Patent Publication Number: US-11641138-B2

Title: Multi-component rotor for an electric motor of an appliance

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 17/101,371 filed Nov. 23, 2020, entitled MULTI-COMPONENT ROTOR FOR AN ELECTRIC MOTOR OF AN APPLIANCE, now U.S. Pat. No. 11,374,448, which is a continuation of U.S. patent application Ser. No. 16/395,600 filed Apr. 26, 2019, entitled MULTI-COMPONENT ROTOR FOR AN ELECTRIC MOTOR OF AN APPLIANCE, now U.S. Pat. No. 10,897,167, which is a continuation of U.S. patent application Ser. No. 14/965,953 filed Dec. 11, 2015, entitled MULTI-COMPONENT ROTOR FOR AN ELECTRIC MOTOR OF AN APPLIANCE, now U.S. Pat. No. 10,326,323, the entire disclosures of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     The device is in the field of rotors for electric motors. Specifically, the device relates to a rotor hub fora rotor of an electric motor included within a laundry appliance. 
     SUMMARY 
     In at least one aspect, a motor for a laundry appliance includes a drive shaft coupled to a drum at a first end. The rotor frame is coupled proximate the second end of the drive shaft, where the rotor frame includes at least one polymeric material. A central hub includes a core and a perimetrical ring that extends circumferentially around the core. A plurality of recesses are defined within a planar surface of the perimetrical ring, wherein a portion of the polymeric material is received within the plurality of recesses to secure the rotor frame to the central hub. 
     In at least another aspect, a rotor for a motor for driving a laundry appliance includes a rotor frame having at least one polymeric material. A central hub includes a core defining a core outer surface and a perimetrical ring concentrically offset from and outside of the core outer surface. The perimetrical ring includes a ring outer surface and an inner ring surface. The inner ring surface and the core outer surface define an attachment portion, wherein a portion of the at least one polymeric material is received within the attachment portion to secure the polymeric frame to the central hub. 
     In at least another aspect, a motor for a laundry appliance includes a drive shaft that is coupled to a drum at a first end. A rotor frame is coupled proximate the second end of the drive shaft. The rotor frame includes at least one polymeric material. A central hub includes a core and a perimetrical ring that is offset from an outside of the core. An attachment portion is defined between the perimetrical ring and the outside of the core. A portion of the at least one polymeric material is received within the attachment portion to secure the polymeric frame to the central hub. 
     These and other features, advantages, and objects of the present device will be further understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG.  1    is a top perspective view of a laundry appliance incorporating a motor that includes an aspect of the dual-ring rotor hub; 
         FIG.  2    is a cross-sectional view of a direct drive motor for a laundry appliance having a rotor that incorporates an aspect of the dual-ring rotor hub; 
         FIG.  3    is a top perspective view of a rotor for a motor incorporating an aspect of the dual-ring rotor hub; 
         FIG.  4    is a cross-sectional view of the rotor of  FIG.  3    taken along line IV-IV; 
         FIG.  5    is a top perspective view of an aspect of the dual-ring rotor hub; 
         FIG.  6    is a cross-sectional view of the dual-ring rotor hub of  FIG.  5   , taken along line VI-VI; 
         FIG.  7    is an enlarged cross-sectional view of the rotor of  FIG.  4    taken at area VII; 
         FIG.  8    is a top perspective view of another aspect of a dual-ring rotor hub; and 
         FIG.  9    is a top perspective view of another aspect of a dual-ring rotor hub. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     For purposes of description herein the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the device as oriented in  FIG.  1   . However, it is to be understood that the device may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     As illustrated in  FIGS.  1 - 7   , reference numeral  10  generally refers to a motor for an appliance  12 , such as a laundry appliance. According to the various embodiments, a motor  10  for the laundry appliance  12 , such as a direct drive, incudes a drive shaft  14  that is coupled to a drum  16  at a first end  18 . A rotor frame  20  is coupled proximate a second end  22  of the drive shaft  14 , where the rotor frame  20  includes at least one polymeric material  24 . A central hub, in the form of a dual-ring rotor hub  26 , is included within the rotor frame  20 , where the central dual-ring rotor hub  26  has a core  28  and a perimetrical ring  30  that extends circumferentially around the core  28 . A plurality of recesses  32  are defined within a planar surface  34  of the perimetrical ring  30 , wherein a portion of the polymeric material  24  is received within the plurality of recesses  32  to secure the rotor frame  20  to the central dual-ring rotor hub  26 . It is also contemplated that a plurality of second recesses  36  can be defined within a second planar surface  38  of the perimetrical ring  30 , wherein a portion of the polymeric material  24  is also received within the plurality of second recesses  36  to secure the rotor frame  20  to the central dual-ring rotor hub  26 . 
     Referring again to  FIGS.  2 - 7   , it is contemplated that the various recesses  32  defined within the planar surface  34  and the second planar surface  38  can define an attachment portion  50  of the central dual-ring rotor hub  26 . It is contemplated that this attachment portion  50  of the central dual-ring rotor hub  26  can be set between the inner ring  52  that defines the core  28  and the outer perimetrical ring  30  that extends around the core  28 . It is contemplated that the planar surface  34  and the second planar surface  38  of the perimetrical ring  30  can be parallel planes, where the perimetrical ring  30  defines a ring shape having a consistent thickness which extends in a concentric offset manner around the core  28  of the central dual-ring rotor hub  26 . According to various alternate embodiments, it is contemplated that the planar surface  34  and the second planar surface  38  can be out of parallel, such that the configuration of the planar surface  34  and the second planar surface  38  contributes to the strength of the connection between the central dual-ring rotor hub  26  and the rotor frame  20 . 
     According to the various embodiments, as exemplified in  FIGS.  2 - 7   , it is contemplated that the rotor frame  20  can include an inner polymeric portion  60  that is made of at least one polymeric material  24 . In such an embodiment, when the rotor frame  20  is formed, at least a portion of the polymeric material  24  is injected, compressed, or otherwise formed into the recesses  32  and/or the second recesses  36  of the perimetrical ring  30  of the central dual-ring rotor hub  26 . In this manner, the forming of the polymeric material  24  within the recesses  32  and the second recesses  36  laterally and rotationally secures the rotor frame  20  to the central dual-ring rotor hub  26 . As such, the polymeric material  24  of the inner polymeric portion  60  of the rotor frame  20  flows around the perimetrical ring  30  of the central dual-ring rotor hub  26  and into the recesses  32  and second recesses  36  defined by the attachment portion  50  located between the core  28  and the perimetrical ring  30 . 
     Referring again to  FIGS.  1 - 4   , according to an exemplified and non-limiting aspect of the appliance  12 , the direct drive motor  10  into which the dual-ring rotor hub  26  is positioned includes a rotor  70  connected to the drive shaft  14  that extends between the rotor  70  and a drum  16  of the appliance  12 . The drum  16  is set within a tub  72  that receives wash water for cleaning various articles set within the drum  16 . The direct drive motor  10  is attached proximate the tub  72 , where a stator  74  of the direct drive motor  10  is coupled to a portion of the tub  72 , thereby substantially fixing the location of the stator  74 . Disposed in the tub  72  is a bearing housing  76  including at least one bearing  78  that allows the drive shaft  14  to be rotated within the wall  80  of the tub  72 . In this manner, as the rotor  70  rotates about the stator  74 , the connection of the rotor  70  to the drum  16  via the drive shaft  14  allows for the transfer of torque from the rotor  70  to the drive shaft  14  and, in turn, to the drum  16 . Typically, the rotor  70  includes magnets  82  that are in communication with windings  84  of the stator  74  and form a permanent synchronous motor  10 . It is contemplated that other types of electric motors  10  can be utilized in conjunction with the dual-ring rotor hub  26 , where the motor  10  includes a rotor  70  that rotates relative to a stator  74 . It is contemplated that the rotor  70  can rotate within the stator  74 , outside the stator  74 , or can include a dual-rotor configuration that rotates inside and outside of the stator  74 . Such motors  10  in which the dual-ring rotor hub  26  can be used can include, but are not limited to, direct drives, motors  10  that are coupled to transmissions, belt-drive motors  10 , and other similar electric motors. Additionally, the various aspects of the dual-ring rotor hub  26  can be used in various orientations of motor  10 , including motors  10  that are positioned along a vertical axis, a horizontal axis and/or an angled axis. Additionally, the various motors  10  using the dual-ring rotor hub  26  and the various embodiments of the rotor  70  can have inner rotor, outer rotor or dual rotor configurations. 
     According to the various embodiments, the various aspects of the rotor  70  described herein can be utilized in various electric motors  10  for use in a variety of appliances  12 . These appliances  12  can include front-load washers, top-load washers, dryers, and other similar appliances  12  having a rotational aspect driven by an electric motor  10 . 
     Referring again to  FIGS.  2 - 7   , according to the various embodiments, the connection between the dual-ring rotor hub  26  and the rotor frame  20  is configured to be a substantially strong connection to withstand the rotational forces exerted on the connection between the rotor frame  20  and the dual-ring rotor hub  26  as the rotor  70  is rotated about the stator  74  to drive the drum  16  and various loads disposed therein. In order to transfer the loads exerted upon the rotor  70  by the magnetic communication with the stator  74 , the rotor frame  20  can be made of various materials that are configured to allow for the transfer of these torque forces from the outer wall  90  of the rotor  70  to the drive shaft  14 . In this manner, the rotor frame  20  can include a continuous polymeric material  24  or a plurality of polymeric materials  24 , where the rotor frame  20  is formed about the plurality of magnets  82  of the rotor  70  and also about the perimetrical ring  30  of the dual-ring rotor hub  26 . It is also contemplated the rotor frame  20  can be made of a variety of materials, where the rotor frame  20  can include the inner polymeric portion  60 , an outer polymeric portion  92 , and at least one metallic portion, such as a metallic disk  94  that extends between the inner polymeric portion  60  and the outer polymeric portion  92 . In such an embodiment, it is contemplated that the inner and outer polymeric portions  60 ,  92  can be molded around the metallic disk  94  to form the rotor frame  20  into a unitary piece having sufficient strength to transfer the rotational and torque-type forces from the outer wall  90  of the rotor  70  to the drive shaft  14 , via the dual-ring rotor hub  26 . 
     According to the various embodiments, the material of the metallic disk  94  can be steel, aluminum, alloys thereof, combinations thereof, and other similar metallic materials. It is contemplated the one or more polymeric materials  24  can include various formable materials that can include, but are not limited to, plastic, resin, polymers, composite-type materials, combinations thereof, and other similar formable materials. 
     According to the various embodiments, as exemplified in  FIGS.  2 - 4   , it is contemplated that the inner polymeric portion  60  and the outer polymeric portion  92  can be made of separate polymeric materials. The stresses experienced by the inner polymeric portion  60  proximate the dual-ring rotor hub  26  can be higher than those experienced by the outer polymeric portion  92  where the rotor  70  is in magnetic communication with the stator  74 . As such, a highly-rigid polymeric material may be used to form the outer polymeric portion  92 . The use of this highly rigid polymeric material can serve to mitigate noise generation during use of the motor  10  of the appliance  12 . Such a rigid polymeric material for use in the outer polymeric portion  92  can include, but is not limited to, a bulk molding compound (BMC) and other similar highly rigid polymers. Alternatively, it is contemplated that a different polymer can be used to form the inner polymeric portion  60  that engages the dual-ring rotor hub  26 . At this location of the rotor  70 , cyclic high stresses can occur in the inner polymeric portion  60  with less sound issues being present. As such, the inner polymeric portion  60  can be made of various plastic materials that can include, but are not limited to, glass-filled polybutylene terephthalate (PBT), polypropylene, nylon, combinations thereof, and other similar high-performance polymers. 
     Referring again to the various embodiments exemplified in  FIGS.  2 - 4   , the outer polymeric portion  92  can also include a stiffening flange  104  that extends around the outer perimeter  106  of the outer polymeric portion  92 . The stiffening flange  104  can increase the rigidity of the rotor  70  by stiffening the circular profile of the rotor  70 . In this manner, the stiffening flange  104  can serve to counteract various deflections and deformations occurring in the rotor  70  during use. 
     Referring again to  FIGS.  2 - 7   , the dual-ring rotor hub  26  can be made of a metallic material, where such metallic materials can include, but are not limited to, steel, aluminum, aluminum alloy, and other formable metallic materials. In this manner, the dual-ring rotor hub  26  can be formed of a single integral piece through metal forming. While metallic materials are typical for the formation of the central dual-ring rotor hub  26 , it is contemplated that various resins and other plastic-type materials can be used for the central dual-ring rotor hub  26 . 
     Referring again to  FIGS.  2 - 7   , the recesses  32  and second recesses  36  defined within the attachment portion  50  between the perimetrical ring  30  and the core  28  can include various configurations and alignments. By way of example, and not limitation, it is contemplated that the recesses  32  defined within the planar surface  34  of the perimetrical ring  30  can be configured to be in vertical alignment with the various second recesses  36  defied within the second planar surface  38  of the perimetrical ring  30 . Alternatively, the recesses  32  and second recesses  36  can be defined as being free of vertical alignment or out of vertical alignment with one another. The various alignments of the recesses  32  and the second recesses  36  of the attachment portion  50  can be determined based upon the design of the appliance  12 , the design of the rotor  70 , and the various structural needs of the connection between the rotor frame  20  and the dual-ring rotor hub  26 . 
     Referring again to  FIGS.  2 - 7   , it is contemplated that the inner ring  52  defined by the core  28  can include a drive shaft receptacle  100 . The drive shaft receptacle  100  of the central dual-ring rotor hub  26  can include a plurality of grooves, or interior teeth  102 , that are adapted to engage a plurality of corresponding shaft grooves (not shown) positioned proximate the second end  22  of the drive shaft  14 . Accordingly, the torque-type forces exerted upon the rotor  70  at the electromagnetic engagement between the rotor  70  and the stator  74  are transferred through the rotor frame  20  and to the dual-ring rotor hub  26  at the engagement between the rotor frame  20  and the attachment portion  50  of the dual-ring rotor hub  26 . These torque-type forces are then transferred to the drive shaft  14  through the engagement of the dual-ring rotor hub  26  at the plurality of interior teeth  102  defined within the drive shaft receptacle  100  and the plurality of shaft grooves at the second end  22  of the drive shaft  14 . It is contemplated that the drive shaft  14  can be connected to the drive shaft receptacle  100  through various other connection methods. These connection methods can include, but are not limited to, fasteners, adhesives, welding, interference mechanisms, threads, combinations thereof and other connection methods. 
     Referring again to  FIGS.  2 - 7   , the rotor  70  for the direct drive motor  10  can include the rotor frame  20  having one or more polymeric materials  24 . Again, the polymeric material  24  can extend continuously through the rotor frame  20  or can be used in conjunction with various metallic or other dissimilar materials to form a unitary rotor frame  20 . Centrally disposed within the rotor frame  20  is the central dual-ring rotor hub  26  that includes the core  28  defining a core outer surface  110  and a perimetrical ring  30  concentrically offset from and outside the core outer surface  110 . The perimetrical ring  30  includes an outer ring surface  112  and an inner ring surface  114 . It is contemplated that the space between the inner ring surface  114  and the core outer surface  110  define an attachment portion  50 . At least a part of the at least one polymeric material  24  can be received within the attachment portion  50  to secure the rotor frame  20  to the central dual-ring rotor hub  26 . 
     Referring again to  FIGS.  4 - 7   , it is contemplated the attachment portion  50  of the dual-ring rotor hub  26  can include a circumferential wall  120  that extends between the core outer surface  110  and the inner ring surface  114 . The circumferential wall  120  substantially divides the attachment portion  50  into opposing first and second channels  122 ,  124 . The circumferential wall  120  disposed through the attachment portion  50  can be oriented to be substantially parallel with a base  128  of the rotor frame  20  and substantially perpendicular to an axis of rotation  130  of the drive shaft  14 . In this manner, the first and second channels  122 ,  124  of the attachment portion  50 , being separated by the circumferential wall  120 , are each configured to receive at least a portion of the polymeric material  24  of the rotor frame  20 . In order to further the engagement between the polymeric material  24  of the rotor frame  20  and the attachment portion  50  of the dual-ring rotor hub  26 , the circumferential wall  120  can include various perforations  132  that extend at least partially into the circumferential wall  120 . 
     According to various embodiments, it is also contemplated that these perforations  132  can extend through the circumferential wall  120 , such that the first and second channels  122 ,  124  of the attachment portion  50  are at least partially in communication with one another through the circumferential wall  120 . In such an embodiment, as the polymeric material  24  is formed into the first and second channels  122 ,  124 , the polymeric material  24  can extend from the first channel  122  and into at least a portion of the second channel  124 , and vice versa. It is also contemplated that the circumferential wall  120  can be free of, or substantially free of, perforations  132 , such that the first and second channels  122 ,  124  of the attachment portion  50  are fully divided by the circumferential wall  120  extending between the core outer surface  110  and the inner ring surface  114 . 
     Referring again to  FIGS.  3 - 7   , in addition to the circumferential wall  120 , it is contemplated that the attachment portion  50  can include a plurality of radial walls  140  that extend from at least one of the core outer surface  110  and the inner ring surface  114 . In this manner, the plurality of radial walls  140  are configured to divide the first channel  122  into the plurality of recesses  32 . It is also contemplated that the plurality of radial walls  140  can divide the second channel  124  into the plurality of second recesses  36 . According to the various embodiments, the plurality of radial walls  140  are configured to extend radially outward from the axis of rotation  130  of the drive shaft  14 . It is also contemplated that the radial walls  140  can include some other geometrical orientation, where such orientations can include, but are not limited to, grid-type configurations, irregular configurations, concentric configurations, combinations thereof, and other similar geometric configurations. 
     According to the various embodiments, the plurality of radial walls  140  can extend fully between the inner ring surface  114  and the core outer surface  110 . In such an embodiment, the recesses  32  and second recesses  36  disposed within the attachment portion  50  are fully separated and each of the recesses  32  and each of the second recesses  36  individually receives portions of the polymeric material  24  when the rotor frame  20  is being formed. It is also contemplated that the plurality of radial walls  140  can extend only partially between the inner ring surface  114  and the core outer surface  110  (exemplified in  FIG.  8   ). In such an embodiment, the various recesses  32  and second recesses  36  can be at least partially in communication with one another, respectively. 
     Referring again to  FIGS.  3 - 7   , it is contemplated that the attachment portion  50  defined between the perimetrical ring  30  and the core  28  can be substantially free of the circumferential wall  120  described above. In such an embodiment, the attachment portion  50  can include the plurality of radial walls  140  that extend between the core outer surface  110  and the inner ring surface  114 . In such an embodiment, the plurality of radial walls  140  serve to divide the attachment portion  50  into a plurality of attachment cavities that are defined by the recesses  32  and second recesses  36  when the circumferential wall  120  is omitted. The plurality of attachment cavities each receive a portion of the polymeric material  24  to define the engagement between the rotor frame  20  and the dual-ring rotor hub  26 . 
     According to the various embodiments, it is contemplated that the plurality of radial walls  140  can include a plurality of first radial walls  150  that are disposed in the first channel  122  and a plurality of second radial walls  152  that are disposed in the second channel  124 . In such an embodiment, it is contemplated that the plurality of first radial walls  150  can be free of alignment with the plurality of second radial walls  152 . In embodiments having the circumferential wall  120 , this configuration results in the recesses  32  being free of alignment with the second recesses  36 . In the various embodiments being free of the circumferential wall  120 , the lack of vertical alignment between the first radial walls  150  and the second radial walls  152  can define a series of alternating attachment cavities defined between the first and second radial walls  150 ,  152  positioned within the attachment portion  50  between the perimetrical ring  30  and the core  28 . 
     The attachment portion  50  defined between the perimetrical ring  30  and the core  28  can include various configurations of the radial walls  140 , circumferential wall  120 , recesses  32 , and second recesses  36  that are configured to maintain the structural integrity of the engagement between the rotor frame  20  and the dual-ring rotor hub  26 . The exact configurations of the various features defined between the perimetrical ring  30  and the core  28  can vary in order to secure the polymeric material  24  within the attachment portion  50  of the dual-ring rotor hub  26 . 
     Referring again to  FIGS.  2 - 7   , the direct drive motor  10  can include the drive shaft  14  that is coupled to the drum  16  at the first end  18 . The rotor frame  20  is coupled proximate the second end  22  of the drive shaft  14 , where the rotor frame  20  includes at least one polymeric material  24  that is configured to engage the central dual-ring rotor hub  26 . The central dual-ring rotor hub  26  includes the core  28  and the perimetrical ring  30  that is offset from and outside of the core  28 . The attachment portion  50  is defined between the core  28  and the perimetrical ring  30 . In this manner, a portion of at least one polymeric material  24  is received within the attachment portion  50  to secure the rotor frame  20  to the central dual-ring rotor hub  26 . 
     According to the various embodiments, the various radial walls  140  and/or circumferential walls  120  can be included within the attachment portion  50  to define the recesses  32 , second recesses  36 , attachment cavities, and other securing features to allow the polymeric material  24  to be formed within the attachment portion  50 , such that the primary attachment between the rotor frame  20  and the dual-ring rotor hub  26  occurs within the attachment portion  50 . Accordingly, the outer ring surface  112  of the perimetrical ring  30  can be substantially smooth and free of the various protrusions, teeth, or other outwardly extending securing features. The lack of these features can provide for an easier system of forming the various structures of the dual-ring rotor hub  26 . Similarly, the core outer surface  110  of the core  28  above and below the perimetrical ring  30  can also be made to be free of protrusions, teeth, and other outwardly extending features. Accordingly, the engagement between the rotor frame  20  and the dual-ring rotor hub  26  is primarily defined between the perimetrical ring  30  and the core  28 . In this manner, the various physical features disposed within the attachment portion  50  of the dual-ring rotor hub  26  allow for a secure engagement between the polymeric material  24  and the various physical features of the attachment portion  50  of the dual-ring rotor hub  26 . 
     According to the various embodiments, it is typical that the outer ring surface  112  of the perimetrical ring  30  and the core outer surface  110  of the core  28  above and below the perimetrical ring  30  will be a substantially smooth and cylindrical surface that is free or substantially free of protrusions, teeth, and other outwardly extending features. It is contemplated, though not typical, that the outer surface of the perimetrical ring  30  and the outward-facing surface of the core  28 , above and below the perimetrical ring  30 , can include various protrusions and other outwardly extending features to further define the engagement between the rotor frame  20  and the dual-ring rotor hub  26 . 
     Referring now to the various embodiments of the device as exemplified in  FIG.  8   , it is contemplated that the attachment portion  50  of a dual-ring rotor hub  26  can include various undulating surfaces  160  that define a substantially continuous recess  32  that extends circumferentially between the core  28  and the perimetrical ring  30 . These undulating surfaces  160  can extend from the outer core surface  110 , the inner ring surface  114 , or a combination of both. As discussed above, the undulating surfaces  160  defined between the perimetrical ring  30  and the core  28  can include various radial walls  140  that extend partially between the perimetrical ring  30  and the core  28  to define the undulating surface  160  and resulting recess  32  defined within the attachment portion  50  of the dual-ring rotor hub  26 . 
     Referring now to various aspects of the device as is exemplified in  FIG.  9   , it is contemplated that the perimetrical ring  30  can be defined by a discontinuous member that includes vertically undulating portions  170 . In such an embodiment, the recesses  32  defined within a first surface of the perimetrical ring  30  can be further defined by the vertically undulating portions  170  of the perimetrical ring  30 . Accordingly, the vertically undulating portions  170  of the perimetrical ring  30  corresponds to a plurality of vertically undulating recesses  32  and second recesses  36  defined within the first and second surfaces of the perimetrical ring  30 . In such an embodiment, it is contemplated that the vertically undulating portions  170  and the perimetrical ring  30  can further define the attachment portion  50  of the dual-ring rotor hub  26 . In the vertically undulating configurations of the perimetrical ring  30 , these vertically undulating portions  170  can be defined by curvilinear undulations, rectilinear undulations, offset portions of the perimetrical ring  30 , and other generally sinusoidal geometrical undulations that occur circumferentially about the core  28  of the dual-ring rotor hub  26 . 
     According to the various embodiments, the primary engagement between the rotor frame  20  and the dual-ring rotor hub  26  occurs within the attachment portion  50  defined between the perimetrical ring  30  and the core outer surface  110 . In this manner, the polymeric material  24  of the rotor frame  20  is configured to conform around the perimetrical ring  30  and into the attachment portion  50 . In this manner, resistance to the various rotational and axial forces exerted between the rotor  70 , the stator  74 , and the drive shaft  14  are received within the attachment portion  50  and the perimetrical ring  30  and transferred through the attachment portion  50  to the core  28  and into the drive shaft receptacle  100  and to the drive shaft  14  for transferring the torque from the drive shaft  14  to the drum  16 . By locating the attachment portion  50  outward from the core  28 , the engagement between the rotor frame  20  and the dual-ring rotor hub  26  is positioned further outward from the axis of rotation  130  of the drive shaft  14  than other conventional rotor hubs. The use of the perimetrical ring  30  to extend the dual-ring rotor hub  26  in an outward direction within the rotor frame  20  serves to provide a more efficient transfer of torque from the rotor frame  20 , through the dual-ring rotor hub  26 , and into the drive shaft  14  for transferring torque from the drive shaft  14  to the drum  16  of the appliance  12 . 
     It will be understood by one having ordinary skill in the art that construction of the described device and other components is not limited to any specific material. Other exemplary embodiments of the device disclosed herein may be formed from a wide variety of materials, unless described otherwise herein. 
     For purposes of this disclosure, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated. 
     It is also important to note that the construction and arrangement of the elements of the device as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations. 
     It will be understood that any described processes or steps within described processes may be combined with other disclosed processes or steps to form structures within the scope of the present device. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting. 
     It is also to be understood that variations and modifications can be made on the aforementioned structures and methods without departing from the concepts of the present device, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. 
     The above description is considered that of the illustrated embodiments only. Modifications of the device will occur to those skilled in the art and to those who make or use the device. Therefore, it is understood that the embodiments shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the device, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.