Abstract:
A blower comprises a blower housing, a fan, a motor and a support member. The blower housing has an air outlet opening. The fan is within the blower housing, the fan is adapted for rotation about a fan axis. The motor has a stator and a rotor. The rotor is rotatably coupled to the stator for rotation about the fan axis. The rotor and fan are coupled such that the fan rotates with the rotor. The support member is connected between the stator of the motor and the blower housing and extends generally radially from the fan axis. The support member supports both the motor and the fan.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    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. 
         [0003]    2. Description of Related Art 
         [0004]    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. 
         [0005]    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. 
         [0006]    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. 
         [0007]    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. 
         [0008]    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. 
       SUMMARY OF THE INVENTION 
       [0009]    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. 
         [0010]    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. 
         [0011]    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. 
         [0012]    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. 
         [0013]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Further features of the invention are set forth in the following detailed description of blower assemblies of the invention and in the drawing figures. 
           [0015]      FIG. 1  is a side elevation view of one side of a blower assembly of the invention, with the opposite elevation view being a mirror image of  FIG. 1 . 
           [0016]      FIG. 2  is an end elevation view of the blower assembly from the left end of the blower assembly as shown in  FIG. 1 . 
           [0017]      FIG. 3  is an upper, left perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0018]      FIG. 4  is an upper, right perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0019]      FIG. 5  is a left perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0020]      FIG. 6  is a right perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0021]      FIG. 7  is a lower, left perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0022]      FIG. 8  is a lower, right perspective view of the blower assembly relative to the blower assembly as shown in  FIG. 2 . 
           [0023]      FIG. 9  is a partially sectioned view of the blower assembly showing portions of the blower housing, fans and motor and showing the interior wall in its entirety. 
           [0024]      FIG. 10  is a view similar to that of  FIG. 9 , but from the opposite side of the blower housing as shown in  FIG. 9 . 
           [0025]      FIG. 11  is an end elevation view of the blower assembly as shown partitioned in  FIGS. 9 and 10 . 
           [0026]      FIG. 12  is a schematic representation of one embodiment of the blower assembly of the invention. 
           [0027]      FIG. 13  is a schematic representation of a further embodiment of the blower assembly. 
           [0028]      FIG. 14  is a schematic representation of a further embodiment of the blower assembly. 
           [0029]      FIG. 15  is a schematic representation of a further embodiment of the blower assembly. 
           [0030]      FIG. 16  is a schematic representation of a further embodiment of the blower assembly. 
           [0031]      FIG. 17  is a schematic representation of a further embodiment of the blower assembly. 
           [0032]      FIG. 18  is a schematic representation of a further embodiment of the blower assembly. 
           [0033]      FIG. 19  is a side elevation of a further embodiment of the blower assembly. 
           [0034]      FIG. 19   a  is a section view taken through the plane of line  19   a - 19   a  of  FIG. 19 . 
           [0035]      FIG. 19   b  is an enlarged fragment view of  FIG. 19   a , showing motor features. 
           [0036]      FIG. 19   c  is a perspective view of the motor of the blower assembly of  FIG. 19 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    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 . 
         [0038]    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  FIGS. 3-8 , the outer wall first end edge  22  forms the cutoff of the blower housing. Additionally, the first  22  and second  24  end edges of the outer wall  18  define opposite sides of a rectangular outlet opening  26  of the blower housing. 
         [0039]    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 . 
         [0040]    An interior wall  44  of the blower housing  12  is shown in  FIGS. 5-11 . The interior wall  44  is a flat, planar wall having a circular center hole  46  through the wall. The interior wall  44  is secured to the interior surface of the blower housing outer wall  18  and is positioned in the interior of the blower housing  12  parallel to the side walls  28 ,  32 . The interior wall center hole  46  is coaxial with the inlet openings  38 ,  42  in the respective side walls  28 ,  32 . The hole  46  through the wall  44  allows a balance of air pressure and air flow on opposite sides of the blower housing interior. In alternate embodiments, the wall  44  could be replaced by a ring having the center hole  46  with the ring connected to the housing interior by three or more circumferentially spaced spokes or webs. In addition, the interior wall  44  is shown in the drawing figures centered in the blower housing  12  relative to the side walls  28 ,  32 . In alternate embodiments of the invention, the interior wall  44  could be positioned off center in the blower housing  12  and more toward one or the other of the side walls  28 ,  32 . Optimum efficiency is achieved when the interior wall concept is employed in a high efficiency blower housing such as those described in pending patent application Ser. Nos. 11/935,726; 12/178,161 and 12/631,415; all of which are incorporated herein by reference. 
         [0041]    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 . 
         [0042]    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  FIGS. 9-11 , the first fan  76  is connected to the peripheral edge  72  of the first annular plate  64  and the second fan  78  is connected to the peripheral edge  74  of the second annular plate  66 . This connects the two fans  76 ,  78  to the rotor  56  with the fans positioned on opposite sides of the blower housing interior wall  44 . On operation of the motor  16 , the rotor  56  rotates freely relative to the stator  52  and drives the fans  76 ,  78  in rotation relative to the blower housing interior wall  44  and the blower housing  12 . 
         [0043]    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 . 
         [0044]    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. 
         [0045]      FIGS. 12-18  are schematic representations of the possible positioning of controls  82  for the motor  16  of the blower assembly and the wiring  84  or other electronics communicating the controls with the motor. 
         [0046]    In  FIG. 12  the motor controls  82  are shown mounted to the exterior of the blower housing outer wall  18 . The wiring  84  for the stator  52  extends through the interior of the housing interior wall  44 . In other embodiments, the housing interior wall  44  could be replaced by a circular ring with a center opening that supports the motor  16  in the same manner as the interior wall  44 , with the ring being secured to the interior of the blower housing outer wall  18  by a plurality of spokes or webs spatially arranged around the ring and extending radially from the ring to the blower housing outer wall  18 . In this variant embodiment, the wiring  84  would extend through one of the radially extending spokes or webs. The wiring  84  extending through the interior wall or one of the spokes or webs provides EMI shielding of the wiring. 
         [0047]      FIG. 13  is a representation of the controls  82  being mounted on the blower housing interior wall  44  or one of the interior spokes or webs. In this arrangement the controls  82  are contained in a housing having a flat or aerodynamic shape so as not to obstruct air flow. The wiring  84  runs through the interior of the interior wall  44  to the motor  16 , or through one of the spokes or webs used as an alternate to the interior wall  44 . Power and signal connections to the controls  82  would also extend through the interior wall  44  or supporting spoke or web to the exterior of the blower housing  12 . 
         [0048]      FIG. 14  represents the motor controls  82  being mounted on the exterior of the blower housing  12 . A heat sink  86  for the controls  82  extends through the blower housing  12  to the interior of the blower housing for access to cooling air. The wiring  84  for the stator  52  extends through the interior wall  44  or through one of the alternative spokes or webs directly to the controls  82 . If the wiring is routed through the interior of the blower housing  12 , it must be positioned to be protected from the blades of the fan  14 . In addition, some EMI shielding of the wiring would likely be required. With the controls  82  positioned on the exterior of the blower housing  12 , the power and signal cables for the controls are easily accessible. 
         [0049]      FIG. 15  is also a representation of the controls  82  being mounted on the exterior of the blower housing  12  with a heat sink  86  extending into the blower housing. In the arrangement shown in  FIG. 15 , the controls  82  are not an integral part of the interior wall  44  supporting the motor  16  as shown in  FIG. 12 . Here again, with the controls  82  positioned on the exterior of the blower housing  12 , the power and signal cables are easily accessible. 
         [0050]      FIG. 16  is a representation of a blower arrangement where the motor is supported by a stationary shaft and the controls  82  being mounted in the center hub  84  of the motor construction, thereby closing the center hub bore  62 . A hollow, stationary shaft  88  extends through the motor controls  82  and supports the motor controls in the interior of the blower housing  12 . The shaft  88  is connected to the blower housing  12  by three circumferentially spaced rods  92  that connect one end of the shaft  88  to the blower housing  12  and three circumferentially spaced rods  94  that connect the opposite end of the shaft  88  to the blower housing  12 . The motor stator  52  is also attached to the stationary shaft  88 . Thus, in the construction represented in  FIG. 16 , there is no need for the interior wall  44  in the blower housing  12 . The power and signal connections for the controls  82  would be routed through the interior of the shaft  88  to the exterior of the blower housing  12 . 
         [0051]      FIG. 17  represents a further arrangement where the center bore  62  is obstructed by the controls  82  positioned at the center of the stator  52 . As in the previously-described embodiments, the stator  52  is supported in the blower housing  12  by the interior wall  44 , or by the alternative spokes or webs. The power and signal connections for the motor controls  82  are routed through the interior of the interior wall  44 , or through the interior of one of the alternative spokes or webs. 
         [0052]      FIG. 18  is a representation of an arrangement where the motor stator  52  is mounted to one side of the blower housing  12  and the motor rotor  56  is mounted to one side of the fan  14  adjacent the stator. The motor controls  82  are mounted to the stator  52  at the side of the blower housing  12 . One end of the fan  14  is supported by bearings  96  positioned between the fan and the stator  52 . The opposite end of the fan  14  is constructed with a center ring  98  and three spokes  102  that extend radially from the ring to the fan. A bearing  104  mounts the fan ring  98  on a shaft  106 . The shaft  106  is held stationary to the blower housing  12  by three rods  108  that connect the shaft  106  to the housing. 
         [0053]      FIGS. 19-19   c  show a blower assembly  110  similar to the blower assembly of  FIGS. 1-11 , but with the center brace being a fin-shaped mount  144  instead of the interior wall  44 . For simplicity, the reference numbers for the elements of the blower assembly  110  are the same as corresponding elements of the blower assembly of  FIGS. 1-11  except the reference numbers for the blower assembly  110  contain the prefix “1”. The fin-shaped mount  144  supports the motor  116  and the blower housing  112 . The fin-shaped mount extends radially from an arcuate portion (shown in  FIG. 19   c ) of the outer periphery of the stator  152 . An end portion of the mount  144  extends radially from the blower housing  112 . The mount end portion is configured for supporting the motor control circuit  182 . Preferably, the mount  144  includes a removable cover member  144   a  for enclosing the motor control circuit. Referring to  FIGS. 19   b  and  19   c , the permanent magnets  168  of the rotor  156  are arranged to form a magnet ring. Each magnet  168  includes an inner edge  168   a  and an outer edge  168   b  (see  FIG. 19   b ). The inner edges  168   a  combine to generally define an inner circumference of the magnet ring. The outer edges  168   b  combine to generally define an outer circumference of the magnet ring. The diameter of the outer circumference is represented as D o  and the diameter of the inner circumference is represented as D i . Preferably, the ratio of the diameters of the outer and inner circumferences D o , D i  is not more than approximately 1.2. Preferably, the blower assembly  110  has nothing obstructing the two inlet openings  138 ,  142 . 
         [0054]    In view of the foregoing, it should be appreciated that the invention achieves several advantages over prior art blowers. 
         [0055]    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. 
         [0056]    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.