Abstract:
In a wheel hub module for motorized land vehicles, there is provided an arrangement comprising a hub module casing member, a hub subassembly composed of permanently joined pre-loaded co-rotating inboard and outboard members, inboard and outboard complements of bearing rolling elements and a constant velocity joint wherein the CV joint&#39;s outer race proper is the inboard wheel bearing&#39;s inner race, and wherein the respective inboard and outboard wheel bearing&#39;s raceways may be of identical or of mutually different geometric dimensions, and wherein the inboard wheel bearing provides full end support to the CV joint outer race itself, making for a simple, robust and compact hub module.

Description:
[0001]    The present application claims the benefit of the currently pending provisional application having Ser. No. 60/859,588, filed Nov. 20, 2006, and it is requested to convert it into a non-provisional application. It is to be noted that the provisional application&#39;s “as submitted” title reading “COMPACT HUB UNIT FEATURING ASSYMMETRICAL BEARINGS AND CONSTANT VELOCITY JOINT OUTER RACE” is herewith requested to be changed to read “COMPACT WHEEL HUB UNIT FEATURING AN INTEGRATED CONSTANT VELOCITY JOINT OUTER RACE” in order to distance itself from similarly titled existing in-force patents. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to improvements in a driven wheel&#39;s unitary hub module comprising inseparably interconnected module components by way of substituting a constant velocity joint (CVJ) outer race member for the inboard bearing&#39;s inner race member, and the method of its integration into the hub module. 
         [0003]    In this invention the term “constant velocity joint outer race proper” is intended to be limiting to the extent that it shall denote only the generally bell shaped part of the outer race which contains the ball grooves inside its cavity for transmitting driving torque from the inner race of the joint, which inner race is non-rotatably connected to the drive axle stub shaft. The term “constant velocity joint&#39;s outer race proper” shall specifically exclude any appendage, whether of reduced diameter or not, which may form an integral part of the outer CVJ race member for the purpose of affixing it to the hub outboard member. Further, the term “driven plane” refers the plane being normal to the outer race&#39;s rotational axis and in line with the flexural center of the CVJ. The term “flexural center” refers to that point, which lies at the intersection of the joint&#39;s driving and driven axes, otherwise know as joint center. The terms “inboard” and “outboard” refer to the ends of the hub assembly being respectively closer to and/or farther from the vehicle&#39;s longitudinal center plane. 
       BACKGROUND TO THE INVENTION 
       [0004]    While numerous types of driven wheel hub concepts have been devised, not one has demonstrably combined simplicity, robustness and desirable geometry in the same package. 
         [0005]    Some have combined simplicity and robustness (e.g., the SKF Hub for Motorized Land Vehicles, commonly known as the “X-Tracker”), and others managed to combine compactness and close-to-desirable geometry (e.g., FAG U.S. Pat. No. 4,986,607), none have combined robustness with simplicity and compactness, which the embodiment herein discloses. 
         [0006]    To reflect upon this invention&#39;s primary advantage, this packaging concept makes negative scrub radius with low kingpin angle easily achievable, even on heavy vehicles such as SUVs and light trucks, because the wheel-end CV joint&#39;s flexural center can be positioned nearer to the wheel center plane than with any other hub design concept, while at the same time the CV joint&#39;s outer race is fully supported by the inboard bearing&#39;s rolling elements, as opposed to being cantilevered as per normal practice. In normal practice the CV joint is cantilevered by virtue of the CVJ proper being an addition to the hub module rather than being integral part thereof, and thus by being inboard of the hub, forcing the CV joint&#39;s flexural center to be considerably inboard of the ideal location, which in turn forces the kingpin axis too far inboard as well, making negative scrub radius hard to achieve at best, or not at all. 
       SUMMARY OF THE INVENTION 
       [0007]    The objective of the present invention is to provide a simple, compact and robust cartridge type of hub module assembly for wheel support in a land vehicle, and that objective is achieved with a permanently interconnected arrangement comprising a driven wheel&#39;s hub composed of form-fittingly joined co-rotating inboard and outboard members, a generally cylindrical outer casing member, a pair of axially spaced apart inboard and outboard wheel bearings occupying the annular space between said hub and said outer casing members, wherein each of said inboard and said outboard bearing rows is comprised of a plurality of rolling elements being suitable for supporting combined axial and radial loads and further, wherein said hub subassembly&#39;s said inboard member is a CV joint outer race proper, and whereof said form fitting means of interconnecting mechanism enables the bearings to be in a preloaded union with their respective inner and outer raceways. 
         [0008]    Further, owing to the fact that the inboard and outboard bearings are independent of one another, the shape geometry and sizes of their respective rolling elements can be optimized and their respective raceway diameters can be mutually independently sized and further, since they can be axially separated sufficiently far apart, potential axle wobble is greatly reduced, thus control of the wheel&#39;s orientation is greatly improved in the presence of applied lateral loads at the wheel/road interface, and the increased mechanical advantages accorded thereto not only lead to reduced bearing stresses, but with steering lock application the bending moments resulting from the application of driving torque in the CVJ are greatly reduced, as full end support is accorded to the CV joint&#39;s outer race proper. 
         [0009]    According to one aspect of the invention, there is provided an interconnecting arrangement for a cartridge type of vehicle axle hub module comprising a generally cylindrical outer casing member with a mounting flange, an interconnected co-axial and co-rotating hub sub-assembly comprised of an outboard and an inboard member with respective inner raceways thereon, wherein said inboard member is defined by a CV joint outer race member having an a shoulder adjacent to and outboard of said raceway thereon for confronting a corresponding planar surface of said outboard member, a form-fitting coaxial generally cylindrical stub axle extending outwardly from said hubs&#39; said inboard member, and a flanged outboard hub member having a generally cylindrical main body with a concentric generally cylindrical through-bore originating on the inboard planar surface thereof and a counterbore at its inboard end therein, inboard and outboard wheel bearings each having a plurality of rolling elements and inboard and outboard bearing seals, wherein said interconnected hub sub-assembly, said inboard and outboard wheel bearings and said seals are arranged on mutually coaxial axes, and wherein said hub sub-assembly is being rotatably supported within said outer casing member by said wheel bearings and said hub flange is having provisions for mounting a road wheel thereto, the arrangement comprising a mechanism for rotatably mounting a road wheel into a suspension upright. 
         [0010]    In this arrangement the hub&#39;s inboard and outboard members are made of induction hardenable or case-hardenable steel alloy, such that surfaces thereof may be selectively hardened independently of their core hardness. Further, said hub&#39;s said integral outwardly extending coaxial cylindrical stub axle is provided with a first set of radially disposed axially oriented pointed teeth thereon and a generally cylindrical counterbore at its outboard end therein. At the time of inseparably joining said inboard member&#39;s said stub axle into said outer member&#39;s bore and counterbore, as said stub axle is being axially forced into said bore of said outer member until said stub axle&#39;s said shoulder confronts the outer member&#39;s said inboard planar surface, the previously hardened said first set of teeth displace material from said outer member&#39;s said bore towards the its outboard end, forming a first set of corresponding teeth therein, and causing a portion of said stub axle to protrude through said outboard member&#39;s outboard end. The joining operation is completed by outwardly deforming said stub axle&#39;s said protruding portion, thus forming a collar upended tightly against said outboard member&#39;s outer end, creating an inseparable assembly therewith. 
         [0011]    According to an alternate concept, the stub axle extending outwardly from the hub inboard member&#39;s outer race proper may be a mechanically integrated discrete segment thereof, so as to permit cost efficient use of mutually exclusive alloys for said axle and said outer race proper, wherein said outer race proper made of rolling contact bearing steel is being provided with a concentric cylindrical bore originating on the outboard planar surface thereof and terminating at the inboard planar surface being within the cage cavity therein, and wherein said stub axle made of induction hardenable or case-hardenable steel is being provided with an inwardly extending concentric annular root, said root originating at the planar inboard end of said stub axle forming an abutting shoulder thereof, wherein said root is provided with a second set of radially disposed axially oriented pointed teeth thereon and a cylindrical counterbore therein. At the time of inseparably joining said stub axle to said CV joint&#39;s outer race proper, as said root is being axially forced into said bore of said outer race proper until said root&#39;s said shoulder confronts the outer race&#39;s said outboard planar surface, the previously hardened said second set of teeth displace material from said outer race&#39;s said bore towards the cage cavity, forming a second set of corresponding teeth therein, and causing a portion of said root protruding into said cage cavity therein. The joining operation is completed by outwardly deforming said root&#39;s said protruding portion, thus forming a collar abutting said inboard planar surface therein, creating an inseparable assembly thereof. The stub axle&#39;s outwardly extending portion is the same as that described in the previous paragraph. 
         [0012]    In one embodiment there is provided an arrangement wherein the inboard and outboard integral annular outer raceway surfaces inside the cartridge casing, and the integral annular inner raceway surfaces on the CV joint and the flanged hub respectively are in bearing contact with their respective compliments of rolling elements, and wherein said inboard and outboard plurality of rolling element sets are ensconced in their respective cages, and wherein the CV joint&#39;s integral coaxial outwardly extending stub axle and the generally cylindrical bore of the flanged hub outboard member form-fittingly and non-rotatably engage one another in a permanently pre-tensioned manner constituting a single interconnecting arrangement of concentrically and rotatably mounted inboard and outboard pair of bearings in said cartridge casing, said cartridge casing comprising said bearings&#39; outer races by virtue of a pair of axially spaced apart concentric counterbores at opposite ends of said main bore thereof for ensconcing said interconnecting arrangement therein, said outer races of said inboard and outboard bearings facing one another for tensioning said pair of adjustable bearings confronting said means of bearing support therein, and said pair of wheel bearings locating and providing full end support at both ends to said rotating interconnecting arrangement in said cartridge casing. 
         [0013]    While the concentric interconnected arrangement of said wheel support assembly may be laid out in any number of ways, in all cases the raceway on said CV joint&#39;s outer race proper is being in bearing contact with the plurality of rolling elements of the inner wheel bearing, and wherein said raceway is in the general area occupied by said CV joint&#39;s driven plane. 
         [0014]    Preferably, the CV joint&#39;s outer race proper and the concentric outwardly extending stub axle thereof are made as a homogenous entity. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Having thus generally described the invention, reference will be made to the accompanying drawings illustrating embodiments thereof, in which: 
           [0016]      FIG. 1  is a side view with a broken out section of the CV joint outer race, noting commonly used terminology occurring throughout this document; 
           [0017]      FIG. 2  is a side view with a broken out section of one arrangement of the CV joint outer race; 
           [0018]      FIG. 3  is a side view with a broken out section of an alternate arrangement of the CV joint outer race; 
           [0019]      FIG. 4  is a cutaway view of one embodiment of an interconnecting arrangement for a vehicle driven wheel hub module and hub drive mechanism; 
           [0020]      FIG. 5  is a cutaway view of a further embodiment of an interconnecting arrangement for a vehicle driven wheel hub module and hub drive mechanism; 
           [0021]      FIG. 6  is a cutaway view of a further embodiment of an interconnecting arrangement for a vehicle driven wheel hub module and hub drive mechanism; 
           [0022]      FIG. 7  is a cutaway view of a further embodiment of an interconnecting arrangement for a vehicle driven wheel hub module and hub drive mechanism; 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    Referring to the drawings in greater detail and by reference characters thereto, in  FIG. 1  there is illustrated a side elevation with broken out sectional view of the CV joint&#39;s outer race, noting the terminology referring to elements thereof and occurring throughout this document. 
         [0024]    Referring to the drawing in  FIG. 2 , there is illustrated a side elevation with broken out sectional view of a CV joint&#39;s outer race  10  with an integral concentric generally cylindrical outwardly extending stub axle  16 . 
         [0025]    The CV joint&#39;s outer race proper  10  is made of induction hardenable or case hardenable steel, whereof said stub axle  16  around its circumference adjacent to the outer race proper is formed with integral axially oriented radially disposed plurality of pointed teeth  17  and further, wherein there is provided a counterbore  18  at its outboard end. 
         [0026]    Referring to the drawing in  FIG. 3 , there is a side elevation with broken out sectional view of an alternate embodiment of a CV joint&#39;s outer race  10  illustrating a subassembly comprising said CV joint&#39;s outer race proper  10  and a concentric mechanically integrated discrete stub axle  13  extending outwardly therefrom. 
         [0027]    The CV joint&#39;s outer race proper  10 , made of rolling contact bearing steel, is provided with a concentric cylindrical bore  10   a  originating on the outboard planar surface  18  thereof and terminating at the inboard planar surface  10   c  being within the cage cavity  10   d  therein. 
         [0028]    Stub axle  13 , being made of induction hardenable or case-hardenable steel, is provided with an inwardly extending concentric annular root  19 , said root originating at the planar inboard shoulder  19   a  of stub axle  13 , wherein said root  19  is being provided with a first set of radially disposed axially oriented pointed teeth  19   c  thereon, a first cylindrical counterbore  19   d  therein at said stub axle&#39;s inboard end, and a second cylindrical counterbore  13   a  at said stub axle&#39;s outboard end. 
         [0029]    At the time of inseparably joining said stub axle  13  to said CV joint  10  outer race proper, the previously hardened teeth  19   c  of stub axle&#39;s said root  19  are being axially forced into the bore  10   a  of said outer race proper, said first set of teeth  19   c  displace material from said outer race&#39;s said bore  10   a  towards the cage cavity  10   d , forming a second set of teeth  10   e  therein, a portion of said root  19  protruding into said cage cavity  10   d  therein. The uniting force is maintained until shoulder  19   a  of said root confronts the outer race&#39;s said planar surface  18 . The joining operation is completed by outwardly deforming said root&#39;s said protruding portion  19  causing the creation of a collar  19   b  abutting said inboard planar surface  10   c  therein, creating an inseparable assembly therewith. 
         [0030]    Referring to the drawing in  FIG. 4 , there is illustrated in sectional view a wheel hub and axle drive mechanism whose inboard and outboard bearing rolling elements  20  and  40  respectively are spherical and their shape geometry and raceway diameters are optimally and mutually independently sized, and whose rows are axially separated, and further, which includes a wheel hub sub-assembly comprised of an inner member defined by a CV joint outer race  10  and outboard member  30 , a plurality of inboard rolling elements  20  retained thereto by spacer cage  21 , a plurality of outboard rolling elements  40  retained thereto by spacer cage  41 , an inboard bearing seal  3 , an outboard bearing seal  5 , and finally wheel mounting threaded lugs  6  and a hub module outer casing member generally designated by reference numeral  80 , said outer casing member having at least one suitable means for securely attaching to a vehicle suspension upright. 
         [0031]    The induction hardenable or case-hardenable steel CV joint outer race  10  is configured to include an annular raceway  11  for being in bearing contact with rolling elements  20  being retained thereto by spacer cage  21 , a machined journal  12  for bearing seal  3 , an integral coaxial outwardly extending stub axle  13 , whereof there is provided an outwardly extending concentric annular nosing  16  and a cylindrical counterbore  17  therein. 
         [0032]    Hub outboard member  30  includes a concentric bore  31  to mate with the coaxial outwardly extending stub axle  13  and a coaxial outboard counterbore  33  thus creating a face  37  therein, said hub outboard member  30  having coaxial journal seat  31  for mating with corresponding journal surface  15  of said stub axle  13 , a face  38  abutting shoulder  18  of said CV joint  10 , and a second raised coaxial journal seat  36  for coming into contact with outboard bearing seal  5 , and finally a hub flange  39  is provided with bolt holes  35  thereon for securing the threaded wheel mounting lugs  6  therein. Said hub  30  is held securely in position on said CV joint  10  coaxial outwardly extending stub axle  13  by said coaxial annular nosing  16  being deformed into permanent union with said concentric outboard shoulder  34  of said hub  30 . 
         [0033]    The integral stub axle  13  of CV joint outer race  10  is provided with a concentric cylindrical surface  15  thereon to snugly slide into bore  31  of said hub module outboard member  30  such that said annular nosing  16  protrudes into said outboard member counterbore  33  of said hub outboard member  30 , and further, at the inboard end of said stub axle  13  adjacent to said CV joint outer race proper  10 , said stub axle  13  is being provided with a first set of circumferentially disposed axially oriented pointed teeth  14  thereon. 
         [0034]    The hub module assembly comprises an inboard hub member defined by a CV joint outer race  10 , a hub outboard member  30 , a hub module outer casing member  80 , a plurality of inboard rolling elements  20  with spacer cage  21 , a plurality of outboard rolling elements  40  with spacer cage  41 , wherein said rolling elements  20  and  40  are in rolling contact with integral inboard  86  and outboard  87  raceways respectively of said outboard casing member  80  and said hub sub-assembly comprised of said outboard member  30  and said inboard member  10  respectively, and wherein said hub module further includes inboard and outboard wheel bearing seals  3  and  5  respectively. 
         [0035]    At the time of inseparably joining said CV joint outer race proper  10  to said hub outboard member  30 , the previously hardened teeth  14  of said stub axle&#39;s said cylindrical surface  15  are being axially forced into the said bore  31  of said hub  30 , said first set of teeth  14  displace material from said hub&#39;s said bore  31  towards the outboard member counterbore  33 , forming a second set of teeth  32  therein, and causing a portion of said annular lip  15  to protrude into said counterbore  33  therein. The uniting force is maintained until shoulder  18  of said CV joint outer race proper  10  abuts said face  38  of said hub  30 , at which time said rolling elements and said inner and outer raceways are drawn to one another with a predetermined level of load. The joining operation is completed by outwardly deforming said protruding portion of said annular nosing  16  causing the creation of a collar  16  confronting said outboard face  31   a  therein, creating an inseparable assembly thereof. 
         [0036]    Referring to the drawing of the first alternate configuration as illustrated in  FIG. 5 , similar reference numerals in the 200&#39;s are used for similar components, and the same reference numerals are used for identical components. The wheel hub and axle drive mechanism shown in  FIG. 5  is essentially the same as that of the first embodiment, the exception being in the details of the inboard wheel bearing arrangement, wherein said bearing&#39;s inboard rolling elements  220  are tapered rollers. 
         [0037]    Closer look at  FIG. 5  reveals a CV joint outer race  210  configured to include an conical raceway  211  being in bearing contact with tapered roller elements  220 , a spacer cage  221  retaining said rolling elements thereto, a machined journal  212  being in sliding contact with seal  203 , and an integral coaxial outwardly extending stub axle  213  having an outwardly extending concentric annular nosing  215  and a cylindrical counterbore  217  at its outboard end thereof. And further, outer casing member  280  is configured to include a conical inboard outer raceway  286  to be in bearing contact with rolling elements  220  and journal surface  283  to receive inboard bearing seal  203 . 
         [0038]    In all other respects, the concept shown in  FIG. 5  is identical to that shown in  FIG. 4 . 
         [0039]    Referring to the drawing of the second alternate configuration as illustrated in  FIG. 6 , similar reference numerals in the 300&#39;s are used for similar components, and the same reference numerals are used for identical components. The wheel hub and axle drive mechanism shown in  FIG. 6  is essentially the same as that of the first embodiment, the exception being in the details of the outboard wheel bearing arrangement, wherein said bearing&#39;s outboard rolling elements  340  are tapered rollers. 
         [0040]    Closer look at  FIG. 6  reveals a hub outer member  330  configured to include an conical raceway  337  being in bearing contact with tapered roller elements  340 , a spacer cage  341  retaining said rolling elements thereto, a machined journal  336  being in sliding contact with seal  305 , and a concentric annular bore  331  at its center. And further, outer casing member  380  is configured to include a conical outboard outer raceway  387  to be in bearing contact with rolling elements  340  and journal surface  382  to receive inboard bearing seal  305 . 
         [0041]    In all other respects, the concept shown in  FIG. 6  is identical to that shown in  FIG. 4 . 
         [0042]    Referring to the drawing of the third alternate configuration as illustrated in  FIG. 7 , similar reference numerals in the 400&#39;s are used for similar components, and the same reference numerals already listed in the application of identical components of previously described iterations in  FIGS. 5 and 6  are used for identical components. The wheel hub and axle drive mechanism shown in  FIG. 7  is essentially the same as that of the first embodiment, the exception being in the details of the inboard and outboard wheel bearing arrangement, wherein said bearing&#39;s inboard and outboard rolling elements are tapered rollers. 
         [0043]    Closer look at  FIG. 7  reveals a hub module assembly comprises an inboard hub member defined by a CV joint outer race  210 , a hub outboard member  330 , a hub module outer casing member  480 , a plurality of inboard rolling elements  220  with spacer cage  221 , a plurality of outboard rolling elements  340  with spacer cage  341 , wherein said rolling elements  220  and  340  are in rolling contact with integral inboard raceway  486  and outboard raceway  487  respectively of said outboard casing member  480  and said hub sub-assembly comprised of said outboard member  330  and said inboard member  210  respectively, and wherein said hub module further includes inboard and outboard wheel bearing seals  203  and  305  respectively. 
         [0044]    In all other respects, the concept shown in  FIG. 7  is identical to that shown in  FIG. 4 . 
         [0045]    It will be understood that the above-described embodiments are for purpose of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.