Abstract:
A fan shroud assembly includes a fixed fan shroud and a removable fan shroud. An upper retention system integral with the fixed and removable fan shrouds secures the two circumferential ends of the removable fan shroud to the fixed fan shroud. A lower retention system integral with the fixed and removable fan shroud secures the center of the removable fan shroud to the fixed fan shroud. No additional fasteners are required to connect the removable fan shroud to the fixed fan shroud because of the integral nature of the upper and lower retention systems.

Description:
FIELD 
     The present disclosure relates to fan shrouds for use in the engine compartment of automobiles. More particularly, the present disclosure relates to a two piece fan shroud assembly that snaps together in one simple motion to provide a sturdy and reliable assembly. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Automotive vehicles typically utilize an internal combustion engine to provide the power to operate the vehicle. Internal combustion engines generate heat due to the combustion process and it is necessary to continuously remove the excess heat from the vehicle&#39;s engine in order to maintain the operating temperature of the vehicle&#39;s engine at a specified level. 
     The usual method of removing this excess heat is an automotive cooling system. The cooling system utilizes a coolant pump which pumps coolant through the vehicle&#39;s engine to absorb the excess heat and then this heated fluid is pumped to a heat exchanger or radiator which removes the excess heat by performing a heat exchange process with ambient air. The coolant which has been cooled by the radiator is returned to the engine and the process continuously repeats itself. Typically, the temperature of the coolant is maintained at a minimum level using a thermostat or some other type of control system. 
     In order to reduce the size and thus the costs of the radiator, the automotive designer strives to have the radiator operate in the most efficient manner. One method used to maximize the efficiency of the radiator is to control the flow of ambient air through the radiator. This is accomplished by providing a fan which draws the ambient air through the radiator and then providing a fan shroud which ensures that the maximum amount of air is drawn through the radiator. 
     Automotive fans for the cooling system can be electrically driven or they can be driven by the vehicle&#39;s engine. Regardless of how they are driven, the maximization of ambient air flow requires that the fan be located within the fan shroud. The use of a fan that is driven by the engine and a fan shroud which is attached to the radiator presents problems during the assembly of the vehicle. In many cases, the vehicle frame, drive train and suspension are constructed first and the fan is attached to the driving component of the engine such as a coolant pump pulley or the crankshaft of the engine. The vehicle&#39;s body, including the radiator and fan shroud, is not assembled to the frame, drive train and suspension assembly until near the end of the assembly line. Since the fan needs to be located within the fan shroud, an interference/clearance issue is created when the body, including the radiator and fan shroud are lowered onto the frame. 
     This interference/clearance issue has been addressed by designing the fan shroud such that it has a removable portion at the bottom of the shroud in order to provide clearance for the fan during the assembly of the body to the frame. Once the body has been assembled to the frame, the removable portion is attached to the fixed portion of the shroud to avoid significant air loss through the radiator. 
     The connection between the removable portion and the fixed portion must be very secure. If it were to become detached during the life of the vehicle, it could lead to undercooling of the vehicle&#39;s engine due to a loss of ambient air through the radiator, or it could come loose and interfere with and possibly damage the fan itself. While it is necessary to adequately secure the removable portion to the fixed portion of the shroud, it still needs to be removable for any service required to the fan. Typically, the only access to the fan is through the removable portion of the fan shroud. Finally, the assembly of the removable portion to the fixed portion of the fan shroud has to be a simple and rapid assembly process in order to accommodate the vehicle as it moves down the assembly line. 
     SUMMARY 
     The present disclosure provides a two-piece fan shroud which includes a removable portion and a fixed portion. The assembly of the two pieces is accomplished using a locating feature and an integral clip thus eliminating the need of any additional fasteners. The assembly of the two pieces can be completed in seconds using a single hand from underneath the vehicle. The assembled fan shroud is robust and secure yet the fan shroud can still be disassembled easily for any service that is required. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a side elevation schematic view illustrating an automotive engine, a radiator, a cooling fan and a fan shroud in accordance with the present disclosure; 
         FIG. 2  is a rear perspective view of the fan shroud assembly in accordance with the present disclosure; 
         FIG. 3  is an exploded rear perspective view of the fan shroud assembly illustrated in  FIG. 2 ; 
         FIG. 4  is an enlarged perspective view of the upper latching system for the fan shroud assembly illustrated in  FIG. 2  in an unassembled condition; 
         FIG. 5  is an enlarged perspective view of the upper latching system for the fan shroud assembly illustrated in  FIG. 2  in an assembled condition; 
         FIG. 6  is an exploded front perspective view of the fan shroud assembly illustrated in  FIG. 2 ; 
         FIG. 7  is an exploded front perspective view of the fan shroud assembly illustrated in  FIG. 2 ; 
         FIG. 8  is an enlarged perspective view of the lower latching system for the fan shroud assembly illustrated in  FIG. 2  in an assembled condition; and 
         FIG. 9  is an enlarged perspective view of the lower latching system for the fan shroud assembly illustrated in  FIG. 2  in an assembled condition. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.  FIG. 1  schematically illustrates an automotive engine  10  positioned behind a radiator  12  as is typically seen in an engine compartment of a vehicle. A pair of hoses (not shown) are corrected between engine  10  and radiator  12  to provide for the flow of coolant. A coolant fan  14  is located between engine  10  and radiator  12  and coolant fan  14  is rotated by engine  10  using pulleys  16  and a drive belt  18 . While coolant fan  14  is illustrated being driven by pulleys  16  and drive belt  18 , it is within the scope of the present invention to have coolant fan  14  driven directly by engine  10 , be driven by an electric motor (not shown) or by any other means for driving coolant fan  14 . 
     A fan shroud assembly  20  is attached to radiator  12  and located in a position that circumferentially surrounds coolant fan  14  in a generally coaxial relationship. When coolant fan  14  is rotated, ambient air from in front of radiator  12  is drawn through radiator  12  to cool the coolant flowing between engine  10  and radiator  12 . Fan shroud assembly  20  covers the rear portion of radiator  12  to ensure that only ambient air from in front of radiator  12  is drawn through radiator  12  in order to maximize the ambient air flow through radiator  12  and thus maximize its cooling capacity 
     Fan shroud assembly  20  comprises a fixed fan shroud  30  and a removable fan shroud  32  both of which are molded plastic components. While fixed fan shroud  30  and removable fan shroud  32  are described as plastic components, it is within the scope of the present invention to utilize any suitable material for fixed fan shroud  30  and removable fan shroud  32 . Removable fan shroud  32  is detachable from fixed fan shroud  30  to create an opening  34  which provides clearance for coolant fan  14  during the assembly of the vehicle&#39;s body to the vehicle&#39;s frame. 
     Fixed fan shroud  30  includes a generally rectangular portion  36  at one end which transitions into a generally circular portion  38 . A semi-circular flange  40  extends axially from circular portion  38  to provide a portion of fan shroud assembly  20  within which coolant fan  14  is located. Fixed fan shroud  30  defines a plurality of mounting supports  42  which are utilized to secure fixed fan shroud  30  to radiator  12 . 
     Removable fan shroud  32  includes a semi-circular portion  44  which mates with semi-circular flange  40  to define a generally circular aperture  46  within which coolant fan  14  is located as illustrated in  FIG. 1 . Removable fan shroud  32  is secured to fixed fan shroud  30  using an upper latching system  48  and a lower latching system  50 . 
     Upper latching system  48  includes a pair of latches  52 , with each latch  52  being located on an opposite end or side of fan shroud assembly  20 . Since both latches  52  are identical except for being on opposite ends or sides of fan shroud assembly  20 , only one latch  52  will be detailed. It is to be understood that the opposite latch  52  includes the same elements as those detailed below. 
     Latch  52  includes a female portion  54  located on fixed fan shroud  30  and a male portion  56  located on removable fan shroud  32 . Female portion  54  includes a generally rectangular housing  60  which defines an aperture or slot  62  which is open toward the lower portion of fixed fan shroud  30  where removable fan shroud  32  is assembled. An angular wall  64  extends downward from rectangular housing  60  to provide a guiding surface for male portion  56  as described below. A rear wall  66  of rectangular housing  60  defines a retention opening  68  for retaining male portion  56  also as is detailed below. 
     Male portion  56  includes a retention finger  70  which circumferentially extends from opposite circumferential ends of semi-circular portion  44  of removable fan shroud  32  to engage female portion  54  of fixed fan shroud  30 . Retention finger  70  defines a retention tab  72  which engages with retention opening  68  to secure removable fan shroud  32  to fixed fan shroud  30  as detailed below. 
     Lower latching system  50  comprises a plurality of retention walls  80  extending from semi-circular portion  44  of removable fan shroud  32 . The present disclosure illustrates three retention walls  80  but there can be two or more retention walls  80  if desired. The plurality of retention walls  80  illustrated includes a first retention wall  82 , a second retention wall  84  and a third retention wall  86  arranged circumferentially along a forward edge of semi-circular portion  44  of removable fan shroud  32 . Retention walls  82 - 86  extend generally over the entire inner circumferential edge of semi-circular portion  44  with a gap  88  being located on opposite sides of second retention wall  84 . 
     Second retention wall  84  is disposed between first and third retention walls  82  and  86 . Second retention wall  84  extends from an inside surface  90  of semi-circular portion  44  while first and third retention walls  82  and  86  extend from an outside surface  92  of semi-circular portion  44 . Thus, as illustrated in  FIGS. 2 and 7 , when removable fan shroud  32  is assembled to fixed fan shroud  30 , circular portion  38  of fixed fan shroud  30  is sandwiched between second retention wall  84  and first and third retention walls  82  and  86 . While second retention wall  84  is disclosed as extending from inside surface  90  and first and third retention walls  82  and  86  are disclosed as extending from outside surface  92 , it is within the scope of the present invention to have second retention wall  84  extending from outside surface  92  and first and third retention walls  82  and  86  extending from inside surface  90  if desired. 
     An inside surface  94  of first retention wall  82 , an inside surface  96  of second retention wall  84  and an inside surface  98  of third retention wall  86  each define one or more retaining members  100  which extend radially towards circular portion  38  of fixed fan shroud  30 . Circular portion  38  of fixed fan shroud  30  defines a plurality of apertures  102  each of which accepts a respective retaining member  100  to secure removable fan shroud  32  to fixed fan shroud  30 . 
     The assembly of removable fan shroud  32  to fixed fan shroud  30  begins by aligning removable fan shroud  32  with fixed fan shroud  30  as illustrated in  FIG. 3 . Then, retention finger  70  of male portion  56  of upper latching system  48  is inserted into aperture  62  of female portion  54  of upper latching system  48  as illustrated in  FIGS. 4 and 5 . Angular wall  64  will help to guide retention finger  70  into aperture  62 . Next, removable fan shroud  32  is moved to sandwich circular portion  38  of fixed fan shroud  30  between retention walls  82 - 86 . Removable fan shroud  32  is urged towards fixed fan shroud  30  until retention members  100  snap into their respective apertures  102  as illustrated in  FIG. 7 . The movement of removable fan shroud  32  towards fixed fan shroud  30  and the engagement between retaining members  100  and apertures  102  will move retention finger  70  within rectangular housing  60  such that retention tab  72  of retention finger  70  extends through retention opening  68  of rear wall  66  as is illustrated in  FIG. 5 . 
     The assembly of removable fan shroud  32  to fixed fan shroud  30  to create fan shroud assembly  20  is completed without the use of additional fasteners or clips. Thus, the assembly can be completed by hand in a minimum of time without using tools. The assembled fan shroud assembly  20  is a robust design because of the circumferential length of retention walls  82 - 86  and it can be easily disassembled by releasing retaining members  100  from apertures  102  which will allow the rotation of removable fan shroud  32  such that retention tabs  72  will be released from retention openings  68  thus allowing for the easy removal of removable fan shroud  32 .