WHEEL BEARING ARRANGEMENT AND METHOD FOR MOUNTING SUCH A WHEEL BEARING ARRANGEMENT

Abstract

A wheel bearing arrangement, preferably for a motor vehicle, with a cardan shaft, a wheel hub, a screw with a screw head, and a pretensioning element. The wheel hub is connected to the cardan shaft by the screw. The pretensioning element is arranged and/or braced between the screw head, preferably a head underside of the screw head, and the wheel hub.

Claims

1. A wheel bearing arrangement, preferably for a motor vehicle, comprising: a cardan shaft, a wheel hub, a screw with a screw head, and a pretensioning element, wherein the wheel hub is connected to the cardan shaft by the screw, wherein the pretensioning element is arranged and/or braced between the screw head, preferably a head underside of the screw head, and the wheel hub.

2. The wheel bearing arrangement according to claim 1, wherein the pretensioning element has a, preferably resilient, spring portion which is arranged and/or braced between the screw head, preferably an underside of the head of the screw head, and the wheel hub, and/or the cardan shaft has a cardan shaft spur toothing which is in meshing engagement with a wheel hub spur toothing of the wheel hub.

3. The wheel bearing arrangement according to claim 1, wherein the pretensioning element, preferably a spring portion of the pretensioning element, is supported on the wheel hub, preferably on a centering contour of the wheel hub, and exerts an axial force on the screw head, preferably on a head underside of the screw head, during assembly and/or mounting of the wheel bearing arrangement, wherein it is preferably provided that the pretensioning element exerts the axial force, preferably in relation to a longitudinal screw axis of the screw, against a screw-in direction of the screw.

4. The wheel bearing arrangement according to claim 1, wherein the pretensioning element has a sleeve portion, and the sleeve portion, preferably an outer circumferential surface of the sleeve portion, forms a wheel centering surface for a vehicle wheel, preferably for a rim of a vehicle wheel, and/or a brake disc.

5. The wheel bearing arrangement according to claim 1, wherein the spring portion is formed by spring tabs, which are arranged distributed in the circumferential direction around a pretensioning element passage and are spaced apart from one another with interposition of slot-shaped recesses.

6. The wheel bearing arrangement according to claim 1, wherein the pretensioning element has a base portion and a, preferably conical, cone portion, and the base portion and/or the cone portion and/or the sleeve portion are in abutment connection with the wheel hub, preferably with a centering contour of the wheel hub.

7. The wheel bearing arrangement according to claim 1, wherein the wheel bearing arrangement has an entrainment means and/or an entrainment means is assigned to the wheel bearing arrangement, wherein it is preferably provided that the entrainment means causes a thread friction between an external thread of the screw and an internal thread of the cardan shaft to increase with respect to an external thread of the screw, at least in portions.

8. The wheel bearing arrangement according to claim 7, wherein the entrainment means is formed by a coating, preferably by a screw locking lacquer, which is applied to the screw, preferably to an external thread of the screw, and/or the entrainment means is formed in that a diameter of the external thread, preferably a core diameter, external diameter and/or pitch diameter of the external thread, is larger than a diameter of the internal thread, preferably a core diameter, external diameter and/or pitch diameter of the internal thread, and/or the entrainment means is formed in that a thread pitch of an external thread of the screw deviates by a pitch deviation from a thread pitch of the internal thread of the cardan shaft.

9. A vehicle with a wheel bearing arrangement according to claim 1.

10. A method for mounting a wheel bearing arrangement according to claim 1, comprising: a preparation step, in which the cardan shaft, the wheel hub, the pretensioning element and the screw are provided, a pre-assembly step, in which the wheel hub and the cardan shaft are guided towards each other and/or brought closer together, and in which the screw is partially screwed into the internal thread of the cardan shaft, and a final mounting step in which the screw is screwed further into the internal thread and tightened with a predefined tightening torque, wherein the pretensioning element is arranged and/or braced between the screw head, preferably a head underside of the screw head, and the wheel hub.

11. The wheel bearing arrangement according to claim 2, wherein the pretensioning element, preferably a spring portion of the pretensioning element, is supported on the wheel hub, preferably on a centering contour of the wheel hub, and exerts an axial force on the screw head, preferably on a head underside of the screw head, during assembly and/or mounting of the wheel bearing arrangement, wherein it is preferably provided that the pretensioning element exerts the axial force, preferably in relation to a longitudinal screw axis of the screw, against a screw-in direction of the screw.

12. The wheel bearing arrangement according to claim 2, wherein the pretensioning element has a sleeve portion, and the sleeve portion, preferably an outer circumferential surface of the sleeve portion, forms a wheel centering surface for a vehicle wheel, preferably for a rim of a vehicle wheel, and/or a brake disc.

13. The wheel bearing arrangement according to claim 3, wherein the pretensioning element has a sleeve portion, and the sleeve portion, preferably an outer circumferential surface of the sleeve portion, forms a wheel centering surface for a vehicle wheel, preferably for a rim of a vehicle wheel, and/or a brake disc.

14. The wheel bearing arrangement according to claim 2, wherein the spring portion is formed by spring tabs, which are arranged distributed in the circumferential direction around a pretensioning element passage and are spaced apart from one another with interposition of slot-shaped recesses.

15. The wheel bearing arrangement according to claim 3, wherein the spring portion is formed by spring tabs, which are arranged distributed in the circumferential direction around a pretensioning element passage and are spaced apart from one another with interposition of slot-shaped recesses.

16. The wheel bearing arrangement according to claim 4, wherein the spring portion is formed by spring tabs, which are arranged distributed in the circumferential direction around a pretensioning element passage and are spaced apart from one another with interposition of slot-shaped recesses.

17. The wheel bearing arrangement according to claim 2, wherein the pretensioning element has a base portion and a, preferably conical, cone portion, and the base portion and/or the cone portion and/or the sleeve portion are in abutment connection with the wheel hub, preferably with a centering contour of the wheel hub.

18. The wheel bearing arrangement according to claim 3, wherein the pretensioning element has a base portion and a, preferably conical, cone portion, and the base portion and/or the cone portion and/or the sleeve portion are in abutment connection with the wheel hub, preferably with a centering contour of the wheel hub.

19. The wheel bearing arrangement according to claim 4, wherein the pretensioning element has a base portion and a, preferably conical, cone portion, and the base portion and/or the cone portion and/or the sleeve portion are in abutment connection with the wheel hub, preferably with a centering contour of the wheel hub.

20. The wheel bearing arrangement according to claim 5, wherein the pretensioning element has a base portion and a, preferably conical, cone portion, and the base portion and/or the cone portion and/or the sleeve portion are in abutment connection with the wheel hub, preferably with a centering contour of the wheel hub.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] Examples of embodiments of the invention are explained in more detail below with reference to the attached schematic drawing.

[0029] In particular:

[0030] FIG. 1 shows a longitudinal sectional view of a wheel bearing arrangement in the final mounted state with a pretensioning element;

[0031] FIG. 2 shows a longitudinal sectional view of process steps for mounting the wheel bearing arrangement as shown in FIG. 1;

[0032] FIG. 3 shows a longitudinal sectional view of process steps for mounting the wheel bearing arrangement as shown in FIG. 1;

[0033] FIG. 4 shows a longitudinal sectional view of process steps for mounting the wheel bearing arrangement as shown in FIG. 1;

[0034] FIG. 5 shows in a perspective view the pretensioning element alone,

[0035] FIG. 6 shows in another perspective view the pretensioning element alone, and

[0036] FIG. 7 shows a longitudinal sectional view of the pretensioning element alone.

DETAILED DESCRIPTION

[0037] FIG. 1 shows a wheel bearing arrangement 1 for a motor vehicle (not shown), preferably for a passenger car, in a final mounted state. The wheel bearing arrangement 1 has a, preferably forged, wheel hub 3, a cardan shaft 5, a pretensioning element 7 and a screw 9 with a longitudinal screw axis A. The positive longitudinal screw axis direction is marked with an arrowhead in FIG. 1. The positive longitudinal screw axis direction corresponds to the screw-in direction of the screw 9.

[0038] The wheel hub 3 has a wheel hub spur toothing 11 on the cardan shaft side and the cardan shaft 5 has a cardan shaft spur toothing 13 on the wheel hub side. The wheel hub spur toothing 11 and the cardan shaft spur toothing 13 correspond to each other and are in meshing engagement with each other in the final mounted state of the wheel bearing arrangement 1. In the final mounted state of the wheel bearing arrangement 1, the wheel hub 3 and the cardan shaft 5 are positively connected to each other via the wheel hub spur toothing 11 and the cardan shaft spur toothing 13.

[0039] The screw 9 has an external thread 14, with which the screw 9 is screwed into an internal thread 10 of the cardan shaft 5 in the final mounted state of the wheel bearing arrangement 1 and turned tight and/or tightened with a predefined tightening torque. In the final mounted state of the wheel bearing arrangement 1, the wheel hub 3 is non-positively connected and/or braced to the cardan shaft 5 by means of the screw 9. In the final mounted state, there is both a non-positive and a positive connection between the wheel hub 3 and the cardan shaft 5, so that even large torques can be transmitted from the cardan shaft 5 to the wheel hub 3 and vice versa. In other words, the connection between the cardan shaft 5 and the wheel hub 3 is made up of at least two types of connection, namely on the one hand by the positive connection via the spur toothing 11 and 13 and on the other handwith the wheel hub 3 and the pretensioning element 7 in between-via the force-fit connection between the screw 9 and the cardan shaft 5.

[0040] The pretensioning element 7 is interposed between an underside 15 of a screw head 17 of the screw 9 and a centering contour 19 of the wheel hub 3. The pretensioning element 7 lies radially on the outside of the centering contour 19, so that the pretensioning element 7 is centered relative to the wheel hub 3 in the final mounted state of the wheel bearing arrangement 1 and is arranged concentrically to it.

[0041] In the illustrated embodiment, the pretensioning element 7 is made of a thin deep-drawn sheet of stainless spring steel, merely as an example. At this point, it should be explicitly pointed out that the pretensioning element 7 can alternatively also be made of other materials, such as plastic. It also does not necessarily have to be a metal sheet made of stainless steel and/or spring steel.

[0042] As shown in FIGS. 5 to 7, the pretensioning element 7 is formed by a composite body that is formed in one piece and of one material. The body has a resilient spring portion 21, a base portion 23, a substantially cone-shaped cone portion 25, a sleeve portion 27 and a fold portion 29. The sleeve portion 27 has the shape of a straight and circular hollow cylinder. The sleeve portion 27 is thin-walled and radially outwards defines a receiving space for the screw head 17.

[0043] An outer circumferential surface of the sleeve portion 27 forms a centering surface on which a wheel rim (not shown) of a vehicle wheel can be pushed onto and/or centered with respect to the wheel hub, preferably with a positive fit and/or a precise fit. The wheel rim is centered and/or concentrically aligned to the wheel hub via the centering surface. In the wheel mounting arrangement 1 shown, the wheel and/or rim is therefore not centered via the wheel hub 3 itself, but by means of a separate component, namely the pretensioning element 7, specifically by means of the outer circumferential surface of the sleeve portion 27 of the pretensioning element 7.

[0044] On its side facing away from the wheel hub 3, the sleeve portion 27 merges directly into the fold portion 29. In the fold portion 29, the deep-drawn sheet is folded radially inwards and in the direction of the wheel hub 3, forming a sheet fold, specifically a parallel open sheet fold. The sheet metal wrap contributes to the mechanical stability of the pretensioning element 7. Preferably slot-shaped recesses can be provided in the area of the sleeve portion 27 and/or the fold portion 29, through which water can run off, which can collect radially on the inside of the sleeve portion 27 and/or the fold portion 29. The recesses are shown in FIGS. 5 to 7.

[0045] The sleeve portion 27 merges directly into the cone portion 25 on the wheel hub side. In the cone portion 25, the pretensioning element 7 tapers, starting from the sleeve portion 27 and in the direction of the wheel hub 3 up to the base portion 23, into which base portion 23 the cone portion 25 merges directly. On the outer circumference, the cone portion 25 is in direct contact with the centering contour 19 of the wheel hub 3, by way of example only.

[0046] The base portion 23 has the shape of a perforated disk, which delimits a circular passage arranged centrally to the perforated disk in a radially outward direction. The base portion 23 is, preferably directly, in contact with the centering contour 19 of the wheel hub 3. The base portion 23 merges directly into the spring portion 21. In the embodiment shown, the spring portion 21 is formed by several spring tabs 33, as shown in FIGS. 5 to 7, merely as an example. The spring tabs 33 each extend from the base portion 23 with their free end radially inwards, i.e., in the direction of the passage, and additionally in the direction of the underside of the head 15. The spring tabs 33 are spaced apart from one another by slot-shaped recesses 35, as shown in FIGS. 5 to 7.

[0047] The spring tabs 33 delimit a pretensioning element passage associated with the pretensioning element 7 radially outwards and lie directly against the underside of the head 15. In the final mounted state of the wheel bearing arrangement 1, the spring plates 33 are braced under mechanical pretensioning between the base portion 23 and the underside of the head 15. The spring tabs 33 are supported via the base portion 23 on the centering contour 19 of the wheel hub 3 and exert an axial force on the underside of the head 15, preferably in relation to the longitudinal screw axis A, during assembly and/or installation of the wheel bearing arrangement, against the positive longitudinal screw axis direction and thus against the screw-in direction of the screw 9. The axial force also acts on the cardan shaft 5 in such a way that the cardan shaft 5 is pressed against the wheel hub 3 under the effect of the axial force when the screw 9 is partially or fully screwed in. This means that once the spur toothing 11 and 13 have been brought into meshing engagement during mounting, the spur toothing 11 and 13 are pressed against each other under the effect of the axial force and held in meshing engagement.

[0048] The spring tabs 33 are very mildly attached to the base portion 23. Thus, when screwing in and/or tightening the screw 9, it can be achieved that only or almost exclusively only the spring tabs 33 deform elastically, with the other portions of the pretensioning element 7 remaining undeformed. In particular, the sleeve portion 27 should neither change its position nor its orientation when the screw 9 is screwed in and/or tightened. This behavior is also favored in particular by the provision of the slot-shaped recesses 35. Of course, in addition or as an alternative to the slot-shaped recesses 35, a material jump and/or a cross-sectional jump can also be provided in order to achieve the described isolated deformation of the spring tabs 33.

[0049] The wheel bearing arrangement 1 has an entrainment means which, in the embodiment shown, is associated with the screw 9, only by way of example. The entrainment means is formed by a screw locking lacquer 37, only by way of example, which is applied to the external thread 14 of the screw 9. The thread friction between the external thread 14 and the internal thread 10 is increased by the entrainment means, specifically by the screw locking lacquer 37. As a result, a frictional force builds up between the external thread 14 and the internal thread 10 when the screw 9 is screwed in and the internal thread 10 comes into contact with the screw locking lacquer 37, which causes the cardan shaft 5 to rotate together with the screw 9 from this point onwards. The entrainment means is arranged on the external thread 14 in such a way that the cardan shaft 5 only rotates with the screw 9 when the tooth tips of the cardan shaft spur toothing lie in a common plane with the tooth tips of the wheel hub spur toothing and/or when the tooth tips of the cardan shaft spur toothing project at least partially into the tooth gaps of the wheel hub spur toothing.

[0050] The cardan shaft 5 thus rotates with the screw 9 under the simultaneous effect of the axial force until the cardan shaft spur toothing 13 engages with the wheel hub spur toothing 11. As described above, the axial force then holds the cardan shaft spur toothing 13 in meshing engagement with the wheel hub spur toothing 11.

[0051] After the cardan shaft spur toothing 13 has meshed with the wheel hub spur toothing 11, the frictional force is overcome when the screw 9 is screwed in further and the screw 9 is tightened with the predefined tightening torque in the internal thread 10 without the cardan shaft 5 rotating with the screw 9. Once established, the meshing between the cardan shaft spur toothing 13 and the wheel hub spur toothing 11 thus remains reliable throughout the entire assembly process of the wheel bearing arrangement 1.

[0052] As an alternative to the screw locking lacquer 37, any other measure can also be used and form the entrainment means which builds up such a high frictional force between the external thread 14 of the screw 9 and the internal thread 10 of the cardan shaft 5 that the cardan shaft 5 rotates together with the screw 9 until the spur toothing 11 and 13 are in meshing engagement for the first time and/or come into meshing engagement for the first time. For example, an outer diameter of the external thread 14 can be slightly larger than an inner diameter of the internal thread. For example, the external thread 14 and the internal thread 10 can also form a correspondingly dimensioned fit and/or mating fit. For example, the external thread 14 and the internal thread 10 can also have different thread pitches. This means that the thread pitch of the external thread 14 deviates from the thread pitch of the internal thread 10 by a pitch deviation of, for example, 0.01 mm. The screw locking lacquer 37 thus represents only one of many examples, in particular examples of a coating, in order to enable and/or promote the build-up of a correspondingly high frictional force between the external thread 14 and the internal thread 10 when screwing in the screw 9. To put it another way: the entrainment means, however it is specifically designed, is such that the screw 9 can only be screwed into the internal thread 10 of the cardan shaft 5 with difficulty in some portionsi.e., with high thread friction.

[0053] The entrainment means, specifically the screw locking lacquer 37, are spaced at least far enough away from a screw tip of the screw 9 in the negative longitudinal axis direction of the screw so that the high frictional force only builds up as soon as there is contact between the end spur toothing 11 and 13. This prevents the cardan shaft 5 from rotating out together with the screw 9 beyond the nearest tooth-on-gap position when it is turned in.

[0054] The wheel hub 3 has a wheel flange 39 to which the vehicle wheel (not shown) is attached. In addition, the wheel hub 3 is assigned a wheel hub passage, which is limited radially outwards by the wheel hub 3 and through which the screw 9 extends.

[0055] A method for mounting the wheel bearing arrangement 1 is described in detail below with reference to FIGS. 1 to 4.

[0056] The method has a preparation step (see FIG. 2), a pre-assembly step (FIG. 3) and a final mounting step (see FIG. 4). The preparation step is carried out before the pre-assembly step. The pre-assembly step is carried out before the final mounting step.

[0057] In the preparation step, the cardan shaft 5, the wheel hub 3, the pretensioning element 7 and the screw 9 are prepared. In addition, the screw 9 is guided with its shaft through the pretensioning element passage and through the wheel hub passage, as shown in FIG. 2. The spring tabs 33 are mechanically relaxed and initially lie force-free against the underside of the head 15. The base portion 23 and the cone portion 25 of the pretensioning element 7 are initially in force-free contact with the centering contour 19. The external thread 14 of the screw 9 is still out of threaded engagement with the internal thread 10 of the cardan shaft 5. The spur toothing 11 and 13 are not yet in contact. The screw 9, the pretensioning element 7 and the wheel hub 3 form a preassembled assembly after completion of the preparation step.

[0058] The pre-assembly step is then carried out, as shown in FIG. 3. In the pre-assembly step, the preassembled assembly and the cardan shaft 5 are guided towards each other and the screw 9 is screwed into the internal thread 10 of the cardan shaft 5 until the external thread 14 of the screw 9 and the internal thread 10 of the cardan shaft 5 are in at least slight threaded engagement. After completion of the pre-assembly step, the spur toothing 11 and 13 are still out of meshing engagement. The screw locking lacquer 37 is still outside the internal thread 10 of the cardan shaft 5 and the spring tabs 33 are still in force-free contact with the underside of the head 15.

[0059] After completion of the pre-assembly step, the final mounting step is carried out, as illustrated in FIG. 4. In the final mounting step, the screw 9 is first screwed further into the internal thread 10 of the steering shaft 5. As the screw 9 is further screwed into the internal thread 10 of the cardan shaft 5, the axial distance between the underside of the head 15 and the cardan shaft 5 is shortened in relation to and/or parallel to the longitudinal axis of the screw A. As a result of the shortening of the axial distance, the spur toothing 11 and 13 come into contact when the screw 9 is screwed in. The contact can be formed by the spur toothing 11 and 13 touching each other in a tooth-on-tooth position or being in a tooth-on-gap position.

[0060] If the spur toothing 11 and 13 touch in a tooth-on-tooth position, the axial distance between the underside of the head 15 and the cardan shaft 5 is further reduced, whereby the spring tabs 33 between the underside of the head 15 on the one hand and the base portion 23 and/or the centering contour 19 on the other hand are elastically prestressed, building up the axial force. This axial force also acts on the face toothing 11 and 13 and presses them against each other in the tooth-on-tooth position.

[0061] If the screw locking lacquer 37 now reaches the internal thread 10 during further screwing in and is screwed into it, a high frictional force builds up, preferably abruptly, between the screw 9 and the internal thread 10 of the cardan shaft 5. Due to the high frictional force, the cardan shaft 5 is rotated together with the screw 9 as the screw 9 is screwed in further. Since the axial force also acts on the underside of the head 15, the cardan shaft 5 rotates together with the screw 9 from the tooth-on-tooth position to the nearest and/or adjacent tooth-on-gap position. This causes the teeth of the cardan shaft spur toothing 13 to slip into the tooth gaps of the wheel hub spur toothing 11, with only a slight and intermediate reduction in the axial force. If the screw 9 is then screwed in further, the teeth of the cardan shaft spur toothing 13 are supported in the circumferential direction on tooth flanks of the teeth of the wheel hub spur toothing 11, so that the screw 9 can continue to be screwed in even under the effect of the high frictional force without the spur toothing 11 and 13 leaving the tooth-on-gap position and/or the cardan shaft 5 continuing to rotate with the screw 9. When the screw 9 is further screwed in under the effect of the high frictional force, the axial force increases again and the tooth-on-gap position is also maintained when the screw 9 is further screwed in, namely until the screw 9 is screwed into the internal thread 10 with the predefined tightening torque and the final mounted state of the wheel bearing arrangement 1 is reached. In the final mounted state of the wheel bearing arrangement 9, the underside of the head 15 lies flat on the base portion 23.

[0062] It is of course also conceivable that the spur toothing 11 and 13 do not happen to be in the tooth-on-tooth position at any time during the final mounting step. In this case, the teeth of the cardan shaft spur toothing 13 are immediately supported in the circumferential direction on the tooth flanks of the teeth of the wheel hub spur toothing 11 when the screw 9 is screwed in and the screw 9 can be screwed in under the effect of the high frictional force without the spur toothing 11 and 13 leaving the tooth-on-tooth position. Furthermore, in this case there is no temporary, slight reduction in the axial force and the screw 9 can be screwed into the internal thread 10 with the predefined tightening torque and the final mounted state of the wheel bearing arrangement 1 (see FIG. 1) can be achieved.

LIST OF REFERENCE NUMERALS

[0063] 1 wheel bearing arrangement [0064] 3 wheel hub [0065] 5 cardan shaft [0066] 7 pretensioning element [0067] 9 screw [0068] 10 internal thread [0069] 11 wheel hub spur toothing [0070] 13 cardan shaft spur toothing [0071] 14 external thread [0072] 15 underside of head [0073] 17 screw head [0074] 19 centering contour [0075] 21 spring portion [0076] 23 base portion [0077] 25 cone portion [0078] 27 sleeve portion [0079] 29 fold portion [0080] 33 spring tab [0081] 35 recess [0082] 37 screw locking lacquer [0083] 39 wheel flange [0084] A longitudinal screw axis