U.S. patent application number 14/547167 was filed with the patent office on 2016-05-19 for centrifugal fan and method.
The applicant listed for this patent is Twin City Fan Companies, Ltd.. Invention is credited to Charles Barry.
Application Number | 20160138606 14/547167 |
Document ID | / |
Family ID | 55961289 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160138606 |
Kind Code |
A1 |
Barry; Charles |
May 19, 2016 |
CENTRIFUGAL FAN AND METHOD
Abstract
An impeller, fan assembly, and associated methods are shown.
Selected configurations are shown that include a circumferential
feature formed within a plate of an impeller and spaced apart from
edges of the plate.
Inventors: |
Barry; Charles; (Plymouth,
MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Twin City Fan Companies, Ltd. |
Plymouth |
MN |
US |
|
|
Family ID: |
55961289 |
Appl. No.: |
14/547167 |
Filed: |
November 19, 2014 |
Current U.S.
Class: |
416/170R ;
29/889.4; 416/186R |
Current CPC
Class: |
B21D 53/267 20130101;
B21D 22/14 20130101; F04D 29/023 20130101; F04D 29/281 20130101;
F05D 2230/54 20130101 |
International
Class: |
F04D 29/28 20060101
F04D029/28; F04D 25/06 20060101 F04D025/06; B21J 5/00 20060101
B21J005/00; F04D 29/053 20060101 F04D029/053; B21D 22/14 20060101
B21D022/14; F04D 17/08 20060101 F04D017/08; F04D 29/62 20060101
F04D029/62 |
Claims
1. A centrifugal fan impeller, comprising: a number of circular
plates, including a back plate, and a ring shaped front plate; a
number of blades coupled between the back plate and the front
plate; and a circumferential feature formed within at least one of
the plates and spaced apart from edges of the plate, the feature
extending outward in a direction normal to a plane of the
plate.
2. The centrifugal fan impeller of claim 1, wherein the
circumferential feature has a semi-circular cross section.
3. The centrifugal fan impeller of claim 1, wherein the
circumferential feature has an angled cross section.
4. The centrifugal fan impeller of claim 1, wherein the components
are formed from steel.
5. The centrifugal fan impeller of claim 1, wherein the components
are formed from aluminum.
6. The centrifugal fan impeller of claim 1, further including an
outer edge formed feature in one or more of the number of circular
plates.
7. The centrifugal fan impeller of claim 1, further including an
inner edge formed feature in one or more of the number of circular
plates.
8. The centrifugal fan impeller of claim 1, wherein the number of
blades includes airfoil blades.
9. The centrifugal fan impeller of claim 1, wherein the number of
blades includes single thickness blades.
10. A fan assembly, comprising: a motor; an impeller coupled to a
shaft of the motor, including: a number of circular plates,
including a back plate, and a ring shaped front plate; a number of
blades coupled between the back plate and the front plate; a
circumferential feature formed within at least one of the plates
and spaced apart from edges of the plate, the feature extending
outward in a direction normal to a plane of the plate; and a
support frame coupled to the motor.
11. The fan assembly of claim 10, wherein the shaft of the motor is
directly coupled to the impeller.
12. The fan assembly of claim 10, wherein the impeller is coupled
to the shaft of the motor using a drive belt.
13. The fan assembly of claim 10, wherein the fan assembly is
configured as a plenum fan.
14. A method, comprising: attaching a number of fan blades
extending substantially normal at periphery of a first circular
plate; forming a circumferential feature within a second circular
plate and spaced apart from edges of the plate, the feature
extending outward in a direction normal to a plane of the plate;
and attaching the second circular plate to the number of fan blades
in a location opposite and substantially parallel to the first
circular plate.
15. The method of claim 14, further including forming a
circumferential feature within the first circular plate and spaced
apart from edges of the plate, the feature extending outward in a
direction normal to a plane of the plate.
16. The method of claim 14, wherein forming a circumferential
feature includes forming a semi-circular cross sectioned
feature.
17. The method of claim 14, wherein forming a circumferential
feature includes forming multiple circumferential features in a
single plate, the multiple features spaced apart from edges of the
plate, the multiple features extending outward in a direction
normal to a plane of the plate.
18. The method of claim 14, wherein forming a circumferential
feature includes spin forming.
19. The method of claim 14, wherein forming a circumferential
feature includes pressing.
Description
TECHNICAL FIELD
[0001] Embodiments described herein generally relate to fan
assemblies. Specific examples may include plenum or plug fan
housings and fan assemblies and centrifugal fan assemblies.
BACKGROUND
[0002] Fan impellers are routinely subjected to large forces such
as centrifugal forces during operation. These forces may eventually
lead to unwanted cracking or fatigue failure in one or more
components of the impeller. Improved configuration and methods are
desired to improve strength and reliability of impellers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is an orthogonal view of a fan assembly in accordance
with some embodiments of the invention.
[0004] FIG. 2A is a cross section view of a fan impeller of the
prior art.
[0005] FIG. 2B is a cross section view of a fan impeller in
accordance with some embodiments of the invention.
[0006] FIG. 3 is a flow diagram of a method of making a fan
impeller in accordance with some embodiments of the invention.
DESCRIPTION OF EMBODIMENTS
[0007] The following description and the drawings sufficiently
illustrate specific embodiments to enable those skilled in the art
to practice them. Other embodiments may incorporate structural,
logical, electrical, process, and other changes. Portions and
features of some embodiments may be included in, or substituted
for, those of other embodiments. Embodiments set forth in the
claims encompass all available equivalents of those claims.
[0008] FIG. 1 shows a fan assembly 100 according to one example.
The fan assembly 100 includes a motor 110, a support fame 140
holding the motor in place, and an impeller 120. In FIG. 1, the
impeller 120 is coupled directly to a shaft of the motor 110,
although the invention is not so limited. In other examples, the
impeller 120 is coupled to a shaft of the motor 110 indirectly
through a belt drive, or other transmission such as a gear box,
etc. A front plate 130 is further shown in FIG. 1 as part of the
fan assembly 100, and a funnel 132 is used to direct air into the
impeller 120.
[0009] The impeller 120 shown in FIG. 1 is configured as a
centrifugal impeller, having a back plate 122, a front plate 124,
and a number of blades 126 coupled between the front plate 124 and
the back plate 122. Blades 126 may include single thickness metal
flat blades, curved blades, airfoil shaped blades, or other
suitable blade shapes.
[0010] The fan assembly 100 shown may be used in a number of
different configurations, including but not limited to a turbine or
plenum fan. The impeller 120 as described in more detail below may
be used in any number of different fan configurations. The fan
assembly 100 shown in FIG. 1 is merely one example for
illustration.
[0011] FIG. 2A shows a centrifugal impeller 200 according to the
prior art. The centrifugal impeller 200 is shown as half a cross
section, with a center of the impeller 200 at location 201. The
centrifugal impeller 200 is shown with a back plate 222, a front
plate 224, and one representative blade 226 of a number of blades.
Centrifugal impellers are often subjected to high cyclic stresses
that can cause cracking and eventual failure in one or more of the
plates. In the configuration of impeller 200, a reinforcing ring
228 is welded onto the front plate 224. An amount of weld material
230 is shown at the interface between the front plate 224 and the
reinforcing ring 228.
[0012] A welding operation to attach the reinforcing ring 228 may
be expensive, and the heat of welding may weaken the plate material
and/or introduce unwanted stress concentration features, such as
notches or other imperfections from the weld material 230.
Additionally, it may be difficult to center the reinforcing ring
228 on the front plate 224, which may lead to an unwanted imbalance
in the impeller 200.
[0013] FIG. 2B shows a centrifugal impeller 120 according to an
example of the present invention. Similar to FIG. 2A, the
centrifugal impeller 120 is shown as half a cross section, with a
center of the impeller 120 at location 121. The centrifugal
impeller 120 is shown with a back plate 122, a front plate 124, and
one representative blade 126 of a number of blades. A
circumferential feature 128 is shown formed within the front plate
124, and spaced apart from an outside edge 152 and an inside edge
154. The circumferential feature 128 extends outward in a direction
normal to a plane of the front plate 124. The circumferential
feature 128 shown in FIG. 2B extends outward to the left of the
front plate 124, however in other examples, the circumferential
feature 128 may extend outward to the right, toward the back plate
122.
[0014] The process of forming the circumferential feature 128
provides a number of advantages, both for manufacturability, and
physical property advantages. For manufacturability, the process or
forming the circumferential feature 128 is less time consuming than
welding an additional reinforcing ring 228 onto the front plate, as
shown in FIG. 2A. With regard to physical properties, when the
circumferential feature 128 is formed, the metal becomes work
hardened in and around the circumferential feature 128, providing
increased strength. The work hardening comes from microstructural
difference in the material that are caused by the forming
process.
[0015] In one example, the location of the circumferential feature
128, in between and spaced apart from the outside edge 152 and the
inside edge 154, provides a strengthening property to the front
plate 124 at a location apart from the edges 152 and 154 that may
be prone to failure. The addition of the circumferential feature
128 may reduce or eliminate a likelihood of failure.
[0016] Although the circumferential feature 128 is shown formed
between and spaced apart from the outside edge 152 and the inside
edge 154, the invention is not so limited. In one example, a
circumferential feature is formed on the back plate 122, between
and spaced apart from an outside edge 125 and the center 121. In
one example a circumferential feature as described is formed in
both a front plate 124 and a back plate 122. Although a single
circumferential feature is shown within the front plate, in other
examples multiple circumferential features may be formed for
additional strengthening between and spaced apart from the outside
edge 152 and the inside edge 154. Multiple circumferential features
may also be formed within the back plate 122 in selected
examples.
[0017] In addition to the formed circumferential feature 128, in
selected examples an outer edge feature and/or an inner edge
feature may be formed at the outside edge 152 and/or the inside
edge 154. Such additional features may further enhance
strengthening of the plates, such as the front plate 124 and the
back plate 122, without the need for welding additional components
onto the plates.
[0018] In the example shown, the circumferential feature 128 shows
a semi-circular cross section. Other geometries for a cross section
of the circumferential feature 128 are also possible, including,
but not limited to angled or V shaped cross sections, box cross
sections, or other suitable cross sections.
[0019] One suitable material for all or a portion of the impeller
120 includes aluminum or an aluminum alloy. Another suitable
material for all or a portion of the impeller 120 includes steel.
Other formable metallic materials are also within the scope of the
invention.
[0020] FIG. 3 shows a flow diagram of one method of forming a fan
assembly according to an embodiment of the invention. In operation
302, a number of fan blades are attached, extending substantially
normal at a periphery of a first circular plate. In operation 304,
a circumferential feature is formed within a second circular plate
and spaced apart from edges of the plate, the feature extending
outward in a direction normal to a plane of the plate. In one
example, attaching the fan blades includes welding the fan
blades.
[0021] As discussed above, the process of forming the
circumferential feature provides a number of advantages, including
simplifying manufacture, and providing increased strength. In one
example, forming the circumferential feature includes pressing, the
circumferential feature into a side of a plate using a die and a
press, such as a hydraulic press. In this operation, the entire
circumferential feature may be formed in one stroke of the press,
which may speed up manufacture.
[0022] In one example, the circumferential feature may be spin
formed into the plate. Spin forming provides an advantage of
ensuring that the circumferential feature is centered about an axis
of rotation of the plate, and/or the impeller as assembled. In one
example, spin forming includes pressing the plate over a mandrel or
die as the mandrel or die is being rotated.
[0023] In operation 306, the second circular plate is attached to
the number of fan blades in a location opposite and substantially
parallel to the first circular plate. In one example, attaching the
second circular plate includes welding the second circular plate to
the fan blades.
[0024] To better illustrate the method and apparatuses disclosed
herein, a non-limiting list of examples is provided here:
[0025] Example 1 includes a centrifugal fan impeller. The impeller
includes a number of circular plates, including a back plate, and a
ring shaped front plate, a number of blades coupled between the
back plate and the front plate, and a circumferential feature
formed within at least one of the plates and spaced apart from
edges of the plate, the feature extending outward in a direction
normal to a plane of the plate.
[0026] Example 2 includes the centrifugal fan impeller of example
1, wherein the circumferential feature has a semi-circular cross
section.
[0027] Example 3 includes the centrifugal fan impeller of any one
of examples 1-2, wherein the circumferential feature has an angled
cross section.
[0028] Example 4 includes the centrifugal fan impeller of any one
of examples 1-3, wherein the components are formed from steel.
[0029] Example 5 includes the centrifugal fan impeller of any one
of examples 1-4, wherein the components are formed from
aluminum.
[0030] Example 6 includes the centrifugal fan impeller of any one
of examples 1-5, further including an outer edge formed feature in
one or more of the number of circular plates.
[0031] Example 7 includes the centrifugal fan impeller of any one
of examples 1-6, further including an inner edge formed feature in
one or more of the number of circular plates.
[0032] Example 8 includes the centrifugal fan impeller of any one
of examples 1-7, wherein the number of blades includes airfoil
blades.
[0033] Example 9 includes the centrifugal fan impeller of any one
of examples 1-8, wherein the number of blades includes single
thickness blades.
[0034] Example 10 includes a fan assembly, including a motor and an
impeller coupled to a shaft of the motor. The impeller includes a
number of circular plates, including a back plate, and a ring
shaped front plate, a number of blades coupled between the back
plate and the front plate, a circumferential feature formed within
at least one of the plates and spaced apart from edges of the
plate, the feature extending outward in a direction normal to a
plane of the plate, and a support frame coupled to the motor.
[0035] Example 11 includes the fan assembly of example 10, wherein
the shaft of the motor is directly coupled to the impeller.
[0036] Example 12 includes the fan assembly of any one of examples
10-11, wherein the impeller is coupled to the shaft of the motor
using a drive belt.
[0037] Example 13 includes the fan assembly of any one of examples
10-12, wherein the fan assembly is configured as a plenum fan.
[0038] Example 14 is a method including attaching a number of fan
blades extending substantially normal at periphery of a first
circular plate, forming a circumferential feature within a second
circular plate and spaced apart from edges of the plate, the
feature extending outward in a direction normal to a plane of the
plate, and attaching the second circular plate to the number of fan
blades in a location opposite and substantially parallel to the
first circular plate.
[0039] Example 15 includes the method of example 14, further
including forming a circumferential feature within the first
circular plate and spaced apart from edges of the plate, the
feature extending outward in a direction normal to a plane of the
plate.
[0040] Example 16 includes the method of any one of examples 14-15,
wherein forming a circumferential feature includes forming a
semi-circular cross sectioned feature.
[0041] Example 17 includes the method of any one of examples 14-16,
wherein forming a circumferential feature includes forming multiple
circumferential features in a single plate, the multiple features
spaced apart from edges of the plate, the multiple features
extending outward in a direction normal to a plane of the
plate.
[0042] Example 18 includes the method of any one of examples 14-17,
wherein forming a circumferential feature includes spin
forming.
[0043] Example 19 includes the method of any one of examples 14-18,
wherein forming a circumferential feature includes pressing.
[0044] The above detailed description includes references to the
accompanying drawings, which form a part of the detailed
description. The drawings show, by way of illustration, specific
embodiments in which the invention can be practiced. These
embodiments are also referred to herein as "examples." Such
examples can include elements in addition to those shown or
described. However, the present inventors also contemplate examples
in which only those elements shown or described are provided.
Moreover, the present inventors also contemplate examples using any
combination or permutation of those elements shown or described (or
one or more aspects thereof), either with respect to a particular
example (or one or more aspects thereof), or with respect to other
examples (or one or more aspects thereof) shown or described
herein.
[0045] In this document, the terms "a" or "an" are used, as is
common in patent documents, to include one or more than one,
independent of any other instances or usages of "at least one" or
"one or more." In this document, the term "or" is used to refer to
a nonexclusive or, such that "A or B" includes "A but not B," "B
but not A," and "A and B," unless otherwise indicated. In this
document, the terms "including" and "in which" are used as the
plain-English equivalents of the respective terms "comprising" and
"wherein." Also, in the following claims, the terms "including" and
"comprising" are open-ended, that is, a system, device, article,
composition, formulation, or process that includes elements in
addition to those listed after such a term in a claim are still
deemed to fall within the scope of that claim. Moreover, in the
following claims, the terms "first," "second," and "third," etc.
are used merely as labels, and are not intended to impose numerical
requirements on their objects.
[0046] The above description is intended to be illustrative, and
not restrictive. For example, the above-described examples (or one
or more aspects thereof) may be used in combination with each
other. Other embodiments can be used, such as by one of ordinary
skill in the art upon reviewing the above description. The Abstract
is provided to comply with 37 C.F.R. .sctn.1.72(b), to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. Also, in the
above Detailed Description, various features may be grouped
together to streamline the disclosure. This should not be
interpreted as intending that an unclaimed disclosed feature is
essential to any claim. Rather, inventive subject matter may lie in
less than all features of a particular disclosed embodiment. Thus,
the following claims are hereby incorporated into the Detailed
Description, with each claim standing on its own as a separate
embodiment, and it is contemplated that such embodiments can be
combined with each other in various combinations or permutations.
The scope of the invention should be determined with reference to
the appended claims, along with the full scope of equivalents to
which such claims are entitled.
* * * * *