U.S. patent application number 11/005541 was filed with the patent office on 2005-09-08 for furnace distribution blower without a blower housing.
Invention is credited to Paulsen, Frederick D., Platz, John A., Post, Steven W..
Application Number | 20050194003 11/005541 |
Document ID | / |
Family ID | 34916130 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050194003 |
Kind Code |
A1 |
Paulsen, Frederick D. ; et
al. |
September 8, 2005 |
Furnace distribution blower without a blower housing
Abstract
A furnace distribution blower for use in a conventional furnace
that is configured without a blower housing. The furnace
distribution blower includes a backward curved impeller mounted
around a drive motor having a central drive shaft. The drive motor
rotates the backward curved impeller to draw air into the inlet of
the impeller. Preferably, the inlet of the impeller is closely
mounted to an inlet bell of the furnace. The furnace distribution
blower can be mounted to a support tray such that the furnace
distribution blower can be moved from an operating position in
which the impeller is positioned beneath the heat exchanger and a
service position in which the impeller is removed from within the
furnace housing. The elimination of the blower housing decreases
the cost of the furnace distribution blower as compared to a blower
having a housing.
Inventors: |
Paulsen, Frederick D.;
(Holiday Island, AR) ; Post, Steven W.;
(Cassville, MO) ; Platz, John A.; (Springfield,
MO) |
Correspondence
Address: |
Joseph D. Kuborn
ANDRUS, SCEALES, STARKE & SAWALL, LLP
Suite 1100
100 East Wisconsin Avenue
Milwaukee
WI
53202-4178
US
|
Family ID: |
34916130 |
Appl. No.: |
11/005541 |
Filed: |
December 6, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60528124 |
Dec 9, 2003 |
|
|
|
60545183 |
Feb 17, 2004 |
|
|
|
Current U.S.
Class: |
126/110R |
Current CPC
Class: |
F04D 29/422 20130101;
F04D 29/4226 20130101 |
Class at
Publication: |
126/110.00R |
International
Class: |
F24H 003/02 |
Claims
What is claimed is:
1. A furnace distribution blower comprising: a drive motor having a
drive shaft; and an impeller having an inlet surrounding the drive
motor, the drive motor being operable to rotate the impeller around
the drive motor to draw a flow of air into the inlet of the
impeller such that the impeller radially discharges the inlet air,
wherein the impeller is not surrounded by a housing.
2. The furnace distribution blower of claim 1 wherein the drive
motor is mounted above an inlet opening of a furnace by a plurality
of mounting arms.
3. The furnace distribution blower of claim 2 wherein the inlet of
the impeller is closely spaced from an inlet bell of the furnace
that defines the inlet opening of the furnace.
4. The furnace distribution blower of claim 1 wherein the impeller
is a backward curved impeller having a plurality of backward curved
impeller blades.
5. The furnace distribution blower of claim 4 wherein the inner
blade tips of each impeller blade are spaced from the drive motor
such that the impeller is rotatable about the drive motor.
6. The furnace distribution blower of claim 1 wherein the impeller
is mounted to a sidewall of the furnace.
7. The furnace distribution blower of claim 1 wherein the impeller
is mounted to a support wall spaced from the bottom wall of the
furnace.
8. A furnace distribution blower for use in a furnace having a
furnace enclosure including a pair of spaced sidewalls and a bottom
wall, the distribution blower comprising: a drive motor having a
drive shaft; an impeller having an inlet surrounding the drive
motor, the drive motor being operable to rotate the impeller around
the drive motor to draw a flow of air into the inlet of the
impeller such that the impeller radially discharges the inlet air,
wherein the impeller is not surrounded by a housing; and a
scroll-shaped outer wall surrounding the impeller, wherein the
scroll-shaped outer wall has an open upper end and directs the flow
of air from the impeller into the furnace enclosure
9. The furnace distribution blower of claim 8 further comprising a
support wall spaced above the bottom wall of the furnace enclosure,
the support wall including an inlet bell aligned with the inlet of
the impeller.
10. A furnace distribution blower for use in a furnace having a
heat exchanger and a support frame, the blower comprising: a drive
motor having a drive shaft; an impeller having an inlet surrounding
the drive motor, the drive motor being operable to rotate the
impeller around the drive motor to draw a flow of air into the
inlet of the impeller such that the impeller radially discharges
the inlet air; and a support tray positioned below the heat
exchanger of the furnace and surrounding the impeller, the support
tray including an inlet bell and a scroll-shaped outer wall to
direct the flow of air from the impeller toward the heat
exchanger.
11. The furnace distribution blower of claim 10 wherein the drive
motor is mounted above the inlet bell formed in the support tray by
a plurality of mounting arms.
12. The furnace distribution blower of claim 11 wherein the inlet
of the impeller is closely spaced from the inlet bell of the
support tray.
13. The furnace distribution blower of claim 10 wherein the
impeller is a backward curved impeller having a plurality of
backward curved impeller blades.
14. The furnace distribution blower of claim 13 wherein the inner
blade tips of each impeller blade are spaced from the drive motor
such that the impeller is rotatable about the drive motor.
15. The furnace distribution blower of claim 10 wherein the support
tray is movable along the support frame of the furnace.
16. The furnace distribution blower of claim 15 wherein the support
tray is movable between an operating position in which the impeller
is positioned beneath the heat exchanger and a service position in
which the impeller is removed from beneath the heat exchanger.
17. The furnace distribution blower of claim 15 wherein the support
tray is formed from stamped metal.
18. The furnace distribution blower of claim 10 wherein the support
tray includes an angled bottom wall, wherein the drive motor and
impeller are mounted to the angled bottom wall such that the
impeller is positioned at an angle relative to horizontal when the
impeller is positioned beneath the heat exchanger.
19. The furnace distribution blower of claim 10 wherein the support
tray includes a pair of spaced side edges that are slidably movable
along the support frame of the furnace such that the support tray
can be moved from an operating position in which the impeller is
positioned beneath the heat exchanger and a service position in
which the impeller is removed from the beneath the heat
exchanger.
20. The furnace distribution blower of claim 10 wherein the support
tray includes a scroll-shaped side wall that directs the flow of
air from the impeller upward toward an outlet of the support tray.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is based on and claims priority to
U.S. Provisional Patent Application Ser. No. 60/528,124, filed on
Dec. 9, 2003 and U.S. Provisional Patent Application Ser. No.
60/545,183, filed on Feb. 17, 2004.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to a furnace, and
particularly to a furnace distribution blower used within the
furnace. More specifically, the present invention relates to a
unique configuration and mounting for a furnace distribution blower
that does not include a blower housing surrounding a rotating
impeller that creates a flow of air over the furnace heat
exchanger.
[0003] Typically, a household furnace includes a furnace
distribution blower that draws a supply of fresh air into the
furnace housing and directs the flow of fresh air over a heat
exchanger. The heated air, after passing over the heat exchanger,
is directed to the environment to be heated.
[0004] In typical prior art furnaces, the furnace distribution
blower includes a blower housing that surrounds a forward curved
impeller wheel. The blower housing includes an inlet opening that
receives the flow of fresh air. The rotating forward curved
impeller directs the fresh air radially outward against a scroll
shaped housing, which ultimately directs the flow of air out of an
outlet formed in the housing and over the heat exchanger of the
furnace. In this type of system, the impeller for the furnace
distribution blower is positioned in the center of the housing such
that the flow of fresh air is directed by the housing.
[0005] One disadvantage of the prior art furnace distribution
blower is the cost and materials required for the housing.
Typically, the housing is formed from either a metallic or plastic
material that must be separately formed and assembled.
[0006] Therefore, it is an object of the present invention to
provide a furnace distribution blower that does not include a
housing yet provides the required airflow characteristics for
proper operation of the furnace.
SUMMARY OF THE INVENTION
[0007] The present invention utilizes a backward curved impeller
mounted on a vertical motor shaft of a drive motor. The backward
curved impeller surrounds the drive motor including the vertical
motor shaft. The drive motor preferably includes a plurality of
brackets that mount the motor to a bell-shaped inlet plate of the
furnace housing to draw air into the impeller from the bottom
portion of the furnace. The bell-shaped portion of the inlet plate
is generally the same size as the inlet of the impeller and is
designed to be close vertically to the inlet of the impeller so
that pressurized air in the furnace will not escape back through
the inlet bell.
[0008] The impeller of distribution blower draws air through the
cool air inlet of the furnace, over the drive motor and moves the
cool air across the heat exchanger. The inlet air flow, now warmed
by the heat exchanger, is exhausted from the top of the
furnace.
[0009] In one embodiment of the invention, the inlet of the
backward curved impeller is mounted slightly above the bottom wall
of the furnace housing such that cool air can be received from the
bottom of the furnace. Alternatively, the impeller can be rotated
90.degree. and mounted to one of the sidewalls of the furnace
housing such that inlet air is received from next to the furnace
housing. In yet another alternate embodiment of the invention, the
impeller can be suspended above the bottom wall of the furnace
housing such that the flow of cool air can be received from both
the bottom and the sides of the furnace housing.
[0010] In yet another alternate embodiment of the invention, the
rotating backward curved impeller can be spaced from the bottom
wall of the furnace housing and surrounded by a scroll-shaped outer
wall. The scroll-shaped outer wall increases the efficiency of the
rotating backward curved impeller by directing the air flow upward
toward the heat exchanger without the use of a housing. The outer
wall allows the inlet air to be drawn from both the side and the
bottom wall of the furnace housing.
[0011] In yet another alternate embodiment of the invention, the
rotating backward curved impeller is spaced above the bottom wall
of the furnace within a scroll-shaped support tray. The support
tray is formed from stamped metal and is supported beneath the heat
exchanger and is movable relative to the furnace housing. The
support tray includes a scroll-shaped outer wall. The scroll-shaped
outer wall directs the flow of air upward from the impeller toward
the heat exchanger of the furnace and increases the efficiency of
the rotating backward curved impeller without the use of a
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The drawings illustrate the best mode presently contemplated
of carrying out the invention.
[0013] In the drawings:
[0014] FIG. 1 is a schematic illustration of a traditional furnace
employing a furnace distribution blower constructed in accordance
with the present invention;
[0015] FIG. 2 is a magnified view of the furnace distribution
blower of the present invention;
[0016] FIG. 3 is a schematic drawing of an alternate placement of
the furnace distribution blower within a traditional furnace;
[0017] FIG. 4 is a schematic drawing of another alternate placement
of the furnace distribution blower in a traditional furnace;
[0018] FIG. 5 is a schematic drawing of yet another alternate
placement of the furnace distribution blower within a traditional
furnace;
[0019] FIG. 6 is a top perspective view of a traditional furnace
incorporating the furnace distribution blower of the present
invention;
[0020] FIG. 7 is a view similar to FIG. 6 illustrating the movement
of the furnace distribution blower and support tray into a service
position;
[0021] FIG. 8 is a view similar to FIG. 7 illustrating the support
tray in the service position;
[0022] FIG. 9 is a partial sectional view taken through the furnace
distribution blower and support tray;
[0023] FIG. 10 is a top perspective view of the furnace
distribution blower and support tray of the first embodiment of the
invention;
[0024] FIG. 11 is a section view taken along line 11-11 of FIG.
10;
[0025] FIG. 12 is a top perspective view of the furnace
distribution blower and a second embodiment of the support
tray;
[0026] FIG. 13 is a section view taken along line 13-13 of FIG.
12;
[0027] FIG. 14 is a top perspective view of yet another alternate
embodiment of the furnace distribution blower and support tray;
[0028] FIG. 15 is a section view taken along line 15-15 of FIG.
14;
[0029] FIG. 16 is a top perspective view of yet another alternate
embodiment of the furnace distribution blower and support tray;
and
[0030] FIG. 17 is a section view taken along line 17-17 of FIG.
16.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] FIG. 1 illustrates a conventional furnace 10 utilized to
warm a supply of air and distribute the warmed air through a
residence. The furnace 10 generally includes an outer housing wall
12 that surrounds a distribution blower 14, a heat exchanger 16,
combustion chamber 18 and draft inducer 20. As is well known, a
supply of fuel is provided to the combustion chamber 18 which
creates a heated supply of air. The heated supply of air circulates
through the heat exchanger 16, as illustrated by arrows 22. The
flow of heated air from the combustion chamber is drawn through the
tortuous path of the heat exchanger 16 by the draft inducer,
including a blower housing 24 and a drive motor 26. The outlet 28
of the draft inducer 20 is connected to an exhaust pipe 30 such
that the combustion gases can be expelled from the furnace 12.
[0032] The furnace distribution blower 14 creates a flow of air 31
that passes over the heat exchanger 16 and flows to the environment
to be heated, as illustrated by arrow 32.
[0033] In prior art furnace configurations, the furnace
distribution blower is typically a blower having a blower housing
with an inlet and an outlet and a drive motor for rotating a
forward curved (FWC) inlet wheel. The forward curved inlet wheel
draws fresh air from outside of the furnace housing 12 and directs
the flow of air over the heat exchanger 16. Typically, the
distribution blower includes an external housing that is formed
from either a molded plastic material or metal and encloses the
rotating forward curved wheel to create the desired flow of air
through the furnace.
[0034] Referring now to FIG. 1, thereshown is an improved furnace
distribution blower 14 that is constructed without a blower housing
in accordance with the present invention. As illustrated, the
furnace distribution blower includes an impeller 34 having a
plurality of impeller blades 36 extending between an inwardly
recessed back plate 38 and a curved front wall 40. As illustrated,
the impeller is a backward curved (BWC) or a radial (RAD) wheel
made from either metal or molded plastic. The impeller 34 includes
a central hub 42 that receives one end 43 of a drive shaft 44 of a
central drive motor 46. As illustrated in FIG. 1, the drive motor
46 and the impeller 34 are concentric such that the impeller 34
rotates around the centrally mounted drive motor 46. As illustrated
in FIG. 1, the inner blade tips 48 of the impeller 34 pass around
the drive motor 46 such that the drive motor 46 can rotate the
impeller.
[0035] The impeller 34 includes an inlet 50 having a diameter
defined by a top lip 52. The top lip 52 of the impeller 34 is
spaced slightly inward from an inlet bell 54 formed as a portion of
the bottom wall 56 of the furnace housing 12. As illustrated, the
close spacing between the top lip 52 of the impeller 34 and the
inlet bell 54 prevents pressurized air within the furnace interior
58 from escaping back through the inlet.
[0036] As illustrated in FIGS. 1 and 2, the impeller 54 has its
inlet 50 mounted facing downward with the motor 46 mounted
vertically inside the impeller inlet 50. The motor 46 can have a
wire-type bellyband mount with three or four radial mounting arms
60 resiliently mounted by connectors 62 to the bottom wall 56. The
bottom wall 56 includes the inlet bell 54 that provides tight
spacing between the bottom wall of the furnace and the inlet end of
the impeller 34. This tight spacing is necessary so that the
discharge side can be pressurized by the rotating impeller 34, thus
forcing air over the furnace heat exchanger 16, and through the
duct system.
[0037] Referring now to FIG. 2, thereshown is a more detailed view
of the distribution blower, including the impeller 34, of the
present invention. As illustrated, the impeller 34 includes
multiple impeller blades 36 that each terminate at a radial blade
tip 64. During rotation of the backward curved impeller 34, the
impeller 34 develops most of its pressure on its blades and thus
can operate efficiently without an external housing. As shown in
FIG. 2, the inlet 50 has a diameter slightly less than the
outermost diameter 66 defined by the impeller blades 64.
[0038] Referring back to FIG. 1, it can be understood that the flow
of cool air, illustrated by arrows 68, is drawn through the inlet
50 and passes over the motor 46. Thus, the rotating impeller 34 not
only provides the required airflow over the heat exchanger 16, but
also supplies a flow of cooling air over the motor 46. The
configuration of the rotating impeller 34 eliminates the need for
an external housing, which dramatically decreases the cost of
creating the furnace distribution blower 14 as compared to the
prior art.
[0039] In the embodiment of the invention illustrated in FIG. 1,
the motor 46 is a conventional and commercially available motor
that is far less costly than a specialized "inside-out" motor
utilized in a conventional motorized wheel application. This design
enables maintenance to occur later in the furnace's life with just
the motor being replaced instead of the entire blower and blower
housing. The embodiment shown in FIG. 1 will reduce the overall
price of the furnace distribution blower 14 as compared to a
traditional forward curved (FWC) unit mounted in an expensive
blower housing.
[0040] Referring now to FIG. 3, thereshown is an alternate
embodiment of the present invention in which the furnace
distribution blower 14 of the present invention is mounted at an
alternate location along the furnace housing 12. Specifically, the
furnace distribution blower 14, including the backward curved
impeller 34, is mounted to a sidewall 70 of the furnace housing 12.
The sidewall 70 includes the inlet bell 72 that is closely spaced
to the inlet 50 of the impeller 34. Like the embodiment illustrated
in FIG. 1, rotation of the impeller 34 creates a radial flow of air
that passes over the heat exchanger 16 of the furnace 10. In the
embodiment illustrated in FIG. 3, the bottom wall 56 of the furnace
housing 12 does not include an inlet opening. The embodiment
illustrated in FIG. 3 is particularly desirable where space
restrictions prevent the inlet opening being formed in the bottom
wall of the furnace housing.
[0041] Referring now to FIG. 4, thereshown is yet another
embodiment of the furnace and furnace distribution blower 14 of the
present invention. As illustrated, the furnace distribution blower
14, including the impeller 34, is suspended above the bottom wall
56 by an intermediate wall 74. The intermediate wall 74 includes
the inlet bell 54 that is closely spaced from the inlet 50 for the
impeller. The use of the intermediate wall 74 allows inlet air to
flow into the furnace from either or both the bottom wall 56 and
the sidewall 70. This type of mounting arrangement increases the
flexibility of the furnace.
[0042] Referring now to FIG. 5, thereshown is yet another alternate
embodiment of the furnace and furnace distribution blower of the
present invention. As illustrated in FIG. 5, the furnace
distribution blower 14, including the impeller 34, is mounted to a
support wall 76 suspended above the bottom wall 56 of the furnace
housing. The support wall 76, in turn, is joined to upstanding
sidewalls 78. The sidewalls 78 are preferably a continuous element
that is scroll-shaped and has an open top 80. Thus, as the impeller
34 rotates, the flow of air 82 is directed radially against the
sidewalls 78 and out of the open top 80 and into contact with the
heat exchanger 16. The curved sidewall 78 has the advantages of
increasing the efficiency of the backward curved impeller 34, while
creating room around the sides and bottom to allow air to be drawn
into the furnace from both the bottom wall 56 and the sidewall 70.
Further, the open top 80 allows for the rails that furnace
companies typically desire to use to slide in the blower. Further,
the open top of the internal housing can be made from a single
piece of sheet metal stamped on a large press.
[0043] The open topped scroll created by the sidewall 78 can also
be created to increase the airflow upward toward the heat exchanger
16 of the furnace. As illustrated in FIG. 5, the bottom support
wall 76 includes an inlet bell 84 to provide tight spacing between
the inlet 50 of the impeller 34 to maintain the pressure within the
open interior 58.
[0044] Referring now to FIGS. 6 and 7, thereshown is a preferred
embodiment of the present invention in which the furnace
distribution blower is mounted within a support tray 86. As shown,
the support tray 86 is movable between an operating position (FIG.
6) and a service position (FIG. 7) in a manner to be described
below. The support tray 86 includes a scroll-shaped outer wall 88
that is joined to a bottom wall 90. As shown in FIG. 8, the bottom
wall 90 receives each of the mounting arms 60 such that the
impeller and motor are mounted above an inlet opening 92 formed in
the bottom wall 90. The inlet opening 92 is generally defined by
the inlet bell 94, as best shown in FIG. 9.
[0045] As illustrated in FIGS. 6 and 8, the support tray 86 is
mounted within an open, lower region 95 defined by a series of
spaced support posts 96 that form part of the furnace frame. Inlet
air can be drawn into the opening 92 from the area surrounding the
support tray 86, as is clearly illustrated.
[0046] Referring back to FIG. 6, the draft inducer 20 is mounted
within a recessed area 98 between the support posts 96, as is
conventional.
[0047] Referring now to FIG. 7, the impeller 34 is positioned
within a scroll-shaped well 100 defined by the outer wall 88 of the
support tray 86. The outer wall 88 depends from a planar top
surface 102 that is defined by a first side edge 104 and a second
side edge 106. The first and second side edges 104, 106 are joined
by a front edge 108. The well 100 includes an upwardly sloping
front wall 110 that, in combination with the scroll shaped outer
wall 88, directs the flow of air from the impeller 34 upward toward
the heat exchanger of the furnace.
[0048] As can be understood in FIG. 8, the housing for the furnace
includes a pair of spaced lower support rails 112 each mounted to
the furnace housing and sized to support one of the side edges 104
or 106 of the support tray 86. As can be understood in FIGS. 7 and
8, the entire support tray 86 can be pulled out from beneath the
metallic grate 114 positioned between the heat exchanger tubes 116
for servicing or initial installation. The flange 118 on the front
edge 108 limits the travel of the support tray 57.
[0049] Referring now to FIG. 9, each of the support rails 112
includes an upstanding lip 119 that receives a U-shaped top edge
120 formed on the sidewall 88 of the support tray 86. The sidewall
88 is integrally formed with the bottom wall 90 to generally
surround the impeller 34. As shown in FIG. 9, the mounting arms 60
support the drive motor 26 and impeller 34 across the inlet opening
92 defined by the inlet bell 94. As the drive motor 26 rotates the
impeller 34, the cooling air is drawn into the impeller and is
directed radially outward against the sloped front wall 110 of the
support tray 86.
[0050] Referring now to FIGS. 10 and 11, the support tray 86 of the
first embodiment of the invention is shown. The support tray 86
includes the generally flat bottom wall 90 that supports the
impeller 34. The generally flat bottom wall 90 is joined to the
upwardly sloping front wall 110 and the scroll shaped side wall 88.
When the impeller 34 rotates, cooling air is drawn into the
impeller through the inlet bell 94 and is expelled radially outward
against the outer wall 88. The outer wall 88 is joined to the
sloping front wall 100 to direct the flow of air upward toward the
heat exchanger. Since the entire support tray 86 is configured to
direct the flow of air upward toward the heat exchanger, the
rotating impeller can be operated without the requirement of a
housing. In the preferred embodiment of the invention, the support
tray 86 is formed from a single sheet of stamped sheet metal in the
configuration shown in FIGS. 10 and 11. As discussed previously,
the support tray 86 includes the U-shaped side edges 104, 106 that
rest upon the side support rails 112 to allow the support tray 86
to be moved between the operating and services positions relative
to the furnace.
[0051] Referring now to FIGS. 12 and 13, thereshown is an alternate
version of the support tray 122. In the alternate version of the
support tray 122, the impeller 34 is mounted at an angle relative
to horizontal, as best seen in FIG. 13. The impeller 34 is mounted
to the generally sloping bottom wall 124 of the support tray 122.
The sloping bottom wall 124 is joined to a generally vertical back
wall 126 by a curved bottom end 128. Likewise, the bottom wall 124
is joined to a pair of spaced sidewalls 130 to define the well 132
that contains the rotating impeller 34. As the impeller 34 rotates,
the flow of cooling air is directed radially outward against the
pair of sidewalls 130. The sidewalls 130 direct the flow of air
into contact with the sloping bottom wall 124. The bottom wall 124
includes an upwardly sloped front end 134 that directs the flow of
cooling air upward into contact with the heat exchanger. It is
anticipated that the sloping bottom wall 124 will aid in directly
the flow of cooling air upward toward the heat exchanger for a more
efficient operating system.
[0052] Referring now to FIGS. 14 and 15, thereshown is yet another
embodiment of the support tray 136 and impeller 138 of the present
invention. Like the support trays identified previously, the
support tray 136 includes a pair of spaced side edges 140, 142 that
allow the support tray 136 to be supported beneath the heat
exchanger of a conventional furnace. As illustrated in FIG. 15, the
furnace blower assembly includes the drive motor 144 connected to
the impeller 138 by the drive shaft 146. However, in the embodiment
of the invention illustrated in FIG. 15, the impeller 138 has an
increased operating height as compared to the previous embodiments
of the invention. The increased operating height of the impeller
136 will aid in the amount of air flow created during the
rotational operation of the impeller 138.
[0053] As illustrated in FIG. 14, the support tray 136 includes a
sidewall 148 that directs the flow of cooling air from the rotating
impeller 138 toward the curved front end 150. As best seen in FIG.
15, the curved front end 115 includes a relatively smooth curve
that directs the flow of cooling air upward toward the heat
exchanger.
[0054] As illustrated in FIG. 15, the support tray 136 includes the
inlet bell 152 that is closely spaced with the inlet 154 for the
impeller 138. The drive motor 144 is mounted within the opening
defined by the inlet bell 152 by the plurality of mounting arms
156. Once again, the mounting arms 156 support the drive motor 144
within the inlet of the impeller 138 such that the flow of cooling
air passes over the drive motor 144.
[0055] Referring now to FIGS. 16 and 17, thereshown is yet another
alternate embodiment of the support tray 158 and impeller 138. In
the embodiment of the invention illustrated in FIG. 16, the support
tray includes a sidewall 158 that is created to direct a flow of
cooling air out of the support tray 158 at the outlet 160.
Specifically, the sidewall 158 includes a scroll shaped bottom wall
162 that is upwardly curved to direct the flow of cooling air out
of the support tray 158. The curved bottom wall 162 starts at its
lowest point defined by the bottom shoulder 164 and curves upward
to its highest position 166 generally aligned with the outlet 160.
Once again, the sidewall 159 of the support tray 158 aids in
directing the flow of air from the impeller 138 upward toward the
heat exchanger of the furnace. As with all of the other embodiments
previously discussed, the furnace blower assembly does not include
a housing surrounding the impeller and the drive motor. Instead,
the embodiment shown in FIGS. 16 and 17 includes a support tray
that is used to create a scroll shape that directs the flow of
cooling air toward the heat exchanger.
[0056] As can be understood in the drawings, the scroll-shape of
the support tray has the advantage of increasing the efficiency of
the backward curved impeller 34 while creating room along the sides
and bottom to allow air to be drawn into the support tray. Further,
the open top of the support tray allows the support tray to be slid
into and out of the furnace housing, as clearly illustrated.
[0057] In the preferred embodiment of the invention, each of the
support trays is formed from a single piece of stamped sheet metal
formed on a large press. However, it is contemplated that the
support trays could be formed from other materials while operating
within the scope of the present invention.
[0058] Although not shown in the Figures, it is contemplated that
the furnace distribution blower could be configured as two backward
curved impellers mounted back-to-back and having a horizontal drive
motor mounted in one of the wheel inlets. The motor would be
mounted to a bracket to provide an inlet area and have a shaft
passing through both of the impellers such that inlet air could be
drawn in from both sides of furnace housing.
[0059] Various alternatives and embodiments are contemplated as
being within the scope of the following claims particularly
pointing out and distinctly claiming the subject matter regarded as
the invention.
* * * * *