Abstract:
An cooling apparatus and method for providing a cooling air flow in a region of a constant velocity joint. The constant velocity joint has a housing comprising a first housing portion and a second housing portion. The first and second housing portions are coupled together by fasteners. The cooling device comprises a load-distributing portion and a fan-blade portion. The load-distributing portion is located between a head of each fastener and either the first or second housing portion, with each fastener inserted into a respective hole in the load-distributing portion. The load-distributing portion distributes a load applied by the fasteners to the first or second housing portion. The fan-blade portion is coupled to the load-distributing portion. The fan-blade portion is configured to create a current of air when the constant velocity joint housing rotates.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention pertains to cooling vehicle components and, more particularly, to coupling a fan to a housing for a constant velocity joint to provide cooling along a driveline of a vehicle. 
         [0002]    In a motor vehicle, various driveshafts are used to transmit power from a power source, such as an internal combustion engine or electric motor, to the vehicle&#39;s wheels. A driveshaft typically includes constant velocity joints, which allow for angular misalignment and, in some cases, axial displacement between the driveshaft and an object to which it is coupled, such as other driveshafts, a transmission, a transfer case, a differential assembly or a wheel hub. 
         [0003]    During operation of the vehicle, various driveline components can generate a significant amount of heat. This is especially problematic when the driveline components are located in a compact space. The heat can reduce the lifespan of those components, as well as other nearby components. In some cases, the heat even leads to outright failure of the component. As a result, it is advantageous to provide cooling to certain portions of the driveline. However, space, assembly and cost concerns make it difficult to cool certain areas and components. 
         [0004]    Based on the above, there exists a need in the art for a way to cool driveline components that is efficient in terms of space, assembly time and cost. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to a cooling assembly and method for providing a cooling air flow in a region of a constant velocity joint. The constant velocity joint has a housing comprising a first housing portion and a second housing portion. The first and second housing portions are coupled together by fasteners. A cooling device comprises a load-distributing portion and a fan-blade portion. The load-distributing portion is located between a head of each fastener and either the first or second housing portion, with each fastener being inserted into a respective hole in the load-distributing portion. The load-distributing portion distributes a load applied by the fasteners to the first or second housing portion. The fan-blade portion is coupled to the load-distributing portion and is configured to create a current of air when the constant velocity joint housing rotates. 
         [0006]    In one preferred embodiment, more than one cooling device is coupled to the constant velocity joint housing. In another preferred embodiment, the fan-blade portion includes more than one fan blade. In a still further preferred embodiment, the fan-blade portion is formed integral with the load-distributing portion. 
         [0007]    Additional objects, features and advantages of the present invention will become more readily apparent from the following detail description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic view of a vehicle driveline including constant velocity joints provided with a cooling system in accordance with the present invention; 
           [0009]      FIG. 2  is perspective view of a portion of a vehicle driveline including a constant velocity joint having a cooling system in accordance with a first embodiment of the present invention; 
           [0010]      FIGS. 3A-E  are perspective views of a cooling system in accordance with the first embodiment of the present invention; 
           [0011]      FIGS. 4A-C  are perspective views of a cooling system in accordance with a second embodiment of the present invention; and 
           [0012]      FIGS. 5A-B  are perspective views of a cooling system in accordance with a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    Detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0014]    With initial reference to  FIG. 1 , there is shown a vehicle  100  with a driveline  105  that includes a power source  110 , such as an internal combustion engine or an electric motor, which is connected to a transmission  115  and a transfer case  120 . Transfer case  120  has a front driveshaft  125  and a rear driveshaft  130  extending therefrom. Front driveshaft  125  connects to a front differential assembly  135  which, in turn, connects to front half shafts  140 ,  141 . Front wheels  145 ,  146  are connected to the other ends of half shafts  140 ,  141 . Rear driveshaft  130  connects to a rear differential assembly  150  which, in turn, connects to rear half shafts  155 ,  156 . Rear wheels  160 ,  161  are connected to the other ends of half shafts  155 ,  156 . These various connections enable power to be transmitted from power source  110  to front wheels  145 ,  146  and rear wheels  160 ,  161 . 
         [0015]    A plurality of constant velocity joints, and associated housings, is provided in driveline  105 . The plurality of constant velocity joints enables power to be transmitted from power source  110  to front wheels  145 ,  146  and rear wheels  160 ,  161  even if the components of driveline  105  change angles due to steering, driveline windup, suspension jounce and rebound, or the like. One or more of the plurality of constant velocity joints has a cooling system coupled thereto in accordance with the present invention, as described below. In  FIG. 1 , the plurality of constant velocity joints is located at each end of front driveshaft  125  (constant velocity joints  170 ,  171 ), rear driveshaft  130  (constant velocity joints  172 ,  173 ), front half shafts  140 ,  141  (constant velocity joints  174 ,  175 ,  176 ,  177 ) and rear half shafts  155 ,  156  (constant velocity joints  178 ,  179 ,  180 ,  181 ). There is also a constant velocity joint  182  in a central portion of rear driveshaft  130 . Similarly, in another embodiment (not shown), a constant velocity joint is provided in a central portion of front driveshaft  125 . The plurality of constant velocity joints is of any of the standard types known in the art, such as plunging tripod, Cantata, cross groove, fixed ball, fixed tripod, double offset, or any combination of these, all of which are commonly known terms in the art for different varieties of constant velocity joints. 
         [0016]    In  FIG. 1 , vehicle  100  is a four-wheel drive vehicle. However, it should be noted that the present invention is not limited to use with a four-wheel drive vehicle. Therefore, the present invention is also usable in front-wheel and rear-wheel drive vehicles. Instead,  FIG. 1  and the above discussion are provided to show the various locations where constant velocity joints are commonly used in a motor vehicle. 
         [0017]    With reference to  FIG. 2 , there is shown a rear driveshaft  130 ′ in accordance with an alternate embodiment of driveline  105 . Rear driveshaft  130 ′ is connected to transmission  115 ′ at one end and rear differential assembly  150 ′ at the other end. Additionally, rear driveshaft  130 ′ has constant velocity joints  172 ,  173 ,  182  with which the present invention can be used. However, rear driveshaft  130 ′ is merely representative. The present invention can be used with any of front driveshaft  125 , rear driveshaft  130 , front half shafts  140 ,  141 , rear half shafts  155 ,  156  or any other driveshaft typically found in a motor vehicle. Similarly, each of the plurality of constant velocity joints can be located at any of the positions indicated with respect to  FIGS. 1 and 2 , as well as any other position where a constant velocity joint is typically found in a motor vehicle. 
         [0018]    In general, and as best shown in  FIGS. 3A-B , constant velocity joint  173  includes a constant velocity joint housing  205  having a first housing portion  210  and a second housing portion  215 , the joint itself being located within housing  205 . First and second housing portions  210 ,  215  are coupled by at least one fastener  220 . In particular,  FIGS. 3A-B  show a plurality of fasteners  220  which, in this embodiment, are constituted by bolts. However, any suitable fastener known in the art may be used. In use, constant velocity joint housing  205  is coupled to rear driveshaft  130 ′ at one end and a second rotatable element (which is axle flange  805  in  FIG. 2 ) at the other end. Axle flange  805  is itself coupled to a portion of rear differential assembly  150 ′. As a result, rotation of rear driveshaft  130 ′ is transmitted to rear differential assembly  150 ′ through axle flange  805 . The constant velocity joint inside housing  205  allows rear driveshaft  130 ′ and axle flange  805  to shift angular and axial positions while still transmitting rotational motion. As mentioned above, in other embodiments, the second rotatable element is another driveshaft, a wheel hub or a portion of a transmission, transfer case or differential assembly, for example. 
         [0019]    With further reference to  FIGS. 3A-E , there is shown a first embodiment of a cooling device  400  for use with a constant velocity joint housing, such as constant velocity joint housing  205 . Cooling device  400  generally comprises a load-distributing portion  405  and a fan-blade portion  410 , which are preferably formed integrally with one another. Load-distributing portion  405  includes at least one mounting hole  415 , with two mounting holes  415 ,  416  being provided in this embodiment as shown in  FIGS. 3C-D . 
         [0020]    In  FIGS. 3A-B , two cooling devices  400 ,  401  can be seen coupled to constant velocity joint housing  205 . In particular, load-distributing portion  405  of cooling device  400  is positioned between fasteners  220  and first housing portion  210 , with fasteners  220  inserted into mounting holes  415 ,  416  of load-distributing portion  405  to securely couple cooling device  400  to constant velocity joint  205 . Load-distributing portion  405  distributes loads applied by fasteners  220  to first housing portion  210 . This prevents damage to areas of first housing portion  210  located directly below fasteners  220 , such damage being caused by applying a large load to a small area. Instead, load-distributing portion  405  functions similarly to a washer in that load-distributing portion  405  spread loads applied by fasteners  220  over a greater area, thereby reducing the likelihood of damaging the areas of first housing portion  210  located directly below fasteners  220 . 
         [0021]    Fan-blade portion  410  of cooling device  400  generates air currents when constant velocity joint housing  205  rotates. In a preferred embodiment, cooling device  400  is used in connection with constant velocity joints  170 ,  171  located on front driveshaft  125  or constant velocity joints  172 ,  173 ,  182  located on rear driveshaft  130 . Accordingly, fan-blade portion  410  generates air currents when power is transmitted from transfer case  120  to front differential assembly  135  (through front driveshaft  125 ) or rear differential assembly  150  (through rear driveshaft  130 ). Rotation of constant velocity joint housing  205  results in movement, about a circular path, of cooling device  400  coupled thereto. As a result of such movement, fan-blade portion  410  generates air currents in a direction that depends on the direction in which constant velocity joint housing  205  rotates. When viewed as shown in  FIG. 3A , clockwise rotation of constant velocity joint housing  205  will result in an air current that moves from constant velocity joint housing  205  toward rear driveshaft  130 ′. Counterclockwise rotation of constant velocity joint housing  205  will result in an air current that moves away from rear driveshaft  130 ′. The air current generated by the movement of fan-blade portion  410  is used to cool various areas of driveline  105  depending on which of the plurality of constant velocity joints, shown in  FIG. 1 , cooling device  400  is coupled. For example, the cooling can be applied to a constant velocity joint itself, a tunnel in which a portion of driveline  105  is located or any of the various driveshafts, as well as other nearby components. 
         [0022]    In  FIG. 3E , there is shown a variation of the first embodiment of a cooling device  400 ′ in accordance with the present invention. Cooling device  400 ′ is similar to cooling device  400 , except that cooling device  400 ′ has more than one fan-blade portion  410 ′ while cooling device  400  has single fan-blade portion  410 . Additionally, load-distributing portion  405 ′ has three mounting holes for receiving fasteners  220 , in contrast with cooling device  400  which has two mounting holes  415 ,  416 . 
         [0023]      FIGS. 4A-C  show a second embodiment of a cooling system in accordance with the present invention. In this embodiment, cooling device  600  again comprises a load-distributing portion  605  and a fan-blade portion  610 . As in the first two embodiments, load-distributing portion  605  includes at least one mounting hole  615 . Specifically, the embodiment shown in  FIGS. 4A-C  includes three mounting holes  615 ,  616 ,  617 . However, in contrast to the first two embodiments, fan-blade portion  610  now has a plurality of fan blades  620 . 
         [0024]    With reference to  FIGS. 4A-B , two cooling devices  600 ,  601  are shown coupled to constant velocity joint housing  205 . In combination, two cooling devices  600 ,  601  form a full circle. Such a shape is sometimes referred to as a “squirrel cage”. As in the first embodiment, fasteners  220  are inserted into mounting holes  615 ,  616 ,  617  to securely couple cooling device  600  to constant velocity joint housing  205 . Load-distributing portion  605  again distributes loads applied by fasteners  220  to first housing portion  210 . Additionally, rotation of constant velocity joint housing  205  results in movement of cooling device  600  attached thereto, with fan blades  620  of fan-blade portion  610  generating air currents depending on the direction of rotation. Specifically, in the view shown in  FIG. 4B , clockwise rotation generates air currents that move from constant velocity joint housing  205  toward rear driveshaft  130 ′, as well as air currents that move from fan blades  620  toward the axis of rotation. Counter-clockwise rotation generates air currents that move away from rear driveshaft  130 ′ and away from the axis of rotation. 
         [0025]    A third embodiment of a cooling device  800  is shown in  FIGS. 5A-B . Specifically, there are two cooling devices  800 ,  801  coupled to an axle flange  805 , which has a plurality of internal splines  810  formed thereon. The plurality of splines enables axle flange  805  to be coupled to a second structure having matching splines. In the embodiment shown in  FIG. 2 , axle flange  805  is located between rear driveshaft  130 ′ and rear differential assembly  150 ′, and splines  810  enable axle flange  805  to be rotatably coupled to a portion of rear differential assembly  150 ′. Additionally, axle flange  805  has a plurality of mounting holes  815  for coupling axle flange  805  to a third structure, such as constant velocity joint housing  205 . In such an embodiment, fasteners  220  extend from constant velocity joint housing  205  and into mounting holes  815 . Cooling device  800  includes a coupling portion  820  and a plurality of fan blades  825 . Coupling portion  820  enables cooling device to couple to axle flange  805 . The plurality of fan blades  825  generates air currents in both radial and axial directions when axle flange  805  rotates. As in the first three embodiments, the specific directions depend on the direction of the rotation of axle flange  805 . 
         [0026]    Although described with reference to various embodiments, it should be readily understood that various changes or modifications, both major and minor, could be made to the invention without departing from the spirit thereof. For example, varying numbers of cooling devices  400  may be coupled to constant velocity joint housing  205 . Similarly, cooling devices  600  may be smaller so that more are needed to form a full circle. Alternatively, less than a full circle of cooling devices  600  may be provided. In addition, fan-blades portions  410 ,  410 ′,  610  may be other shapes and sizes. Also, fan blade portion  410  may extend past mounting holes  415 ,  416  or fan-blade portion  610  may have a different number of fan blades  620 . In general, the invention is only intended to be limited by the scope of the following claims.