Abstract:
A dampener mount for an axle to absorb/dampen/inhibit power-hop induced oscillations in a rear axle assembly. A housing for the axle assembly incorporates a mount for attaching a shock absorber/dampener which is in turn connected to the unsparing mass of a vehicle. Preferably the shock absorber/dampener is secured to a bracket connected or otherwise formed with the housing cover.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The preset invention is directed to a dampener mount for an axle housing and particularly to such a mount for connecting a dampener to the sprung mass of a vehicle.  
         [0003]     2. Discussion of the Related Art  
         [0004]     Vehicles equipped with axle assemblies, and more particularly differential axle assemblies, are old and well known in the art.  FIGS. 1A-1C  depict several conventional assemblies.  FIGS. 1A-1B  show banjo type rigid rear axle assemblies and  FIG. 1C  shows a Salisbury type rear axle assembly. Each assembly is connected to the vehicle through a suspension system. As previously mentioned, such assemblies are well known.  
         [0005]     During conditions of high torque, and particularly low traction, a vehicle can experience an undesired power-hop condition. Power-hop is a condition of driveline instability initiated when the tractive effort decreases due to tire slip beyond an optimal slip value. If the engine torque is sufficiently high a power-hop condition can be sustained, resulting in both torsional oscillation of the vehicle driveline and vertical oscillation of suspension members. For example, in the assembly of  FIG. 1A , during a power hop condition, the leaf springs will deform and the axle tubes will move both longitudinally and vertically relative to the vehicle. The torque induced power hop condition imposes oscillating forces on the rigid axle housing which are undesirable.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is directed to a dampener mount for an axle to absorb power-hop induced oscillations in a rear axle assembly. A housing for the axle assembly incorporates a mount for attaching a shock absorber/dampener which is in turn connected to the sprung mass of a vehicle. Preferably the mount includes a bracket connected or otherwise secured to the housing cover. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIGS. 1A-1C  depict conventional rear axle assemblies.  
         [0008]      FIG. 2  depicts an isolated rear view of an axle housing cover with mounting bracket according to the present invention.  
         [0009]      FIG. 3  depicts an isolated side view of the axle housing cover according to  FIG. 2 .  
         [0010]      FIG. 4  is a schematic view of the axle housing cover and dampener connected to a vehicle according to a preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0011]      FIGS. 1A, 1B ,  1 C depict several conventional rear axle assemblies. In each of these assemblies it is known to secure a removable cover to expose the gearing of the differential assembly disposed therein.  FIG. 1A  depicts a portion of a cover as shown by reference number  10 . In each of the assemblies of  FIG. 1A, 1B ,  1 C, an axle housing contains a gear set disposed within said housing for permitting differential rotation between a pair of output shafts drivingly connected to a pair of wheels.  FIG. 1A  depicts a rigid rear axle beam and banjo type axle housing assembly. In an effort to resolve the problems associated with power hop conditions, which can be particularly troublesome in rigid rear axle assemblies, the present invention employs a mounting bracket secured directly to the axle housing for connecting a shock absorber/damper between the housing and the sprung mass of the vehicle.  
         [0012]      FIG. 2-3  depicts a rear cover  110  having a mounting bracket  113  secured to a top portion  115  of the cover  110 . In a preferred embodiment, the mounting  113  is in the form of a U-shaped bracket  113  having juxtaposed parallel upright members  117  each having an aligned bore  119  for receiving a bolt (not shown) to connect with said shock absorber. The U-shaped bracket  113  may be simply bolted to a substantially planar top portion  115  of the rear cover  110 . A bolt  121  may extend through a bore (not shown) of a lower portion of the U-shaped bracket and threadingly engages a threaded bore (not shown) formed in the planar top surface  115  of the cover  110 . Alternately, the bracket  113  may be welded or homogenously formed as a unitary body with the rear cover  110  such as during a casting of stamping process.  FIG. 3  depicts an isolated side view of the rear cover  110  revealing the bracket  113  and its parallel upright members  117  and aligned bores  119 . It is to be understood, that while an isolated view of the shock absorber connected to the bracket is not depicted, forming such a connection is well within the knowledge of one of ordinary skill in the art. A shock absorber/damper having a conventional ball joint type or other connection may simply be connected to the bracket with an appropriately sized bolt. Therefore, no further detailed description of such a connection is needed.  
         [0013]     The mount/bracket  113  may be formed in many fashions. For example, the bracket may be formed of steel, stamped or forged to meet load requirements. The bracket may also be made of the same material as the rear cover  113  for example if cast or stamped homogeneously with the forming of the cover  113 .  
         [0014]      FIG. 4  depicts a schematic view of the axle housing  150  and mounting bracket  113  arrangement in a vehicle  200 . In order to dampen longitudinal oscillations induced to the axle housing  150 , the shock absorber/dampener  130  extends substantially horizontally and substantially in a longitudinal direction of said vehicle  200  and is disposed proximate a centerline of the vehicle  200 . The shock absorber/dampener  130  may be connected directly to the vehicle frame  140  or otherwise secured to the sprung mass of the vehicle. It is to be understood that the term “sprung mass” is a commonly understood term in the art which refers to the part of the vehicle  200  supported by springs such as the vehicle frame  140  and vehicle body. In contrast, unsprung mass refers to the mass of the vehicle that is not supported by springs such as the wheels and axles.  
         [0015]     In a preferred embodiment the mount/bracket  113  is secured directly to the rear cover  110 . Such an arrangement facilitates an easy and simple installation. Moreover, because the rear cover  110  is a removable and easily replaceable component of the axle assembly  150 , such an arrangement is particularly useful for retrofit installations. No alterations to conventional axle assemblies are needed. The shock absorber  130  is simply connected to the bracket  113  and a corresponding mount need only be secured to the sprung mass of the vehicle such as the vehicle frame  140  to facilitate connection of the opposite end of the shock absorber/dampener  130 . As previously indicated, it is well within the skill of one of ordinary skill in the art to connect a shock absorber  130  to the vehicle frame  140 . For example, a second U-shaped bracket may be simply welded or bolted to the vehicle frame  140  or other suitable portion of the sprung mass and the shock absorber  130  installed with bolts as conventional shock absorbers are installed.  
         [0016]     It is also understood, that the size and capacity of the shock absorber  130  will depend on the particular vehicle to which it is installed. Heavier vehicles and vehicles with significantly large torque loads will require larger and heavier duty dampeners. It is contemplated the off the shelf shock absorbers may be employed in certain applications where specifications match.  
         [0017]     While the foregoing invention has been shown and described with reference to a preferred embodiment, it will be understood by those possessing skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. For example, in heavy-duty vehicles, the rear cover  110  may need to be strengthened to accommodate the forces transmitted by the shock absorber  130 . In such a case the cover may be strengthened in any fashion such as integrated reinforcing ribs, increasing the thickness of the cover or any other conventional means to strengthen the cover. Furthermore, while the present invention has been shown with the shock absorber  130  extending rearward from the differential cover  110 , the shock absorber may also extend forward and connect to an intermediate cross frame member (not shown) or other portion of the sprung mass of the vehicle. IT is to be understood that it is well within the skill of one of ordinary skill to alternatively mount the shock absorber is a forward oriented position.