Abstract:
The invention relates to a wheel bearing for a driven wheel provided with a roller bearing module, comprising an outer ring and a hub which can be slide onto the outer ring from at least from one side such that it encompasses a partial area of the outer covering of the outer ring, wherein at least one area of the outer covering of the outer ring and one area of an inner covering of the hub are embodied in the form of a conical covering so that they match each other and can be arranged adjacent to each other.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a wheel bearing of a driven wheel with a roller bearing assembly, comprising an outer ring, and with a hub which can be slipped onto the outer ring at least from one side, surrounding a partial region of the outer jacket of the outer ring. 
       BACKGROUND DISCUSSION 
       [0002]    For example, DE 199 61 710 C1 discloses a wheel bearing arrangement of a driven axle which is made such that a roller bearing assembly and the hub surrounding the roller bearing assembly adjoin one another in the manner of a circular cylindrical jacket and that to change the brake disks at least parts of the roller bearing assembly must be dismounted at the same time. 
       SUMMARY 
       [0003]    The object of the invention is to devise an improved wheel bearing of a driven wheel which is characterized especially also by ease of dismounting. 
         [0004]    For example, compared to the initially described wheel bearing of DE 199 61 710 C1, based on the adjoining surface in the shape of the jacket of a truncated cone between the hub and outer ring for the wheel bearing as disclosed herein, dismounting is advantageously clearly simplified. 
         [0005]    In one advantageous embodiment a brake disk assembly can be slipped over the outer ring. Compared to the initially described wheel bearing of DE 199 61 710 C1, after dismounting of the hub the brake disk assembly can be easily dismounted without in doing so the roller bearing assembly having to be dismounted at the same time; this protects the roller bearing assembly especially advantageously against damage. This is especially advantageous since during the normal service life of the wheel bearing the brake disk must be changed at least once, conversely the roller bearing assembly lasts the entire service life. 
         [0006]    Other advantages and details of the invention will become apparent from the embodiments of the invention described below. 
     
    
     
       BRIEF DESCRIPTION OF DRAWING FIGURES 
         [0007]      FIG. 1  shows a lengthwise section through a wheel bearing of a driven wheel in a first embodiment of the invention. 
           [0008]      FIG. 2  shows a perspective exploded representation of the wheel bearing of  FIG. 1 . 
           [0009]      FIG. 3  shows a lengthwise section through a wheel bearing of a driven wheel in a second embodiment of the invention. 
           [0010]      FIG. 4  shows a perspective exploded representation of the wheel bearing of  FIG. 3 . 
           [0011]      FIG. 5  shows a lengthwise section through the wheel bearing of a driven wheel in a third embodiment of the invention. 
           [0012]      FIG. 6  shows a perspective exploded view of the wheel bearing of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  shows a lengthwise section through the wheel bearing of a driven wheel as a first embodiment of the invention.  FIG. 2  which goes with it shows a perspective exploded representation of the wheel bearing of  FIG. 1 . The wheel bearing comprises a sleeve-like axle shaft  12  which properly does not rotate, in which there is a drive shaft  16  which on its front end side comprises a drive shaft flange  18  which has been molded on. The front is that side from which the rim of the wheel is mounted; this corresponds to the left in  FIG. 1 . Furthermore the outer jacket of the axle shaft  12  is formed to accommodate a two-row tapered roller bearing with the corresponding bearing seat. In this connection the bearing seat is bordered by the thread to the front and by the shoulder of the axle shaft to the rear. On the bearing seat there is an axially split inner ring  22  of a tapered roller bearing, the inner ring  22  being braced against the shoulder of the axle body using a lockable axle nut  28  which can be screwed onto the threaded region of the axle shaft  12 . 
         [0014]    Furthermore, the two-row tapered roller bearing in an O-arrangement encompasses an outer ring  24 , between the inner ring  22  and the outer ring  24  there being truncated cone-like roll bodies  26  which are guided in a cage which is not shown. Here the outer ring  24  is made such that its outer jacket, proceeding from the front region, widens in the manner of the jacket of a truncated cone to the rear. In the rear area the outer jacket of the outer ring  24  is made such that several wedges  25  which are uniformly distributed in the peripheral direction extend on a circular cylinder-like jacket surface, thicken radially from front to back and at least in their front partial region continues the truncated cone jacket-like region of the outer ring  24 . Thus, the rear area of the outer jacket of the outer ring  24  has a type of rectangle-shaped toothing when the circumferential line is unwound into a plane. 
         [0015]    For mounting and dismounting of the brake disk assembly  40  it can be moved over a large part of the axial length of the outer ring  24 . 
         [0016]    In this connection the brake disk assembly  40  comprises a hollow-cylinder like brake disk carrier  42  with the actual brake disk  44  located on its rear region. In the front region of the inner jacket the brake disk carrier  42  is made with toothing corresponding to that of the outer ring with teeth which extend to the inside. In this connection the outer ring  24  and the brake disk assembly  40  are made matched to one another such that when the teeth of the brake disk assembly  40  engage the gaps of the toothing of the outer ring  24  the brake disk assembly  40  can be slipped on from the front over the outer ring  24  to the rear, at least as far as the position shown in the figure. After the brake disk assembly  40  has been slipped on, a crown gear  50  and then a hub  30  are slipped onto the outer ring  24  during mounting. 
         [0017]    On the inner jacket of the crown gear  50 , for engaging the teeth of the outer ring  24  there are the corresponding teeth so that the crown gear  50  is located torsionally strong on the outer ring  24 . In this connection the crown gear  50  comprises holes which are arranged uniformly distributed in the peripheral direction. In the front flange-like region the brake disk carrier  42  also comprises the corresponding holes which are made relative to the holes of the crown gear  50  such that congruency between the holes of the crown gear  50  and of the brake disk carrier  42  is only achieved when the brake disk carrier  42  so to speak is turned by roughly one half tooth division with respect to the tooth division of the outer ring  24 . Thus the brake disk carrier  42  with respect to tensile loading from the front sits securely on the outer ring  24  such that bracing of the hub  30  on the outer ring  24  is possible, which will be described below. 
         [0018]    At least one partial region of the inner jacket of the hub  30  which is to be attached to the outer ring  24  is made with a corresponding truncated cone jacket-like region to fit the truncated cone jacket-like region of the outer ring  24 . In this connection the hub  30  can be made to comprise cast iron and/or a lightweight metal. So that the hub  30  can be mounted on the outer ring  24  from the front and also can be dismounted again, the pitches of the truncated cone jacket-like regions are selected to be barely above self-locking. 
         [0019]    The hub  30  furthermore has a radially outside, flange-like region  32  with holes  33  to which the rim of the wheel can be attached. Furthermore the hub  30  in the forward region is provided with holes  35  such that the flange  18  of the drive shaft  16  can be screwed to the hub  30  by means of corresponding screws  19 . 
         [0020]    Furthermore the hub  30  comprises holes  37  which axially penetrate the hub  30 , which are arranged distributed in the peripheral direction, and which are made to linearly continue the holes of the crown gear  50  in the axial direction. By means of screws  39  which engage the brake disk assembly  40  through the holes  37  of the hub  30  and the crown gear  50 , the hub  30  can be drawn onto the outer ring  24  by tightening the screws  39  and can be held braced accordingly, since as described above the brake disk assembly  40  is drawn against the wedges  25  of the outer ring  24  by the offset by half a tooth. The crown gear  50  prevents the entire arrangement from turning during operation and especially the brake disk assembly  40  from no longer being able to keep the hub  30  braced. 
         [0021]    The hub  30  in the forward region of its outer jacket is made such that for the holes  35  there are elevations which are bulged to the outside in the shape of a hemisphere, which extend in the axial direction and which are uniformly distributed in the peripheral direction, then there being holes  37  for the screws  39  so-to-speak on the gaps between the elevations. 
         [0022]      FIG. 3  shows as a second embodiment of the invention a lengthwise section through the wheel bearing of a driven wheel.  FIG. 4  shows along with it a perspective exploded representation of the wheel bearing of  FIG. 3 . The wheel bearing comprises a sleeve-like axle shaft  12 ′ which properly does not rotate, in which there is a drive shaft  16 ′ which on its front end side comprises a drive shaft flange  18 ′ which has been molded on. The front is that side from which the rim of the wheel is mounted; this corresponds to the left in  FIG. 3 . Furthermore the outer jacket of the axle shaft  12 ′ is formed to accommodate a two-row tapered roller bearing with the corresponding bearing seat. In this connection the bearing seat is bordered by a thread to the front and by the shoulder of the axle shaft to the rear. On the bearing seat there is an axially split inner ring  22 ′ of the tapered roller bearing, the inner ring  22 ′ being braced against the shoulder of the axle body using a lockable axle nut  28 ′ which can be screwed onto the threaded region of the axle shaft  12 ′. Furthermore the two-row tapered roller bearing in an O-arrangement encompasses an outer ring  24 ′, between the inner ring  22 ′ and the outer ring  24 ′ there being truncated cone-like roll bodies  26 ′ which are guided in a cage which is not shown. 
         [0023]    The wheel bearing comprises a brake disk assembly  40 ′ which can be moved for mounting and dismounting over a large part of the axial length of the outer ring  24 ′. In this connection the brake disk assembly  40 ′ can be slipped from forward over the outer ring  24 ′ to the rear, at least to the position shown in the figure. The brake disk assembly  40 ′ comprises a hollow cylinder-like brake disk carrier  42 ′ with the actual brake disk  44 ′ located on its rear region. In the forward flange-like region the brake disk carrier  42 ′ comprises holes which are arranged uniformly distributed in the peripheral direction. 
         [0024]    The outer ring  24 ′ is made such that its outer jacket, proceeding from the front region, widens to the rear in the manner of the jacket of a truncated cone. At least one partial region of the inner jacket of the hub  30 ′ which is to be attached to the outer ring  24 ′ is made with a corresponding truncated cone jacket-like region to fit the truncated cone jacket-like region of the outer ring  24 ′. 
         [0025]    In this connection, the hub  30 ′ can be made to comprise cast iron and/or a lightweight metal. So that the hub  30 ′ can be mounted and dismounted on the outer ring  24 ′ from the front, the pitches of the truncated cone jacket-like regions are selected to be barely above self-locking. 
         [0026]    The hub  30 ′ has a radially outside, flange-like region  32 ′ with holes  33 ′ to which the rim of the wheel can be attached. Furthermore the hub  30 ′ comprises holes  37 ′ which are arranged distributed in the peripheral direction, which axially penetrate the hub  30  for connecting the brake disk assembly  40 ′ to the hub  30 ′ by means of screws  39 ′, and linearly continue the holes of the brake disk assembly  40 ′ in the axial direction. 
         [0027]    The outer ring  24 ′ is made lengthened to the front. In this connection the inside jacket of the outer ring  24 ′ in the frontmost region is made with toothing into which for corresponding transfer of the rotary motion from the drive shaft  16 ′ to the outer ring  24 ′ and thus to the hub  30 ′ the outer jacket of the drive shaft flange  18 ′ is made with the corresponding toothing which engages the toothing of the outer ring  24 ′. The outer jacket of the outer ring  24 ′ is furthermore made provided with a thread in the frontmost region onto which a nut  60 ′ can be screwed for bracing of the hub  30 ′ on the outer ring  24 ′. On its front face side the nut  60 ′ is made with a rim with an inside diameter which is dimensioned to be smaller than the maximum outside diameter of the toothed drive shaft flange  18 ′ so that the drive shaft  16 ′ is held in the axle shaft  12 ′ at the same time when the nut  60 ′ is screwed on. 
         [0028]    In addition, for wheel bearings of a driven wheel according to this invention the hub can be made such that it has a hollow cylindrical region which extends axially forward and which essentially surrounds a nut which can be screwed for example on the outer jacket of the outer ring in the properly mounted state and in the axial direction projects over it. In this connection, on the inner jacket of this hollow cylindrical region, in that region in which for a properly mounted wheel bearing the front face surface the nut comes to rest, there is a ring-like groove such that a ring, especially a snap ring, can be inserted into the groove, which protrudes radially to the inside over the inside cylinder jacket of the hollow cylindrical region and over the outer cylinder jacket of the nut. In this way the nut is locked and the hub can be easily dismounted from the roller bearing assembly without dismounting the roller bearing assembly by the hub being removed at the same time with the corresponding rotation of the nut via the snap ring. In this connection the nut on the front face side is provided with means which can be engaged by a tool for turning the nut. Furthermore the front face side of the outer ring is likewise made with means which when the nut is turned stop the concomitant turning of the outer ring using a tool which engages the indicated means. In one embodiment the means can comprise recesses which are machined from the face side into the nut or into the outer ring. Especially because the hub is made as a separate component which can be detached from the roller bearing assembly, the hub can be dismounted in a controlled manner, preventing damage to the roller bearing assembly, since the roller bearing unit need not be dismounted at the same time so that the brake disk which is located in the axial direction farther to the rear than the flange of the hub and overlaps with the flange when viewed in the axial direction can be very advantageously replaced. Here it should be watched that during the normal service life of the wheel bearing the brake disk should be replaced at least once and furthermore for a wheel bearing in which the hub and outer ring can only be dismounted as a unit, dismounting of this unit generally leads to the pertinent roller bearing assembly being damaged during dismounting especially in the region of the seals such that cost-intensive complete replacement of the wheel bearing is necessary. 
         [0029]    In addition, the wheel bearings of a driven wheel as claimed in this invention can be made with a pulse generator ring, for example for the antilock system. Here the pulse generator ring is made such that proceeding from its proper attachment site forward it is made free of overlaps with the outer ring in the axial direction. The pulse generator ring can be replaced especially advantageously with the hub dismounted from the front without dismounting the roller bearing assembly. 
         [0030]    In addition the wheel bearing of the driven wheel as claimed in this invention can be made with the seal of the truncated cone jacket-like regions. In this connection the seal comprises sealing means with which especially penetration of moisture between the two truncated cone jacket-like regions is prevented so that corrosion is prevented there and the hub can also be reliably and easily dismounted after a comparatively long operating life under rough ambient conditions. The sealing means comprise a front and a rear sealing element which is made essentially annular. 
         [0031]    In addition, for the wheel bearings of the driven wheel as claimed in this invention, the split inner ring, comprising the front inner ring and the rear inner ring, can be made as follow: On that side on which the two inner rings properly adjoin one another, the two inner rings are made to engage one another in the axial direction. For this purpose each of the inner rings in the end region toward the indicated side is provided with an annular groove which is made to form an undercut in the axial direction in interplay with an annular region which is forward of the groove in the direction to the indicated end. The facing jacket surfaces of the ring-like regions are each provided with a thread which fits one another. Since the threads in the properly installed state no longer touch one another and moreover none of the forces which occur during wheel bearing operation are to be transferred, a comparatively rough execution of the thread is sufficient—a fine thread need not be provided. In the properly installed state the back face surface of the annular region of the front inner ring adjoins the face surface which borders the groove of the rear inner ring to the rear. Moreover force is also transferred. The two threads do not engage one another. 
         [0032]    The axial extension of the annular grooves is chosen such that it is larger than the axial extension of the annular regions provided for engagement. With respect to initial mounting on the axle shaft, advantageously the two inner rings can be delivered captively against one another screwed into one another via the thread so that the inner rings screwed into one another are slipped onto the axle shaft until the rear inner ring adjoins properly in order to move afterwards by turning the front inner ring to the rear such that the two inner rings are released from one another on their threads and properly adjoin one another. The interlocking of the two inner rings is furthermore advantageous for dismounting of the inner rings for any reasons, since the rear inner ring is removed at the same time with detachment of the front inner ring. 
         [0033]      FIG. 5  shows as a third embodiment of the invention a lengthwise section through the wheel bearing of the driven wheel.  FIG. 6  shows along with this a perspective exploded view of the wheel bearing of  FIG. 5 . Compared to the wheel bearing of  FIGS. 3 and 4  the wheel bearing of  FIGS. 5 and 6  differs in the execution of the rear region of the outer ring  24 ″ of the tapered roller bearing, the hub  30 ″ and the brake disk assembly  40 ″. Otherwise what was described above for the wheel bearing of  FIGS. 3 and 4  applies accordingly. In this connection the components of the wheel bearing of  FIGS. 5 and 6  are identified with respect to the corresponding components of the wheel bearing of  FIGS. 3 and 4  with the same reference numbers, provided with an additional apostrophe. 
         [0034]    For the wheel bearing of  FIGS. 5 and 6 , the outer jacket of the outer ring  24 ″ is also made in the manner of the jacket of a truncated cone in its rear region in a continuous extension of its middle region. The inside jacket of the brake disk assembly  40 ″, especially of the brake disk carrier  42 ″, is made accordingly in the manner of the jacket of a truncated cone in its front region so that it is accordingly adjacent to the rear region of the outer jacket of the outer ring  24 ″. Compared to the hub  30 ′ of  FIGS. 3 and 4  the hub  30 ″ of  FIGS. 5 and 6  is made free of holes  37 ′. For this purpose the hub  30 ″ and the brake disk assembly  40 ″ on their facing end sides are made to engage the toothing with axially projecting teeth so that a braking moment can be transferred via this toothing between the hub  30 ″ and the brake disk  44 ″. Between the indicated end sides of the hub  30 ″ and brake disk assembly  40 ″ there is furthermore a disk spring pair  70 ″ in the region outside the aforementioned toothing so that the connection between the hub  30 ″ and the brake disk assembly  40 ″ is kept under tension and the brake disk  44 ″ is centered. 
         [0035]    In another embodiment, especially as an alternative to the toothing of the drive shaft flange  18 ′ and  18 ″ of  FIGS. 3 to 6  which engages the outer ring  24 ′ and  24 ″, the drive shaft flange can directly engage the correspondingly made hub by means of toothing, the drive shaft flange being made to be screwed to the outer ring and being pressed against an essentially radially extending surface of the hub for fixed bracing of the hub on the outer ring with screwing down of the drive shaft flange.