Abstract:
An automatic clutch for a vehicle drive train to selectively connect and disconnect a drive portion of the drive train to a driven portion of the drive train, the drive and driven portions having adjacent and mated spline portions at a designated position in the drive train. A clutch ring slidably mounted to one of the spline portions and slidable into engagement with the other spline portions. The designated position adjacent a portion of the vehicle frame and a remote controlled actuator secured to the portion of the vehicle frame. A bearing member of the actuator engaging the clutch ring for urging sliding movement of the clutch ring. Improvements to the above include application of the actuator clutch to front and rear wheel ends for conversion of the vehicle between two-wheel and four-wheel drive, the actuator being mounted to the steering knuckles. Also, improved bearing packs are provided for better performance and to facilitate assembly.

Description:
This application is a continuation of application Ser. No. 08/953,278 filed on Oct. 17, 1997 now U.S. Pat. No. 6,109,411 which is a continuation-in-part of application Ser. No. 08/651,384 filed May 22, 1996 now U.S. Pat. No. 5,740,895. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to transfer of torque between components of a vehicle drive line (sometimes referred to as a drive train) exemplified by the automated engagement/disengagement of a wheel to a vehicle&#39;s drive line. 
     BACKGROUND OF THE INVENTION 
     A common drive system for certain types of vehicles includes the ability to shift from two-wheel drive to four-wheel drive. Either the front wheels or the back wheels are permanently engaged with the vehicle&#39;s drive train and the remaining set of wheels is shifted into and out of engagement with the drive train. For purposes of discussion, the rear wheels will hereafter be considered permanently engaged with the drive train and the front wheels are in part-time engagement, but the reader will appreciate that the invention is equally applicable to the front wheels being permanently engaged with a drive train and the rear wheels in part-time engagement. 
     Whereas a drive train will include a transmission that transmits drive power from the vehicle&#39;s engine to a propeller shaft that extends to the differential and then the wheel axles, e.g, of the rear wheels, in order to provide four-wheel drive, there is a further propeller shaft that extends forward to the differential of the front wheels, e.g., via a transfer case that also receives drive power from the transmission. A shift mechanism in the transfer case engages and disengages the drive power to the propeller shaft for the front wheels. 
     In the disengaged position, the front wheels are not being driven but then the passive turning of the front wheels drives the front wheel axles and front wheel propeller shaft unless there is also a disconnect mechanism between each front wheel and its axle. It is the disconnect mechanism between the wheel and axle to which the present invention is primarily directed although those skilled in the art will appreciate the further application of the invention, e.g., to other components of the drive train. 
     Returning to the front wheel connect/disconnect mechanism, historically this mechanism was located in the wheel hub and advanced from manual to automatic operation. The structural arrangement included a cylindrically configured spindle which was fixedly mounted to the vehicle chassis, i.e., on the steering knuckle. The axle protruded through the center of the spindle and a wheel hub was mounted on the exterior of the spindle and surrounding the axle. Each of the wheel hub and axle was independently rotatable relative to the spindle and a clutch mechanism at the outboard end of the spindle produced the desired connect/disconnect of the wheel hub to the axle. A later version referred to as a live spindle provided for the spindle to be rotatably mounted to the vehicle chassis and the wheel hub was fixedly mounted to the spindle. The axle as before was protruded through the spindle and a clutch mechanism at the outboard end of the spindle produced the connect/disconnect operation. 
     BRIEF DESCRIPTION OF THE PRESENT INVENTION 
     In the ongoing development of clutch mechanism and particularly as related to automatically actuated clutch mechanism, several factors remained a concern. The material of the various clutch components being extended to the outboard end of the spindle added weight and enlarged the king pin radius, both of which are undesirable. Also, the components had to be packaged to fit within the confined space of the wheel hub interior and as concerns the live spindle version, all of the components for automatic actuation of a clutch mechanism had to be mounted on a rotating member, i.e., the rotating wheel hub, the rotating spindle or the rotating axle. Whereas hydraulic and pneumatic automatic actuating devices were developed, such relied on creating a sealed chamber as between two relatively rotating components and such chambers were subject to undesired leakage. 
     The present invention obviates much or all of these deficiencies by the strategic placement of the clutch mechanism at the inboard end of the spindle. In the preferred embodiment, the axle and spindle are cooperatively configured to provide mated and adjacent spline portions at circumferentially exterior locations adjacent to a non-rotating portion of the chassis, e.g., the knuckle. The automatic actuation mechanism is fixedly mounted to the knuckle and the rotating clutch ring is axially displaced through a bearing interface between the actuator and the clutch ring. 
     Whereas the above substantially describes the structure of parent U.S. patent application Ser. No. 08/651,384 referred to above, a number of improvements are herein additionally disclosed. The structure as described above readily adapts to other drive train types, e.g., wherein the front wheels are permanently engaged with the front axles in full time four-wheel drive, and wherein the front wheels are permanently disengaged from the drive train in two-wheel drive only. Thus, widely varying wheel end designs for different drive train types can be avoided. A further improvement includes multiple sensors to provide feed back for ABS braking as well as other sensing needs, e.g., determining whether the clutch is engaged or disengaged. The reduced mechanism between the knuckle and wheel hub (outboard of the clutch mechanism) allows a shorter distance between the load center of the wheel hub (tire) and the king pin axis and a reduced mass for the axle end (resulting in weight reduction). The allowable increased circumference of the clutch ring and thus a greater number of splines (because it is not confined to the wheel hub) enables shorter overlap of the clutch ring splines with the splines of the axle and wheel hub, again shortening the axial depth of the clutch mechanism. Also, part of the new disclosure is improved forms of bearing members (cartridge type, ball type, split bearing with one bearing half attached by fastener or press fit into the knuckle, etc.) which provides more efficient assembly of the clutch components as well as improved performance. 
    
    
     The above and other features, benefits and advantages will become apparent upon reference to the following detailed description and drawings referred to therein. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a vehicle; 
     FIG. 2 is a view as viewed on view lines  2 — 2  of FIG. 1; 
     FIG. 3 is a view of an integrated wheel end incorporating an automatic clutch of the present invention; 
     FIG. 4 is a view similar to FIG. 3 illustrating another embodiment of the automatic clutch; 
     FIG. 5 is an exploded view of the automatic clutch mechanism of FIG. 4; 
     FIGS. 6,  7  and  8  are views illustrating alternate bearing mounting arrangements for the wheel spindle; and 
     FIGS. 9 and 10 are views illustrating other embodiments of the automatic clutch. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a schematic illustration of a vehicle that may be driven either in two-wheel drive mode or four-wheel drive mode. Typically either the rear wheels are driven full time and the front wheels are engaged or disengaged from the drive train or conversely, the front wheels are driven full time and the rear wheels are engaged or disengaged from the drive train as desired. In this embodiment, the rear wheels are considered to be engaged full time with the drive train of the vehicle. A mechanism in the transfer case determines when drive power is connected or disconnected to the portion of the drive train for driving the front wheels, and clutch mechanism at the front wheels disengage the front wheels from the drive train to render the portion of the drive train between the transfer case and front wheels inactive. 
     Referring to FIG. 1, the vehicle has an engine  10  coupled to a transmission  12  to provide rotative power to the front and rear wheels. A propeller shaft  14  extends from the transmission  12  and is connected to a rear differential  16 . Axles  18  extend laterally from the differential  16  and are coupled to rotate the rear wheels  19 . The rear wheels  19  are engaged with the axles  18  in a full time mode. A transfer case  20  is coupled to the transmission  12 . The transfer case  20  has shift mechanism  22  that will disengage the drive train of the transfer case  20  from the transmission  12 . A front propeller shaft  24  extends from the transfer case  20  and is coupled to a front differential  26 . Axles  28  extend from the front differential to the front wheels and associated mechanism referred to in general as wheel assemblies  30 . 
     The vehicle illustrated in FIG. 1 is arranged to be driven in either two-wheel drive mode or four-wheel drive mode. The rear wheels  19  provide the propelling force in two-wheel drive mode and the rear wheels  19  in combination with the front wheels provide the propelling force in four-wheel drive mode. When driven in the two-wheel drive mode, the transfer case  20  is disconnected from the transmission  12  by the shift mechanism  22 . The transmission  12  will then not provide rotative power to the front drive shaft  24  and thus the front wheel assemblies  30 . The front wheel assemblies  30 , however, are preferably disconnected from the front axles  28  so that the front wheels do not passively rotate the front drive train including the front axles  28 , and the front propeller shaft  24 . The front wheel assemblies  30  include clutch mechanisms that will selectively disconnect the wheels from the front axles  28  or connect the front wheels to the front axles  28 . 
     Refer now to FIG. 2 of the drawings which illustrates the mounting arrangement of a front wheel assembly  30 . The wheel assembly  30  is rotatably mounted on a portion of the frame structure of the vehicle referred to as a knuckle  32 . The knuckle  32  is in turn pivotally mounted to suspension structure  33  of the frame of the vehicle. The knuckle  32  is arranged not only to support the wheel assembly  30  but also to provide the steering capability of the front wheels. As shown in the figure, an axis  34  is extended through the wheel assembly  30 . Another axis  36 , which corresponds to the pivotal axis of the knuckle  32  and is referred to as the king pin axis is extended to intersect with the axis  34 . It is desirable to have the king pin axis  36  intersect the axis  34  at the road surface to provide what is referred to as a king pin radius having a zero offset. Many prior devices, due to the necessary structure of the wheel assembly and the corresponding clutch mechanisms, were such that the king pin radius was either a positive (axis  36  intersects axis  34  below the road surface) or a negative (axis  36  intersects axis  34  above the road surface) offset. The arrangement of the present integrated wheel end system provides for a zero offset king pin radius and it also provides for a shorter distance between axis  34  and the king pin axis  36  measured axially along the wheel&#39;s axis (distance X in FIG.  2 ). 
     Refer now to FIG. 3 of the drawings which illustrates one embodiment of an automatic clutch arranged to engage or disengage the axle  28  to and from a wheel spindle  44  of the wheel assembly  30 . The spindle  44  is rotatably mounted in the knuckle  32  on bearings  45 ,  46 . The outer races (cones)  47 ,  48  of the bearings  45 ,  46  are mounted in a bore  52  of the knuckle  32  in abutment against an inward protruding ring  50 . A cup assembly (which includes an inner race  53  and rollers  55 ) of the bearing  45  is fitted on the spindle  44  with the inner race  53  in abutment with a flange end  62  of the spindle. The spindle  44  is mounted in the knuckle  32  with the rollers  55  of the inner race  53  mating the outer race  47 . A cup assembly (which includes an inner race  57  and rollers  55 ) is mounted on the spindle with the rollers  55  of the inner race  57  mating the outer race  48 . A rotor  66  is mounted on a splined end  68  of the spindle  44  and is in abutment with the inner race  57 . A nut  70  threadably installed on the end of the spindle  44  secures the spindle and the rotor to the knuckle  32 . 
     FIG. 3 illustrates the rotor  66  as being formed integral with a hub portion that mounts on the splined end  68  of the spindle  44 . The rotor may have other forms such as illustrated in FIGS. 6,  7  and  8  which illustrate the rotor mounted to a separate rotor support member. 
     The inner flanged end  62  of the spindle  44  has gear like teeth  64  formed on its periphery. An end of the axle  28  is received in and rotatably supported in the spindle  44  on bearings  74  and  76 . The axle  28 , when installed, has a section adjacent the flanged end  62  of the spindle  44  that has the same diameter as the flanged end  62  and also is provided with gear-like teeth  78 . The teeth  64  on the flanged end  62  and the teeth  78  on the end portion of the axle  28  are of the same type and have the same profile. A ring-like member referred to as a clutch ring  80  has teeth  82  formed on its interior surface that have the same profile and are matable with the teeth  64  of the flange end  62  and the teeth  78  of the axle end  28 . The clutch ring  80  is arranged to be slidable axially along the teeth  78  of the axle end  28 . The clutch ring  80  is moveable in one direction so that it is only engaged with the teeth  78  on the axle and  28  (the dash line position of FIG.  3 ), and is movable in the opposite direction such that the teeth  82  of the clutch ring  80  will be engaged with both teeth  78  and teeth  64  on the axle end  28  and the flange end  62 , respectively (the solid line position of FIG.  3 ). The clutch ring  80  thus is movable to be only engaged with the axle end  28  or is movable such that it will be engaged with both the axle end  28  and the flanged end  62 . The clutch ring  80  thus is movable to either disconnect the wheel assembly  30  from the drive train of the vehicle or to connect the wheel assembly to the drive train of the vehicle. 
     The clutch ring  80  has a flange  84  that extends axially from the main body of the clutch ring  80 . A circular electro magnet  88  is mounted to the knuckle  32  in a conventional manner and is positioned strategic to the clutch ring  80 . The electro magnet  88  when energized will cause the clutch ring  80  to move out of engagement with the flange end  62  of the spindle  44  (the dash line position) to only be engaged with the teeth  78  of the axle end  28 . A spring  90  in abutment with a shoulder  92  on the clutch ring  80  and a shoulder  94  on the axle end  28  is provided to urge the clutch ring  80  to move into engagement with both the axle end  28  and the flange end  62  of the spindle  44  (the solid line position). The electro magnet  88  when energized provides a force sufficient to compress the spring  90  by movement of the clutch ring  80 . When the electro magnet  88  is de-energized the spring  90  will force the clutch ring  80  to move toward and into engagement with the flange end  62  of the spindle  44  to thus couple the wheel assembly  30  to the axle  28  and thus to the drive train of the vehicle. 
     Refer now to FIG. 4 of the drawing which illustrates another embodiment of the automatic clutch of the present invention. A spindle  44  is rotatably mounted in a knuckle  132  as previously described. A clutch mechanism  100  is fixedly attached to the knuckle  132  and is arranged to slidably move a clutch ring  130 . The clutch ring  130  is axially slidably movable in one direction to be only engaged with the axle  28  and is movable in the opposite direction to be engaged with both the axle  28  and the spindle  44 . The clutch mechanism  100  is further illustrated in the exploded view of FIG.  5 . 
     The clutch mechanism  100  has a housing  102  that is mountable to the knuckle  132 . The housing  102  has extending tabs  104  to facilitate mounting the clutch mechanism to the knuckle  132 . The extending tabs  104  have bores  106  to receive conventional fasteners. The housing  102  is ring-like and has a circular bore  108  formed on its interior. The inner circular bore  108  in combination with an outer side wall  110  of housing  102  forms a circular inset or groove  112 . The circular groove  112  is arranged to receive a biasing spring  115  and a backup ring  114 . A shoulder  111  is formed in the side wall  110  of housing  102 . A tapped through bore  109  is provided in the side wall  110  to facilitate installing a fitting such as a conventional nipple connectable, e.g., to an air hose. 
     In this embodiment the spring  115  is of the wave type however it will be appreciated that other types may be utilized. The backup ring  114  has an axial extending flange  116  that fits in the circular groove  112 . The backup ring  114  has apertures  118  to receive fasteners  120 . A resilient diaphragm  124  has an axially extending flange  126  that fits snugly in the bore  108  of the housing  102 . The flange  126  fitting snugly in the bore  108  will prevent any entry or exit of air from the housing  102 . A radially extending flange  128  is of a diameter to fit on the shoulder  111  of the housing  102 . Apertures  129 , alignable with the apertures  118  in the backup ring are provided in the flange portion  128 . 
     A circular clutch ring  130  has radially inwardly extending teeth that are matable with the teeth  78  on the end of the axle  28  and with the teeth  64  on the flange of spindle  44 . The clutch ring  130  has a groove  134  formed around its periphery with the groove  134  arranged to receive a flange of a shifting fork  140 . 
     The shifting fork  140  has apertures  142  provided in a radially extending flange  144  that are alignable with the apertures  118  in the backup ring  114  and the apertures  129  in the diaphragm  124 . The shifting fork is circular in shape forming a portion of a circle that has an arc greater than 180 degrees. The shifting fork  140  is of a resilient material and thus may be flexed to fit on the clutch ring  130 . The shifting fork  140  has a radially inwardly extending flange  146  that will be received in the groove  134  of the clutch ring  130  when assembled. Multiple tabs  148  are provided on the external periphery of the clutch ring  130  adjacent the flange  144 . 
     The backup ring  114 , the diaphragm  124  and the shifting fork  140  are assembled by the fasteners  120  to secure them together as a unit. The shifting fork  140  is mounted to the clutch ring  130  with the radially inward extending flange  146  being received in the groove  134  of the clutch ring  130 . The clutch ring  130  is rotatable relative to the shifting fork  140 . 
     The diaphragm  124  in this embodiment is mounted to the backup ring  114  and the shifting fork  140  by fasteners  120 . It will be appreciated that the diaphragm  124  may be mounted to the backup ring  114  and to the fork  140  by other means. One method is to have snap fasteners such as detents on the diaphragm  124  that will engage the backup ring  114  and fork  140  to secure them together as an assembly. 
     An anti-rotation ring  150  is provided to prevent rotation of the shifting fork  140  when the unit is assembled. The ring  150  has inwardly extending tabs  156  that will be received between adjacent tabs  148  of the clutch ring  140 . The ring  150  further has a radially extending circular portion  158  that fits in close proximity to the side wall  110  of the housing  102 . The circular portion  158  secures the extending flange portion  128  of the diaphragm  124  against the shoulder  111 . A circular snap ring  162  is provided to secure the assembly together as a unit in a conventional manner. 
     Referring again to FIG. 4 the automatic clutch assembly  100  is mounted to the knuckle  132 . The housing  102  is secured to the knuckle  132  by conventional fasteners extending through the bores  106  and threadably installed in tapped bored holes provided in the knuckle  132 . These are not shown in the drawings since they are of conventional design and are well known in the art. The axle  28  extends through the bore  108  of the housing  102  and is rotatably mounted in the spindle  44 . The clutch ring  130  having teeth  133  surrounds the axle  28  and as will be explained, the clutch ring  130  is axially movable in one direction to be engaged with only the teeth  78  of the axle  28  (as shown in FIG. 4) and is movable in the opposite direction to be engaged with both the teeth  78  of the axle and the teeth  64  on the flange end  62  of the spindle  44 . 
     A fitting, such as a nipple  170  is installed in the bore  109  and an air line  172  is attached to the nipple  170 . The air line  172  is connected to an air source such as the intake manifold of the vehicle engine  10 . 
     The housing  102  in combination with the resilient diaphragm  124  defines a chamber or cavity that may be expanded and contracted. The housing  102  is fixedly mounted to the knuckle  132  and the only part of the mechanism  100  that rotates is the clutch ring  130 . This eliminates the requirement for rotary type seals. As shown, the clutch ring  130  is mounted exterior of the defined chamber. 
     In this embodiment air is evacuated from the defined chamber of the mechanism  100  to contract the chamber. When air is withdrawn from the chamber through the nipple  170  and air line  172  the differential air pressure will cause the diaphragm  124  and the attached backup ring  114  and shift fork  140  to move inwardly into the housing  102 . The differential air pressure creates a force sufficient to compress the spring  115 . This will cause the clutch ring  130  to move axially along the teeth  78  of the axle  28  in a direction away from the teeth  64  of flange end  62  of the spindle  44 . When the negative air pressure is released (the pressure within the housing  102  returns to atmospheric pressure), the spring  115  urges the diaphragm  124  and attached components to move outwardly from the housing  102  causing the defined chamber to expand. This will cause the fork  140  to move the clutch ring  130  axially toward the teeth  64  of flange end  62  of the spindle  44 . The clutch ring  130  will be moved into engagement with both the teeth  78  of the axle  28  and the teeth  64  of the flange end  62  of the spindle  44 . 
     FIG. 4 shows the clutch ring  130  in solid lines moved axially by the evacuation of air to be engaged only with the teeth  78  on the axle  28 . This disengages the spindle  44  from the axle  28  and thus the wheel assembly  30  is disconnected from the drive train of the vehicle. FIG. 4 shows the clutch ring  130  in dash lines moved axially by the spring  115  to be engaged with both the teeth  78  of the axle  28  and the teeth  64  of the flange end  62  of the spindle  44 . This engages the spindle  44  with the axle  28  to couple the wheel assembly  30  to the drive train of the vehicle. 
     Whereas both the devices of FIGS. 3 and 4 are spring biased into engagement and actuated by a power source out of engagement, such can be readily reversed with the spring urging disengagement. The illustrated arrangement produces default to engagement and when reversed, produces default to disengagement. A different type of engagement mechanism is referred to as pulse actuated engagement/disengagement where there is no default position, i.e., no return spring. (See U.S. Pat. No. 5,586,632) 
     FIG. 4 also illustrates sensors mounted to the knuckle  132  to provide feedback information. A ring  180  is mounted on the spindle  44  between the inner races  53 ,  57  of the bearings  45 ,  46  providing rotatable support between the spindle  44  and the knuckle  132 . Note that the ring  180  is spaced from the inner races  53 ,  57  so that the ring  180  does not interfere with the pre-load on the bearings  45 ,  46  established by the tightening of the nut  70 . The ring  180  is of the type that will generate a signal when passed by a sensor. A sensor  182  is threadably installed in a bore  184  in the knuckle  132 . The sensor  182  is positioned in close proximity to the ring  180 . When the spindle  44  is rotated, the ring  180  and sensor  182  in combination will generate and send a signal to a control device  200  (FIG. 1) of the vehicle  10 . The ring  180  and sensor  182  will input information on the rotation rate of the spindle  44  which is beneficial for anti-lock brakes for example. 
     A proximity sensor  186  is positioned strategic to the flange end  62  of the spindle  44  and is utilized to confirm that the clutch ring  130  has been moved into engagement with the teeth  64  of the spindle  44  or that the clutch ring  130  is out of engagement with the teeth  64  of the spindle  44 . In an alternative arrangement, the sensor  186  can be configured to also sense the rotation rate of the flange end  62  and thus the spindle  44  for anti-lock brake purposes, thereby eliminating the need for sensor  182 . 
     The sensor  186  may be positioned so that it will detect or sense the position of other members of the clutch mechanism  100  to determine whether or not the clutch ring  130  is engaged with the spindle  44 . The sensor may, for example, be arranged to detect the position of the shift fork  140  or the diaphragm  124  or the anti-rotation ring  150 . 
     A sensor (not shown but incorporated in the sensor  182 ) is of the type that will transmit the operating temperature within the knuckle  132  and may for example transmit the temperature of the bearings  45 ,  46 . 
     The spindle  44  is illustrated as being rotatably mounted in the knuckle  32  and  132  in FIGS. 3 and 4 by bearings  45 ,  46 . Other bearing arrangements may be provided to rotatably support the spindle  44  in the knuckle. Some examples are illustrated in FIGS. 6,  7  and  8 . 
     FIG. 6 illustrates a spindle  44  rotatably mounted in a knuckle  210 . The knuckle  210  has a bore  212  in which an outer race  220  is installed with the outer race  220  abutting a shoulder  214 . The knuckle  210  has another bore  216  that is of a different diameter than the bore  212  and the bore  216  has a formed shoulder  218 . An outer race  222  is installed in the bore  216  with the race  222  in abutment with the shoulder  218 . A cup assembly which includes an inner race  224  and rollers  226  are installed on the spindle  44  with the inner race  224  in abutment with the flange end  62  of the spindle  44 . A rotor support member  230  has a cup assembly including an inner race  232  and rollers  234  installed on a turned diameter  236 . The turned diameter  236  terminates at a shoulder  238  and the inner race  232  is in abutment with the shoulder  238 . The spindle  44  is installed in the knuckle  210  with the rollers  226  matingly engaging the outer race  222 . The rotor support member  230  is installed on the spindle  44  with the rollers  234  mating with the outer race  220 . A nut  70  is threadably installed on the end of the spindle  44  to secure the spindle  44  and the rotor support  230  to the knuckle  210 . 
     FIG. 7 illustrates another bearing arrangement for rotatably supporting the spindle  44  in a knuckle  240 . As shown in the figure, the knuckle  240  is arranged to receive an adapter  242 . The adapter  242  is fastened to the knuckle  240  by fasteners  244 . The adapter  242  includes inclined surfaces  246  and  248  that serve as outer races for the bearing set that rotatably supports the spindle  44 . A cage assembly including an inner race  250  and rollers  252  are mounted on the spindle  44  with the inner race  250  being in abutment with the flange end  62  of the spindle  44 . The spindle  44  is installed into the adapter  242  with the rollers  252  coming into mating contact with the outer race portion  248 . Another cage assembly including an inner race  254  and rollers  256  is installed on the spindle  44  with the rollers  256  matingly engaging the outer race portion  246  of the adapter  242 . A rotor support  258  is installed on the spindle with the rotor support  258  abutting the inner race  254 . A nut  70  is threadably installed on the end of the spindle  44  to secure the spindle  44  to the adapter  242  and thus the knuckle  240 . The flange-type cartridge bearing of FIG. 7 is illustrated with rollers. It is also suited for ball-type bearing arrangement. 
     FIG. 8 illustrates another bearing arrangement for supporting the spindle  44  in a knuckle  270 . A combination outer race  272  is installed on the knuckle  270  with the combination race  272  being in abutment with the shoulder  274 . The combination race  272  is retained on the knuckle  270  by a conventional snap ring  276 . The combination race  272  has inclined flats  278  and  280  that serve as outer bearing races. A cage assembly including an inner race  284  and rollers  286  are installed on the spindle  44  with the inner race  284  being in abutment with the flange end  62  of the spindle  44 . The spindle  44  is installed in the knuckle  270  and another cup assembly including an inner race  288  and rollers  290  are installed on the spindle  44  with the rollers  290  matingly engaging the outer race portion  278 . A rotor support  294  is installed on the spindle with the rotor support  294  coming into contact with the inner race  288 . A nut  70  threadably installed on the end of the spindle  44  secures the spindle assembly in the knuckle  270 . 
     FIG. 9 illustrates another embodiment of the integrated wheel end and automatic clutch. A spindle  300  is rotatably mounted to a knuckle  302  by a bearing pack  304 . The bearing pack  304  is secured to the knuckle  302  by fasteners  306  in a conventional manner. The bearing pack  304  is mounted on the spindle  300  and is held captive between a flanged end  308  of the spindle  300  and a coupler  310  mounted on the end of the spindle  300 . The coupler  310  has internal splines  314  that are in mesh with external splines  316  on the spindle  300 . A roll formed hub  312  retains the bearing pack  304  and the coupler  310  on the spindle  300 . A rotor  299  and a wheel  301  are mountable to the spindle  300  in a conventional manner. 
     A clutch mechanism  100  as previously described is mounted to the knuckle  302 . The teeth  133  of the clutch ring  130  are engaged with teeth  320  provided on an axle  322 . An end of the axle  322  extends into the spindle  300  and is rotatably supported on bearings  324  and  326 . 
     The clutch ring  130  is movable in one direction by the clutch mechanism  100  to be engaged only with the teeth  320  of the axle  322  and is movable in the other direction to be engaged with both the teeth  320  of the axle  322  and the teeth  318  provided on the periphery of the coupler  310 . When the clutch ring  130  is moved in the direction where it only engages the teeth  320  of the axle  322 , the spindle  300  (and the wheel  301  mounted thereon) is not coupled to the axle  322 . When the clutch ring  130  is moved to be engaged with both the teeth  320  of the axle  322  and the teeth  318  of the coupler, the spindle  300  is coupled to the axle  322  to rotate with the axle  322 . 
     FIG. 10 is similar to FIG. 9 except that a retaining nut  330  threadably installed on the spindle is utilized to retain the coupler  310  and the bearing pack  304  on the spindle  300 . The end of the spindle adjacent the splines  316  is threaded in a conventional manner to receive the nut  330 . 
     It will be appreciated that other bearing arrangements not described or illustrated may be provided to rotatably mount the spindle in the configured knuckle. It will be appreciated that the structure of the clutch ring mechanism is not visible from the wheel hub exterior and adds neither weight or wheel end extension relative to the king pin axis. A simple modification to fix the clutch ring to either its engaged or disengaged position (or elimination of the ring altogether) produces either full time four-wheel drive or full time two-wheel drive. Such would allow elimination of the actuator and related components in the case of the two-wheel drive only version, from the entire front wheel (or rear wheel) drive train to reduce cost. The actuator components are not necessary for full-time four-wheel drive since all wheels are engaged at all times with the drive train. The actuator would be replaced by a suitable housing or cover to seal the bearing cavity to prevent entry of foreign material. More importantly, a car manufacturer could produce these various drive train types and avoid any significant design changes. 
     Those skilled in the art will recognize that modifications and variations may be made without departing from the true spirit and scope of the invention. The invention is therefore not to be limited to the embodiments described and illustrated but is to be determined from the appended claims.