Patent Publication Number: US-2022231562-A1

Title: Compact busbar assembly

Description:
FIELD OF INVENTION 
     The present disclosure relates to a busbar assembly. 
     BACKGROUND 
     Electric motors generally include a stator, rotor, and other components. One such component is a busbar or contact carrier, which provides an electrical interface with a stator. Based on the varying shapes and sizes of electric motors, busbars can take on a variety of shapes, sizes, and configurations. 
     There is a general desire to provide more efficient electric motor designs as well as a desire to provide compact designs, which are relatively uncomplicated to manufacture and cost effective. 
     SUMMARY 
     A busbar assembly is disclosed that includes a carrier, and a plurality of conductors arranged within the carrier such that at least a portion of each of the plurality of conductors are exposed in a radial direction and define electrical contact sites. The carrier can be formed by molding the carrier about the plurality of conductors. 
     The conductors can include a first phase conductor, a second phase conductor, a third phase conductor, and a neutral conductor. The first conductor and the second conductor can be arranged in a first axial plane that extends perpendicular to an axis of the carrier, and the third conductor and the neutral conductor can be arranged in a second axial plane that extends perpendicular to the axis of the carrier. 
     The first phase conductor, the second phase conductor, the third phase conductor, and the neutral conductor each define a predetermined quantity of electrical contact sites, and the neutral conductor has more electrical contact sites than the other conductors. 
     In one embodiment, the neutral conductor is arranged such that the contacts of the neutral conductor are defined on a radially inner side of the carrier. 
     The carrier can include a plurality of retainers each dimensioned or configured to hold an electrical wire. The retainers are arranged along at least one of a radially inner surface or a radially outer surface of the carrier. The retainers include a first set of retainers defining slots oriented in a radial direction and a second set of retainers defining slots oriented in a circumferential direction. 
     The of conductors each have a square profile in one aspect. 
     Additional embodiments are disclosed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing Summary and the following Detailed Description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the disclosure. In the drawings: 
         FIG. 1  is a perspective view of a busbar assembly through a cross-section of the busbar assembly according to one aspect. 
         FIG. 2  illustrates the busbar assembly of  FIG. 1  implemented with a stator assembly. 
         FIG. 3  is a perspective view of a busbar assembly of  FIG. 1 . 
         FIG. 4  is a front cross-sectional view of the busbar assembly of  FIG. 1 . 
         FIG. 5  is a side cross-sectional view of the busbar assembly of  FIG. 1  from an elevated perspective. 
         FIG. 6  is a perspective view of a busbar assembly including wire retainers. 
         FIG. 7  is a front cross-sectional view of the busbar assembly of  FIG. 6 . 
         FIG. 8  is another front cross-sectional view of the busbar assembly of  FIG. 6  in a region different than the region shown in  FIG. 7 . 
         FIG. 9  illustrates the busbar assembly of  FIG. 6  implemented with a stator assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Certain terminology is used in the following description for convenience only and is not limiting. “Axially” refers to a direction along an axis (X) of an assembly. “Radially” refers to a direction inward and outward from the axis (X) of the assembly. “Circumferentially” refers to a direction extending along a curve or circumference of a respective element relative to the axis (X) of the assembly. 
     A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import. 
     As shown in the Figures, a busbar assembly  10  is disclosed. The busbar assembly generally includes a carrier  12  and a plurality of conductors  20 ,  30 ,  40 ,  50  arranged within the carrier  12 . 
     The carrier  12 , which is also known as an insulator body, is formed around each of the plurality of conductors  20 ,  30 ,  40 ,  50  such that at least a portion of each of the plurality of conductors  20 ,  30 ,  40 ,  50  are exposed (i.e. not completely encapsulated). The carrier  12  can be molded, i.e. overmolded, around the conductors or otherwise formed such that the carrier  12  envelopes or covers a majority of the conductors. In another aspect, an insulating body or carrier can be formed as a tray style configuration in which the carrier is formed or manufactured separately prior to the addition or joining of any conductors. The conductors can be placed or arranged inside of channels defined by the already formed carrier. Exposed portions of the conductors  20 ,  30 ,  40 ,  50  define electrical contact sites  22 ,  32 ,  42 ,  52 , also known as contact pads. In one aspect, the configuration is asymmetrical because no additional phase terminals need to be added to the conductors  20 ,  30 ,  40 ,  50 . As used herein, the term asymmetrical with respect to the configurations means that the incoming current arrived to the conductors at the terminals (i.e. the locations indicated by reference numerals  24 ,  34 , and  44 ) and travels the full length of the conductor to reach the final contact site. In contrast, a symmetrical arrangement requires that the incoming current and contact sites are split equally on either side of the terminal site. Thus, in a symmetrical arrangement, there is a symmetric amount of current provided to a symmetric quantity of windings on either side of the terminal location. 
     As shown in  FIG. 4 , the electrical contact sites  22 ,  32 ,  42 ,  52  can be formed by slight variations in either a radially outward or radially inward direction such that portions of the conductors  20 ,  30 ,  40 ,  50  are bent or deviate from a generally circular profile to define the electrical contact sites  22 ,  32 ,  42 ,  52 . 
     In one aspect, the plurality of conductors includes a first phase conductor  20 , a second phase conductor  30 , a third phase conductor  40 , and a neutral conductor  50 . For example, the three phases can correspond to the U, V, and W phases. One of ordinary skill in the art would recognize based on the present disclosure that the number of phases and configuration of conductors can vary. 
     In one aspect, the conductors  20 ,  30 ,  40 ,  50  each have a square profile when viewed in the circumferential direction. One of ordinary skill in the art would understand that the shape of the conductors  20 ,  30 ,  40 ,  50  can vary and can be circular or any other shape. 
     As shown in  FIG. 5 , the first conductor  20  and the second conductor  30  are arranged in a first axial plane P 1  that extends perpendicular to an axis (X) of the carrier  12  and the third conductor  40  and the neutral conductor  50  are arranged in a second axial plane P 2  that extends perpendicular to the axis (X) of the carrier  12 . In other words, a first set of conductors (i.e. the first conductor  20  and the second conductor  30 ) are stacked on top of each other in a radial direction, and a second set of conductors (i.e. the third conductor  40  and the neutral conductor  50 ) are axially spaced away or offset from the first set of conductors and are stacked on top of each other in the radial direction. 
     The first phase conductor  20 , the second phase conductor  30 , the third phase conductor  40 , and the neutral conductor  50  each define a predetermined quantity of electrical contact sites  22 ,  32 ,  42 ,  52 . In one aspect, the predetermined quantity of electrical contact sites  52  of the neutral conductor  50  is greater than any one of the predetermined quantities of electrical contact sites of the first phase conductor  20 , the second phase conductor  30 , or third phase conductor  40 . One of ordinary skill in the art would recognize that the quantity of electrical contact sites  22 ,  32 ,  42 ,  52  can vary. In another aspect, the quantity of neutral contact sites  52  can equal a sum of all of the quantities of contact sites  22 ,  32 ,  42  for the other phase conductors. 
     In one aspect, the neutral conductor  50  is arranged such that the contacts  52  of the neutral conductor  50  are defined on a radially inner surface  14  of the carrier  12 . This configuration can be modified such that the neutral conductor contacts  52  are defined on a radially outer surface  16  of the carrier  12 . 
     A stator assembly is generally shown in  FIGS. 2 and 9 , and illustrates wires or windings  70  configured to engage with the electrical contact sites  22 ,  32 ,  42 ,  52  of the conductors  20 ,  30 ,  40 ,  50 . In a fully assembled state, the wires  70  are connected to the electrical contact sites  22 ,  32 ,  42 ,  52  of the conductors  20 ,  30 ,  40 ,  50 . For example, the connections between these elements can be provided by laser welding, silver soldering, resistance welding, or any other form of connection. 
     Each of the conductors  20 ,  30 ,  40 ,  50  has a predetermined thickness (t), and the carrier  12  has an overall axial thickness (T A ) defined between a third axial plane (P 3 ) and a fourth axial plane (P 4 ), as shown in  FIG. 5 . An entirety of the busbar assembly  10  is axially constrained between the third axial plane (P 3 ) and the fourth axial plane (P 4 ). 
     The conductor thickness (t) is less than 40% of the overall axial thickness (T A ) of the conductor  12  in one embodiment. In another aspect, the conductor thickness (t) is 25%-45% of the overall axial thickness (T A ) of the conductor  12 . In one aspect, the thickness (t) of the conductor is a function of the application and current requirements, as well as any manufacturing requirements. 
     Based on the conductors  20 ,  30 ,  40 ,  50  having a square profile (at least in regions away from the contacts), the thickness (t) of the conductors  20 ,  30 ,  40 ,  50  is the same in the radial and axial direction. As shown in  FIG. 5 , an overall radial thickness (T R ) is also predefined for the carrier  12 , and the conductor thickness (t) is less than 40% of the overall radial thickness (T R ) in one embodiment. In another aspect, the conductor thickness (t) is 25%-45% of the overall radial thickness (T R ). In one aspect, thicknesses (T A ) and (T R ) are a function of the thickness (t) and the electrical insulation requirements. 
     One of ordinary skill in the art would understand that the dimensions of the carrier  12  and the conductors  20 ,  30 ,  40 ,  50  can vary. The present disclosure generally provides an axially and radially compact configuration for the busbar assembly  10 . 
     As shown in  FIG. 2 , ends  24 ,  34 ,  44  of the first, second, and third conductors  20 ,  30 ,  40  can include a terminal  25 ,  35 ,  45 . The ends  24 ,  34 ,  44  of the first, second, and third conductors  20 ,  30 ,  40  extend in an entirely radial direction and radially outward from the carrier  12 . In one aspect, the terminals can be created or formed from the conductor itself. In other words, a separate terminal component or element may not be required. 
     As shown in  FIGS. 6-9 , the carrier can include a plurality of retainers  60  each configured or dimensioned to hold the electrical wires  70  in place. In one aspect, the retainers are configured to hold the wires  70  in place during manufacturing or assembly. The carrier  12  in  FIGS. 6-9  is otherwise identical to the carrier  12  in  FIGS. 1-5 . The retainers  60  can be formed in a variety of configurations and shapes, and can be located in a variety of locations along the carrier  12 . In one aspect, the plurality of retainers  60  are arranged along at least one of a radially inner surface  14  or a radially outer surface  16  of the carrier  12 . In one embodiment, the retainers  60  are provided on both the radially inner surface  14  and the radially outer surface  16  of the carrier  12 . 
     In one aspect, the retainers  60  include a first set of retainers  62  defining slots  64  oriented in a radial direction, and a second set of retainers  66  defining slots  68  oriented in a circumferential direction. The specific shape, location, and quantity of the retainers  60  can vary, as one of ordinary skill in the art would understand based on the present disclosure. As shown in the drawings, the retainers  60  each circumferentially overlap with at least one of the electrical contact sites  22 ,  32 ,  42 ,  52 . In one aspect, the retainers  60  are arranged circumferentially directly adjacent to two electrical contact sites and axially directly adjacent to another electrical contact site (as illustrated in  FIG. 9 ). In other words, the retainers  60  can be arranged such that they are surrounded on at least three sides by electrical contact sites. 
     Having thus described the present disclosure in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the embodiments, could be made without altering the inventive concepts and principles embodied therein. 
     It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. 
     The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the embodiments being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein. 
     LOG OF REFERENCE NUMERALS 
     busbar assembly  10   
     carrier  12   
     radially inner surface  14  of carrier 
     radially outer surface  16  of carrier 
     first phase conductor  20   
     first phase conductor electrical contact site  22   
     first phase conductor end  24   
     first phase conductor terminal  25   
     second phase conductor  30   
     second phase conductor electrical contact site  32   
     second phase conductor end  34   
     second phase conductor terminal  35   
     third phase conductor  40   
     third phase conductor electrical contact site  42   
     third phase conductor end  44   
     third phase conductor terminal  45   
     neutral conductor  50   
     neutral conductor electrical contact site  52   
     retainers  60   
     first set of retainers  62   
     slots  64   
     second set of retainers  66   
     slots  68   
     wires  70