1. Field of the Invention
The present invention pertains to a blower assembly for an air handler in which an electric motor is integrated into the constructions of the impeller fan and the blower housing of the blower assembly. More specifically, the present invention pertains to a blower assembly in which an axial flux motor has its stator integrated into the construction of the blower housing of the assembly and has its rotor integrated into the construction of the impeller fan of the assembly.
2. Description of Related Art
The typical construction of a blower assembly for an air handler, for example as a furnace, includes a fan that is rotated by an electric motor and a blower housing that contains the fan.
The typical blower housing is comprised of a scroll-shaped outer wall and a pair of side walls that are connected to opposite sides of the scroll-shaped outer wall. The outer wall has opposite ends that are positioned on opposite sides of an outlet opening of the blower housing. The side walls are also positioned on opposite sides of the outlet opening. The side walls have circular, coaxial holes through the side walls that function as air inlet openings of the blower housing.
The motor is typically mounted to one of the blower housing side walls. The shaft of the motor is coaxial with the center axes of the blower housing inlet openings. This positions the motor either directly adjacent one of the side wall inlet openings, or in some constructions, the motor extends through the side wall inlet opening into a portion of the motor housing interior.
The impeller fan is mounted to the motor shaft in the blower housing interior. The typical impeller fan has a circular plate at one axial end of the fan or at an intermediate portion of the fan that is connected to the motor shaft.
The common blower assembly construction described above includes features that detract from the efficiency of the blower assembly. Positioning the motor adjacent or partially extending into one of the air inlet openings of the blower housing restricts the air flow through that inlet opening and thereby contributes to the inefficiency of the blower assembly. Additionally, the circular plate of the impeller fan that connects the fan to the motor shaft restricts the free flow of air through the interior of the impeller fan and thereby also contributes to the inefficiency of the blower assembly.
The blower assembly of the present invention overcomes disadvantages associated with the constructions of conventional blower assemblies by having the construction of the motor integrated into the constructions of intermediate portions of the impeller fan and the blower housing. This eliminates the prior art positioning of the motor adjacent one of the blower housing inlet openings or extending through one of the blower housing inlet openings and thereby eliminates the inefficiencies associated with this prior art positioning of the motor. In addition, the portion of the motor integrated into the fan construction includes a cylindrical hub with a center bore through the hub that balances pressure and the free flow of air through the interior of the fan.
The blower housing of the invention comprises a scroll-shaped outer wall having a length with opposite first and second ends that are positioned at opposite sides of the outlet opening of the housing. The housing also comprises a pair of side walls that are secured to the opposite sides of the scroll-shaped outer wall. The side walls have circular holes that are coaxially aligned and function as the air inlet openings of the blower housing. The novel construction of the blower housing of the invention includes an interior wall. The interior wall is parallel to the side walls and is secured stationary to the interior surface of the housing outer wall at a centered position between the two side walls. The interior wall has a circular hole through the wall that is coaxial with the air inlet openings of the two side walls.
The motor of the blower assembly is mounted to the interior wall of the blower housing. This eliminates the inefficiencies associated with the prior art positioning of the motor adjacent an air inlet opening of the prior art blower housing or extending into the air inlet opening of the prior art blower housing. Although other motor types which have short axial lengths could be used, the preferred motor is an axial flux motor having a circular stator construction integrated into the construction of the interior wall at the hole through the wall. The wiring associated with the stator and the control systems of the motor are run through or along the interior wall to the exterior of the blower housing. The rotor of the motor includes a hollow cylindrical hub that is mounted for rotation by one or more bearings inside the stator. The hub has a pair of annular plates connected to the axially opposite ends of the hub. The plates extend radially outwardly from the center hub over opposite sides of the interior wall. The magnets of the motor are secured to at least one of the plates.
The impeller fan of the blower assembly is comprised of a pair of centrifugal or squirrel-cage fans. These fans may have different width dimensions for air flow purposes. The fans are positioned on the opposite sides of the interior wall and are connected to the pair of plates that extend radially from the cylindrical hub of the rotor.
The blower assembly of the invention described above has no obstructions to the free flow of air through the inlet openings of the blower housing side walls into the interior of the fan contained in the blower housing. The blower assembly also has a smaller size than comparable prior art blower assemblies that have motors that project out from one side of their blower housings. This enables the blower assembly of the invention to be used in a narrower air handler enclosure. This is accomplished by the positioning of the motor in the interior of the housing on the interior wall of the housing. Employing the axial flux motor construction allows for the free flow of air through the interior of the blower housing between the two centrifugal fans. This eliminates the inefficiencies associated with prior art centrifugal fans due to the center plates of the fans restricting air flow through the fans.
Further features of the invention are set forth in the following detailed description of blower assemblies of the invention and in the drawing figures.
a is a section view taken through the plane of line 19a-19a of
b is an enlarged fragment view of
c is a perspective view of the motor of the blower assembly of
The blower assembly of the present invention is basically comprised of a blower housing 12, a fan 14 contained inside the blower housing, and a motor 16.
The blower housing 12 has an outer wall 18 having a scroll-shaped length that extends from a first end edge 22 of the outer wall to an opposite second end edge 24 of the outer wall. As best seen in drawing
The blower housing also includes first 28 and second 32 side walls. As seen in the drawing figures, portions of the peripheries of the two side walls 28, 32 are connected to the opposite sides of the outer wall 18. The first 28 and second 32 side walls also have respective straight edge portions 34, 36. The straight edge portions 34, 36 of the two side walls are also positioned at opposite sides of the blower housing outlet opening 26 and with the outer wall first end edge 22 and second end edge 24 define the rectangular configuration of the outlet opening. Each of the side walls 28, 32 is also provided with a circular hole 38, 42 through the side wall. The circular holes 38, 42 are coaxially aligned and function as the air inlet openings of the blower housing 12.
An interior wall 44 of the blower housing 12 is shown in
The motor 16 of the blower assembly is an axial flux motor. The stator 52 of the motor is integrated into the construction of the housing interior wall 44 at the center hole 46 through the wall. The interior wall 44 can be constructed in such a manner that allows for the wiring associated with the stator 52 and the control systems of the motor 16 to be run through the interior of the interior wall 44. Alternatively, the wiring can be run across the exterior surface of the interior wall 44. The stator windings 54 extend radially inwardly from the interior wall 44 into the center hole 46. In the illustrated embodiment of the blower assembly, the stator has thirty six slots and eighteen windings 54. The rotor 56 of the motor includes a hollow cylindrical hub 58 having a bore 62 through the hub 58. The hub 58 is mounted by bearings on the stator 52 for rotation of the hub 58 inside the stator 52. A pair of first and second annular plates 64, 66 project radially outwardly from the opposite ends of the hub 58 over opposite sides of the stator 52 and opposite sides of the interior wall 44. The hub interior bore 62 defines center holes through the plates 64, 66. The hub interior bore 62 and the holes through the plates 64, 66 are all coaxially aligned with the inlet openings 38, 42 through the respective side walls 28, 32 of the blower housing 12. The permanent magnets 68 of the rotor 56 are secured to the interior surface of at least one of the plates 64, 66 that opposes the stator windings 54. In the illustrated embodiment thirty magnets are employed on the rotor 56. In alternate embodiments of the blower assembly, permanent magnets could be provided on both of the plates 64, 66. The circular peripheral edges 72, 74 of the respective plates 64, 66 are secured to the fan 14 of the blower assembly. In addition, the motor 16 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 44 supporting the motor 16.
The impeller fan 14 of the blower assembly is comprised of a first centrifugal or squirrel-cage fan 76 and a second centrifugal or squirrel-cage fan 78. The two fans 76, 78 are basically the same in construction. As shown in
The bore 62 through the stator hub 58 allows for the balancing of pressure between the interiors of the two fans 76, 78. The bore 62 also allows for the free flow of air between the interiors of the two fans 76, 78 and the two sides of the blower housing interior on opposite sides of the interior wall 44.
The blower assembly constructed in the manner above has no obstructions to the free flow of air through the inlet openings of the blower housing side walls into the interiors of the fans contained in the blower housing. The blower housing assembly also has a smaller size than comparable prior art blower assemblies 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.
In
c show a blower assembly 110 similar to the blower assembly of
In view of the foregoing, it should be appreciated that the invention achieves several advantages over prior art blowers.
As various modifications could be made in the constructions herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
It should also be understood that when introducing elements of the present invention in the claims or in the above description of exemplary embodiments of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US11/44702 | 7/20/2011 | WO | 00 | 5/2/2013 |
Number | Date | Country | |
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61366347 | Jul 2010 | US |