Patent Publication Number: US-2023148460-A9

Title: Terminal box assembly for an electric motor assembly

Description:
BACKGROUND 
     The field of the disclosure relates generally to an electric motor assembly having a terminal box assembly, and more particularly, to a terminal box assembly that reduces or prevents the accumulation of debris where the terminal box assembly connects to the motor housing while allowing for the mounting of the terminal box in multiple orientations. 
     At least some known electric motor assemblies include a junction box or terminal box coupled to housing of the electric motor assembly. The terminal box serves as a place to house the connections made to power from the motor leads to the incoming power leads. Traditionally, a terminal box is designed so that it can be mounted in several orientations by the installer by removing fasteners, dismounting the junction box, and re-installing in a new orientation. However, this design inherently leads to debris collecting features in the design which is disadvantageous in the end use, especially in industries such as the food industry. Specifically, At least some known electric motor assemblies mount the terminal box to a stainless steel adaptor, which leaves a gap between the terminal box and stainless steel housing. This gap is an area where contaminants can reside. 
     One known approach is to fully weld the terminal box to the housing to prevent forming a gap therebetween. However, in such a situation, the terminal box is no longer rotatable relative to the housing and the conduit engagement hole is permanently located in a single fixed location. As such, the terminal box cannot be manipulated into various orientations with respect to the motor housing. 
     BRIEF DESCRIPTION 
     In one embodiment, a terminal box assembly for use with an electric motor assembly having a housing is provided. The terminal box assembly includes an annular adaptor fixedly coupled to the housing, a mounting hub extending from the housing and positioned within the adaptor, and an annular terminal box rotatably coupled to the adaptor. The terminal box includes a baseplate having a central opening defined therein and configured to receive the mounting hub therethrough. The terminal box assembly also includes a mounting bracket coupled to the mounting hub and positioned within the terminal box such that the baseplate is positioned between the mounting bracket and the adaptor. At least one fastener is inserted through an opening in the mounting bracket and is configured to selectively engage the base plate to compress the terminal box and the adaptor together. 
     In another embodiment, a method of assembling a terminal box assembly for use with an electric motor assembly having a housing is provided. The method includes fixedly coupling an annular adaptor to the housing around a mounting hub that extends from the housing and is positioned within the adaptor, and rotatably coupling an annular terminal box to the adaptor. The terminal box includes a baseplate having a central opening defined therein and configured to receive the mounting hub therethrough. The method also includes coupling a mounting bracket to the mounting hub such that the mounting bracket is positioned within the terminal box and such that the baseplate is positioned between the mounting bracket and the adaptor. The method further includes selectively engaging the base plate with at least one fastener that is inserted through an opening in the mounting bracket to compress the terminal box and the adaptor together, wherein engaging the baseplate prevents rotation of the terminal box relative to the adaptor and to seal an interior of the terminal box and the adaptor from an exterior environment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an exemplary electric motor assembly including an exemplary terminal box assembly; 
         FIG.  2    is an exploded view of the exemplary terminal box assembly shown in  FIG.  1   ; 
         FIG.  3    is a side cross-sectional view of the exemplary terminal box assembly shown in  FIG.  1   ; 
         FIG.  4    is a front cross-sectional view of the exemplary terminal box assembly shown in  FIG.  1   ; 
         FIG.  5    is a perspective cross-sectional view of the exemplary terminal box assembly shown in  FIG.  1   ; and 
         FIG.  6    is a top cross-sectional view of the exemplary terminal box assembly shown in  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments described herein relate to a terminal box assembly for use with an electric motor assembly and methods of assembling the same. The terminal box assembly is fully sealed to prevent debris collection and moisture ingress between the terminal box assembly and motor housing while still maintaining lead access opening orientation flexibility. Specifically, the embodiments relate to a terminal box assembly that includes an adaptor fixedly coupled to the motor housing and a terminal box that is selectively rotatably coupled to the adaptor. The cylindrical adaptor mates with the terminal box to seal an interior of the terminal box assembly from debris and moisture. As such, the adaptor prevents ingress and accumulation of debris and also provides an easily cleaned surface devoid of gaps and crevices where debris can congregate 
     A mounting bracket and accompanying fasteners selectively secure the terminal box to the adaptor to seal the interior of the terminal box and adaptor from debris and moisture. More specifically, in order to provide compression to the O-ring seal between the adaptor and the terminal box, the mounting bracket engages with the mounting hub groove thereby capturing the closed end of the terminal box between the mounting bracket and the adaptor. The mounting bracket contains one or more fastener engagement acceptance means that are intended to accept the fasteners used to interface to the fastener acceptance engagement means in the closed end of the terminal box. As these fasteners are tightened, the O-ring sealed relationship between the terminal box and terminal box adaptor experiences compression which is necessary to prevent moisture ingress. When the mounting bracket and fasteners are loosened, that is, partially disengaged from the terminal box, the terminal box may then be rotated relative to the adaptor to allow a technician to position a lead access opening in the terminal box into a desired orientation. Arcuate slots formed in a baseplate of the terminal box allow the terminal box to be rotated without damaging lead wires that extend from the motor housing into and through the terminal box assembly. Accordingly, the present embodiments remove the debris collecting features in the current art while still allowing the installer to orient the lead access opening in the terminal box in any angular orientation. 
       FIG.  1    is a perspective view of an exemplary electric motor assembly  10  including an exemplary terminal box assembly  12 . Motor assembly  10  includes a housing  14 , a motor  16  positioned within housing  14 , and a shaft  18  that is rotated by motor  16  and coupled to a load (not shown) 
       FIG.  2    is an exploded view of terminal box assembly  12 ,  FIG.  3    is a side cross-sectional view of terminal box assembly  12 ,  FIG.  4    is a front cross-sectional view of terminal box assembly  12 ,  FIG.  5    is a perspective cross-sectional view of terminal box assembly  12 , and  FIG.  6    is a top cross-sectional view of terminal box assembly  12 . 
     In the exemplary embodiment, terminal box assembly  12  includes a terminal box adaptor  20  that is fixedly and permanently coupled to an exterior surface of housing  14 . In one embodiment, adaptor  20  is welded to housing  14 . In another embodiment, adaptor  20  is integrally formed with housing  14  as a single casting. Adaptor  20  is annular or circular in shape and defines an interior chamber  22 . Fixedly coupling adaptor  20  to housing  14  seals interior  22  from an external environment to prevent debris from entering interior  22 . 
     A mounting hub  24  extends from a base  50  of adaptor  20  and is positioned within a circumference of adaptor  20 . More specifically, mounting hub  24  is positioned at a center of adaptor  20 . Similar to adaptor  20 , mounting hub  24  is one of welded or integrally formed with housing  14 . In the exemplary embodiment, mounting hub  24  includes a circumferential groove  26  formed near a distal end  28  of mounting hub  24 . 
     In the exemplary embodiment, an annular terminal box  30  is rotatably coupled to adaptor  20 . Terminal box  30  and adaptor  20  are both annular, that is, circular, and define a substantially similar diameter such that terminal box  30  also defines interior chamber  22 . A compressible O-ring  32  is positioned between terminal box  30  and adaptor  20  to allow rotation movement of terminal box  30  relative to adaptor  20 , but also to seal interior chamber  22  from the external environment. 
     Terminal box  30  includes an annular wall  34  and a baseplate  36 . In the exemplary embodiment baseplate  36  includes a central opening  38  that receives mounting hub  24  therethrough when terminal box  30  is coupled to adaptor  20 . In the exemplary embodiment, baseplate  36  also includes a pair of lead slots  40  that at least partially circumscribe central opening  38 . As best shown in  FIG.  6   , lead slots  40  are arcuate in shape to enable rotation of terminal box  30  relative to adaptor  20  while maintaining alignment of a portion of one of lead slots  40  with a housing lead opening  42  formed in housing  14 . As such, arcuate lead slots  40  allow for mounting of terminal box  30  in multiple different orientations with respect to adaptor  20 . 
     In the exemplary embodiment, terminal box assembly  12  includes a lead separator  44  that is positioned within lead opening  42  in housing  14  and includes a plurality of openings  46 . More specifically, adaptor  20  includes a base  50  that includes a flange  52  that extends into lead opening  42 . Flange  52  circumscribes an aperture  54  in base  50  into within lead separator  44  is positioned. Lead separator  44  maintains separation between the wire motor leads to eliminate the possibility of moisture ingress into housing  14  on the surface of the lead wires. In some embodiments, a sealing mechanism, such as an epoxy resin, is poured into adaptor  20  after the lead wires are threaded through lead separator  44  to seal openings  42  and  46  and aperture  54 . Furthermore, annular wall  34  of terminal box  30  includes a lead access opening  48  defined therethrough. Rotation of terminal box  30  relative to adaptor  20  enables a technician to change the location of lead access opening  48  to a desired position. 
     In operation, lead wires from motor  16  extend through openings  46  in lead separator  44  and into chamber  22 . The lead wires then pass through one of the arcuate slots  40  into terminal box  30  and through lead access opening  48  in annular wall  34 . The arcuate shape of slots  40  allow rotation of terminal box  30  without damaging the lead wires. 
     In the exemplary embodiment, terminal box assembly  12  also includes a mounting bracket  56  coupled to mounting hub  24  and positioned within terminal box  30  such that baseplate  36  is positioned between mounting bracket  56  and adaptor  20 . More specifically, mounting bracket  56  is coupled within groove  26  of mounting hub  24  such that groove  26  at least partially receives mounting bracket  56 . In one embodiment, mounting bracket  56  is a C-shaped plate that partially circumscribes mounting hub  24 . Alternatively, mounting bracket  56  can be any shape that facilitates operation of terminal box assembly  12  as described herein. 
     Mounting bracket  56  includes a pair of fastener openings  58  defined therethrough that each receive a fastener  60  of terminal box assembly  12 . In the exemplary embodiment, fasteners  60  engage baseplate  36  to compress terminal box  30  and adaptor  20  together. More specifically, baseplate  36  includes a pair of indentations  62 , as best shown in  FIG.  4   , that selectively engage with fasteners  60  to compress O-ring  32  and secure terminal box  30  and adaptor  20  together. 
     In operation, when fasteners  60  are tightened, their distal ends engage indentations  62  and push against baseplate  36  of terminal box  30  to compress O-ring  32  and secure terminal box  30  to adaptor  20 . As such, when fasteners  60  are fully tightened and fully engaged with baseplate  36 , terminal box  30  prevented from rotating relative to adaptor  20  and interior chamber  22  of terminal box  30  and adaptor  20  is sealed from the exterior environment. When fasteners  60  are at least partially disengaged from indentations  62  in baseplate  36 , terminal box  30  is able to be rotated relative to adaptor  20  to allow a technician to position lead access opening  48  in any desired orientation. 
     In the exemplary embodiment, terminal box assembly  12  also includes a grounding mechanism  64  coupled to baseplate  36  for grounding a ground of the lead wires. Furthermore, a cover plate  66  is coupled to terminal box  30  opposite adaptor  20  and seals chamber  22 . In one embodiment, cover plate  66  is threadably coupled to terminal box  30 . Alternatively, cover plate  66  is coupled to terminal box  30  in any manner that facilitates operation of terminal box assembly  12  as described herein. Additionally, an O-ring  68  is coupled between cover plate  66  and terminal box  30  to seal chamber  22  from the external environment. 
     The embodiments described herein relate to a terminal box assembly for use with an electric motor assembly and methods of assembling the same. The terminal box assembly is fully sealed to prevent debris collection and moisture ingress between the terminal box assembly and motor housing while still maintaining lead access opening orientation flexibility. Specifically, the embodiments relate to a terminal box assembly that includes an adaptor fixedly coupled to the motor housing and a terminal box that is selectively rotatably coupled to the adaptor. The adaptor of the terminal box assembly is permanently fixed to the motor housing in a manner that is not intended to be manipulated or changed by a technician. The cylindrical adaptor mates with the terminal box to seal an interior of the terminal box assembly from debris and moisture. As such, the adaptor prevents ingress and accumulation of debris and also provides an easily cleaned surface devoid of gaps and crevices where debris can congregate 
     A mounting bracket and accompanying fasteners selectively secure the terminal box to the adaptor to seal the interior of the terminal box and adaptor from debris and moisture. More specifically, in order to provide compression to the O-ring seal between the adaptor and the terminal box, the mounting bracket engages with the mounting hub groove thereby capturing the closed end of the terminal box between the mounting bracket and the adaptor. The mounting bracket contains one or more fastener engagement acceptance means that are intended to accept the fasteners used to interface to the fastener acceptance engagement means in the closed end of the terminal box. As these fasteners are tightened, the O-ring sealed relationship between the terminal box and terminal box adaptor experiences compression which is necessary to prevent moisture ingress. When the mounting bracket and fasteners are loosened, the terminal box may then be rotated relative to the adaptor to allow a technician to position a lead access opening in the terminal box into a desired orientation. Arcuate slots formed in a baseplate of the terminal box allow the terminal box to be rotated without damaging lead wires that extend from the motor housing into and through the terminal box assembly. Accordingly, the present embodiments remove the debris collecting features in the current art while still allowing the installer to orient the lead access opening in the terminal box in any angular orientation. 
     The methods and apparatus are not limited to the specific embodiments described herein, but rather, components of apparatus and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. 
     Exemplary embodiments of terminal box assemblies for electric motor assemblies are described above in detail. The terminal box assemblies and its components are not limited to the specific embodiments described herein, but rather, components of the systems may be utilized independently and separately from other components described herein. For example, the components may also be used in combination with other motor systems, methods, and apparatuses, and are not limited to practice with only the systems and apparatus as described herein. Rather, the exemplary embodiments can be implemented and utilized in connection with many other applications. 
     Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention 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 languages of the claims.