Abstract:
Disclosed herein is a multi-axle component for a constant-velocity drive type driveshaft joint system, comprising: a rotation shaft comprising an end distal to a joint region, and an end proximate to the joint region; a generally cylindrical ball receiving housing located at the proximate end, comprising a cylindrical wall adapted to receive at least a partially spherically shaped shaft end; at least two holes provided in the cylindrical wall that are axially displaced from one another along a rotation axis of the multi-axle component; and a pin that extends through only one of the axially displaced holes at a time to join the shaft end with the multi-axle component. Furthermore, a wheel axle system for a constant-velocity drive type driveshaft joint, is provided that uses the multi-axle component

Description:
BACKGROUND 
       [0001]    Disclosed herein is a wheel axle for constant-velocity drive (CVD) type driveshaft joint and an associated system utilizing such a joint. Constant-velocity joints, also called homokinetic joints, allow a drive shaft to transmit power through a variable angle, at constant rotational speed. This is done while keeping friction and play at a minimum. 
         [0002]    In known such devices, the location of the joint itself remains at a fixed axial distance from a shaft to which a wheel hex used to mount the shaft, and thus, the characteristics of the CVD joint system cannot be readily varied. 
       SUMMARY 
       [0003]    Therefore, various embodiments of the invention are described herein that provide a more flexible CVD joint system. Disclosed herein is a multi-axle component for a constant-velocity drive type driveshaft joint system, comprising: a rotation shaft comprising an end distal to a joint region, and an end proximate to the joint region; a generally cylindrical ball receiving housing located at the proximate end, comprising a cylindrical wall adapted to receive at least a partially spherically shaped shaft end; at least two holes provided in the cylindrical wall that are axially displaced from one another along a rotation axis of the multi-axle component; and a pin that extends through only one of the axially displaced holes at a time to join the shaft end with the multi-axle component. 
         [0004]    Furthermore, a wheel axle system for a constant-velocity drive type driveshaft joint, is provided that uses the multi-axle component described above, wherein the rotation shaft is a first rotation shaft; and the system further comprises a dog-bone component comprising a second rotation shaft comprising an end distal to a joint region, and an end proximate to the joint region; wherein: the spherically shaped shaft end comprises an engagement portion that engages the pin and pivotally links the first rotation shaft with the second rotation shaft. 
         [0005]    As used herein, unless otherwise indicated, the following terms related to the shaft will be defined as: “proximate” to mean proximate with respect to the joint portion or joint ends of the respective shafts, and “distal” to mean distal with respect to the joint portion or joint ends of the respective shafts. Also, the term “axially displaced” means displaced in a direction along the shaft axis, and is distinguished from “radially displaced”, which means displaced rotationally about the shaft axis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Various embodiments of the invention are illustrated in the drawings, as described below: 
           [0007]      FIG. 1  is an exploded perspective view of a multi-axle CVD joint; 
           [0008]      FIG. 2  is a perspective view of the multi-axle; 
           [0009]      FIG. 3A  is a side view of an attachment portion of the related art; 
           [0010]      FIG. 3B  is a side view of the multi-axle; 
           [0011]      FIG. 3C  is a cross-section view along A-A in  FIG. 3B ; 
           [0012]      FIGS. 4A-C  are side views of the multi-axle CVD joint in three different configurations; 
           [0013]      FIG. 5A  is a side view of the dog-bone portion with exemplary measurements, according to an embodiment; 
           [0014]      FIG. 5B  is a cross section of the dog-bone portion illustrated in  FIG. 5A ; 
           [0015]      FIG. 6A  is a side view of the multi-axle portion with exemplary measurements, according to an embodiment; and 
           [0016]      FIG. 6B  is a cross section of the multi-axle portion illustrated in  FIG. 6A . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIG. 1 , an embodiment of the multi-axle CVD joint system  10  is illustrated, which has, as primary elements, a multi-axle component  20  comprising a first rotation shaft  22 , and a dog-bone portion  50  comprising a second rotation shaft  52 . 
         [0018]    The first rotation shaft  22  interfaces with other components connected to a vehicle or other machine via, e.g., a wheel hex  12 . In the embodiment illustrated, the wheel hex  12  has a hole  16  that axially slides onto the first rotation shaft  22 , past a shaft hole  24 . A wheel hex pin  14  may be inserted through this hole, with a protruding portion of the pin  14  engaging a notch  18  on the wheel hex  12  to prevent the wheel hex  12  from sliding off of the shaft. At an opposite side from the notch  18 , a wheel hex face  19  may abut a stop portion  23  on the shaft that is larger than the hole. Thus, the wheel hex  12  is held in place via the pin  14  engaging the notch  18 , and the face  19  abutting the stop portion  23 . 
         [0019]    At a joint (proximate) end  26  of the first rotation shaft  22 , that is opposite a distal end  27 , is a cylindrical ball receiving housing  30 . This receiving housing  30  comprises a ball receiving hole  32 , with a plurality of receiving housing holes  36   a,    36   b  placed in a cylindrical wall  31  of the receiving housing. The holes have a differing axial placement, meaning, e.g., that a first hole  36   a  may be closer to the distal end of the first rotation shaft  22 , and a second hole  36   b  may be closer to the proximate end of the first rotation shaft  22 . The significance of this placement will be discussed in more detail below. The holes may be paired, e.g., as illustrated in  FIG. 1 , with two holes  36   b,    36   b  having a same axial placement along the first rotational shaft  22 , but on opposite sides of the housing cylinder  30 . Also, although two holes  36   a,    36   b  having different axial placement are illustrated in  FIG. 1 , the number of holes is not so limited, and can be any number of holes having differing axial placement. The housing  30  may further comprise a lip  33 . 
         [0020]    The second rotation shaft  52  comprises a distal end  53  which may include a distal ball portion  54  having projections  56  for engaging with other components connected to the vehicle or other machine. 
         [0021]    At the proximal or joint end  58  of the second rotation shaft  52  is a ball portion  60  that fits within the ball receiving hole  32  of the first rotations shaft  22 . The ball portion comprises a ball hole  62 , and a ball slit  64  that is provided on the spherical surface of the ball portion  60  and is aligned axially with the second rotation shaft  52 . The ball hole  62  has an axis that is generally perpendicular to the ball slit  64 . The slit  64  may be provided on opposite sides of the spherical surface of the ball potion  60 . 
         [0022]    As can be seen in  FIG. 1 , a cylindrical barrel  40  is sized to fit within the ball hole  62 , and comprises a barrel pin hole  42  that is designed to face the slit  64  when the barrel  40  is inserted into the hole  62 . When assembled, the ball portion  60  of the second rotation shaft  52 , with the barrel  40  inserted therein, is inserted into the ball receiving hole  32  of the first rotation shaft  22 . The receiving housing pin  38  may be inserted into one of the holes or hole pairs  36   a,    36   b  of the receiving housing  30 , through the slit  64 , and through the barrel pin hole  42 —this construction forms the CVD joint  70 . With this configuration, the second rotation shaft  52  can be driven at the same rotational frequency as the first rotation shaft  22  at a wide range of pivot angles about the axis of the cylindrical barrel  40 . 
         [0023]    Advantageously, utilizing different axially placed holes  36   a,    36   b,  i.e., providing multiple axial positions of the CVD joint  70 , results in different performance characteristics. Depending on which set of holes  36   a,    36   b  is being used, the position of the CVD joint  70  in relation to the wheel hex  12  is adjusted. This adjustment changes the feel of e.g., the car when throttle is applied and will, in a context of use for a model car, allow the user to set a model car up for various conditions and surfaces. 
         [0024]    The adjustable length of the total length of the CVD using just one axle allows the driver to tune how the car reacts on and off power and during cornering. Shortening the overall length of the CVD gives the car more on power traction on corner exit and the car has a tendency to “straighten up” quicker. This change also makes the car “pivot” quicker on corner entry. Conversely, lengthening the overall length of the CVD gives the car more stability in the corners allowing the car to carve a smoother line, but it will not have as much rotation on corner entry and will not “straighten up” as fast on corner exit. 
         [0025]      FIG. 2  provides an embodiment of the multi-axle  20  with three set of holes: a first  36   a  that is furthest from the end, and thus closest to the wheel hex  12  when assembled, a second  36   b  that is further from the end than the first set  36   a,  and finally, a third  36   c  that are furthest from the end, and thus furthest from the wheel hex  12  when assembled. As can be seen in  FIG. 2 , the third set of holes  36   c  are so close to the end that they may cut into the lip  33  of the housing  30  in order to maximize the distance between the wheel hex  12  and the joint  70 . 
         [0026]      FIG. 3A  illustrates a related art design in which a plurality of holes  36 ′ are provided in the receiving housing  30 ′. However, all though the plurality of holes  36 ′ are radially spaced from one another, they are not axially displaced, as are the holes  36   a,    36   b,  and  36   c,  as described herein.  FIG. 3B  is a side view of the multi-axle that clearly illustrates the difference in the axial displacement of the respective holes  36   a,    36   b,    36   c,  versus the non-axially displaced holes  36 ′ of the related art shown in  FIG. 3A . The cylindrical wall  31  region is longer axially than in the related art design of  FIG. 3A .  FIG. 3C  shows a sectional view along line A-A, in which the receiving hole region  32  can be seen, including the back wall  34 . 
         [0027]      FIGS. 4A-C  illustrate the differences in the multi-axle CVD joint system when the different holes are used. In  FIG. 4A , the pin  38  is placed into the first holes  36   a,  which creates a minimum distance X between the joint  70  and the wheel hex  12 . In this configuration, the ball  60  is at its closest position to the wheel hex  12 , since the end portion of the ball  60  nearly abuts the back wall of the ball receiving hole. 
         [0028]    In  FIG. 4B , the pin  38  is placed into the second holes  36   b,  which creates a medium distance Y between the joint  70  and the wheel hex  12 . 
         [0029]    Finally, in  FIG. 4C , the pin  38  is placed into the third holes  36   c,  which creates a maximum distance Z between the joint  70  and the wheel hex  12 . The holes are placed as close to the end  26  as possible while still providing the structural integrity to hold the pin  38  (and, as noted before, can possibly extend to the lip portion  33 ). The closest distance to the end  26  would depend on the strengths of the materials involved (metal, being stronger than plastic, would allow a placement closer to the end  26 ) as well as the anticipated forces involved (e.g., weight of the vehicle). One of ordinary skill in the art using a strength of materials analysis could determine the closest distance permitted to the end  26  while maintaining the necessary structural integrity. 
         [0030]    The possible angle between the first rotation shaft  22  and the second rotation shaft  52  is greatest in the  FIG. 4C  configuration (in which the pin  38  is as close as possible to the proximate end  26 ), and is least in the  FIG. 4A  configuration (in which the edge of the ball portion  60  is as close as possible to a back wall region of the ball receiving hole  34 ). As can be seen in  FIGS. 4A-C , the back wall/end  34  of the receiving hole has a hemispherical shape that is preferably just slightly larger than the ball portion  60 . This shape allows a full accommodation of rotation of the ball portion  60 . However, this could be shortened or flattened in the event that an end portion of the ball portion  60  is flattened as well, to accommodate the more limited angle of motion when the joint is configured as shown in  FIG. 4A . 
         [0031]      FIGS. 5A-6B  provide exemplary measurements for the multi-axle  20  and the dog-bone  50 . The measurements shown are in millimeters, which are appropriate for a model vehicle—however, the invention should not be limited to a model vehicle, and the measurements could be easily scaled to a full-size vehicle or any other form of machine using a CVD type driveshaft joint. Of significance is the exemplary distance variance possible between the shaft hole  24  of the multi-axle and the projections  56  of the dog-bone  50 . In its shortest configuration, this overall distance in the exemplary illustration is 25.2+59=84.2. In its longest configuration, this overall distance is 25.2+59+3=87.2 (a 3.6% increase). These dimensions could easily be varied to achieve different min./max. ratios. However, as cylindrical axis length of the ball receiving hole  32  becomes longer with respect to its diameter (and presuming the holes  36   a  and  36   c  are at the outer extremes of their positions), the relative angle of motion for the dog-bone portion  50  possible becomes smaller when mounted in the holes  36   a.    
         [0032]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated as incorporated by reference and were set forth in its entirety herein. 
         [0033]    For the purposes of promoting an understanding of the principles of the invention, reference has been made to the preferred embodiments illustrated in the drawings, and specific language has been used to describe these embodiments. However, no limitation of the scope of the invention is intended by this specific language, and the invention should be construed to encompass all embodiments that would normally occur to one of ordinary skill in the art. 
         [0034]    The embodiments may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of components that perform the specified functions. 
         [0035]    The particular implementations shown and described herein are illustrative examples of the invention and are not intended to otherwise limit the scope of the invention in any way. For the sake of brevity, conventional aspects of the systems (and components of the individual operating components of the systems) may not be described in detail. Furthermore, the connecting lines, or connectors shown in the various figures presented are intended to represent exemplary functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device. Moreover, no item or component is essential to the practice of the invention unless the element is specifically described as “essential” or “critical”. 
         [0036]    The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
         [0037]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) should be construed to cover both the singular and the plural. Furthermore, recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Finally, the steps of all methods described herein are performable in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. 
         [0038]    The words “mechanism” and “element” are used herein generally and are not limited solely to mechanical embodiments. Numerous modifications and adaptations will be readily apparent to those skilled in this art without departing from the spirit and scope of the invention. 
       TABLE OF REFERENCE NUMERALS 
       [0000]    
       
           10  multi-axle CVD joint system 
           12  wheel hex 
           14  wheel hex pin 
           16  wheel hex hole 
           20  multi-axle 
           22  first rotation shaft 
           24  shaft hole 
           26  first rotation shaft (joint) proximate end 
           27  first rotation shaft joint distal end 
           30  cylindrical ball receiving housing 
           30 ′ cylindrical ball receiving housing (related art) 
           31  cylindrical wall of housing 
           32  ball receiving hole 
           33  housing lip 
           34  back wall of the ball receiving hole 
           36 ′ related art housing hole 
           36   a  receiving housing first hole 
           36   b  receiving housing second hole 
           36   c  receiving housing third hole 
           38  CVD receiving housing pin 
           40  CVD cylindrical barrel 
           42  barrel pin hole 
           50  dog-bone 
           52  second rotation shaft 
           53  second rotation shaft distal end 
           54  distal ball portion 
           56  projections 
           58  second rotation shaft proximate (joint) end 
           60  proximate ball portion/at least partially sphere shaped portion 
           62  ball barrel hole 
           64  ball slit 
           70  CVD joint