Abstract:
This invention relates to method for fabricating a vehicle hub, bearing and brake disc assembly wherein the brake surface of the brake disc is oriented in a predetermined relationship relative to the outer race of the bearing assembly. The method comprises the steps of: (a) providing a vehicle hub including a hub flange; (b) providing a bearing assembly having an outer race; (c) installing the bearing assembly about the vehicle hub; (d) providing a separately formed brake disc having a brake surface; (e) securing the brake disc to the hub flange of the vehicle hub to produce a vehicle hub, bearing and brake disc assembly; (f) supporting the vehicle hub, bearing and brake disc assembly on a machining apparatus; and (g) using the machining apparatus to machine the brake surface of the brake disc of the vehicle hub, bearing and brake disc assembly whereby the brake surface is oriented in a predetermined relationship relative to the outer race of the bearing assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a continuation of PCT/US98/03825, filed Feb. 27, 1998, which is a continuation-in-part of U.S. Ser. No. 08,807,079, filed Feb. 27, 1997, now U.S. Pat. No. 5,915,502; U.S. Ser. No. 08/859,696, filed May 21, 1997, now U.S. Pat. No. 5,899,305; and U.S. Ser. No. 08/994,904, filed Dec. 19, 1997 U.S. Pat. No. 5,937,499. 
    
    
     BACKGROUND OF THE INVENTION 
     The subject invention relates to in general to vehicle brakes and, more specifically, to a method for producing a vehicle hub, bearing and brake disc assembly used in such a vehicle brake system. 
     With the advent of front wheel drive vehicles and disc brakes, the assembly which is driven by the drive shaft comprises a vehicle hub presenting a hub flange supporting a brake disc having opposed brake surfaces and with a bearing assembly surrounding the vehicle hub with an outer race presenting a bearing flange for attachment to a steering knuckle of a vehicle. When fully assembled on the vehicle, the brake surfaces of the disc rotor are disposed adjacent a pair of brake pads of a disc brake assembly and separated from engagement therewith by a normal brake running clearance when the disc brake assembly is not actuated. When the disc brake assembly is actuated, the brake pads take up the clearance and engage the brake surfaces of the brake disc. 
     In order to provide the normal brake running clearance, the brake disc must be manufactured to close tolerances with the brake surfaces oriented in a perpendicularly relationship relative to the axis of the brake disc and in parallel relationship relative to one another. A method of machining to close tolerances on a brake disc which is mounted through a bearing on a fixed stub shaft is disclosed in U.S. Pat. No. 5,430,926, to Dean J. Hartford. Normally, however, in a front drive or driven wheel a bearing assembly is disposed about the vehicle hub, rather than in the vehicle hub as in the aforementioned patent, and after the brake surfaces have been machined. As the assembly is mounted to the vehicle, the bearing assembly is loaded to finalize the relationship or orientation between the brake surfaces and the axis of rotation and can result in misalignment of the brake surfaces. 
     SUMMARY OF THE INVENTION 
     This invention relates to method for fabricating a vehicle hub, bearing and brake disc assembly wherein the brake surface of the brake disc is oriented in a predetermined relationship relative to the outer race of the bearing assembly. The method comprises the steps of: (a) providing a vehicle hub including a hub flange; (b) providing a bearing assembly having an outer race; (c) installing the bearing assembly about the vehicle hub; (d) providing a separately formed brake disc having a brake surface; (e) securing the brake disc to the hub flange of the vehicle hub to produce a vehicle hub, bearing and brake disc assembly; (f) supporting the vehicle hub, bearing and brake disc assembly on a machining apparatus; and (g) using the machining apparatus to machine the brake surface of the brake disc of the vehicle hub, bearing and brake disc assembly whereby the brake surface is oriented in a predetermined relationship relative to the outer race of the bearing assembly. As a result of producing the vehicle hub, bearing and brake disc assembly in this manner, tighter tolerances are maintained in the brake surfaces of the brake disc. 
     Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross sectional view of portion of a vehicle having a vehicle hub, bearing and brake disc assembly produced according to the method of the present invention installed thereon. 
     FIG. 2 is a cross sectional view of a portion of the vehicle hub, bearing and brake disc assembly illustrated in FIG.  1 . 
     FIG. 3 is a view taken along line  3 — 3  of FIG.  2 . 
     FIG. 4 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 1, showing the vehicle hub, bearing and brake disc assembly attached to a first embodiment of a clamping fixture used to produce the vehicle hub, bearing and brake disc assembly in accordance with a first method of this invention. 
     FIG. 5 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 4 disposed in a first embodiment of a machine for machining the brake surfaces of the brake disc in accordance with this invention. 
     FIG. 6 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 1, showing the vehicle hub, bearing and brake disc assembly attached to a second embodiment of a clamping fixture used to produce the vehicle hub, bearing and brake disc assembly in accordance with a second method of this invention. 
     FIG. 7 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 6 disposed in a second embodiment of a machine for machining the brake surfaces of the brake disc in accordance with this invention. 
     FIG. 8 is a cross sectional view of a pressure plate illustrated in FIGS. 6 and 7. 
     FIG. 9 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 1, showing the vehicle hub, bearing and brake disc assembly attached to a third embodiment of a clamping fixture used to produce the vehicle hub, bearing and brake disc assembly in accordance with a third method of this invention. 
     FIG. 10 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 9 disposed in a third embodiment of a machine for machining the brake surfaces of the brake disc in accordance with this invention. 
     FIG. 11 is a plan view of a pressure plate illustrated in FIGS. 9 and 10. 
     FIG. 12 is a side view of the pressure plate illustrated in FIG.  11 . 
     FIG. 13 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 1, showing the vehicle hub, bearing and brake disc assembly attached to a fourth embodiment of a clamping fixture used to produce the vehicle hub, bearing and brake disc assembly in accordance with a fourth method of this invention. 
     FIG. 14 is a cross sectional view of the vehicle hub, bearing and brake disc assembly illustrated in FIG. 13 disposed in a fourth embodiment of a machine for machining the brake surfaces of the brake disc in accordance with this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, wherein like numerals indicate like or corresponding parts throughout the several views, a vehicle hub, bearing and brake disc assembly produced in accordance with the subject invention is generally shown at  10  in FIG.  1 . The vehicle hub, bearing and brake disc assembly  10  includes a vehicle hub and bearing subassembly, generally shown at  12 , and a brake disc or rotor  26 . The vehicle hub and bearing subassembly  12  includes a vehicle hub  14  and a bearing assembly  15 . The vehicle hub  14  extends between a drive end  16  and a wheel end  18  thereof. The vehicle hub  14  is provided with a radially outwardly extending hub flange  20  and a bore  22  extending between the drive end  16  and the wheel end  18  for receiving a drive shaft  24 . 
     The illustrated brake disc  26  is ventilated and includes a mounting flange  28  and a pair of opposed friction plates  29  and  30  which are spaced apart from one another by a plurality of intermediate ribs or posts (not shown) in a known manner. The friction plates  29  and  30  define a pair of opposed generally parallel brake surfaces  29 A and  30 B. Alternatively, the brake disc  26  can be of other constructions if so desired. 
     The bearing assembly  15  surrounds the vehicle hub  14  between the drive end  16  and the hub flange  20  for supporting the vehicle hub  14 . To support the vehicle hub  14 , the bearing assembly  15  includes an outer race  32  presenting a bearing flange  34  for attachment to a support structure, such as a steering knuckle  36 . In the illustrated embodiment, the bearing flange  34  is generally triangular in peripheral configuration, as shown FIG.  2 . The bearing flange  34  includes a plurality of threaded holes  38  at the apexes for receiving bolts  40  which, in turn, extend through holes provided in the knuckle  36 . The bolts  40  have threaded ends  40 A which are received in threaded holes  38  to secure the bearing assembly  15  to the knuckle  36 . The knuckle  36  is rotatably supported by a strut  42  in a known manner. A ball joint  44  connects the knuckle  36  to the car structure (not shown). A drive shaft  24  is provided and includes a head  46  in engagement with the bearing assembly  15 . A nut/washer  48  is installed on a threaded end  24 A of the drive shaft  24  in order to place the drive shaft  24  in tension, load the bearing assembly  15 , and rotate the vehicle hub  14  which drives a vehicle wheel (not shown). The driving force is delivered through a drive axle  50  and a universal coupling, i.e., a constant velocity joint,  52 , all of which is well known in the art. 
     Turning now to FIGS. 4-5, a first method for fabricating a vehicle hub, bearing and brake disc assembly  10  in accordance with this invention will now be discussed. The first method comprises various steps which may be performed in numerous different sequences. 
     The first step is the machining of a radially extending gage surface  54  on the bearing flange  34  of the outer race  32  of the bearing assembly  15 . This is followed by disposing roller elements  56  and the outer race  32  of the bearing assembly  15  around the vehicle hub  14  with the gage surface  54  facing the drive end  16  of the vehicle hub  14 . A race lock member  58  is secured to the vehicle hub  14  by a press fit to retain the bearing assembly  15  on the vehicle hub  14  under a predetermined pre-load. At the same time, seals  60  are positioned between each end of the bearing assembly  15 , the vehicle hub  14 , and the race lock member  58 . Separators or cages  62  are also disposed between the roller elements  56 . 
     A plurality of threaded wheel studs  64  are secured to the hub flange  20  to extend axially therefrom toward the wheel end  18  of the vehicle hub  14 , the studs  64  being press fit in non-threaded holes  20 A provided in the hub flange  20 . As will be discussed below, the threaded ends of the studs  64  extend through openings provided in the brake disc  26  and holes provided in a vehicle wheel (not shown), as is well known in the art. 
     The next step is the attaching of the brake disc  26  to the vehicle hub and bearing subassembly  12 , with the wheel studs  64  extending through holes  28 A provided in the mounting flange  28  of the brake disc  26 . The mounting flange  28  of the brake disc  26  is secured to the vehicle hub and bearing subassembly  12  by screws  66 . In the illustrated embodiment, the screws  66  extend through non-threaded countersunk openings  28 B provided in the mounting flange  28  of the brake disc  26 . The threaded ends  66 A of the screws  66  are received in the threaded openings  20 B provided in the hub flange  20  to secure the brake disc  26  to the vehicle hub and bearing subassembly  12 . Alternatively, other means can be used to secure the brake disc  26  to the vehicle hub and bearing subassembly  12  if so desired. 
     A spring washer  68  is disposed on a head  70  of a fixture post  72 , the fixture post  72  being supported vertically for receiving the vehicle hub  14 . The spring washer  68  is illustrated as a plurality of Belleville washers but may comprise an elastomeric, or the like. A washer  69  is disposed between the Belleville washers  68  and the race lock member  58 . The vehicle hub  14  is placed on the fixture post  72  with the spring washer  68  in engagement with the race lock member  58  as the fixture post  72  is inserted through the spring washer  68 , the washer  69 , and through the bore  22  to extend from the wheel end  18  of the vehicle hub  14 . Preferably, the fixture post  72  snugly engages the interior of the bore  22  of the vehicle hub  14  in a press fit therewith. 
     While in the vertical position, a clamp plate  74  is disposed about the wheel end  18  of the vehicle hub  14  and in engagement with the mounting flange  28  of the brake disc  26 . The clamp plate  74  has a central opening  74 A surrounding a projection  76  at the wheel end  18 . A washer/nut  78  is disposed over the clamp plate  74  and in threaded engagement with a threaded end  72 A of the post  72  to place the post  72  in tension to urge the spring washer  68  against the bearing lock member  58  and the clamp plate  74  against the mounting flange  28  of the brake disc  26 . This maintains the pre-load on and retains the bearing assembly  15  to the vehicle hub  14 ; this prevents the race lock member  58  from changing position to maintain the pre-loading the same as occurs when the assembly is mounted on the vehicle, as shown in FIG.  1 . This also provides a clamp load between the brake disc  26  and the hub face. 
     This subassembly is then moved to a machining station, as shown in FIG. 5, and placed in position to be clamped or grasped by a cam chuck  80  mounted on a stationary machine. The cam chuck  80  has jaws  82  which clamp the outer race  32  of the bearing assembly  15  and draws the gage surface  54  against a gage  84  to properly orient the outer race  32  about a fixed axis A. The gage  84  is shown as engaging only one area of the circumference of the gaging surface  54 ; however, the gage  84  engages most of the circumference of the gaging surface  54  and includes air sensors (not shown) to confirm that the gaging surface  54  is property oriented and engaging the gage  84  in all quadrants. 
     Once the outer race  32  is clamped in a fixed position relative to the fixed axis A, the next step is engaging the clamp plate  74  with a rotating member  86  to rotate the clamp plate  74  about a floating axis B. More specifically, the clamp plate  74  presents a step or shoulder  88  and the rotating member  86  is a power chuck with rotating jaws  90 . The rotating jaws  90  rotate about the axis B which is floating, i.e., not fixed, to allow some relative radial movement between the outer race  32  and the vehicle hub  14  or the brake disc  26 . As a result, the rotating member  86  is operative to drive and rotate the clamp plate  74  and therefore, the vehicle hub  14  and the brake disc  26 . 
     The final step is the machining of the brake surfaces  29 A and  30 A of the friction plates  29  and  30 , respectively, of the brake disc  26  while rotating the vehicle hub  14  and the brake disc  26  relative to the outer race  32 . This machining is accomplished with cutting inserts  92  which are supported on shafts  94  disposed on opposite sides of the friction plates  29  and  30  of the brake disc  26 . Thus, the brake surfaces  29 A and  30 A are machined in a predetermined relationship relative to the outer race  32 . Subsequently, the fixture post  72  is removed and the completed vehicle hub, bearing and brake disc assembly  10  is installed onto the knuckle  36 , as shown in FIG.  1 . 
     Turning now to FIGS. 6-8, a second method for fabricating a vehicle hub, bearing and brake disc assembly  10  in accordance with this invention will now be discussed. The second method comprises various steps which may be performed in numerous different sequences. 
     The first step is the machining of a radially extending gage surface  54  on the bearing flange  34  of the outer race  32  of the bearing assembly  15 . This is followed by disposing roller elements  56  and the outer race  32  of the bearing assembly  15  around the vehicle hub  14  with the gage surface  54  facing the drive end  16  of the vehicle hub  14 . A race lock member  58  is secured to the vehicle hub  14  by a press fit to retain the bearing assembly  15  on the vehicle hub  14  under a predetermined pre-load. At the same time, seals  60  are positioned between each end of the bearing assembly  15 , the vehicle hub  14 , and the race lock member  58 . Separators or cages  62  are also disposed between the roller elements  56 . 
     A plurality of threaded wheel studs  64  are secured to the hub flange  20  to extend axially therefrom toward the wheel end  18  of the vehicle hub  14 , the studs  64  being press fit in non-threaded holes  20 A provided in the hub flange  20 . As will be discussed below, the threaded ends of the studs  64  extend through openings provided in the brake disc  26  and holes provided in a vehicle wheel (not shown), as is well known in the art. 
     The next step is the attaching of the brake disc  26  to the vehicle hub and bearing subassembly  12 , with the wheel studs  64  extending through holes  28 A provided in the mounting flange  28  of the brake disc  26 . The mounting flange  28  of the brake disc  26  is secured to the vehicle hub and bearing subassembly  12  by screws  66 . In the illustrated embodiment, the screws  66  extend through non-threaded countersunk openings  28 B provided in the mounting flange  28  of the brake disc  26 . The threaded ends  66 A of the screws  66  are received in the threaded openings  20 B provided in the hub flange  20  to secure the brake disc  26  to the vehicle hub and bearing subassembly  12 . Alternatively, other means can be used to secure the brake disc  26  to the vehicle hub and bearing subassembly  12  if so desired. 
     The head  170  of a fixture post  172  has an annular shoulder  169  for engaging the race lock member  58 . The fixture post  172  is supported vertically for receiving the vehicle hub  14 . The vehicle hub  14  is placed on the fixture post  172  with the head  170  thereof in engagement with the race lock member  58  as the post  172  is inserted through the hub bore  22  to extend from the wheel end  18  of the vehicle hub  14 . Preferably, the fixture post  172  snugly engages the interior of the bore  22  of the vehicle hub  14  in a press fit therewith. 
     While in the vertical position, a pressure plate  174  is disposed about the wheel end  18  of the vehicle hub  14  and in engagement with the mounting flange  28  of the brake disc  26 . The pressure plate  174  has a central opening  174 A surrounding a projection  176  at the wheel end  18  of the wheel hub  14 . A plurality of bushings  175  are press fit into openings  174 B provided in the pressure plate  174  and surround, in spaced relationship, each of the studs  64 . The bushings  175  are preferably constructed of brass, which is softer than the studs  64 , to prevent damage to the threads of the studs  64 . 
     The pressure plate  174  further includes a plurality of circumferentially spaced tabs  190 A and  190 B provided thereon. The tabs  190 A are spaced radially inwardly relative to the holes  174 B, and the tabs  190 B are spaced radially outwardly relative to the holes  174 B. The inner tabs  190 A and outer tabs  190 B engage the mounting flange  28  of the brake disc  26  for simulating the pressure points exerted by a vehicle wheel. In this fashion, the brake disc  26  is machined under conditions which are as near the running conditions of the brake disc  26  when mounted on a vehicle with a vehicle wheel attached. 
     A washer  177  and nut  178  are disposed over the pressure plate  174  with the nut  178  in threaded engagement with the post  172  to place the post  172  in tension between the race lock member  58  and the pressure plate  174  to urge the tabs  190 A and  190 B into engagement with the mounting flange  28  of the brake disc  26  for simulating the pressure points exerted by a vehicle wheel. This maintains the pre-load on and retains the bearing assembly  15  to the vehicle hub  14 , and prevents the race lock member  58  from changing position to maintain the pre-loading the same as occurs when the assembly  10  is mounted on the vehicle as shown in FIG.  1 . This also provides a clamp load between the brake disc  26  and the hub face. 
     The subassembly is then moved to a machining station, as shown in FIG. 6, and placed in position to be clamped or grasped by a cam chuck  180  mounted on a stationary machine. The cam chuck  180  has jaws  182  which are operative to clamp the outer race  32  of the bearing assembly  15  and draw the gage surface  54  against a gage  84  in order to properly orient the outer race  32  about a fixed axis A. The gage  84  is shown as engaging only one area of the circumference of the gaging surface  54 ; however, the gage  84  is operative to engage most of the circumference of the gaging surface  54  and includes air sensors (not shown) to confirm that the gaging surface  54  is properly oriented and engaging the gage  84  in all quadrants. 
     Once the outer race  32  is clamped in a fixed position relative to the fixed axis A, the next step is engaging the pressure plate  174  with a rotating member  186  to thereby rotate the pressure plate  174  about a floating axis B. More specifically, a resilient pad  168  is sandwiched between the pressure plate  174  and the rotating member  186  in a plane generally perpendicular to the floating axis B and urges the rotating member  186  against the pressure plate  174  to compress the resilient pad  168  between the rotating member  186  and the pressure plate  174 . Accordingly, the rotating member  186  rotates about the axis B which is floating, i.e., not fixed, to allow some relative radial movement between the outer race  32  and the vehicle hub  14  or the brake disc  26 . The resilient pad  168  allows relative radial movement between the rotating member  186  and the pressure place  174  as the rotating member  186  is urged or forced axially into engagement with the resilient pad  168 . As a result, pressure plate  174 , and therefore the vehicle hub  14  and disc brake  26 , are frictionally driven and rotated by the rotating member  186 . 
     The final step is the machining of the brake surfaces  29 A and  30 A of the brake disc  26  while rotating the vehicle hub  14  and brake disc  26  relative to the outer race  32  of the bearing assembly  15 . This machining is accomplished with cutting inserts  92  which are supported on shafts  94  disposed on opposite sides of the friction plates  29  and  30  of the brake disc  26 . Thus, the brake surfaces  29 A and  30 A are machined in a predetermined relationship relative to the outer race  32 . Subsequently, the fixture post  72  is removed and the completed vehicle hub, bearing and brake disc assembly  10  is installed onto the knuckle  36 , as shown in FIG.  1 . 
     Turning now to FIGS. 9-12, a third method for fabricating a vehicle hub, bearing and brake disc assembly  10  in accordance with this invention will now be discussed. The third method comprises various steps which may be performed in numerous different sequences. 
     The first step is the machining of a radially extending gage surface  54  on the bearing flange  34  of the outer race  32  of the bearing assembly  15 . This is followed by disposing roller elements  56  and the outer race  32  of the bearing assembly  15  around the vehicle hub  14  with the gage surface  54  facing the drive end  16  of the vehicle hub  14 . A race lock member  58  is secured to the vehicle hub  14  by a press fit to retain the bearing assembly  15  on the vehicle hub  14  under a predetermined pre-load. At the same time, seals  60  are positioned between each end of the bearing assembly  15 , the vehicle hub  14 , and the race lock member  58 . Separators or cages  62  are also disposed between the roller elements  56 . 
     A plurality of threaded wheel studs  64  are secured to the hub flange  20  to extend axially therefrom toward the wheel end  18  of the vehicle hub  14 , the studs  64  being press fit in non-threaded holes  20 A provided in the hub flange  20 . As will be discussed below, the threaded ends of the studs  64  extend through openings provided in the brake disc  26  and holes provided in a vehicle wheel (not shown), as is well known in the art. 
     The next step is the attaching of the brake disc  26  to the vehicle hub and bearing subassembly  12 , with the wheel studs  64  extending through holes  28 A provided in the mounting flange  28  of the brake disc  26 . The mounting flange  28  of the brake disc  26  is secured to the vehicle hub and bearing subassembly  12  by screws  66 . In the illustrated embodiment, the screws  66  extend through nonthreaded countersunk openings  28 B provided in the mounting flange  28  of the brake disc  26 . The threaded ends  66 A of the screws  66  are received in the threaded openings  20 B provided in the hub flange  20  to secure the brake disc  26  to the vehicle hub and bearing subassembly  12 . Alternatively, other means can be used to secure the brake disc  26  to the vehicle hub and bearing subassembly  12  if so desired. 
     The head  270  of a fixture post  272  has an annular shoulder  269  for engaging the race lock member  58 . The fixture post  272  is supported vertically for receiving the vehicle hub  14 . The vehicle hub  14  is placed on the post  272  with the head  270  of the fixture post  272  in engagement with the race lock member  58  as the post  272  is inserted through the bore  22  to extend from the wheel end  18  of the vehicle hub  14 . Preferably, the post  272  extends through the bore  22  of the hub  14  in a clearance fit therewith. 
     While in the vertical position, a pressure plate  274  having a central opening  274 B is disposed about wheel end  18  and in engagement with the vehicle hub  14 . More specifically, a pocket  73  is formed in the wheel end  18  of the vehicle hub  14  which is surrounded by a projection  76  extending from the wheel end  18 . The pocket  73  is radially within the circumference of the vehicle hub  14  as defined by that circumference of the vehicle hub  14  upon which the roller elements  56  are in rolling engagement. The pressure plate  274  comprises a nose  274 A which is disposed radially within the pocket  73  and engages the vehicle hub  14  within its outer circumference. 
     At least one spoke, a circular disc  277  as illustrated, extends radially from the pressure plate  274  and in an axially spaced relationship to the mounting flange  28  of the brake disc  26  and in a circumferential driving relationship with the studs  64 . It is important that the pressure plate  274  exert no axial forces on the hub flange  20  to prevent a moment on the bearing assembly  15  which would not exist when in the installed condition of FIG. 1. A plurality of bushings  275  are press fit into the spoke  277  to surround, in spaced relationship, each of the studs  64 . The bushings  275  are of brass or rubber, which is softer than the studs  64 , to prevent damage to the threads of the studs  64 . 
     A washer/nut  278  are disposed over the pressure plate  274  and in threaded engagement with a threaded end  272 A of the post  272  to place the post  272  in tension between the race lock member  58  and the pressure plate  274  to urge the nose  274 A of the pressure plate  274  into engagement with the pocket  73  of the vehicle hub  14 . This maintains the pre-load on and retains the bearing assembly  15  to the vehicle hub  14 ; this prevents the race lock member  58  from changing position to maintain the pre-loading the same as occurs when the assembly is mounted on the vehicle as shown in FIG.  1 . 
     This subassembly is then moved to a machining station, as shown in FIG. 10, and placed in position to be clamped or grasped by a cam chuck  280  mounted on a stationary machine. The cam chuck  280  has jaws  282  which clamp the outer race  32  of the bearing assembly  15  and draws the gage surface  54  against a gage  284  to properly orient the outer race  32  about a fixed axis A. The gage  284  is shown as engaging only one area of the circumference of the gaging surface  54 ; however, the gage  284  engages most of the circumference of the gaging surface  54  and includes air sensors (not shown) to confirm that the gaging surface  54  is properly oriented and engaging the gage  284  in all quadrants. 
     Once the outer race  32  is clamped in a fixed position relative to the fixed axis A, the next step is engaging the washer portion  278 A of the washer/nut  278  with a rotating member  286  to rotate the pressure plate  274  about a floating axis B. More specifically, a resilient pad  268  is sandwiched between the washer portion  278 A of the washer/nut  278  and the rotating member  286  in a plane perpendicular to the floating axis B and urging the rotating member  286  against the washer portion  278 A of the washer/nut  278  to compress the resilient pad  268  between the rotating member  286  and the washer portion  278 A of the washer/nut  278 . Accordingly, the rotating member  286  rotates about the axis B which is floating, i.e., not fixed, to allow some relative radial movement between the outer race  32  and the vehicle hub  14  or brake disc  26 . 
     The resilient pad  268  allows relative radial movement between the rotating member  286  and the washer portion  278 A of the washer/nut  278  as the rotating member  286  is urged or forced axially into engagement with the resilient pad  268 . As a result, washer/nut  278 , and therefore the pressure plate  274 , the vehicle hub  14 , and the brake disc  26 , are frictionally driven and rotated by the rotating member  286  solely within the circumference of the vehicle hub  14  at the wheel end  18  to thereby apply axial forces resulting from the frictional engagement through the vehicle hub  14  without applying axial forces to the hub flange  20  of the vehicle hub  14  and the mounting flange  28  of the brake disc  26 . This prevents axial forces from being applied to the hub flange  20  and the mounting flange  28  of the brake disc  26 . Said another way, this method includes placing the washer/nut  278  in threaded engagement with the fixture post  272  and tightening the washer/nut  278  against the pressure plate  274  and engaging the washer portion  278 A of the washer/nut  278  with the rotating member  286  through the pad  268 . 
     In this embodiment, an annular seal  290  disposed between the head  270  of the fixture post  272  and the outer race  32  to prevent contaminants from entering into bearing assembly  15  during the machining of the brake disc  26 , i.e., to prevent the metal removed by such machining from entering the bearing assembly  15 . In addition, in this embodiment, an annular plastic ring  298  is supported annularly by the chuck  280  and extends to a taper  299  in the space between the bearing flange  34  and the inner end of the friction plate  29  of the brake disc  26  to prevent chips from the machining of the brake disc  26  from entering into the bearing assembly  15 . The gage  284  extends through a hole  296  in the chuck  280 . 
     The final step is the machining of the brake surfaces  29 A and  30 A of the brake disc  26  while rotating the vehicle hub  14  and brake disc  26  relative to the outer race  32  of the bearing assembly  15 . This machining is accomplished with cutting inserts  92  which are supported on shafts  94  disposed on opposite sides of the friction plates  29  and  30  of the brake disc  26 . Thus, the brake surfaces  29 A and  30 A are machined in a predetermined relationship relative to the outer race  32 . Subsequently, the fixture post  272  is removed and the completed vehicle hub, bearing and brake disc assembly  10  is installed onto the knuckle  36 , as shown in FIG.  1 . 
     Turning now to FIGS. 13-14, a fourth method for fabricating a vehicle hub, bearing and brake disc assembly  10  in accordance with this invention will now be discussed. The fourth method comprises various steps which may be performed in numerous different sequences. 
     The first step is the machining of a radially extending gage surface  54  on the bearing flange  34  of the outer race  32  of the bearing assembly  15 . This is followed by disposing roller elements  56  and the outer race  32  of the bearing assembly  15  around the vehicle hub  14  with the gage surface  54  facing the drive end  16  of the vehicle hub  14 . A race lock member  58  is secured to the vehicle hub  14  by a press fit to retain the bearing assembly  15  on the vehicle hub  14  under a predetermined pre-load. At the same time, seals  60  are positioned between each end of the bearing assembly  15 , the vehicle hub  14 , and the race lock member  58 . Separators or cages  62  are also disposed between the roller elements  56 . 
     A plurality of threaded wheel studs  64  are secured to the hub flange  20  to extend axially therefrom toward the wheel end  18  of the vehicle hub  14 , the studs  64  being press fit in non-threaded holes  20 A provided in the hub flange  20 . As will be discussed below, the threaded ends of the studs  64  extend through openings provided in the brake disc  26  and holes provided in a vehicle wheel (not shown), as is well known in the art. 
     The next step is the attaching of the brake disc  26  to the vehicle hub and bearing subassembly  12 , with the wheel studs  64  extending through holes  28 A provided in the mounting flange  28  of the brake disc  26 . The mounting flange  28  of the brake disc  26  is secured to the vehicle hub and bearing subassembly  12  by screws  66 . In the illustrated embodiment, the screws  66  extend through non-threaded countersunk openings  28 B provided in the mounting flange  28  of the brake disc  26 . The threaded ends  66 A of the screws  66  are received in the threaded openings  20 B provided in the hub flange  20  to secure the brake disc  26  to the vehicle hub and bearing subassembly  12 . Alternatively, other means can be used to secure the brake disc  26  to the vehicle hub and bearing subassembly  12  if so desired. 
     The head  370  of a fixture post  372  has an annular shoulder  369  for engaging the race lock member  58 . The fixture post  372  is supported vertically for receiving the vehicle hub  14 . The vehicle hub  14  is placed on the post  372  with the head  370  of the fixture post  372  in engagement with the race lock member  58  as the post  372  is inserted through the bore  22  to extend from the wheel end  18  of the vehicle hub  14 . Preferably, the post  372  extends through the bore  22  of the hub  14  in a clearance fit therewith. 
     While in the vertical position, a pressure plate  374  is disposed about wheel end  18  and in engagement with the vehicle hub  14 . The pressure plate  374  has a central opening  374 A surrounding a projection  76  at the wheel end  18  of the wheel hub  14 . A plurality of bushings  375  are press fit into openings  374 B provided in the pressure plate  374  and surround, in spaced relationship, each of the studs  64 . The bushings  375  are preferably constructed of rubber to prevent damage to the threads of the studs  64 . Alternatively, the bushings  375  may be formed of other materials if so desired. The pressure plate  374  further includes a plurality of circumferentially spaced tabs  374 B and  374 C provided thereon. The tabs  374 B and  374 C are similar to the tabs described above in connection with the plate  174 , best shown in FIG.  8 . As a result, tabs  374 B and  374 C engage the mounting flange  28  of the brake disc  26  for simulating the pressure points exerted by a vehicle wheel. 
     A washer/nut  378  is disposed over the pressure plate  374  and in threaded engagement with a threaded end  372 A of the post  372  to place the post  372  in tension between the bearing lock member  58  and the pressure plate  374  to urge the tabs  374 B and  374 C against the mounting flange  28  of the brake disc  26 . This maintains the pre-load on and retains the bearing assembly  15  to the vehicle hub  14 ; this prevents the race lock member  58  from changing position to maintain the pre-loading the same as occurs when the assembly is mounted on the vehicle, as shown in FIG.  1 . This also provides a clamp load between the brake disc  26  and the hub face. 
     This subassembly is then moved to a machining station, as shown in FIG. 14, and placed in position to be clamped or grasped by a cam chuck  380  mounted on a stationary machine. The cam chuck  380  has jaws  382  which clamp the outer race  32  of the bearing assembly  15  and draws the gage surface  54  against a gage  384  to properly orient the outer race  32  about a fixed axis A. The gage  384  is shown as engaging only one area of the circumference of the gaging surface  54 ; however, the gage  384  engages most of the circumference of the gaging surface  54  and includes air sensors (not shown) to confirm that the gaging surface  54  is properly oriented and engaging the gage  384  in all quadrants. The gage  384  extends through a hole  396  in the chuck  380 . 
     Once the outer race  32  is clamped in a fixed position relative to the fixed axis A, the next step is engaging the washer portion  378 A of the washer/nut  378  with a rotating member  386  to rotate the pressure plate  374  about a floating axis B. More specifically, a resilient pad  368  is sandwiched between the washer portion  378 A of the washer/nut  378  and the rotating member  386  in a plane perpendicular to the floating axis B and urging the rotating member  386  against the washer portion  378 A of the washer/nut  378  to compress the resilient pad  368  between the rotating member  386  and the washer portion  378 A of the washer/nut  378 . Accordingly, the rotating member  386  rotates about the axis B which is floating, i.e., not fixed, to allow some relative radial movement between the outer race  32  and the vehicle hub  14  or brake disc  26 . The resilient pad  368  allows relative radial movement between the rotating member  386  and the pressure place  374  as the rotating member  386  is urged or forced axially into engagement with the resilient pad  368 . As a result, pressure plate  374 , and therefore the vehicle hub  14  and disc brake  26 , are frictionally driven and rotated by the rotating member  386 . 
     In this embodiment, an annular seal  390  is disposed between the head  370  of the fixture post  372  and the outer race  32  to prevent contaminants from entering into bearing assembly  15  during the machining of the brake disc  26 , i.e., to prevent the metal removed by such machining from entering the bearing assembly  15 . In addition, in this embodiment, an annular plastic ring  398  is supported annularly by the chuck  380  and extends to a taper  399  in the space between the bearing flange  34  and the inner end of the friction plate  29  of the brake disc  26  to prevent chips from the machining of the brake disc  26  from entering into the bearing assembly  15 . Also, the ring  398  is operative to direct the flow of air which is normally produced by the chuck  380  in a direction (shown by arrows F) which is effective to exhaust any chips which may enter through the passageways  26 A of the brake disc  26 . Alternatively, a source of compressed air  400  can be provided and supplied through one or more openings  380 A (only one opening  380 A illustrated in this embodiment), which are provided in the chuck  380  to supplement the air normally produced by the chuck  380 . 
     The final step is the machining of the brake surfaces  29 A and  30 A of the brake disc  26  while rotating the vehicle hub  14  and brake disc  26  relative to the outer race  32  of the bearing assembly  15 . This machining is accomplished with cutting inserts  92  which are supported on shafts  94  disposed on opposite sides of the friction plates  29  and  30  of the brake disc  26 . Thus, the brake surfaces  29 A and  30 A are machined in a predetermined relationship relative to the outer race  32 . Subsequently, the fixture post  372  is removed and the completed vehicle hub, bearing and brake disc assembly  10  is installed onto the knuckle  36 , as shown in FIG.  1 . 
     Although the invention has been described and illustrated in connection with the particular vehicle hub, bearing and brake disc assembly  10  disclosed herein, it will be appreciated that this invention may be used in other types of vehicle hub, bearing and brake disc assemblies. For example, the hub may be of a different construction, the bearing may be of a different construction, and/or the brake disc may be of a different construction if so desired. Also, while the annular seal  290 ,  390  the plastic ring  298 ,  398 , and the air means  400  have been shown in the method of the third and/or the fourth embodiments of this invention, the seal  290 ,  390  and/or the ring  298 ,  398 , and/or the air means  400  can be used in any of the other embodiments disclosed herein if so desired. 
     In accordance with the provisions of the patents statues, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from the scope or spirit of the attached claims.