Patent Publication Number: US-2021172453-A1

Title: Fan hub configuration for an electric motor assembly

Description:
BACKGROUND 
     The following disclosure relates generally to electric motor assemblies and, more particularly, a fan shroud configuration for electric motor assemblies. 
     Electric motor assemblies are used in commercial refrigeration equipment, such as display cases, reach-in coolers, ice machines, and others to blow air for cooling products within the equipment. At least some known motor assemblies are relatively large with respect to the size of the equipment in which it is to be used and therefore limits placement of the motor assembly within the equipment and also the available space for products within the equipment. Additionally, at least some known motor assemblies channel a less than desired amount of air at a predetermined speed and static pressure, and are therefore less efficient. In order to channel the desired amount of air, some such known motor assemblies rotate at higher than desired speeds, which generates undesired noise. 
     BRIEF DESCRIPTION 
     In one example, a fan hub for use in a fan assembly configured to rotate about an axis is provided. The hub includes a core ring, a first inner ring circumscribing the core ring, and a first plurality of circumferentially-spaced ribs extending between the core ring and the first inner ring. The hub also includes a second inner ring circumscribing the first inner ring and a second plurality of circumferentially-spaced ribs extending between the first inner ring and the second inner ring. 
     In another example, an electric motor assembly is provided. The electric motor assembly includes an electric motor and a fan assembly coupled to the electric motor and configured to rotate therewith about an axis. The fan assembly includes a hub including a core ring, a first inner ring circumscribing the core ring, and a first plurality of circumferentially-spaced ribs extending between the core ring and the first inner ring. The hub also includes a second inner ring circumscribing the first inner ring and a second plurality of circumferentially-spaced ribs extending between the first inner ring and the second inner ring, and a plurality of circumferentially-spaced blades coupled to an outer periphery of the hub. 
     In yet another example, a method of balancing a fan assembly is provided. The method includes coupling a fan assembly to an electric motor such that the fan assembly is configured to rotate about an axis. The fan assembly includes a hub including a first inner ring, a second inner ring circumscribing the first inner ring, and a second plurality of circumferentially-spaced ribs extending between the first inner ring and the second inner ring. The method further includes removing a portion from at least one of the second plurality of ribs to facilitate balancing the fan assembly. 
     The features, functions, and advantages that have been discussed can be achieved independently in various examples of the present disclosure or may be combined in yet other examples, further details of which can be seen with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary electric motor assembly illustrating a shroud, an electric motor, and a fan assembly; 
         FIG. 2  is a partially exploded view of the electric motor assembly shown in  FIG. 1  illustrating a rotor assembly of the electric motor; 
         FIG. 3  is a cross-sectional view of the electric motor assembly shown in  FIG. 1 ; 
         FIG. 4  is an enlarged view of a portion of the cross-sectional view shown in  FIG. 3 ; 
         FIG. 5  is a top view of the electric motor assembly shown in  FIG. 1 ; 
         FIG. 6  is a top view of the exemplary fan assembly illustrating a hub and a plurality of blades; 
         FIG. 7  is a side view of the fan assembly shown in  FIG. 6 ; 
         FIG. 8  is an enlarged, cross-sectional view of a portion of the fan assembly shown in  FIG. 7 ; 
         FIG. 9  is a bottom view of the hub of the fan assembly shown in  FIG. 7 ; 
         FIG. 10  is a bottom perspective view of the hub of the fan assembly shown in  FIG. 7 ; 
         FIG. 11  is a cross-sectional view of the fan assembly shown in  FIG. 7 ; and 
         FIG. 12  is a top view of an exemplary blade of the fan assembly shown in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     The implementations described herein relate to an electric motor assembly for moving air in refrigeration equipment and other applications. The electric motor assembly includes an electric motor, a fan assembly coupled to the electric motor and configured to rotate therewith about an axis, and a shroud coupled to the electric motor and extending about the fan assembly. The shroud includes a central hub coupled to the electric motor, an inlet ring, and a plurality of arms extending between the central hub and the inlet ring. Each arm of the plurality of arms includes a curved radial portion extending from the central hub and a planar axial portion extending from the radial portion to the inlet ring. The fan assembly includes a hub including a cylindrical portion and an inlet surface coupled to an inlet end of the cylindrical portion. The fan assembly also includes a plurality of blades coupled to an outer periphery of the cylindrical portion, wherein the inlet surface is tapered to direct an inlet airflow toward the plurality of blades. An outlet end of the hub includes a core ring, a first inner ring circumscribing the core ring, and a first plurality of circumferentially-spaced ribs extending between the core ring and the first inner ring. The hub also includes a second inner ring circumscribing the first inner ring and a second plurality of circumferentially-spaced ribs extending between the first inner ring and the second inner ring. 
     The electric motor assembly described herein delivers an increased airflow at a higher efficiency with a lower noise level than other known air moving assemblies. The shroud arms are curved and swept in the direction of the airflow to allow the air to more easily pass through to reduce turbulence and improve efficiency. Also, the shroud arms are spaced to reduce blade tones. Similarly, the hub inlet surface is tapered to guide the incoming airflow into the blades at a predetermined angle to increase the amount of air flowing through the fan assembly. Additionally, the hub includes pluralities or ribs and rings that provide structural support to the fan assembly to maintain the fan assembly in position on the rotor and prevent vibrations to result in a reduced noise level. Moreover, the fan assembly is easily replaceable. Furthermore, the electric motor assembly described herein occupies a smaller volume than other known air moving assemblies and therefore allows a user to utilize smaller refrigeration equipment to take up less floor space. Additionally, the smaller size of the electric motor assembly described herein provides additional space within the refrigeration equipment to place products for sale. 
       FIG. 1  is a perspective view of an exemplary electric motor assembly  100  illustrating a shroud  102 , an electric motor  104 , and a fan assembly  106 .  FIG. 2  is a partially exploded view of electric motor assembly  100  illustrating a rotor assembly  105  of electric motor  104 .  FIG. 3  is a cross-sectional view of electric motor assembly  100 .  FIG. 4  is an enlarged view of a portion of the cross-sectional view shown in  FIG. 3 . In the exemplary embodiment, shroud  102  is fixedly coupled to electric motor  104  and fan assembly  106  is rotatably coupled to electric motor  104  such that operation of electric motor  104  causes fan assembly  106  to rotate about a rotational axis  108 . Fan assembly  106  includes a hub  110  having a cylindrical portion  112  and an inlet surface  114  coupled to cylindrical portion  112 . Additionally, fan assembly  106  includes a plurality of circumferentially-spaced blades  116  coupled to and extending from an outer periphery  118  of cylindrical portion  112 . 
     In the exemplary embodiment, shroud  102  includes a central hub  120 , a plurality of arms  122 , and an inlet ring  124 . Arms  122  extend from central hub  120  to inlet ring  124  and are substantially s-shaped. That is, each arm  122  includes two curves as arm  122  extends radially away from central hub  120 . More specifically, each arm  122  includes a radial portion  126  extending from central hub  120  and an axial portion  128  extending from radial portion  126  to inlet ring  124 . 
     As best shown in  FIG. 3 , electric motor assembly  100  includes an inlet  130  defined by inlet ring  124  and an outlet  132  proximate radial portion  126  or arms  122 . In operation, as fan assembly  106  rotates about axis  108 , air is drawn into inlet  130  and is channeled through inlet ring  124  between blades  116 , passed motor  104 , and discharged at outlet  132 . In the exemplary embodiment, inlet ring  124  includes an inlet end  134  and an opposing outlet end  136  that define an axial ring height Hr therebetween. Similarly, each blade  116  includes a leading edge  138  proximate inlet  130  and an opposing trailing edge  140  that define an axial blade height Hb therebetween. As shown in  FIG. 3 , trailing edge  140  of blades  116  is axially spaced from outlet end  136  of inlet ring  124 . Specifically, blades  116  and inlet ring  124  are positioned to expose a predetermined amount of blade height Hb. In one embodiment, for example when fan assembly  106  includes a diameter of 8 inches, between approximately 17% and approximately 25% of blade height Hb is positioned axially between inlet ring outlet end  136  and a point along blade trailing edge  140  where blade height Hb is at a maximum. That is, the axial distance between an axial plane aligned with inlet ring outlet end  136  and the point along blade trailing edge  140  where blade height Hb is at a maximum defines an exposed blade height He (shown in  FIG. 4 ) that is between approximately 17% and approximately 25% of blade height Hb. More specifically, the exposed blade height He is approximately 22% the distance of blade height Hb. In another embodiment, for example when fan assembly  106  includes a diameter of 7 inches, the axial distance between an axial plane aligned with inlet ring outlet end  136  and the point along blade trailing edge  140  where blade height Hb is at a maximum defines an exposed blade height He (shown in  FIG. 4 ) that is between approximately 28% and approximately 34% of blade height Hb. More specifically, in such an embodiment, the exposed blade height He is approximately 31% the distance of blade height Hb. Positioning trailing edge  140  axially offset from outlet end  136  reduces tones that may be produced by blades  116  and also reduces the stall point of the airflow through the blades. 
     In the exemplary embodiment, as best shown in  FIG. 4 , inlet ring  124  includes an axial portion  142 , a radial portion  144 , and a transition portion  146  extending between axial portion  142  and radial portion  144 . As shown in  FIG. 4 , axial portion  142  may be obliquely oriented with respect to axis  108  such that a diameter of inlet ring  124  narrows from inlet end  134  to outlet end  136 . Alternatively, axial portion  142  is oriented parallel to axis  108  such that the diameter of inlet ring  124  is constant between ends  134  and  136 . Furthermore, leading edge  138  of blades  116  is positioned entirely within axial portion  142  of inlet ring  124  such that leading edge  138  overlap only axial portion  142  and do not extend into transition portion  146 . Such a configuration reduces noise generated by electric motor assembly  100  and also reduces the blade tones. 
     In the exemplary embodiment, transition portion  146  is designed to increase the surface area of inlet ring  124  that interacts with the airflow being channeled therethrough to increase the flow rate. Transition portion  146  is defined by the curved inlet surface  147  of inlet ring  124  at inlet  130  and defines a non-symmetrical fillet design. Specifically, inlet surface  147  is defined between a first transition point  149  and a second transition point  151 . Transition point  149  represents the transition between axial portion  142  and transition portion  146 . Similarly, transition point  151  represents the transition between radial portion  144  and transition portion  146 . In the exemplary embodiment, inlet surface  147  extends a first distance D 1  in the radial direction between transition points  149  and  151 , as shown in  FIG. 4 . Similarly, inlet surface  147  extends a second distance D 2  in the axial direction between transition points  149  and  151 , as shown in  FIG. 4 . In the exemplary embodiment, radial distance D 1  is greater than axial distance D 2 . More specifically, radial distance D 1  is approximately 1.5 times the length of radial distance D 2 . Furthermore, as shown in  FIG. 4 , inlet surface  147  extends from transition point  149  in an oblique direction at an angle £, and inlet surface  147  extends from transition point  151  in an oblique direction at an angle δ that is smaller than angle ε. Specifically, angle ε is between approximately 25 degrees and approximately 35 degrees. More specifically, angle ε is approximately 30 degrees. Similarly, angle δ is between approximately 10 degrees and approximately 20 degrees. More specifically, angle δ is approximately 15 degrees. As such, inlet surface  147  is a continuously curved spline line between transition points  149  and  151 . 
       FIG. 5  is a top view of electric motor assembly  100  illustrating the array of arms  122  of shroud  102 . In the exemplary embodiment, radial portion  126  of arms  122  is substantially S-shaped and includes a plurality of curves, while axial portion  128  is substantially linear. Furthermore, radial portion  126  includes a first, inner end  148  coupled to central hub  120  and an opposing second, outer end  150  coupled to axial portion  128 . In the exemplary embodiment, radial portion includes a radially inner first curved portion  152  extending from central hub  120  and a radially outer second curved portion  154  extending between first curved portion  152  and axial portion  128 . Specifically, first curved portion  152  includes a radius of between approximately 4.0 inches and approximately 4.5 inches. More specifically, first curved portion  152  includes a radius of approximately 4.2 inches. Similarly, second curved portion  154  includes a radius of between approximately 6.6 inches and approximately 7.0 inches. More specifically, second curved portion  154  includes a radius of approximately 6.7 inches. 
     Furthermore, as shown in  FIG. 5 , radial portion  126  defines a sweep angle α of between approximately 10 degrees and approximately 15 degrees. More specifically, in the exemplary embodiment, radial portion  126  defines a sweep angle α of approximately 12 degrees. As used herein, the term “sweep angle” is meant to describe the portion of the circumference of a circle taken up between a radial line connecting the axis  108  and inlet end  148  of radial portion  126  and a radial line connecting axis  108  and outlet end  150  of radial portion  126 . 
     The configuration resulting from the combination of curved portions  152  and  154  and the sweep angle α increases the structural integrity of shroud  102  and also facilitates smoothing the airflow past arms  122  to reduce airflow turbulence and, therefore, the noise level of electric motor assembly  100 . Additionally, arms  122  are spaced about central hub  120  such that as one blade  116  begins to pass under one arm  122 , an immediately adjacent blade  116  is clearing an immediately adjacent arm  122 . Specifically, each blade  116  includes a root  156  that extends from hub periphery  118  and a tip  158  at the distal end of blade  116 . When the leading edge  138  at the tip  158  of one blade  116  begins to overlap one arm  122 , the trailing edge  140  at the tip  158  of an immediately adjacent blade  116  is ending its overlap with an immediately adjacent arm  122 . Such a configuration further reduces overall noise and blade tones. 
       FIG. 6  is a top view of fan assembly  106  illustrating hub  110  and plurality of blades  116 .  FIG. 7  is a side view of fan assembly  106 .  FIG. 8  is an enlarged view of a portion of fan assembly  100  shown in  FIG. 7 . In the exemplary embodiment, hub  110  includes cylindrical portion  112  having an inlet end  160  and an outlet end  162 . Furthermore, hub  110  includes inlet surface  114  coupled to inlet end  160 . As shown in  FIGS. 6-8 , inlet surface  114  is tapered to direct airflow toward leading edges  138  of blades  116 . Such a configuration reduces the noise level and increases the airflow volume through fan assembly  106  for improved efficiency. 
     In the exemplary embodiment, fan assembly  106  also includes a hub cap  164  configured for insertion into a cap cavity  166  defined in inlet surface  114 . Cavity  166  includes a central opening  168  having a planar portion  170 . A threaded fastener (not shown), such as a bolt, is configured to be inserted through central opening  168  and a corresponding faster, such as a nut, is inserted into cavity  166  to secure fan assembly  106  to a rotor assembly  172  of electric motor  104 . Hub cap  164  is inserted into cavity  166  to both secure the nut in place and also to eliminate turbulent airflow by providing a smooth transition to inlet surface  114 . Hub cap  164  includes a planar surface (not shown) that aligns with planar portion  170  of central opening  168  to secure hub cap  164  to hub  110 . Such a configuration prevents undesired removal of hub cap  164  from hub  110  and still allows hub cap  164  to be removed for replacement of fan assembly  106 . 
     In the exemplary embodiment, inlet surface  114  includes a first portion  174  extending obliquely from inlet end of cylindrical portion  112  and a second portion  176  extending obliquely from first portion  174 . As shown in  FIGS. 6-8 , first surface  174  circumscribes second portion  176 . As best shown in  FIG. 8 , first portion  174  is oriented at a first angle θ with respect to a plane  178  perpendicular to axis  108 . Similarly, second portion  176  is oriented at a second angle β with respect to plane  178 . In the exemplary embodiment, first angle θ is greater than second angle β. Specifically, first angle θ of first portion  174  is oriented between approximately 5 degrees and approximately 10 degrees with respect to plane  178 . More specifically, first angle θ of first portion  174  is oriented approximately 7 degrees with respect to plane  178 . Similarly, second angle β of second portion  176  is oriented between approximately 2 degrees and approximately 5 degrees with respect to plane  178 . More specifically, second angle β of second portion  176  is oriented approximately 3 degrees with respect to plane  178 . Such a configuration provides for a smooth transition of airflow across inlet surface  114  and into blades  116 . 
       FIG. 9  is a bottom view of outlet end  162  of hub  110 .  FIG. 10  is a perspective view outlet end  162 .  FIG. 11  is a cross-sectional view of the fan assembly shown in  FIG. 1 n    the exemplary embodiment, hub  110  includes a core ring  180 , a first inner ring  182  circumscribing core ring  180 , and a first plurality of circumferentially-spaced ribs  184  extending radially between core ring  180  and first inner ring  182 . Additionally, hub  110  includes a second inner ring  186  circumscribing first inner ring  182  and a second plurality of circumferentially-spaced ribs  188  extending between first inner ring  182  and second inner ring  186 . As such, second plurality of ribs  188  are positioned radially outward of first plurality of ribs  184 . 
     In the exemplary embodiment, the quantity of ribs in first plurality of ribs  184  is equal to the quantity of ribs in second plurality of ribs  188 . Furthermore, the quantity of blades  116  of fan assembly  106  is equal to the quantity of rib in both first and second pluralities  184  and  188 . More specifically, in one embodiment, each rib  188  is radially aligned with a circumferential midpoint of a corresponding blade along outer periphery  118 . 
     As best shown in  FIG. 9 , first plurality of ribs  184  define a first radial length L 1 , and second plurality of ribs  188  define a second radial length L 2  that is longer than the first radial length L 1 . Specifically, the second radial length L 2  is at least twice as long as first radial length L 1 . Furthermore, first plurality of ribs  184  is circumferentially offset from second plurality of ribs  188 . Specifically, each rib of first plurality of ribs  184  is connected to first inner ring  182  approximately midway between adjacent ribs of second plurality of ribs  188 . In operation, pluralities of ribs  184  and  188  provide structural reinforcement to maintain fan assembly  106  parallel to rotor assembly  172  by distributing loads from the shaft (not shown) of electric motor  104  evenly among blades  116 . 
     In the exemplary embodiment, second plurality of ribs  188  are deformable to facilitate balancing fan assembly  106 . That is, a portion of at least one rib  188  can be removed from to balance fan assembly  106  and maintain its position parallel to rotor assembly  172 . In one embodiment, material can be removed from at least one rib  188  by carving blade  188  with a tool. In another embodiment, each rib  188  includes score marks that removal or predetermined portions of rib  188  as needed to balance fan assembly  106 . As such, material is removed from fan assembly  106  to facilitate balancing rather than adding weights or other counterbalancing devices that may not be available. 
     As shown in  FIGS. 8 and 9 , first inner ring  182  includes at least one alignment device  190  extending axially therefrom. Specifically, first inner ring  182  includes a plurality of alignment devices  190  equally spaced about first inner ring  182  and configured to mate with a respective one of a plurality of alignment openings  192  (shown in  FIG. 2 ) on rotor assembly  172 . Alignment devices  190  engage alignment openings  192  to facilitate attaching fan assembly  106  to motor  104  and to distribute rotational loads from rotor assembly  172 . 
     In the exemplary embodiment, hub  110  also includes an outer ring  194  that circumscribes second inner ring  186  to define a radial gap  196  therebetween. Gap  194  forms a continuous circle around second inner ring  186  and is configured to receive at least one balancing weight for balancing fan assembly  106 . By either removing material from second plurality of ribs  188  or adding a weight to gap  196 , or both, the balance of fan assembly  106  can be adjusted without adding weights to blades  116  or outer periphery  118  of hub  110  to maintain a clean visual appearance of fan assembly  106 . 
     Outer ring  194  forms a portion of cylindrical portion  112  and outer periphery  118  of hub  110 . Specifically, outer ring  194  includes an axial height H 1  that is equal to the axial length of cylindrical portion  112 . Additionally, as shown in  FIG. 11 , second inner ring  186  includes an axial height H 2  that is less than axial height H 1  of outer ring  194 . Furthermore, as shown in  FIG. 11 , outer ring  194  includes a first radial thickness T 1 , and second inner ring  186  includes a second radial thickness T 2  that is substantially similar to first radial thickness T 1 . 
       FIG. 12  is a top view of blade  116  of fan assembly  106 . In the exemplary embodiment, blade  112  is defined by leading edge  138 , trailing edge  140 , inner profile  198  extending between edges  138  and  140  at root  156 , and outer profile  200  extending between edges  138  and  140  at tip  140 . As shown in  FIG. 12 , inner profile  198  is defined by a curve having a radius R 1 , and outer profile  200  is defined by a curve having a radius R 2  that is larger than radius R 1 . Specifically, radius R 2  of outer profile  200  is approximately twice as large as radius R 1  of inner profile  198 . More specifically, radius R 1  of inner profile  198  is between approximately 40 millimeters (mm) and approximately 60 mm. Even more specifically, radius R 1  of inner profile  198  is approximately 50 mm. Similarly, radius R 2  of outer profile  200  is between approximately 90 mm and approximately 110 mm. Even more specifically, radius R 2  of outer profile  200  is approximately 100 mm. 
     Furthermore, in the exemplary embodiment, inner profile  198  defines a sweep angle γ of between approximately 18 degrees and approximately 24 degrees along root  156  between edges  138  and  140 . More specifically, inner profile  198  defines a sweep angle γ of approximately 21 degrees. Similarly, outer profile  200  defines a sweep angle λ of between approximately 28 degrees and approximately 32 degrees along tip  158  between edges  138  and  140 . More specifically, outer profile  200  defines a sweep angle λ of approximately 30 degrees. As such, the sweep angle λ of outer profile  200  is greater than sweep angle γ of inner profile  198 . Overall, blade  116  defines a sweep angle σ of between approximately 30 degrees and approximately 35 degrees from tip  158  of leading edge  138  to root  156  of trailing edge  140 . More specifically, blade  116  defines a sweep angle σ of approximately 33 degrees from tip  158  of leading edge  138  to root  156  of trailing edge  140 . As used herein, sweep angle is meant to describe the portion of the circumference of a circle taken up between radial lines connected at axis  108 . 
     In the exemplary embodiment, trailing edge  140  is substantially planar between inner profile  198  and outer profile  200 . Leading edge  138  includes a radius R 3  of between approximately 165 mm and approximately 175 mm between inner profile  198  and outer profile  200 . More specifically, leading edge  138  includes a radius R 3  of approximately 170 mm between inner profile  198  and outer profile  200 . 
     Additionally, in the exemplary embodiment, blade  116  includes a pressure side, a suction side, and a blade thickness defined therebetween. The blade thickness varies between leading edge  138  and trailing edge  140  such that the blade thickness is greatest approximately one third the distance from leading edge  138  to trailing edge  140 . Furthermore, each blade  116  may include at least one are of surface roughness to retain the airflow on blade and improve efficiency. Specifically, the pressure side of blade  116  may have one surface roughness, and the suction side of blade  116  may include a different surface roughness. Additionally, the surface roughness may vary between root  156  and tip  158  on the same side of blade  116 . Surface roughness can include either protrusions extending upward from blade  116 , or may include dimples that are formed in the surface of blade  116 . 
     The implementations described herein relate to an electric motor assembly for moving air in refrigeration equipment and other applications. The electric motor assembly includes an electric motor, a fan assembly coupled to the electric motor and configured to rotate therewith about an axis, and a shroud coupled to the electric motor and extending about the fan assembly. The shroud includes a central hub coupled to the electric motor, an inlet ring, and a plurality of arms extending between the central hub and the inlet ring. Each arm of the plurality of arms includes a curved radial portion extending from the central hub and a planar axial portion extending from the radial portion to the inlet ring. The fan assembly includes a hub including a cylindrical portion and an inlet surface coupled to an inlet end of the cylindrical portion. The fan assembly also includes a plurality of blades coupled to an outer periphery of the cylindrical portion, wherein the inlet surface is tapered to direct an inlet airflow toward the plurality of blades. An outlet end of the hub includes a core ring, a first inner ring circumscribing the core ring, and a first plurality of circumferentially-spaced ribs extending between the core ring and the first inner ring. The hub also includes a second inner ring circumscribing the first inner ring and a second plurality of circumferentially-spaced ribs extending between the first inner ring and the second inner ring. 
     The electric motor assembly described herein delivers an increased airflow at a higher efficiency with a lower noise level than other known air moving assemblies. The shroud arms are curved and swept in the direction of the airflow to allow the air to more easily pass through to reduce turbulence and improve efficiency. Also, the shroud arms are spaced to reduce blade tones. Similarly, the hub inlet surface is tapered to guide the incoming airflow into the blades at a predetermined angle to increase the amount of air flowing through the fan assembly. Additionally, the hub includes pluralities or ribs and rings that provide structural support to the fan assembly to maintain the fan assembly in position on the rotor and prevent vibrations to result in a reduced noise level. Moreover, the fan assembly is easily replaceable. Furthermore, the electric motor assembly described herein occupies a smaller volume than other known air moving assemblies and therefore allows a user to utilize smaller refrigeration equipment to take up less floor space. Additionally, the smaller size of the electric motor assembly described herein provides additional space within the refrigeration equipment to place products for sale. 
     This written description uses examples to disclose various implementations, including the best mode, and also to enable any person skilled in the art to practice the various implementations, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.