Abstract:
A retainer plate for preventing or at least mitigating loosening of an axle nut of a vehicle. The retainer plate comprises a generally flat section of rigid material that couples to an axle nut in a non-rotatable fashion and to a portion of the wheel to maintain the axle nut in tight threaded engagement with the axle. The retainer plate can have a central bore that non-rotatably engages the axle nut and a radially outward feature that engages the wheel to prevent the axle nut from loosening.

Description:
FIELD OF INVENTION 
     This invention relates generally to a plate for a vehicle that couples to wheel mounting studs and to an axle nut to prevent the axle nut from loosening from the axle. 
     BACKGROUND OF THE INVENTION 
     Fundamental to any wheeled vehicle, such as all-terrain vehicles (“ATVs”) and recreational off-road vehicles (“ROVs”) are wheels carried by axles. Live axles are driven by the vehicle&#39;s engine, and the turning axle causes the wheels to rotate. The coupling between the axle and the wheel ensures that energy provided by the engine can translate into movement of the wheel and ultimately propelling the vehicle. The axle has an axle nut at the end of the axle to hold the wheel and perhaps a hub assembly to the axle. Occasionally, the axle nut can work loose or even fall off the axle. Previous attempts at solving this problem, such as a simple cotter pin passing through the axle nut, are often inadequate. In some cases, the cotter pin shears off under high impact loads. These attempts provide no effective impediment to the axle nut loosening—merely an indication that the axle nut has rotated some unknown degree. There is a need for a lightweight and economical device to ensure that the axle nut does not rotate relative to the axle and loosen. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an axle nut retainer for a vehicle having an axle with a rotational axis and a wheel. The retainer plate interfaces with an axle nut. The axle nut is configured to fasten to an axle of a vehicle, the axle nut having a keyed shape, such as a hexagonal outer shape or other non-circular shape. The plate also has a corresponding keyed axle nut-receiving portion and a lug-receiving portion. The “keyed” axle nut-receiving portion is preferably keyed to at least a portion of the keyed shape of the axle nut, but may not be keyed to the complete outer shape of the axle nut. The axle nut-receiving portion is spaced apart from the lug-receiving portion in a direction perpendicular from the rotational axis of the axle. The lug-receiving portion is coupled to a hub lug. (i.e., the lug bolt or wheel stud of the wheel) The axle nut is positioned within the keyed nut-receiving portion. The axle nut and the keyed axle nut-receiving portion of the plate are non-rotatably coupled together to inhibit rotation of the axle nut relative to the axle. In at least one embodiment, the plate comprises an elongated member extending from the axle nut-receiving portion to the radially outward portion. 
     In other embodiments, the present invention is directed to a wheel assembly including a hub and a plurality of lugs. The hub is coupled to an axle of a vehicle, the axle having an axis of rotation. The plurality of lugs extend from the hub in a direction generally parallel with the axis of rotation and spaced apart from the axle in a direction generally perpendicular to the axis of rotation. The wheel assembly further includes a nut coupled to the axle and configured to hold the hub to the axle, and a retaining plate non-rotatably coupled to the nut and coupled to one or more of the lugs. The wheel assembly can further include a wheel coupled to the lugs with the retaining plate between the hub and the wheel, wherein the retaining plate prevents the nut from rotating relative to the axle. 
     In still further embodiments, the present invention includes a retaining plate for a wheeled vehicle having an axle, an axle nut, and a wheel. The retaining plate includes a generally flat region extending in a direction perpendicular to the axle, and a first engagement portion being non-rotatably coupled to the axle nut. The retaining plate also includes a second engagement portion coupled to a portion of the wheel that rotates as the wheel rotates. The portion of the wheel is spaced apart from the axle, and the retaining plate resists rotation of the axle nut relative to the axle by virtue of a moment arm formed by the portion of the retaining plate spanning the distance between the first and second engagement portions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. 
         FIG. 1  is an exploded view of a wheel assembly, a hub assembly, and a retaining plate according to embodiments of the present invention.  FIG. 3  shows a similar exploded view to that of  FIG. 1 , however the retaining plate is positioned outbound of the wheel. 
         FIG. 2  is an assembled view of the wheel assembly of  FIG. 1  according to embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is an exploded view of a wheel assembly  100  according to embodiments of the present invention. The wheel assembly  100  can be used with a vehicle  110 , such as a recreational off-road vehicle (“ROV”) or an all-terrain vehicle (“ATV”) or any other suitable wheeled vehicle. The vehicle  110  has an axle  114  supported by a knuckle assembly  116  and a rear suspension  118 . The axle  114  includes an axle nut  150  that threadably engages the end of the axle  114 . The wheel assembly  100  includes a hub assembly  120  that is non-rotatably coupled to the axle  114  and rotates with the axle  114 . The nut  150  secures the hub assembly  120  to the vehicle  110 . The hub assembly  120  has non-circular features, such as teeth  122  that mesh with corresponding teeth  115  on the axle  114  to ensure that rotation of the axle  114  is transmitted to rotation of the hub  120 . The hub assembly  120  also includes a disc  124  for braking purposes, a base  126 , and lugs  128  extending from the base  126 . The wheel assembly  100  also includes a wheel  130  having lug holes  132  that engage the lugs  128  to secure the wheel  130  to the hub assembly  120 . The wheel  130  is secured to the hub assembly  120  by lug nuts  134 . 
     The wheel assembly  100  also includes a retaining plate  140 , which can be positioned between the hub assembly  120  and the wheel  130  (as shown in  FIG. 1 ). The retaining plate  140  can alternatively be positioned outboard of the wheel  130 . With the retaining plate  140  positioned between the hub assembly  120  and wheel  130  and with the hub assembly  120  and wheel  130  clamped against the retaining plate  140 , the friction between the components is sufficient to prevent the axle nut  150  from loosening. The plate  140  includes a radially outward portion  148  spaced apart radially from the center of the plate  140 , defining a moment arm between the center of the plate  140  and the radially outward portion  148 . The retaining plate can have a first aperture  142  and at least one second aperture  144  on the radially outward portion  148  spaced apart from the first aperture  142 . Preferably, plate  140  includes second apertures  144  for each lug  128  with an appropriate clearance between the lugs  128  and the second apertures  144 . For example, an appropriate clearance is one that enables installation but prevents excessive rotation of the plate  140 . In the illustrated embodiment the first aperture  142  is positioned centrally on the plate  140  and the second apertures  144  are positioned around a periphery of the plate  140 , and there are four second apertures  144  corresponding to the four lugs  128 . The axle  114  protrudes through the hub assembly  120  and is engaged with the nut  150 , which is engaged non-rotatably with the retaining plate  140 . The nut  150  can be a hexagonal nut or other keyed shape to facilitate the non-rotational coupling with a tightening tool (not shown). The first aperture  142  of the retaining plate  140  has a corresponding keyed shape that engages the nut  150  such that the plate  140  prevents the nut  150  from loosening or rotating relative to the axle  114 . In the preferred embodiment, the plate  140  includes twelve evenly spaced recesses to engage the hexagonal nut  150  at multiple rotational placements. The second apertures  144  engage the lugs  128 . The distance between the first aperture  142  and the second apertures  144  serves as a moment arm by which the retaining plate resists rotation of the nut  150  relative to the axle  114  to prevent loosening of the axle nut  150 . In some embodiments the primary retaining force is the friction between the retaining plate  140 , the wheel  130 , and the hub assembly  120 . The lugs  128  and second apertures  144  can be a secondary retaining force. For example, if the wheel  130  and hub assembly  120  loosen and friction lessens, the lugs  128  engage the retaining plate  140  to resist loosening of the nut  150 . In other embodiments the engagement between the lugs  128  and the second apertures  144  is itself the primary resisting force. 
     In other embodiments the apertures  142 ,  144  can be any suitable engagement feature, such as a C-shaped recess or clip or bolt that secures to the nut  150  and lug  128 , respectively. In other embodiments, the retaining plate  140  can engage with a portion of the wheel  130  other than the lugs  128 , such as a protrusion and or recess feature of the hub  120  and or wheel or the spokes of the wheel  130 . The retaining plate  140  can engage with any feature that, during operation of the vehicle  110 , rotates with the nut  150  so that the retaining plate  140  can prevent or at least substantially mitigate loosening of the nut  150 . In other embodiments the retaining plate  140  is not a plate at all; rather, the plate  140  can be a single member extending from the nut  150  and one of the lugs  128 , somewhat resembling a crescent wrench, but still having non-rotating engagement features  142 ,  144  to prevent loosening of the axle nut  150 . In some embodiments, two or more of these members can be usedone for each lug  128 . With more members engaging more lugs  128 , the loosening resistance is increased. In some cases where loosening is particularly prevalent and potentially harmful, a retaining plate engaging many lugs  128  can be used. In other circumstances where the loosening phenomenon is less prevalent or less severe, fewer engagement apertures  144  can be used at the discretion of the operator. The preferred plate shown, which engages all four lugs also operates to keep the spacing between the hub and the wheel consistent. 
     In general, the greater the distance separating the lugs  128  (or other point at which the retaining plate  140  engages the hub  120  and or wheel  130 ) and the nut  150  the greater the loosening resistance due to the greater leverage. However, even a small distance between the first aperture  142  and second aperture  144  strongly resists loosening of the nut  150 . 
     The retaining plate  140  can include a shaped portion  146  that protrudes from the body of the plate  140 . The shaped portion  146  can allow the plate  140  to conform to the shape of the wheel  130  and more particularly to the hub against which the plate  140  rests. The profile of the retaining plate  140  can vary according to the space in which the plate  140  is disposed. The plate  140  can, in some embodiments, be thin enough to be inserted between wheel components of an existing vehicle that was not specifically designed for use with the retaining plate  140 , but that, nevertheless, benefits from the nut loosening prevention that the plate  140  provides. In some embodiments, the plate  140  can be placed outboard of the wheel  130 , in which case there is presumably more room in which the plate  140  can operate. In such embodiments, the plate  140  can engage the lug nuts  134 , and not the lugs  128  directly. In some embodiments in which the axle nut  150  does not protrude beyond the outer surface of the hub, the retaining plate  140  can include a shaped portion  146  that protrudes inboard from the body of the plate  140  to engage the axle nut  150 . The shape of the wheel  130  can determine how the retaining plate  140  will engage the axle nut  150  and lugs  128 . 
       FIG. 2  illustrates a wheel assembly  100  according to the present disclosure in which the retaining plate  140  is positioned on the hub assembly  120 . The first aperture  142 , or engagement portion, is non-rotatably coupled to the axle nut  150 . In this embodiment, the nut  150  is a hexagonal nut, but the nut  150  can have any keyed shape that enables a torque to be applied to the nut. The second apertures  144  of the retaining plate  140  engage with the lugs  128 . The retaining plate  140  permits the wheel  130  shown in  FIG. 1  to be mounted normally to the lugs  128 . The retaining plate  140  prevents, or at least substantially mitigates, loosening of the nut  150 . 
     While the preferred embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiments. For example, the present invention can include other mechanical equivalents that prevent an axle nut from loosening from the axle, including a retaining arm extending from the axle nut to a single lug or to another portion of the wheel. Other embodiments are also possible. Accordingly, the invention should be determined entirely by reference to the claims that follow.