanical performance
of the axial machines in a condition without increasing energy
consumption.
[0028] It is worth of note that the fluid on the present invention
is included but not limited to fluid such as air, water or oil.
[0029] Although the present invention has been described with
reference to the preferred embodiment thereof, it will be
understood that the invention is not limited to the details
thereof. Various substitutions and improvements have been suggested
in the foregoing description, and others will occur to those of
ordinary skill in the art. Therefore, all such substitutions and
improvements are intended to be embraced within the scope of the
invention as defined in the appended claims.
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