Abstract:
A battery assembly according to an exemplary aspect of the present disclosure includes, among other things, a tray, a battery array mounted to the tray, a cover positioned about the battery array and a reinforcement member disposed between the cover and the battery array.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to a battery assembly, and more particularly, but not exclusively, to a reinforcement member for absorbing and/or transferring energy within a battery assembly during a loading event. 
       BACKGROUND 
       [0002]    Electrified vehicles, such as hybrid electric vehicles (HEV&#39;s), plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s), or fuel cell vehicles differ from conventional motor vehicles because they are powered by electric machines (i.e., electric motors and/or generators) instead of or in addition to an internal combustion engine. High voltage current for powering these types of electric machines is typically supplied by high voltage battery assemblies. 
         [0003]    Electrified vehicle battery assemblies include one or more battery arrays. Each battery array includes a plurality of battery cells that are supported relative to one another. The battery arrays may be subjected to loading during vehicle testing, vehicle operation, or other loading events. The packaging of battery arrays may therefore benefit from structural energy management. 
       SUMMARY 
       [0004]    A battery assembly according to an exemplary aspect of the present disclosure includes, among other things, a tray, a battery array mounted to the tray, a cover positioned about the battery array and a reinforcement member disposed between the cover and the battery array. 
         [0005]    In a further non-limiting embodiment of the foregoing battery assembly, the reinforcement member is L-shaped and extends between a wall of the cover and the battery array. 
         [0006]    In a further non-limiting embodiment of either of the foregoing battery assemblies, the reinforcement member is T-shaped and extends between the cover and the battery array and between the battery array and a second battery array. 
         [0007]    In a further non-limiting embodiment of any of the foregoing battery assemblies, a plurality of reinforcement members are positioned between the cover and the battery array. 
         [0008]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is made of a high density foam. 
         [0009]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is made of an expandable foam. 
         [0010]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is made of a non-foamed polymer. 
         [0011]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is made of rubber. 
         [0012]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is mounted to at least one of the cover and the battery array. 
         [0013]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is mounted to the cover but spaced from the battery array. 
         [0014]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is a loosely fitted structure positioned between the cover and the battery array. 
         [0015]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the reinforcement member is at least as wide as the battery array. 
         [0016]    A battery assembly according to another exemplary aspect of the present disclosure includes, among other things, a first battery array, a second battery array and a cover positioned about the first battery array and the second battery array. A reinforcement member extends between the first battery array and the second battery array or between the cover and at least one of the first battery array and the second battery array. 
         [0017]    In a further non-limiting embodiment of the foregoing battery assembly, the reinforcement member is positioned near a centerline of the first battery array and the second battery array. 
         [0018]    In a further non-limiting embodiment of either of the foregoing battery assemblies, the reinforcement member includes a first portion that extends between the first battery array and the second battery array, and a second portion that extends between the cover and the at least one of the first battery array and the second battery array. 
         [0019]    In a further non-limiting embodiment of any of the foregoing battery assemblies, a second reinforcement member is disposed between the cover and at least one the first battery array and the second battery array. 
         [0020]    A method according to another exemplary aspect of the present disclosure includes, among other things, positioning a reinforcement member between a cover and a battery array and transferring a first portion of a load applied to the battery array from the battery array, through the reinforcement member, and then to the cover. 
         [0021]    In a further non-limiting embodiment of the foregoing method, the method includes absorbing a second portion of the load with the reinforcement member. 
         [0022]    In a further non-limiting embodiment of either of the foregoing methods, the positioning step occurs after the cover is mounted over the battery array. 
         [0023]    In a further non-limiting embodiment of any of the foregoing methods, the method includes injecting a material into an expandable bag attached to the cover after the cover is mounted over the battery array to form the reinforcement member. 
         [0024]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0027]      FIG. 2  illustrates a battery assembly of an electrified vehicle. 
           [0028]      FIG. 3  illustrates the battery assembly of  FIG. 2  with a cover of the assembly removed. 
           [0029]      FIGS. 4A ,  4 B,  4 C,  4 D and  4 E illustrate exemplary configurations of a battery assembly reinforcement member. 
           [0030]      FIG. 5  illustrates a battery assembly according to another embodiment of this disclosure. 
           [0031]      FIG. 6  illustrates a battery assembly according to yet another embodiment of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    This disclosure relates to a battery assembly for an electrified vehicle. The battery assembly includes at least one battery array and a cover positioned over and/or beside the battery array. A reinforcement member may be disposed between the cover and the battery array for absorbing and/or transferring energy from the battery array in response to a loading event. These and other features are discussed in greater detail herein. 
         [0033]      FIG. 1  schematically illustrates a powertrain  10  for an electrified vehicle  12 . Although depicted as a HEV, it should be understood that the concepts described herein are not limited to HEV&#39;s and could extend to other electrified vehicles, including, but not limited to, PHEV&#39;s and BEV&#39;s. 
         [0034]    In one embodiment, the powertrain  10  is a power-split powertrain system that employs a first drive system and a second drive system. The first drive system includes a combination of an engine  14  and a generator  18  (i.e., a first electric machine). The second drive system includes at least a motor  22  (i.e., a second electric machine), the generator  18 , and a battery assembly  24 . In this example, the second drive system is considered an electric drive system of the powertrain  10 . The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels  28  of the electrified vehicle  12 . 
         [0035]    The engine  14 , which may include an internal combustion engine, and the generator  18  may be connected through a power transfer unit  30 , such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine  14  to the generator  18 . In one non-limiting embodiment, the power transfer unit  30  is a planetary gear set that includes a ring gear  32 , a sun gear  34 , and a carrier assembly  36 . 
         [0036]    The generator  18  can be driven by the engine  14  through the power transfer unit  30  to convert kinetic energy to electrical energy. The generator  18  can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft  38  connected to the power transfer unit  30 . Because the generator  18  is operatively connected to the engine  14 , the speed of the engine  14  can be controlled by the generator  18 . 
         [0037]    The ring gear  32  of the power transfer unit  30  may be connected to a shaft  40 , which is connected to vehicle drive wheels  28  through a second power transfer unit  44 . The second power transfer unit  44  may include a gear set having a plurality of gears  46 . Other power transfer units may also be suitable. The gears  46  transfer torque from the engine  14  to a differential  48  to ultimately provide traction to the vehicle drive wheels  28 . The differential  48  may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels  28 . In one embodiment, the second power transfer unit  44  is mechanically coupled to an axle  50  through the differential  48  to distribute torque to the vehicle drive wheels  28 . 
         [0038]    The motor  22  can also be employed to drive the vehicle drive wheels  28  by outputting torque to a shaft  52  that is also connected to the second power transfer unit  44 . In one embodiment, the motor  22  and the generator  18  cooperate as part of a regenerative braking system in which both the motor  22  and the generator  18  can be employed as motors to output torque. For example, the motor  22  and the generator  18  can each output electrical power to the battery assembly  24 . 
         [0039]    The battery assembly  24  is an example type of electrified vehicle battery assembly. The battery assembly  24  may include a high voltage battery pack that is capable of outputting electrical power to operate the motor  22  and the generator  18 . Other types of energy storage devices and/or output devices can also be used to electrically power the electrified vehicle  12 . 
         [0040]      FIGS. 2 and 3  illustrate a battery assembly  24  that can be incorporated into an electrified vehicle, such as the electrified vehicle  12  of  FIG. 1 . The battery assembly  24  may include one or more battery arrays. Two battery arrays  60 A,  60 B are depicted in the illustrated embodiment. However, this disclosure is not limited to any specific number of battery arrays. 
         [0041]    Each battery array  60 A,  60 B may include a plurality of battery cells  62 . The battery cells  62  are disposed along a longitudinal axis A between opposing end plates  64 ,  66 . Side rails  68 ,  70  are disposed on each side of the battery cells  62  between the end plates  64 ,  66 . The battery cells  62  are held in position by the end plates  64 ,  66  and the side rails  68 ,  70 . 
         [0042]    The battery arrays  60 A,  60 B may be mounted to a tray  72  of the battery assembly  24 . In one embodiment, fasteners are inserted through openings in the end plates  64 ,  66  to secure the battery arrays  60 A,  60 B to the tray  72 . 
         [0043]    The battery assembly  24  may additionally include a cover  74  that can be attached to the tray  72  to cover the battery arrays  60 A,  60 B. The cover  74  is shown in phantom in  FIG. 2  and is removed in  FIG. 3  to better illustrate the interior features of the battery assembly  24 . The tray  72  and the cover  74  establish an enclosure that houses the various hardware and electronics of the battery assembly  24 , including but not limited to the battery arrays  60 A,  60 B. The cover  74  may be attached to the tray  72  in any known manner. In one non-limiting embodiment, the cover  74  is bolted to the tray  72 . 
         [0044]    One or more reinforcement members  76  may be disposed between the cover  74  and each battery array  60 A,  60 B. In the illustrated embodiment, the battery assembly  24  employs three reinforcement members  76 A,  76 B and  76 C. However, the battery assembly  24  could include only a single reinforcement member  68  (see, for example,  FIG. 5 ) or any other number of reinforcement members. 
         [0045]    In one non-limiting embodiment, the reinforcement members  76 A,  76 B and  76 C are positioned near a centerline C of the battery arrays  60 A,  60 B. In one embodiment, the centerline C is transverse to the longitudinal axis A. Although located near the centerline C in this embodiment, the reinforcement members  76 A,  76 B and  76 C could be positioned anywhere along the length of the battery arrays  60 A,  60 B. 
         [0046]    In the illustrated non-limiting embodiment, the reinforcement member  76 A is L-shaped and is disposed between a side wall  78  of the cover  74  and the side rail  68  of the battery array  60 A. A first portion  79  of the reinforcement member  76 A extends along the side rail  68  of the battery array  60 A and a second portion  81  that is transverse to the first portion  79  extends along a top surface  83  of the side rail  68  (see  FIG. 3 ). 
         [0047]    The reinforcement member  76 B may be T-shaped and can be positioned to extend between the battery arrays  60 A,  60 B as well as between the battery arrays  60 A,  60 B and a top wall  80  of the cover  74 . For example, a first portion  85  of the reinforcement member  76 B may extend between the side rail  70  of the battery array  60 A and the side rail  68  of the battery array  60 B (see  FIG. 3 ), and a second portion  87  of the reinforcement member  76 B may extend between the battery arrays  60 A,  60 B and the top wall  80  of the cover  74  (see  FIG. 2 ). The first portion  85  may extend in part along only a portion of the side of the battery arrays  60 A,  60 B or could extend all the way down to the surface supporting the battery arrays  60 A,  60 B. 
         [0048]    In another embodiment, the reinforcement member  76 B need not be T-shaped. For example, the reinforcement member  76 B could be configured as a foam wall that simply extends between the battery arrays  60 A,  60 B. 
         [0049]    The reinforcement member  76 C is similar to the reinforcement member  76 A. In one embodiment, the reinforcement member  76 C is L-shaped and extends between a sidewall  82  of the cover  74  and the side rail  70  of the battery array  60 B. A first portion  89  of the reinforcement member  76 CA extends along the side rail  70  of the battery array  60 B and a second portion  91  that is transverse to the first portion  89  extends along a top surface  93  of the side rail  70 . Various other shapes and configurations of the reinforcement members  76 A,  76 B and  76 C are also contemplated as is further discussed below. 
         [0050]    The reinforcement members  76 A,  76 B and  76 C may be made of a variety of materials. In one embodiment, the reinforcement members  76 A,  76 B and  76 C are made of high density foam. In another embodiment, the reinforcement members  76 A,  76 B and  76 C are made of a resilient plastic, such as a high density polyethylene (HDPE). In another embodiment, the reinforcement members  76 A,  76 B and  76 C are made of an insulator material. In yet another embodiment, the reinforcement members  76 A,  76 B and  76 C are made of an elastomeric rubber. In yet another embodiment, the reinforcement members  76 A,  76 B and  76 C are made of a non-foamed polymer. The material used to form the reinforcement members  76 A,  76 B and  76 C could also act as a conductor, or the cover  74  could include an insulating material. 
         [0051]    The reinforcement members  76 A,  76 B and  76 C are configured to absorb and/or transfer loads that are applied to the battery assembly  24  or developed from the battery assembly  24  due to inertial effects. For example, during vehicle operation or vehicle testing, the battery assembly  24  may be subjected to a loading event in which a load is applied to the battery assembly  24  or an inertial load is developed along the X-axis or the Z-axis (see  FIG. 2 ). When these loads are applied, the battery arrays  60 A,  60 B of the battery assembly  24  may engage one or more of the reinforcement members  76 A,  76 B and  76 C to restrict the amount of deformation that occurs along the X-axis or the Z-axis. 
         [0052]    By way of one non-limiting example, such as when a load is applied along the positive X-axis, the battery array  60 B may engage the reinforcement member  76 C. A first portion of the load may be absorbed by the reinforcement member  76 C, and a second portion of load may be transferred through the reinforcement member  76 C into the cover  74  to help withstand the force and reduce the amount of bending experienced by the battery array  60 B. 
         [0053]    In response to the same load, the battery array  60 A may engage the reinforcement member  76 B. The reinforcement member  76 B may similarly absorb some of the load and transfer another portion of the load into the cover  74  and/or onto the battery array  60 B. 
         [0054]    In another embodiment, such as when a load is applied along the negative X-axis, the reinforcement member  76 A may be engaged by the battery array  60 A and the reinforcement member  76 B may be engaged by the battery array  60 B to absorb and/or transfer energy. In yet another embodiment, loads applied along the positive Z-axis may be absorbed and/or transferred into the cover  74  through portions of the reinforcement members  76 A,  76 B and  76 C that are disposed between the battery arrays  60 A,  60 B and the cover  74 . 
         [0055]    The material make-up of one or more of the reinforcement members  76 A,  76 B and  76 C can be tailored to either absorb more energy or transfer more energy in response to one or more of the loadings events described above. For example, a more rigid reinforcement member may be provided to transfer more of the energy generated during the loading event, whereas a less rigid reinforcement member may be provided to absorb more of the energy. Similarly, a more resilient member may recover its shape to a pre-loaded state after the load, whereas a more deforming member may absorb the energy of the load and not recover fully to its original shape. 
         [0056]      FIGS. 4A ,  4 B,  4 C,  4 D and  4 E illustrate various alternative configurations of a reinforcement member  76  that can be employed within a battery assembly  24 . Referring first to  FIG. 4A , the reinforcement member  76  is mounted to the cover  74  (and/or a battery array  60 ) and extends between a wall  99  of the cover  74  and the battery array  60 . The wall  99  could be either a top wall or a side wall of the cover  74 . The reinforcement member  76  may just contact the battery array  60  when the cover  74  is placed over the battery array  60 , or can be designed to establish an interference fit between the cover  74  and the battery array  60 . The reinforcement member  76  may limit the upwards motion of the battery array  60  by resisting compression, and may limit the sideways motion of the battery array  60  by resisting shear. 
         [0057]    Referring to  FIG. 4B , the reinforcement member  76  may be spaced from the battery array  60  such that it is not in contact with the battery array  60  during non-loading events. In this embodiment, the reinforcement member  76  is in relative close proximity to the battery array  60  such that if the battery array  60  begins to bend under a load, the reinforcement member  76  is quickly engaged to absorb and/or transfer energy into the cover  74 . 
         [0058]    The reinforcement member  76  could alternatively be a free floating structure positioned between the cover  74  and the battery array  60  (see  FIG. 4C ). In other words, the reinforcement member  76  may be loosely fitted and not positively retained to any structure but bound in place by the presence of one or more structures. The reinforcement member  76  can also be designed such that it includes a width W that is equivalent to the width of the battery array  60  (see  FIG. 4D ). In yet another embodiment, the reinforcement member  76  may be configured such that it extends between both a side wall  78  of the cover  74  and the battery array  60  and a top wall  80  of the cover  74  and the battery array  60  (see  FIG. 4E ). 
         [0059]    It should be understood that the embodiments of  FIGS. 4A-4E  are not mutually exclusive. For example, the embodiments of  FIGS. 4A-4C  could be combined with the embodiment of  FIG. 4D , which may be combined with the embodiment of  FIG. 4E  in any combination. 
         [0060]      FIG. 5  illustrates a battery assembly  124  according to another exemplary embodiment of the disclosure. In this disclosure, like reference numbers designate like elements where appropriate and reference numerals with the addition of 100 or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding original elements. 
         [0061]    In this embodiment, the battery assembly  124  includes a single reinforcement member  176 . The reinforcement member  176  may extend across a width W that spans both a first battery array  160 A and a second battery array  160 B, or multiple arrays. The reinforcement member  176  is disposed between a cover  174  (shown in phantom) and the first battery array  160 A and the second battery array  160 B. The reinforcement member  176  may include a body  109  having a first leg  111 , a second leg  113 , and a third leg  115 . In one embodiment, the first leg  111  extends between a side wall  178  of the cover  174  and the first battery array  160 A, the second leg  113  extends between the first battery array  160 A and the second battery array  160 B, and the third leg  115  extends between a side wall  182  of the cover  174  and the second battery array  160 B. 
         [0062]      FIG. 6  illustrates yet another battery assembly  224 . In this embodiment, a cover  274  is positioned over a battery array  260  and mounted to a tray  272  without any reinforcement member in place between the cover  274  and the battery array  260 . A cavity  221  extends between the battery array  260  and a wall  299  of the cover  274 . The cavity  221  defines a space for forming a reinforcement member inside the battery assembly  224  after the cover  274  has been mounted to the tray  272  (i.e., after the cover  274  has been positioned over the battery array  260 ). 
         [0063]    An expandable bag  225  may be attached to the cover  274 . A material M may be injected into the expandable bag  225  with a tool  227  through an aperture  229  formed through a wall  299  in order to fill the expandable bag  225 . In one embodiment, the material M includes an expandable foam. In another embodiment, the material M includes a non-foaming, resilient polymer. As the expandable bag  225  expands, it reduces the size of the cavity  221 . In one embodiment, the material M may cure within the expandable bag  225  to form a reinforcement member  276  between the cover  274  and the battery array  260 . 
         [0064]    The reinforcement member  276  may alternatively be formed by inserting the material M into the expandable bag  225  just prior to mounting the cover  274  to the tray  272  such that the material M is still formable during the assembly but later cures to a rigid or semi-rigid state. In another embodiment, the expandable bag  225  may be filled with a compound that is formable, but later cures to a desired rigidity. The expandable bag  225  could also be filled with one or more compounds that are mixed together upon placement of the cover  274  over the batter array  260 . The compounds may then chemically react with one another and cure to form a rigid or semi-rigid reinforcement member. The expandable bag  225  could alternatively be filled with a liquid that does not cure but enables load transfer from the battery array  260  to the cover  274  by developing pressure within the fluid filled bag. 
         [0065]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0066]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0067]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.