Abstract:
A center bearing hanger assembly ( 68 ) for supporting a drive shaft ( 62 ) of a vehicle is provided. The center bearing hanger assembly ( 68 ) includes a center bearing ( 66 ), which supports the drive shaft, having an outer housing ( 76 ). The outer housing ( 76 ) is mechanically coupled to a male hanger ( 102 ). The male hanger ( 102 ) is received by a female receptacle ( 104 ). The female receptacle ( 104 ) is attached to an undercarriage of the vehicle. The center bearing hanger assembly ( 68 ) increases the ease of vehicle assembly.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates generally to a center bearing hanger assembly particularly suited for automotive vehicle applications and more particularly, to an apparatus for attaching a center bearing to an undercarriage of an automotive vehicle while eliminating fasteners.  
         BACKGROUND OF THE INVENTION  
         [0002]    There is a continuous effort to reduce the number of components in automotive vehicles. The reduction in components should be done in a manner such that the costs to produce the components and the vehicle are reduced while still maintaining or increasing ease of manufacturing and assembly of the vehicle.  
           [0003]    Now referring to FIG. 1, a typical two-piece drive shaft  10  of an automotive vehicle is shown having a first half  12  and a second half  14 . The drive shaft  10  has three U-joints  18 ; a first U-joint  18   a  attaching the first half  12  to a transmission, a second U-joint  18   b  attaching the first half  12  to the second half  14 , and a third U-joint  18   c  attaching the second half  14  to a rear axle. The center of the drive shaft  10  is supported by a center bearing  22  supported by and fastened to a crossmember or bracket  24  using washers  25  and threaded fasteners  26 . The crossmember  24  is directly fastened to an undercarriage of the vehicle with additional threaded fasteners  28 .  
           [0004]    The driveshaft  10  is used when larger distances exist between the transmission and the rear axle of the vehicle. The center bearing  22  provides support in the center of the drive shaft  10  while still allowing the drive shaft  10  to rotate and transfer mechanical energy from the transmission to the rear axle.  
           [0005]    The existing attachment method used to attach the center bearing  22  to the undercarriage of the vehicle isolates the center bearing  22  from the undercarriage in only the vertical direction (Z-direction). Therefore, undesired vibration and noise created by the rotation of the drive shaft and movement in the fore, aft, and lateral directions (X and Y directions) are transferred through the undercarriage into an occupant compartment of the vehicle.  
           [0006]    A disadvantage also exists during assembly of the vehicle, in that the drive shaft  10  needs to be supported while fasteners  28  are torqued through the crossmember  24  to the undercarriage of the vehicle. Therefore, it is difficult for a single operator to attach the center bearing  22  to the undercarriage without having assistance from additional operators or equipment. This method may increase time, energy, and costs in assembly of the vehicle.  
           [0007]    It would be desirable, to support the drive shaft and center bearing of a vehicle without using fasteners. The reduction of fasteners can reduce assembly time, energy, and costs.  
           [0008]    It would also be desirable to isolate the drive shaft in the X and Y directions from the undercarriage of the vehicle, thereby preventing the potential for vibration and noise to enter the occupant compartment of the vehicle.  
         SUMMARY OF THE INVENTION  
         [0009]    The forgoing and other advantages are provided by a center bearing hanger assembly for a vehicle having a drive shaft. The center bearing hanger assembly includes a center bearing, which supports the drive shaft, having an outer housing. The outer housing is mechanically coupled to a male hanger. The male hanger is received by a female receptacle. The female receptacle is attached to an undercarriage of the vehicle.  
           [0010]    The present invention has several advantages over existing center bearing support assemblies. The present invention decreases the number of assembly components, thereby saving time, energy, and costs in manufacturing and assembling of a vehicle.  
           [0011]    Another advantage of the present invention is that it isolates a drive shaft in all directions from an undercarriage of a vehicle. Therefore, vibration and noise created by the rotation of the driveshaft is prevented from entering an inner compartment of a vehicle.  
           [0012]    The present invention itself, together with further objects and attendant advantages, is best understood by reference to the following detailed description, with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0013]    For a more complete understanding of this invention reference should now be had to the embodiment(s) illustrated in greater detail in the accompanying drawing(s) and described below by way of (an) example(s) of the invention.  
         [0014]    In the drawings:  
         [0015]    [0015]FIG. 1 is a perspective view of a conventional center bearing hanger assembly attached to a driveshaft of a vehicle.  
         [0016]    [0016]FIG. 2 is a schematic view of a drivetrain of a vehicle in accordance with the present invention.  
         [0017]    [0017]FIG. 3 is a perspective view of a center bearing hanger assembly attached to a driveshaft of a vehicle according to the present invention.  
         [0018]    [0018]FIG. 4A is a side view of a center bearing hanger assembly according to an embodiment of the present invention.  
         [0019]    [0019]FIG. 4B is a front view of a center bearing hanger assembly according to an embodiment of the present invention.  
         [0020]    [0020]FIG. 5 is a side view of a male hanger and a female receptacle according to another embodiment of the present invention.  
         [0021]    [0021]FIG. 6 is a side view of a male hanger and a female receptacle according to a further embodiment of the present invention.  
         [0022]    [0022]FIG. 7 is a side view of a male hanger and a female receptacle according to another embodiment of the present invention.  
         [0023]    [0023]FIG. 8 is a side view of a male hanger and a female receptacle according to a further embodiment of the present invention.  
         [0024]    [0024]FIG. 9 is a side view of a male hanger and a female receptacle according to another embodiment of the present invention.  
         [0025]    [0025]FIG. 10 is a side view of a male hanger and a female receptacle according to another embodiment of the present invention.  
         [0026]    [0026]FIG. 11 is a side view of a male hanger and a female receptacle according to another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]    The present invention may be applied in various vehicle applications. In the following figures the same reference numerals are used to refer to the same components. Also in the following description, various operating parameters and components are described for one constructed embodiment. These specific parameters and components are included as examples and are not meant to be limiting.  
         [0028]    Referring now to FIG. 2, a schematic view of a drivetrain  50  of a vehicle  51  wherein the present invention may be used to advantage is shown. The drivetrain  50  includes an engine  52  powering a transmission  54 . The transmission  54  transfers mechanical power/energy to a front axle drive assembly  56 , which rotates a pair of front wheels  58  of the vehicle  51 . The transmission  54  also transfers mechanical energy to a rear axle assembly  60  via a drive shaft  62 , which in turn rotates the rear wheels  64  of the vehicle  51 .  
         [0029]    A portion of the drive shaft  62  rotates within a center bearing  66 , which is supported by a center bearing hanger assembly  68 . The center bearing hanger assembly  68  is attached to an undercarriage  69  of the vehicle  51 . The undercarriage  69  may include a floor pan and a vehicle frame. The center bearing  66  isolates the drive shaft  62  from the undercarriage  69  of the vehicle  51  while still allowing the drive shaft  62  to rotate without restriction.  
         [0030]    Now referring to FIG. 3, a perspective view of a center bearing hanger assembly  68  attached to the drive shaft  62  of the vehicle  51  according to one embodiment of the present invention is shown. The drive shaft  62  has a first portion  70  and a second portion  72 . The drive shaft  62  also has three U-joints  74 . The three U-joints  74  allow the first portion  70  and the second portion  72  to rest and operate at different angles relative to not only the transmission  54  and the rear axle assembly  60  but also to each other. The first U-joint  74   a  attaches the first portion  70  to the transmission  54 . The second U-joint  74   b  attaches the first portion  70  to the second portion  72 . The third U-joint  74   c  attaches the second portion  72  to the rear axle assembly  60 . The center bearing  66  is preferably mounted just forward or just rearward of the second U-joint  74   b  on either the first portion  70  or the second portion  72 . The center bearing  66  has an outer housing  76  for attachment thereto. The center bearing  66  is supported and attached to the undercarriage  69  by the center bearing hanger assembly  68 .  
         [0031]    Now referring also to FIG. 4A, a side view of a center bearing hanger assembly  68  according to an embodiment of the present invention is shown. The center bearing hanger assembly  68  has a bracket  100  surrounding the center bearing  66 . The bracket  100  is attached to two male hangers  102  (one shown), which are inserted into two female receptacles  104  (one shown). The receptacles  104  have inner grommets  106  and outer sleeves  108 . The hangers  102  are allowed to move within the receptacles  104 .  
         [0032]    The bracket  100  is preferably made from a rigid material such as steel or other rigid material so as to provide support between the bracket  100  and the center bearing  68 . The bracket  100  may be a separate component as shown or may be integrated as part of an outer housing  76  of the center bearing  68 .  
         [0033]    The hangers  102  are cylindrical rods having a first bend  110 . The hangers are able to move in a fore direction and aft direction longitudinally along a center line  111  of the receptacles  104 . The hangers  102  may be sealed, using seal  113 , to the bracket  100 . The seal  113  aids in preventing dirt or other undesirable elements from entering the center bearing  66  and may also prevent bearing lubricant from escaping the center bearing  66  causing degradation to the inner components of the center bearing  66 . The seal  113  may be a weld between the hangers  102  and the outer housing  76  or may be sealing material such as: rubber, silicone, gasket material, or some other sealing form or material known in the art.  
         [0034]    Although the hangers  102  are shown as cylindrical rods they may be square, round, triangular, or other various shapes. Also, although the hangers  102  are shown as separate components they may be integrated with the bracket  100  and outer housing  76  into a single unified component. The hangers  102  may also be threaded into the bracket  100 . The hangers  102  may also be attached to the center bearing  66  by other methods including: welding, molding, stamping, or other various methods known in the art. The hangers  102  may also be of various materials including: steel, alluminum, graphite, ceramic, plastic, or other rigid materials.  
         [0035]    The receptacles  104  are toroidal shaped and have sleeves  108  on exterior sides  112  and interior channels  114  in the inner grommets  106 . The sleeves  108  may be of various rigid materials, having varying sizes and shapes, and are attached to the undercarriage  69  of the vehicle  51 . The sleeves  108  may be part of, or integrally formed to, a bracket or other attachment mechanism, which is attached to the undercarriage  69  or may be molded directly into the undercarriage  69  itself. The inner grommets  106  preferably comprise: rubber, fabric, elastomers, synthetics, plastic, polyvinyl chloride, polyvinyl acetate, polypropylene, polyethylene, or other material having similar properties to the before mentioned materials. The inner grommets  106  provide ease of assembly, flexibility, and allow for movement in all directions. The grommets  106  include inner channels  114  for receiving and allowing hangers  102  to extend therethrough. During vehicle assembly the hangers  102  are “slipped” into the grommets  106 .  
         [0036]    Now referring also to FIG. 4B, a front view of a center bearing hanger assembly  68  according to an embodiment of the present invention is shown. The bracket  100  is a toroidal shaped bracket that is formed to the exterior shape of the center bearing  66 . The bracket  100  is attached preferably to the two hangers  102 . The two hangers  102  provide stability for drive shaft  62  in the lateral directions.  
         [0037]    The hangers  102  may separate from the receptacles  104 , under extreme circumstances caused by the drivetrain  50  of the vehicle  51  having the ability to move in the fore and aft directions (X-direction). To prevent separation of the hangers  102  and the receptacles  104  the center bearing hanger assembly  68  may have various attachment mechanisms to prevent the hangers  102  from separating from the receptacles  104 . Of course, by simply varying the lengths of the hangers  102  separation from the receptacles  104  may be avoided without the use of any further attachment mechanisms. On-the-other-hand, the attachment mechanisms not only prevent separation of the hangers  102  from the receptacles  104  but they also provide an operator attaching the assembly  68  with a method of determining when the hangers  102  are properly engaged within the receptacles  104 . Another simple techniques to prevent separation of the hangers  102  and the receptacle  104  is to decrease clearances and tighten tolerances between the dimensions of the hangers  102  and the dimensions of the inner channel  114  of the receptacle  104 . Smaller clearances and tighter tolerances will provide for a “snug” fit and prevent separation between the hangers  102  and the receptacles  104 . The following FIGS.  5 - 10  refer to possible attachment mechanisms for alternate embodiments of the present invention.  
         [0038]    Now referring to FIG. 5, a male hanger  150  having a conical shaped end  152  is shown. The conical shaped end  152  provides ease of attachment and prevents the male hanger  150  from pulling out of the receptacle  104 . Another alternate embodiment of the present invention is shown in FIG. 6 which includes a male hanger  160  having a clip  162  or recessed bearing to prevent the hanger  160  and receptacle  104  from separating. In FIG. 7, a male hanger  170  is shown, which may have a grove  172  by which a snap ring  174  could engage to prevent the hanger  170  and receptacle  104  from separating.  
         [0039]    Now referring to FIG. 8, a male hanger  180  may have a second bend  182  with varying angle  183  to prevent the hanger  180  from “slipping out” of the receptacle  104 . Of course, multiple bends with varying angles may be used.  
         [0040]    Now referring to FIG. 9, a female receptacle  190  having a second sleeve  192  inserted in an inner channel  194  is shown. The second sleeve  192  may have a notch  196  or other attachment mechanism that correlates to a grove  198  or indent on a male hanger  200  to prevent separation of the hanger  200  from the receptacle  190 . Of course, other combinations of attachment mechanisms between the hanger  200  and the receptacle  190  may be used.  
         [0041]    Now referring to FIG. 10, a male hanger  210  having a hole  212  for a cotter pin  214  to extend there through is shown to prevent separation of hanger  210  and the receptacle  104 .  
         [0042]    Now referring to FIG. 11, an example of a male hanger  220  having different dimensions than the inner channel  114  is shown. The difference in dimensions between the hanger  220  and the receptacle  106  create gaps  222 . The gaps  222  create a “loose” fit for easy assembly. When a loose fit is used a prevention method as described above to prevent the hanger  220  from separating from the receptacle  106  is recommended.  
         [0043]    The above described attachment mechanisms are not meant to be limiting, other attachment mechanisms may be applied. The aforementioned provides a center bearing support assembly that is low cost, easy to assemble, while at the same time it provides isolation of a drive shaft from an undercarriage of a vehicle. The above-described apparatus and manufacturing method, to one skilled in the art, is capable of being adapted for various purposes and is not limited to vehicle applications. The above-described invention can also be varied without deviating from the true scope of the invention.  
         [0044]    While particular embodiments of the invention have been shown and described, numerous variations alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.