Abstract:
A vehicle having: vehicle structure including a pair of opposed sides and a rear, with a floor extending horizontally between the sides and rear; a battery-pack mounted above the floor; a fan assembly having a housing with a motor mounted therein directly behind the battery-pack, with the housing including a pair of flanges having U-slots with slot openings facing downward; and fasteners extending horizontally through the U-slots and secured to the battery-pack.

Description:
BACKGROUND OF INVENTION 
     The present invention relates to a vehicle battery pack assembly, and more particularly to the mounting of a fan assembly that cools the battery pack. 
     In vehicles that employ batteries for propulsion, such as for example, hybrid electric or battery electric vehicles, the batteries are often located behind the rear seats in a rear cargo area. The battery system may include a cooling fan assembly that creates a cooling flow inside the battery to maintain the desired battery temperature. While it may be desirable from a packaging and cooling efficiency standpoint to locate the cooling fan assembly right next to the batteries, it is not desirable to have the fan assembly pushed into the batteries during a vehicle impact event. 
     Accordingly, some have mounted the cooling fan motor and that portion of the cooling fan assembly offset laterally to the side of the batteries. In this way, in a vehicle rear impact event, the fan motor likely will not be pushed into the batteries. Others have mounted the cooling fan motor and that portion of the cooling fan assembly offset above the batteries, again reducing the chances that the fan motor is pushed into the batteries during a vehicle rear impact event. However, for some vehicles, it may be difficult due to packaging constraints or possibly less efficient for cooling to locate the cooling fan assembly offset from the batteries. 
     SUMMARY OF INVENTION 
     An embodiment contemplates a vehicle having: vehicle structure including a pair of opposed sides and a rear, with a floor extending horizontally between the sides and rear; a battery-pack mounted above the floor; a fan assembly having a housing with a motor mounted therein directly behind the battery-pack, the housing including a pair of flanges having U-slots with slot openings facing downward; and fasteners extending horizontally through the U-slots and secured to the battery-pack. 
     An advantage of an embodiment is that the cooling fan assembly for the battery-pack may be mounted in the vehicle directly behind the battery-pack, while minimizing a risk of the cooling fan assembly, and especially the motor unit, from damaging battery-pack internal components during a vehicle rear impact event. This allows for flexibility in locating the cooling fan assembly taking into account packaging, weight, and efficiency constraints. Moreover, the mounting of the cooling fan assembly is relatively simple, quick, while still allowing for the desired functionality during a vehicle rear impact event. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic, side view of a portion of a vehicle. 
         FIG. 2  is a schematic, plan view of a portion of a vehicle. 
         FIG. 3  is a schematic, perspective view of a cooling fan assembly mounted to a portion of a battery-pack. 
         FIG. 4  is a schematic, side view looking rearward at the cooling fan assembly. 
         FIG. 5  is a schematic, plan view of the cooling fan assembly. 
         FIG. 6  is an enlarged, schematic view looking in the direction of arrows  6 - 6  in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show an automotive vehicle  20  having a front end  22  and a rear end  24 , as well as two sides  26 . The vehicle  20  includes front seats  28  and rear seats  30  in a passenger compartment  31 . A rear portion of a floor  32  is located behind the rear seats  30  and extends between the sides  26  to the rear end  24  of the vehicle  20 . 
     Mounted above the floor  32 , behind the rear seats  30  is a battery-pack  34 . The term battery-pack, as used herein, may include other electronic components, such as power electronics, in addition to the actual battery cells themselves (not shown). A housing  36  of the battery-pack  34  includes a rear wall  38  that includes fluid flow openings that correspond to fluid flow openings in a cooling fan assembly  40 . 
     The cooling fan assembly  40  will now be discussed relative to  FIGS. 1-6 . The cooling fan assembly  40  includes a fan housing  42 . The fan housing  42  may be formed from plastic, or other suitable material. A pair of front ducts  44  include openings  46  in fluid communication with openings in the housing  36  to allow for fluid flow, such as air flow, between the battery-pack  34  and the fan housing  42 . This fluid flow may be air drawn from the passenger compartment  31 , through the battery-pack  34  to maintain a desired temperature range, and into the fan housing  42  via the front ducts  44 . The fluid may then be drawn through fan vanes in a motor unit and vane assembly  46  by operating the motor  47  to spin the vanes. The air pressure from the vanes then pushes the fluid through an opening  48  in an outlet duct  50  of the fan housing  42 . 
     The cooling fan assembly  40  is secured in the vehicle  20  at three mounting locations. A first pair of mounting locations  52  include a pair of mounting flanges  54  extending from the fan housing  42  into contact with the battery-pack housing  36 . Each of the mounting flanges  54  includes a U-shaped slot  56  (hereinafter referred to as U-slots). Each U-slot  56  has a bottom opening  58 . A fastener  59  extends through each U-slot  56  to secure the cooling fan assembly  40  to the battery-pack housing  36  via the mounting flanges  54 . Thus, each U-slot  56 , having a closed top portion of the mounting flange  54 , will support the weight of the fan assembly  40 , but still allow for a generally upward force to push the fan assembly  40  upward relative to the battery-pack  34 . Each of the fasteners  59  may be, for example, a nut and bolt, a screw or other similar type of fastener, and may include grommets  70  mounted in the U-slots  56 . The grommets  70  may have circular portions on each side of the corresponding flange  54 , with a smaller diameter portion extending through the respective U-slot  56 . 
     A remaining mounting location is a floor mount  60 , which includes a support arm  62  extending downward and somewhat radially out from a portion of the fan housing  42  adjacent to the motor unit and vane assembly  46 . The support arm  62  includes a floor mount hole  64 , which may be circular. A fastener  66  extends through the mount hole  64  to secure the support arm  62  to the floor  32  of the vehicle  20 . This fastener  66  may also include a grommet  72 , if so desired. 
     The flanges  54  and support arm  62  are configured to support the fan assembly  40 , and in particular, the motor  47 , directly behind the battery-pack  34 . When using the term “directly behind” herein, this means that the particular component is adjacent to a second component, between the second component and the rear  24  of the vehicle, without being offset to the side, above or below the second component. Thus, the motor  47 , in particular, is located in the vehicle installed fan assembly  40  adjacent to the battery-pack  34 , and between the battery-pack  34  and rear  34  of the vehicle, without being offset to one of the sides  26  of the vehicle (relative to the battery-pack  34 ), or offset above or below the battery pack. 
     The response of various components of the vehicle  20 , should the vehicle be subjected to a rear impact event, will now be discussed. In a significant rear impact event, the floor  32  begins to crush, which will tend to cause the floor  32  to push upward on the lower, rear portion of the fan assembly  40 . As the floor  32  pushes into the fan assembly  40 , the mounting flanges  54  will tend to slip upward relative to the fasteners  59 , with the bottom openings  58  of the U-slots  56  allowing the mounting flanges  54  to eventually slip free of the fasteners  59 . This allows the portion of the fan assembly  40  contacting the battery-pack housing  36  to slip upward and over the top of the battery-pack  34 . 
     Also, as the floor  32  begins to crush, the fan assembly  40  will tend to pivot about the fastener  66  securing the support arm  62  to the floor  32 . Thus, the fan assembly  40 , overall, pivots about this fastener  66  upward over the battery-pack  34 , minimizing the potential for the fan assembly  40 , and in particular the motor  47  from being pushed into the battery-pack  34  far enough to damage internal components of the battery-pack  34 . 
     While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.