U.S. patent application number 10/868876 was filed with the patent office on 2005-12-22 for axial-flow type fan having an air inlet blade structure tipped with leading corners.
This patent application is currently assigned to Sunonwealth Electric Machine Industry Co., Ltd.. Invention is credited to Hong, Yin-Rong, Horng, Alex.
Application Number | 20050281692 10/868876 |
Document ID | / |
Family ID | 35480762 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050281692 |
Kind Code |
A1 |
Horng, Alex ; et
al. |
December 22, 2005 |
Axial-flow type fan having an air inlet blade structure tipped with
leading corners
Abstract
An axial-flow type fan includes a fan housing consisting of an
air-boosting inlet, an air outlet and an air channel, and a fan
wheel consisting of a hub and fan blades arranged about a rotary
axis of the hub. Each of the fan blades has a tipped leading corner
to constitute an air inlet blade structure which forms a topmost
portion in a longitudinal direction and a forefront portion in a
rotational direction. The tipped leading corners are situated in
the air-boosting inlet of the fan housing while the air channel
accommodates the fan wheel. When the fan wheel is rotated, the
tipped leading corners of the fan blades are able to eliminate air
turbulence and air noise in the air-boosting inlet of the fan
housing.
Inventors: |
Horng, Alex; (Kaohsiung,
TW) ; Hong, Yin-Rong; (Kaohsiung, TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Assignee: |
Sunonwealth Electric Machine
Industry Co., Ltd.
Kaohsiung
TW
|
Family ID: |
35480762 |
Appl. No.: |
10/868876 |
Filed: |
June 17, 2004 |
Current U.S.
Class: |
417/423.7 ;
417/423.3 |
Current CPC
Class: |
F04D 29/384 20130101;
F05D 2240/303 20130101 |
Class at
Publication: |
417/423.7 ;
417/423.3 |
International
Class: |
F04B 017/00; F04B
035/04 |
Claims
What is claimed is:
1. An axial-flow type fan, comprising: a fan housing including an
air inlet side and an air outlet side at its either side; an
air-boosting inlet provided on the air inlet side of the fan
housing; an air channel connecting between the air-boosting inlet
and the air outlet side; a fan wheel accommodating in the channel
and including a hub; a plurality of fan blades arranged about a
rotary axis of the fan wheel and tilted on the hub, and each of the
fan blades having an inlet bottom point connecting to the hub of
the fan wheel; and a plurality of tipped leading corners, each
provided on the fan blade to form a topmost portion in a
longitudinal direction of the fan housing and a forefront portion
in a rotational direction of the fan wheel, the tipped leading
corner situated in the air-boosting inlet and including a curved
leading edge connecting between an inlet leading corner point of
the tipped leading corner and the inlet bottom point; wherein when
the fan wheel is rotated, the tipped leading corners of the blades
are able to eliminate air turbulence and air noise in the
air-boosting inlet of the fan housing.
2. The axial-flow type fan as defined in claim 1, wherein the
air-boosting inlet forms with an annular tapered surface along the
longitudinal direction of the fan housing.
3. The axial-flow type fan as defined in claim 1, wherein each of
the fan blades further includes an outlet bottom point so that the
fan blade tilts between the inlet bottom point and the outlet
bottom point of an outer circumference of the hub.
4. The axial-flow type fan as defined in claim 3, wherein the each
of the fan blades further includes a ridge protruded on a leeward
surface of the fan blade connecting between an inlet leading corner
point of the tipped leading corner and the outlet bottom point,
thereby the ridge stabilizing airflow.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an axial-flow type fan
having an air inlet blade structure tipped with leading corners.
More particularly, the present invention relates to an axial-flow
type fan having an air inlet blade structure tipped with leading
corners situated in an air-boosting inlet of a fan housing, thereby
reducing air-shearing noise in operation.
[0003] 2. Description of the Related Art
[0004] Referring initially to FIG. 1, it illustrates a conventional
fan housing structure having an air outlet connecting with an air
inlet. The construction of the conventional fan structure is
disclosed in U.S. Pat. Nos. 4,734,015, 4,743,173, Re34,456,
4,806,081, 4,992,029, 5,028,216, 5,135,363 and 5,267,842 etc. The
fan structure consists of a fan housing 10 and a fan wheel
(so-called impeller) 20 accommodating therein. The construction of
the fan housing 10 is shaped square including an air inlet side
(so-called upstream side) 11 and an air outlet side (so-called
downstream side) 11' disposed at its either side. The air inlet
forms an air-boosting inlet 12 while the air outlet (not labeled)
forming an air-expanding outlet. An air channel 13 connects between
the air-boosting inlet 12 and the air-expanding outlet. The fan
wheel 20 is accommodated in the air channel 13, and consists of a
hub 21 and a plurality of fan blades 22 arranged about a rotary
axis of the hub 21. The construction of the hub 21 is a
barrel-shaped object having an outer circumference on which
equi-spaced and titled the fan blades 22 each of which forms a flat
vane. In operation, when the fan wheel 20 is rotated, the fan
blades 22 drives air to suck into the fan, housing 10 through the
air-boosting inlet 12 that increases the pressure of air inlet.
Subsequently, airflow may pass through the air channel 13 and
exhaust from the air-expanding outlet that steadies an exhausting
airflow.
[0005] However, there exist several drawbacks of the axial-flow
type fan in use. Each flat vane of the fan blade 22 forms an inlet
corner portion 221 as well as a flat portion at its endmost corner.
The inlet corner portion 221 of the fan blade 22 is situated in the
longitudinal section of the air-boosting inlet 12 and almost
perpendicular to a surface of the air-boosting outlet 12. When the
fan blades 22 drive a mass of the inlet air entering through the
air-boosting inlet 12, the mass of the inlet air may impact the
annular surface of the air-boosting inlet 12 that guides the inlet
air for entering into the fan housing 10. In the radial section of
the air-boosting inlet 12, the flat vane portion of the inlet
corner portion 221 extends a straight leading edge 220 proximate
the air inlet side. Also, when the fan blades 22 is rotated, the
straight leading edge 220 aggravates the air turbulence generated
on the annular surface of the air-boosting inlet 12 and causes
air-shearing noise. Hence, there is a need for an inlet corner
portion of the fan blade for improving air-shearing noise.
[0006] The present invention intends to provide an axial-flow type
fan having an air inlet blade structure tipped with leading corners
situated in an air-boosting inlet of a fan housing. When the fan is
rotated, the leading corners are able to increase air pressure and
to reduce air-shearing noise in the air-boosting inlet of the fan
housing in such a way to mitigate and overcome the above
problem.
SUMMARY OF THE INVENTION
[0007] The primary objective of this invention is to provide an
axial-flow type fan having an air inlet blade structure tipped with
leading corners, each of which forming a topmost blade portion in a
longitudinal direction, which is situated in an air-boosting inlet
of a fan housing, thereby the leading corners reducing air
noise.
[0008] The secondary objective of this invention is to provide the
axial-flow type fan having the air inlet blade structure tipped
with leading corners, each of which forming a forefront portion in
a rotational direction, which is situated in an air-boosting inlet
of a fan housing, thereby the leading corners reducing air
noise.
[0009] The third objective of this invention is to provide the
axial-flow type fan having the air inlet blade structure tipped
with leading corners radially approaching an annular surface of the
air-boosting inlet and situated in an air-boosting inlet of a fan
housing, thereby the leading corners reducing air noise.
[0010] The fourth objective of this invention is to provide the
axial-flow type fan having the air inlet blade structure tipped
with leading corners, each of which including a ridge on a leeward
side connecting between an inlet leading corner point and an outlet
trailing bottom point to thereby guide airflow.
[0011] The axial-flow type fan in accordance with the present
invention includes a fan housing consisting of an air-boosting
inlet, an air outlet and an air channel, and a fan wheel consisting
of a hub and fan blades arranged about a rotary axis of the hub.
Each of the fan blades has a tipped leading corner to constitute an
air inlet blade structure which forms a topmost portion in a
longitudinal direction and a forefront portion in a rotational
direction. The tipped leading corners are situated in the
air-boosting inlet of the fan housing while the air channel
accommodates the fan wheel. When the fan wheel is rotated, the
tipped leading corners of the fan blades are able to eliminate air
turbulence and air noise in the air-boosting inlet of the fan
housing.
[0012] Other objectives, advantages and novel features of the
invention will become more apparent from the following detailed
description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described in detail with
reference to the accompanying drawings wherein:
[0014] FIG. 1 is a cutaway cross-sectional view of a conventional
fan housing structure in accordance with the prior art;
[0015] FIG. 2 is an exploded perspective view of an axial-flow type
fan having an air inlet blade structure tipped with leading corners
in accordance with a preferred embodiment of the present
invention;
[0016] FIG. 3 is a top plan view of the axial-flow type fan having
the air inlet blade structure tipped with leading corners in
accordance with the preferred embodiment of the present
invention;
[0017] FIG. 4 is a cross-sectional view, taken along line 4-4 in
FIG. 3, of the axial-flow type fan having the air inlet blade
structure tipped with leading corners in accordance with the
preferred embodiment of the present invention; and
[0018] FIG. 5 is a cross-sectional view, similar to that shown in
FIG. 4, of an axial-flow type fan having the air outlet blade
structure tipped with leading corners in accordance with the
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIGS. 2 through 4, reference numerals of the
preferred embodiment of the present invention have applied the
identical numerals of the conventional fan structure, as shown in
FIG. 1. The construction of the fan structure in accordance with
the preferred embodiment of the present invention has similar
configuration and same function as that of the conventional fan
structure and detailed descriptions may be omitted.
[0020] Referring to FIGS. 2 through 4, an axial-flow type fan in
accordance with a preferred embodiment of the present invention
includes a fan housing 10 and a fan wheel 20.
[0021] Referring again to FIGS. 2 through 4, the construction of
the fan housing 10 shall be described in detail. The fan housing 10
is made of plastic or metal material, and formed with a square or
circular hollow body. The fan housing 10 includes an air inlet side
11 and an air outlet side 11' at its either side, as best shown in
FIGS. 2 and 4. Further, the fan housing 10 consists of an
air-boosting inlet 12, an air channel 13, a base 14, a plurality of
supporting ribs 15 and an air-expanding outlet 16. The air inlet
side 111 of the fan housing 10 provides with the air-boosting inlet
12 which is formed with an annular tapered surface for increasing
air inflow and air pressure. The air-boosting inlet 12 further
communicates with the air channel 13. Meanwhile, the air outlet
side 11' of the fan housing 10 provides with the air-expanding
outlet 16 which is formed with an annular expanded surface for
increasing air outflow. The base 14 is disposed in the
air-expanding outlet 16 to support a motor stator 30 which is
combined with the fan wheel 20 as well as a motor rotor (not
labeled), as best shown in FIG. 2. The supporting ribs 15 are
arranged about a rotary axis of the fan housing 10, and thus
connect between the base 14 and the fan housing 10.
[0022] Turning now to FIGS. 2 through 5, the construction of the
fan wheel 20 shall be described in detail. The fan wheel 20 is made
of plastic or metal material, and consists of a hub 21 and a
plurality of fan blades 22 arranged about a rotary axis of the hub
21. The construction of the hub 21 is a barrel-shaped object having
an outer circumference on which equi-spaced and titled the fan
blades 22 each of which forms a curve vane. The curve vane of each
fan blade 22 has a tipped leading corner 221', an inlet bottom
point 222, a ridge 223 and an outlet bottom point 224.
Particularly, each of the fan blades 22 has a tipped leading corner
221' to constitute an air inlet blade structure which forms a
topmost portion in a longitudinal direction. Namely, the tipped
leading corner 221' of the fan blade 22 is closely aligned with a
horizontal plane of the air inlet side 11, as best shown in FIG. 4.
And the tipped leading corner 221' of the fan blade 22 also forms a
forefront portion in a rotational direction and is radially
approaching an annular surface of the air-boosting inlet 12 of the
fan housing 10, as best shown in FIG. 3. Furthermore, a curved
leading edge 220' of the fan blade 22 extends along a curve line
connecting between the tipped leading corner 221' and the inlet
bottom point 222. Regarding the curved leading edge 220', the
tipped leading corner 221' forms a forefront point, as best shown
in FIG. 3. Between the an inlet bottom point 222 and the outlet
bottom point 224, each of the fan blade 22 tilts on the outer
circumference of the hub 21, as best shown in FIG. 2. Additionally,
the ridge 223 protrudes on a leeward surface of the fan blade 22
connecting between an inlet leading corner point of the tipped
leading corner 221' and the outlet bottom point 224, as best shown
in FIG. 5.
[0023] Referring again to FIGS. 4 and 5, when the fan housing 10
and the fan wheel 20 are assembled, there are several assembled
relationships between the fan housing 10 and the fan wheel 20.
First, an inlet leading corner point C of the tipped leading corner
221' is situated between a starting point A and a terminal point B
of the air-boosting inlet 12 in a longitudinal direction, thereby
precisely reducing air turbulence on the surface of the
air-boosting inlet 12. Second, the leading point C of the tipped
leading corner 221' and the position D of the inlet bottom point
222 are situated on a common plane, thereby the tipped leading
corner 221' effectively reducing air turbulence within the
air-boosting inlet 12. Alternatively, the leading point C of the
tipped leading corner 221' is slightly higher than the position D
of the inlet bottom point 222 in the longitudinal direction,
thereby the tipped leading corner 221' effectively reducing air
turbulence within the air-boosting inlet 12. By use such an
assembled relationship, when the fan blades 22 drive a mass of the
inlet air entering into the air-boosting inlet 12, the air-boosting
inlet 12 compresses the inlet air for increasing air pressure in
the air channel 13 of the fan housing 10. Subsequently, the
forefront portion of the tipped leading corner 221' radially
approaching the air-boosting inlet 12 can avoid generating air
noise and air turbulence. Meanwhile, the curved leading edge 220'
of the fan blade 22 with the tipped leading corner 221' can
eliminate a transverse airflow in the air-boosting inlet 12 when
rotated. Also, the ridge 223 of the fan blade 22 can guide airflow
in the air-boosting inlet 12, thereby the smooth airflow exhausting
from the air-expanding outlet 16. Consequently, the tipped leading
corner 221' of the fan blade 22 carries out a preferred
air-shearing effect that can reduce air noise in the air-boosting
inlet 12 of the present invention.
[0024] Referring back to FIG. 1, the conventional axial-flow type
fan includes the air-boosting inlet 12, and the fan blades 22
having the air inlet corner portions 221' which may cause air
turbulence on an inner circumference of the air-boosting inlet 12
of the fan housing 10 that generates air noise. Furthermore, the
conventional axial-flow type fan includes the straight leading edge
220 of the each fan blade 22 which may aggravates the air
turbulence generated on the annular surface of the air-boosting
inlet 12. However, as best shown in FIG. 4, the present invention
employs each of the fan blades 22 having the tipped leading corner
221' proximate the annular surface of the air-boosting inlet 12
that may reduce generating air turbulence and air noise. In
addition to the tipped leading corner 221', each of the fan blades
22 further includes curved leading edge 220' extending along a
curve line in the rotational direction, and corresponding to the
air-boosting inlet 12 that may eliminate a transverse airflow in
the air-boosting inlet 12 when rotated.
[0025] Although the invention has been described in detail with
reference to its presently preferred embodiment, it will be
understood by one of ordinary skill in the art that various
modifications can be made without departing from the spirit and the
scope of the invention, as set forth in the appended claims.
* * * * *