BACKGROUND OF THE INVENTION
A major problem with standard backward curved and backward inclined impellers utilized in a blower for a standard air handler, fan coils, and furnaces is that the noise and sound is too high to be acceptable to the consumer since these backward curved and backward inclined impellers must operate at a higher speed than a standard blower. To compound the issue, consumers also require significant energy savings over standard blowers.
The typical construction of a high efficiency furnace 10 is shown in FIG. 1. The furnace 10 has an external housing enclosure 12 with an interior volume 14. Several portions of the side walls of the furnace enclosure 12 shown in FIG. 1 have been removed to illustrate the interior components of the furnace. The dimensions of the furnace enclosure 12 are determined to contain all of the component parts of the furnace in the furnace enclosure 12, without the enclosure occupying a significant area in the residence in which the furnace is installed. In contrast, commercial furnaces are typically mounted on the roof of a building or at some other location outside the building where there are no size restraints. Because commercial furnaces with their large capacity are located outside the structures they serve, there is no need to position the component parts of the furnace relative to each other to minimize the size of the furnace enclosure as there is in residential furnaces.
An air inlet opening is typically provided in a side wall or in the bottom of the furnace enclosure. The air inlet opening can be covered by an air filter that allows ambient air in the environment surrounding the furnace enclosure 12 to easily pass through the opening and enter the enclosure interior 14. Alternatively and more frequently, the air inlet opening of the furnace enclosure communicates with a cold air return duct system of the residence. The cold air return duct system channels ambient air from throughout the residence to the furnace enclosure 12.
The furnace enclosure 12 also has an air distribution outlet opening 18. The outlet opening communicates with an air distribution conduit or duct system of the residence in which the furnace is installed. In FIG. 1, the air distribution outlet opening 18 is located at the top of the furnace enclosure 12. The air heated by the high efficiency furnace 10 is discharged to the air distribution conduit system (not shown) through the air distribution outlet opening 18.
In the typical construction of a high efficiency furnace represented in FIG. 1, a primary heat exchanger 22 is located at the top of the furnace enclosure 12 adjacent the air distribution outlet opening 18. A secondary heat exchanger 24 that qualifies the furnace as a high efficiency furnace is located directly below the primary heat exchanger 22.
An air distribution blower 26 that draws ambient air into the furnace enclosure 12 is positioned just below the secondary heat exchanger 24. A motor (not shown) of the blower rotates a fan wheel 28 in the interior of the blower in a clockwise direction as viewed in FIG. 1. This rotation of the fan wheel 28 draws the ambient air into the blower 26 as represented by the arrow labeled (AIR FLOW) in FIG. 1, and pushes the ambient air out of the blower 26 through the secondary heat exchanger 24, then through the primary heat exchanger 22, and then out of the enclosure through the air distribution outlet opening 18.
A typical blower 26 includes a blower housing that contains the fan wheel 28. The typical blower housing includes an exterior or outer wall 32. The outer wall 32 spirals around the fan wheel 28 in the direction of fan wheel rotation.
SUMMARY OF INVENTION
In another aspect of the invention, a blower is disclosed. The blower includes a blower housing having a cutoff and a top portion with an air outlet opening, a fan within the blower housing, the fan being adapted for rotation about a fan axis and having an outer diameter with a distance between the outer diameter of the fan and the top portion of the air outlet opening extending along a vertical line between the fan axis and the air outlet opening being less than seventy-five percent of the distance between the outer diameter of the fan and the cutoff of the blower housing extending along a line between the fan axis and the cutoff, and a motor having a stator and a rotor, the rotor being rotatably coupled to the stator for rotation about the fan axis, the rotor and fan being coupled such that the fan rotates with the rotor.
In another aspect of the invention, a blower is disclosed. The blower includes a blower housing having a cutoff and a top portion with an air outlet opening, a fan within the blower housing, the fan being adapted for rotation about a fan axis and having an outer diameter, the fan comprising a first set of backward curved impeller blades, and a second set of backward curved impeller blades, the first set of backward curved impeller blades being spaced axially from the second set of backward curved impeller blades and a distance between the outer diameter of the fan and the top portion of the air outlet opening extending along a vertical line between the fan axis and the air outlet opening being less than seventy-five percent of the distance between the outer diameter of the fan and the cutoff of the blower housing extending along a line between the fan axis and the cutoff and the angle between the vertical line extending between the fan axis and the air outlet opening and the line extending between the fan axis and the cutoff being at least ten degrees, a motor having a stator and a rotor, the rotor being rotatably coupled to the stator for rotation about the fan axis, the rotor and fan being coupled such that the fan rotates with the rotor, and a support member connected between the stator of the motor and the blower housing and extending generally radially from the fan axis, the support member supporting both the motor and the fan, the support member located between the first set of backward curved impeller blades and the second set of backward curved impeller blades.
Still yet another aspect of the present invention is that a method for utilizing a fan within the blower housing is disclosed. The method includes utilizing a fan within the blower housing, having a cutoff and a top portion with an air outlet opening, wherein the fan being adapted for rotation about a fan axis and having an outer diameter with a distance between the outer diameter of the fan and the top portion of the air outlet opening extending along a vertical line between the fan axis and the air outlet opening being less than seventy-five percent of the distance between the outer diameter of the fan and the cutoff of the blower housing extending along a line between the fan axis and the cutoff, and utilizing a motor having a stator and a rotor, the rotor being rotatably coupled to the stator for rotation about the fan axis, the rotor and fan being coupled such that the fan rotates with the rotor.
These are merely some of the innumerable aspects of the present invention and should not be deemed an all-inclusive listing of the innumerable aspects associated with the present invention. These and other aspects will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
FIG. 1 is a partial view of the construction of a prior art high efficiency furnace;
FIG. 2 is a partial view of the high efficiency furnace of FIG. 1 employing the unique blower with an enlarged backward curved impeller of the present invention;
FIG. 3 is a back perspective view of the blower shown in FIG. 2;
FIG. 4 is the perspective view of the blower shown in FIG. 3 with a first outer wall removed and an isolated view of a distance between the outer diameter of the impeller blades and an outlet opening;
FIG. 5 is a perspective view of the blower shown in FIG. 3 revealing the outlet opening;
FIG. 6 is a perspective view of the blower shown in FIG. 4 without the blower housing;
FIG. 7 is the perspective view of the blower shown in FIG. 3 with an axial flux motor with a stator and rotor;
FIG. 8 is an end elevation view of the blower as shown partitioned in FIG. 7; and
FIG. 9 is a schematic representation of an embodiment of the blower of the present invention.
Reference characters in the written specification indicate corresponding items shown throughout the drawing figures.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as to obscure the present invention.
Referring now to FIG. 2, which is a perspective, cut away view of the high efficiency furnace of the invention that employs an enlarged backward curved impeller. The furnace of the invention is primarily constructed in the same manner as known high efficiency furnaces. Because much of the construction of the furnace shown in FIG. 2 is the same as that of FIG. 1, the same component parts of the furnace of FIG. 2 will be described only generally and are identified by the same reference numbers used in identifying the component parts in FIG. 1, but with the reference numbers being followed by a prime (′).
The high efficiency furnace 10′ of the present invention also includes an external housing enclosure 12′ that contains the interior volume 14′ of the furnace 10′. Only a rear wall 12R and a left side wall 12LS of the external housing enclosure 12′ are entirely shown in FIG. 2. The front wall 12F and right side wall 12RS are shown with portions removed to provide a view of the interior components of the furnace. It should be understood that the front and rear walls have the same width and height dimensions and the left side wall 12LS and the right side wall 12RS have the same width and height dimensions whereby the enclosure has the exterior configuration that may preferably, but not necessarily, have the shape of a rectangular cube. The front wall 12F of the external housing enclosure 12′ or the bottom of the external housing enclosure 12′ is provided with an air inlet opening that allows ambient air of the residence in which the furnace is used to enter into the enclosure interior 14′. The air inlet opening is often communicated with a cold air return duct system of the residence. Air that is heated by the furnace 10′ is discharged to an air distribution conduit system of the residence (not shown) through an air distribution outlet opening 18′. The air distribution outlet opening 18′ is positioned at the top of the external housing enclosure 12′ shown in FIG. 2.
The primary heat exchanger 22′ is positioned at the top of the enclosure interior volume 14′ adjacent the air distribution outlet opening 18′. The secondary heat exchanger 24′ is positioned just below the primary heat exchanger 22′. The use of both a primary heat exchanger and a secondary heat exchanger qualifies the furnace of the invention as a high efficiency furnace, or a 90+ AFUE furnace.
The blower 38 of the invention is positioned in the enclosure interior 14′ at the same position as the prior art blower 26′ shown in FIG. 1, i.e., just below the secondary heat exchanger 24′. The fan wheel 42 has an axis of rotation 44 that defines mutually perpendicular axial and radial directions relative to the blower 38. As shown in FIG. 2, the fan wheel 42 rotates in a clockwise rotation direction when the blower 38 is operating. Rotation of the fan wheel 42 draws ambient air into the blower 38 as represented by the arrow labeled (AIR FLOW) in FIG. 2. In the preferred embodiment, the fan wheel 42 is comprised of a plurality of backward curved impeller blades 46. However, any type of a myriad of fan wheels and types of fans may be utilized with the present invention.
Referring now to FIGS. 3, 4 and 5, the blower 38 includes the fan wheel 42 that is contained with a blower housing 48. The blower housing 48 has an outer wall 50 having a scroll-shaped length that extends from a first end edge 52 of the outer wall to an opposite second end edge 54 of the outer wall 50. The outer wall first end edge 52 forms the cutoff 51 of the blower housing 48. In addition, the first end edge 52 and second end edge 54 of the outer wall 50 define opposite sides of an outlet opening 56, which is preferably but not necessarily rectangular, of the blower housing 48.
The blower housing 48 also includes first side wall 58 and second side wall 60. As seen in the FIGS. 3-5 and 7, portions of the peripheries of the first side wall 58 and the second side wall 60 are connected to the opposite sides of the outer wall 50. The first side wall 58 has a first straight edge portion 62 and the second side wall 60 has a second straight edge portion 64. The first straight edge portion 62 and second straight edge portion 64 of the first side wall 58 and the second side wall 60, respectively, are also positioned at opposite sides of the outlet opening 56 for the blower housing 48 with the outer wall 50, the first end edge 52 and the second end edge 54 defining the outlet opening 56, which preferably, but not necessarily, have a rectangular configuration. The first side wall 58 includes a first circular aperture 66, shown in FIG. 3, which is through the first side wall 58. The second side wall 60 includes a second circular aperture 68, shown in FIG. 5, which is through the second side wall 60. The first circular aperture 66 and the second circular aperture 68 are coaxially aligned and function as the air inlet openings of the blower housing 48.
An interior wall 70 of the blower housing 48 is shown in FIGS. 5, 6 and 8 is utilized with a center mount motor. However, any of a wide variety of motors and mounting techniques may be utilized with the present invention. The interior wall 70 is a flat, planar wall. There is an interior wall center hole 72, preferably circular, through the interior wall 70, shown in FIG. 8. The interior wall 70 is secured to the interior surface of the outer wall 50 and is positioned in the interior of the blower housing 48 parallel to the first side wall 58 and the second side wall 60. The interior wall center hole 72 for the interior wall 70 is coaxial with the first circular aperture 66 in the first side wall 58 and the second circular aperture 68 in the second side wall 60. The interior wall center hole 72 through the interior wall 70 allows a balance of air pressure and air flow on opposite sides of the interior of the blower housing 48. In alternate embodiments, interior wall 70 could be replaced by a ring having the circular center hole 72 with the ring connected to the housing interior by three or more circumferentially spaced spokes or webs. In addition, the interior wall 70 is shown in the drawing figures centered in the blower housing 48 relative to first side wall 58 and the second side wall 60. In alternate embodiments of the invention, the interior wall 70 could be positioned off-center in the blower housing 48 and more toward one or the other of the side walls, i.e., the first side wall 58 and the second side wall 60.
Referring now to FIG. 8, the motor 74 of the blower 38 is preferably, but not necessarily, an axial flux motor. However, with this present invention any of a myriad of motors will suffice. The stator 76 of the motor 74 is integrated into the construction of the interior wall 70 at the interior wall center hole 72 through the interior wall 70. The interior wall 70 can be constructed in such a manner that allows for the wiring 106 associated with the stator 76 and the control systems of the motor 74 to be run through the interior of the interior wall 70, as shown in FIG. 9. Alternatively, the wiring 106 can be run across the exterior surface of the interior wall 70. The stator windings 78 extend radially inwardly from the interior wall 70 into the interior wall center hole 72, referring again to FIG. 8. In the illustrated, but nonlimiting, embodiment of the blower 38, the stator 76 has thirty-six (36) slots and eighteen (18) stator windings 78. The rotor 80 of the motor 74 includes a hollow cylindrical hub 82 having a bore 84 through the hollow cylindrical hub 82. The hollow cylindrical hub 82 is mounted by bearings 86 on the stator 76 for rotation of the hollow cylindrical hub 82 inside the stator 76.
As shown in FIG. 8, a pair of a first annular plate 88 and a second annular plate 90 project radially outwardly from the opposite ends of the hollow cylindrical hub 82 over opposite sides of the stator 76 and opposite sides of the interior wall 70. The bore 84 of the hollow cylindrical hub 82 defines center holes through the first annular plate 88 and the second annular plate 90. The bore 84 of the hollow cylindrical hub 82 and the holes through the first annular plate 88 and the second annular plate 90 are all coaxially aligned with the first circular aperture 66 and the second circular aperture 68 through the respective first side wall 58 and second side wall 60 of the blower housing 48. The permanent magnets 92 of the rotor 80 are secured to the interior surface of at least one of the first annular plate 88 and a second annular plate 90 that opposes the stator windings 78. In the illustrated, but nonlimiting, embodiment, thirty (30) permanent magnets 92 are employed on the rotor 80. In alternate embodiments of the blower 38, permanent magnets 92 could be provided on both of the plates, i.e., first annular plate 88 and a second annular plate 90. The first circular peripheral edge 94 for the first annular plate 88 and the second circular peripheral edge 96 for the second annular plate 90 are secured to the fan wheel 42 of the blower 38. In addition, the motor 74 need not be positioned at the center of the blower housing interior and could be positioned to either side of the interior by relocating the interior wall 70 supporting the motor 74, e.g., axial flux motor.
As also shown in FIG. 8, the fan wheel 42, which includes the backward curved impeller blades 46 of the blower 38, is formed of a first set of backward curved impeller blades 98 and a second set of backward curved impeller blades 100 with the first set of backward curved impeller blades 98 being spaced axially from the second set of backward curved impeller blades 100. The two sets of backward curved impeller blades 98 and 100 forming the backward curved impeller blades 46 are basically the same in construction. However, just as virtually any fan design can be utilized with the present invention, a single set of impeller blades can also be utilized. Although a backward curved impeller design is optimal, this invention is not limited to this type of structure.
The first set of backward curved impeller blades 98 is connected to the first circular peripheral edge 94 of the first annular plate 88 and the second set of backward curved impeller blades 100 is connected to the second circular peripheral edge 96 of the second annular plate 90. This connects the first set of backward curved impeller blades 98 and second set of backward curved impeller blades 100 to the rotor 80 with the first set of backward curved impeller blades 98 and second set of backward curved impeller blades 100 positioned on opposite sides of the interior wall 70 of the blower housing 48. On operation of the motor 74, the rotor 80 rotates freely relative to the stator 76 and drives the backward curved impeller blades 46 in rotation relative to the interior wall 70 and the blower housing 48.
The bore 84 through the hollow cylindrical hub 82 for the stator 76 allows for the balancing of pressure between the interiors of the first set of backward curved impeller blades 98 and the second set of backward curved impeller blades 100. The bore 84 also allows for the free flow of air between the interiors of the first set of backward curved impeller blades 98, the second set of backward curved impeller blades 100 and the two sides of the interior of the blower housing 48 on opposite sides of the interior wall 70.
The blower 38 as is constructed in the manner above has no obstructions to the free flow of air through the first circular aperture 66 of the first side wall 58 and the second circular aperture 68 of the second side wall 60 of the blower housing 48 into the backward curved impeller blades 46, which includes a first set of backward curved impeller blades 98 and the second set of backward curved impeller blades 100 contained in the blower housing 48. The blower housing 48 also has a smaller size than comparable prior art blower assemblies that typically have motors projecting from one side of their blower housings. This enables it to be used in a narrower air handler enclosure. This is accomplished by positioning the motor in the interior of the blower housing on the inner wall of the housing.
Referring now to FIGS. 3, 5, 6 and 8, the axis of rotation for the backward curved impeller blades 46, which includes the first set of backward curved impeller blades 98 and the second set of backward curved impeller blades 100, is indicated by numeral 44 and an outside diameter of the backward curved impeller blades 46 is indicated by numeral 53. As best shown in FIG. 4, a first distance between the outside diameter 53 of the backward curved impeller blades 46 and the outlet opening 56 is indicated by numeral 102 that extends along a vertical line 110 that extends directly from the axis of rotation 44 for the backward curved impeller blades 46. A second distance between the outside diameter 53 of the backward curved impeller blades 46 and the cutoff 51 is indicated by numeral 104 that extends along a line 112 that extends from the axis of rotation 44 for the backward curved impeller blades 46 to the cutoff 51. The first distance 102 is at a maximum less than seventy-five percent of the second distance 104. Other design options include the first distance 102 being less than fifty percent, twenty-five percent, ten percent and five percent of the second distance 104 and every variation thereof between zero percent and seventy-five percent. Optimally, the backward curved impeller blade radius 46 are as close as possible to the outlet opening 56 and it is possible for the outside diameter 53 of the backward curved impeller blades 46 to extend above the outlet opening 56. The angle 114 between line 110 and line 112 should be ten degrees or greater and may be fifteen degrees or greater, twenty degrees or greater and optimally at least thirty degrees.
Maximizing the size of the backward curved impeller blades 46 to reduce the ratio of the first distance 102 to the second distance 104 provides a significant advantage in that the revolutions per minute (rpms) are reduced which controls noise. The blower housing 48 will effectively have an oversized outlet opening 56 considerably larger than even a high efficiency blower, i.e., HEB, which will reduce pressure loss through a furnace. Furthermore, the blower 38 utilizing backward curved impeller blades 46 can be sold as a center mount motor/impeller only. Therefore, the manufacturer of the furnace can utilize a blower housing 48 that meets minimum requirements as a component of a lower blower housing cabinet in a furnace. An illustrative, but nonlimiting example, would be to have fourteen (14) inch backward curved impeller blades 46 housed in a fifteen and one-half (15.5) inch blower housing 48.
There are numerous potential ways to position the motor controls 108 for the motor 74, e.g., axial flux motor, as shown in FIG. 9. The motor controls 108 are shown mounted to the exterior of the outer wall 50 for the blower housing 48. The wiring 106 for the stator 76 extends through the interior of the interior wall 70. In other embodiments, the interior wall 70 could be replaced by a circular ring with a center opening that supports the motor 74, e.g., axial flux motor, in the same manner as the interior wall 70, with the ring being secured to the interior of the outer wall 50 of the blower housing 48 by a plurality of spokes or webs spatially arranged around the ring and extending radially from the ring to the outer wall 50 of the blower housing 48. In this variant embodiment, the wiring 106 would extend through one of the radially extending spokes or webs. The wiring 106 extending through the interior wall 70 or one of the spokes or webs provides EMI shielding of the wiring.
Nonlimiting examples of numerous other ways of mounting the motor controls 108 and running the wiring 106 are found in International Application No. PCT/US2011/044702 for “Blower Assembly with Motor Integrated into the Impeller Fan and Blower Housing Constructions,” filed Jul. 20, 2011, claiming a priority of Jul. 20, 2010, which is incorporated by referenced herein, in its entirety.
Furthermore, it should be understood that when introducing elements of the present invention in the claims or in the above description of the preferred embodiment of the invention, the terms “have,” “having,” “includes” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.” Similarly, the term “portion” should be construed as meaning some or all of the item or element that it qualifies.
Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.
Patent Application
20130170945
