Bearing assembly, use of bearing assembly and method for manufacturing bearing device

Abstract

A bearing assembly comprises an outer element and an inner element, which are supported against each other in the manner of a rolling element bearing by at least two rows of rolling elements, wherein the outer element comprises two surface areas for contact with the rolling elements and the inner element comprises two surface areas for contact with the rolling elements, wherein at least one of the rows of rolling elements is embodied as rollers.

Description

Technical Field

[0001] The invention relates to a bearing assembly, a use of a bearing assembly and a method for producing a bearing device. Background Art

[0002] From the prior art, bearing assemblies (e.g. wheel bearings) are known, which include a raceway element and two axially spaced rows of rolling elements arranged to roll on the raceway element, thereby forming a rolling element bearing. Various embodiments of bearing assemblies are known herein. In one embodiment, the rolling elements of the wheel bearing are embodied as balls. The raceway element is embodied as an outer ring comprising two raceways for the two rows of balls. The other raceway element is embodied as an inner ring. In order for the wheel bearing to be assemblable, the inner ring comprises only one raceway for one row of rolling elements. The inner ring also comprises a recess into which another raceway element can be inserted, the other raceway element comprising a raceway for the other row of rolling elements. The other raceway element is inserted after the introduction of the corresponding row of balls and is connected to the inner ring, for example, by orbital forming. Summary of the invention

[0003] An object of the present invention is to provide an improved bearing assembly, which can be used in particular as a wheel bearing. Another object of the present invention is to provide a method for manufacturing a bearing assembly.

[0004] This object is achieved by the subject matter of claims 1 and 8. Advantageous embodiments are described in the dependent claims.

[0005] The invention is based in particular on the recognition that many bearing assemblies and in particular wheel bearing assemblies are relatively complex in design and require a plurality of components and method steps for their production. In this respect, a simplification of the design and production is desirable. In particular, the weight of the bearing and the resulting loads are to be taken into account. In the case of wheel bearing assemblies, high axial and radial loads are particularly present during cornering.

[0006] Therefore, as an embodiment of the present invention, a bearing assembly is provided, which includes an outer element ( / outer element) and an inner element ( / inner element); the outer element and the inner element are supported relative to each other in the manner of a rolling element bearing by at least two rows of rolling elements, wherein the outer element includes two surface areas for contacting the rolling elements, and the inner element includes two surface areas for contacting the rolling elements, wherein at least one row of rolling elements in the at least two rows of rolling elements ( / inner elements) is implemented as rollers.

[0007] The outer element can be implemented as an outer ring, in which two rolling element bearing raceways are formed. Here, the raceways are formed directly in the outer ring, that is, the rolling elements roll directly on the outer ring. The inner element can be implemented as an inner ring, in which two rolling element bearing raceways are formed. By designing one of the rows of rolling elements as rollers, the bearing assembly can be assembled even in the case where a high-load rolling element bearing is to be provided and therefore a large number of rolling elements and a large number of rollers per row are to be provided. Therefore, the rated load of the bearing assembly can be designed to be relatively high at a relatively low structural cost. Therefore, in an embodiment of the bearing assembly according to the invention, during the assembly of the bearing assembly, even when the surface areas are already positioned radially one inside the other and the inner element is almost or completely located in the center of the outer element, the roller can be introduced between the outer element and the inner element and contact the surface area. This is not possible in known bearing embodiments, for example in the case of two rows of balls, the inner ring must be located eccentrically in the outer ring so that the second row of balls can be filled. Here, only a limited number of balls can be filled, thereby correspondingly limiting the rated load ( / load rating) of the bearing. In order to achieve a higher load rating by using more rolling elements in each row, it is therefore common for known bearings to divide the outer ring or inner ring, ie not to implement it as one piece. Thus, a "half" of the outer ring or inner ring can be installed after the second rolling element row.

[0008] The rollers can preferably be implemented as tapered rollers, which due to their shape may be easily inserted during installation, while having good axial and radial load capacity. This can also be achieved by tilting cylindrical rollers. When the radial load component is very low, it may be advantageous to use cylindrical rollers.

[0009] In a preferred embodiment of the invention, a retaining element for the roller is included, which is retained on the inner element or the outer element and comprises a sliding surface for the roller. Thus, the roller can be guided and retained on the inner element or the outer element. The retaining element can be implemented as a separate component, for example in the form of a retaining ring. After the roller is introduced, it can be retained on the outer element or the inner element. By optimizing the retaining position, a defined preload can be applied to the roller via the sliding surface.

[0010] In a preferred embodiment of the invention, the inner element or the outer element comprises an abutment surface extending at least partially in the radial direction, against which the retaining element abuts. Thus, the retaining element can be mounted in a simple manner. For example, a protrusion produced on the inner element or the outer element can be used to attach the retaining element.

[0011] A preferred embodiment of the invention comprises a bearing cage for guiding the rollers, wherein the bearing cage is constructed so that it can at least temporarily expand in the radial direction. The bearing cage can include, for example, interruptions so that it is flexible and can be mounted on the inner element during installation. Another row of rolling elements can also be guided by another bearing cage.

[0012] In a preferred embodiment of the invention, the bearing assembly is used to support a vehicle wheel unit of a motor vehicle. Therefore, the bearing assembly is preferably implemented as a wheel bearing assembly. In known wheel bearings, separate inner ring elements or outer ring elements are usually provided to ensure mountability, each inner ring element or outer ring element having a rolling element raceway; after the rolling elements have been introduced, the separate inner ring elements or outer ring elements are assembled together to form a wheel bearing. In an embodiment of the invention, both the outer element and the inner element are implemented as a one-piece assembly.

[0013] As an embodiment of the present invention, a method for manufacturing a bearing assembly is provided, the method comprising the following method steps:

[0014] - Manufacturing the inner element, the outer element and the first row of rolling elements and the second row of rollers;

[0015] - introducing the first row of rolling elements into the outer element;

[0016] - introducing the inner element into the outer element so that the rolling elements of the first row are in contact with corresponding surface areas of the inner element and the outer element;

[0017] - Introducing the roller between the outer element and the inner element such that the roller comes into contact with corresponding surface areas of the inner element and the outer element.

[0018] Preferably, the retaining element is inserted after the rollers of the second row of rolling elements have been introduced.

[0019] In one embodiment of the invention, it is further provided that the following method steps are performed before the introduction of the retaining element:

[0020] - measuring the distance between the outer end side of the roller and the abutment surface for the retaining element,

[0021] - Based on the measured distance, the retaining element is processed so that when the retaining element is subsequently brought into abutment against the abutment surface, the end side of the roller can be acted upon by the sliding surface of the retaining element with a predetermined contact force.

[0022] Thus, the bearing assembly can be adjusted flexibly with respect to preload or bearing clearance and manufacturing tolerances can be compensated during assembly. Other commonly encountered component pairings can be omitted, which further simplifies the assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a cross-sectional view showing a wheel bearing assembly according to one embodiment of the present invention.

[0024] Figure 2 It is shown Figure 1 Magnified view of the area enclosed by the dashed rectangle in .

[0025] Figure 3 is a cross-sectional view showing a wheel bearing according to another embodiment of the present invention.

[0026] Figure 4 is a flow chart schematically depicting a method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0027] Advantages, features and details of the invention result from the exemplary embodiments of the invention described below with reference to the drawings.

[0028] Figure 1 The upper area of ​​a longitudinal section through a wheel bearing assembly 1 according to one embodiment of the invention is shown, which is suitable for holding and supporting a wheel on a motor vehicle. The wheel bearing assembly 1 comprises an outer ring 3 and an inner ring 5, wherein the inner ring 5 is arranged inside the outer ring 3. The wheel bearing assembly 1 also comprises two rows of rolling elements spaced apart in the axial direction, which are here marked as tapered rollers 7 and 9. The outer ring 3 comprises two raceways 11 and 13 for the tapered rollers 7 and 9. The inner ring 5 also comprises two raceways 15 and 17 for the tapered rollers 7 and 9. The tapered roller 7 is arranged between the raceways 11 and 15 and rolls on them. The tapered roller 9 is arranged between the raceways 13 and 17 and rolls on them. Thus, the inner ring 5 is supported rotatably relative to the outer ring 3.

[0029] On the outer ring 3, radial projections 21 are provided, into which holes 23 are introduced. The outer ring 3 can be connected to a motor vehicle using the projections 21. The inner ring 5 comprises a formation 25 which is axially spaced apart from the tapered rollers 7; the formation 25 comprises a hole 27 to which a wheel unit of the vehicle can be attached. Figure 1 The screw 29 is shown.

[0030] In contrast to known embodiments, the inner ring 5 is manufactured from one workpiece ( / the inner ring 5 is manufactured in one piece), so that no separate raceway elements are required for the tapered rollers 9. In order to reduce the overall weight of the wheel bearing 1, the inner ring 5 is designed to be as thin as possible, so that it comprises a relatively large radial built-in cavity 31, which expands in a funnel-shaped manner in the axial direction ( / axial course). Two support elements 33 and 35 are arranged in the cavity 31, which are arranged below the raceways 15 and 17 so that the inner ring 5 is supported in the area of ​​the raceways 15 and 17, in which the load is abutted via the tapered rollers 7 or 9. The support elements 33 and 35 are tapered radially outwards in a manner corresponding to the contour of the inner ring 5. They comprise radial built-in recesses 37 and 39, into which the shaft ends of the drive shaft can be introduced and releasably connected to the inner ring by nuts. The shaft end may also include a shoulder ( / shaft shoulder) which presses against the support element 35 so that the support element 35 is pressed against the inner ring 5. The inner ring 5 includes axially external teeth 41 which can be connected with corresponding counterparts of the drive shaft. The inner ring 5 can thus be set to rotate. As an option, radial teeth can be introduced in the support elements 33 and / or 35.

[0031] As an alternative, the support element 35 can be a component of the shaft end, ie fixedly connected to the shaft end or formed thereby. The teeth can also be introduced radially outwards into the shaft and formed in the support element 35 or the inner ring 5 respectively.

[0032] Due to the design of the outer ring 3 and the inner ring 5, the power density of the wheel bearing 1 can be significantly increased compared to known designs. Since relatively few components are used, the wheel bearing 1 is particularly compact, i.e. particularly short in the axial direction. The outer ring 3 and the inner ring 5 can be embodied as forged parts, which are or are formed in such a way that no machining methods need to be used for their manufacture. As a result, the material yield is also optimized.

[0033] The outer ring 3 comprises a flange 51 on which the tapered rollers 7 are guided. The tapered rollers 7 are also guided by a cage 53. Between the outer ring 3 and the inner ring 5, a seal 55 (here only schematically depicted) is provided in the region of the tapered rollers 7.

[0034] exist Figure 2 In Figure 1 The marked area enclosed by the dashed rectangle in FIG. 1 is enlarged to explain further details.

[0035] In the region of the tapered rollers 9, the outer ring 3 comprises an axial, radially circumferential projection 57, which forms a radial shoulder 59 at the end of the raceway 13. At the shoulder 59 there is a retaining ring 61, which comprises a sliding surface 63 for the tapered rollers 9. The retaining ring 61 is held axially between the shoulder 59 and the projection 65, so that the retaining ring 61 is pressed axially against the shoulder 59. The tapered rollers 9 are guided by a cage 67. Between the outer ring 3 and the inner ring 5, a seal 69 is held in the region of the projection 57.

[0036] The retaining ring 61 can be implemented, for example, from steel or sintered material including an introduced lubricant. Thus, the contact between the tapered roller 9 and the sliding surface 63 can be optimized with respect to friction. The sliding surface 63 is also implemented in a manner corresponding to the course of the abutment end side of the tapered roller 9 and is therefore inclined with respect to the axial direction or radial direction in the present exemplary embodiment.

[0037] For the assembly of the wheel bearing 1, as in the known embodiment, the outer ring 3 and the tapered roller 7 are first assembled together with the cage 53 and the seal 55. Then, the tapered roller 9 is installed in the space formed between the outer ring 3 and the inner ring 5, and the cage 67 is inserted. For this purpose, the cage 67 is interrupted at one point of its circumference so that the cage 67 can be expanded to be fitted on the corresponding end of the inner ring 5.

[0038] Depending on the manufacturing tolerances of the assembly, for each wheel bearing 1, the axially outer end side of the tapered roller 9 has an offset of different sizes relative to the shoulder 59. Thus, the end side will, for example, protrude axially beyond the shoulder 59 by a few microns; depending on the manufacturing tolerances, it will be more or less microns. As an option, the end side can also be located substantially behind the shoulder. The offset is determined during assembly by measurement, after the tapered roller 9 has been inserted and the bearing has rolled. Based on the measurement results, the retaining ring 61 is finished, for example by machining, so that on the one hand it abuts the shoulder 59 axially and on the other hand the tapered roller 9 can slide ( / slip) against the sliding surface 63 with a defined preload. As an option and depending on the application, a defined bearing clearance ( / support clearance) can also be set. The complex pairing of the tapered rollers with the rings can be omitted.

[0039] Therefore, when the tapered roller 9 protrudes axially beyond the shoulder 59, it may be necessary, for example, to remove more or less material from the retaining ring 61 in the region of the sliding surface 63. When the shoulder 59 protrudes axially beyond the end side of the tapered roller 9, it may also be necessary to remove material in the region of the retaining ring 61 abutting the shoulder 59.

[0040] Then, the retaining ring 61 is inserted. At this point in time, the projection 65 is not yet present in the assembly; it is only produced by staking after the retaining ring 61 has been inserted. As an option, the retaining ring 61 can also be connected to the outer ring 3 by an adhesive, welding, screw connection or a soldering connection. Finally, the seal is inserted.

[0041] As an option, it is also possible to hold the retaining ring 61 on the inner ring 5 .

[0042] Due to the use of the retaining ring 61, both the outer ring 3 and the inner ring 5 can be realized as one piece ( / integral), ie the raceways 11 to 17 are formed in the outer ring 3 or the inner ring 5. Neither the outer ring 3 nor the inner ring 5 need to be realized separately. Therefore, no separate raceway element is required.

[0043] Due to the use of tapered rollers 7 and 9 in both rows of rolling elements, the wheel bearing is particularly load-bearing and can be used, for example, in trucks.

[0044] exist Figure 3 In FIG. 1 , a wheel bearing 101 is depicted as another embodiment of the present invention. Figure 1 The wheel bearing 1 of FIG. 1 is implemented substantially identically, wherein reference numerals have been adopted. In the following, the parts implemented differently will be mainly discussed. Thus, the wheel bearing 101 includes a row of balls 107 instead of tapered rollers 7. Thus, raceways 111 and 115 are formed in the outer ring 103 or the inner ring 105. Figure 1 Compared to the embodiment of the present invention, the inner ring 105 is formed thicker in the area of ​​the raceway 115, so that no supporting elements are required and the inner ring 105 can support the load required for use. The inner ring 105 includes an abutment surface 121 for abutting a nut of the shaft end of the drive shaft. The wheel bearing 101 can be used for example in an automobile or a light commercial vehicle.

[0045] If the left-hand rolling element row is designed as tapered rollers, a correspondingly thicker inner ring can also be provided in the region of the left-hand raceway. Figure 1 In a slightly modified embodiment, the support element 35 can also be omitted.

[0046] In further exemplary embodiments, many details can be optimized, such as, for example, the material thickness of the inner ring and the axial distance between the rolling element areas. Thus, a wheel bearing can be provided which is as compact as possible, weight-optimized, simple to manufacture and can be configured for various purposes and loads.

[0047] Instead of the tapered rollers 7 and 9, other types of rollers may also be used, such as, for example, cylindrical rollers arranged obliquely.

[0048] exist Figure 4 In the figure, a method according to a preferred embodiment of the present invention is schematically depicted.

[0049] In a first method step 501, the outer ring 3 or 103, the inner ring 5 or 105 and the rolling elements are manufactured. In a second method step 503, the first row of rolling elements is introduced into the outer ring 3 or 103 and is held by the cage. In a third method step 505, the inner ring 5 or 105 is introduced into the outer ring 3 or 103 so that the first row of rolling elements, i.e. the tapered rollers 7 or the balls 107, are in contact with the corresponding raceways 11 and 15 or 111 and 115. In a fourth method step 507, the tapered rollers 9 are placed between the outer ring 3 or 103 and the inner ring 5 or 105 so that they are in contact with the raceways 13 and 17. The cage 67 is also inserted.

[0050] In a fifth method step 509, the distance between the outer end side of the tapered roller 9 and the shoulder 59 is first measured. Here, the minimum distance is preferably measured. In a sixth method step 511, the retaining ring 61 is processed in a manner depending on the measured distance, so that when the retaining ring 61 is subsequently brought into contact with the shoulder 59, the end side of the tapered roller 9 is acted upon by the sliding surface 63 with a predetermined contact force. The preload ( / preload) or the bearing clearance ( / bearing clearance) of the bearing is thereby set. Depending on the measured distance, the processing of the retaining ring 61 can be mechanical processing, in which material is removed from the retaining ring 61 in the area where the sliding surface 63 is located. As Figure 2 As depicted in , this occurs when the end side of the tapered roller 9 protrudes axially beyond the shoulder 59. Here, the amount of material to be removed is determined by the measured distance and the preload ( / preload) or bearing clearance ( / bearing clearance) to be set.

[0051] In a seventh method step 513, the retaining ring 61 is inserted so that it abuts against the shoulder 59 and the sliding surface 63 exerts a predefined force on the tapered roller 9. For this purpose, a tool can be used to press the retaining ring 61 against the shoulder 59. Then, a projection 65 is produced by punching or the like, so that the retaining ring 61 is held on the shoulder 59.

Claims

1. A bearing assembly comprising an outer element and an inner element, the outer element and the inner element being supported against each other in the manner of a rolling element bearing by at least two rows of rolling elements, wherein: The external element includes two surface areas for contacting the rolling elements, and the internal element includes two surface areas for contacting the rolling elements, wherein at least one column of rolling elements in the column is implemented as rollers; the internal element is formed as a thin-walled structure, and the internal element includes two supporting elements arranged corresponding to the two surface areas, and the supporting elements extend radially inward from the inner wall of the internal element.

2. The bearing assembly according to claim 1, characterized in that: The bearing assembly further comprises a retaining element for the rollers, the retaining element being retained on the inner element or the outer element and comprising a sliding surface for the rollers.

3. The bearing assembly according to claim 2, characterized in that: The inner element or the outer element comprises an abutment surface extending at least partially in the radial direction, against which the retaining element abuts.

4. The bearing assembly according to claim 1 or 2, characterized in that: The bearing assembly further comprises a bearing cage for guiding the rollers, wherein the bearing cage is configured such that it can be expanded at least temporarily in the radial direction.

5. The bearing assembly according to claim 1 or 2, characterized in that: The inner element includes a radially inner recess into which a shaft portion connectable to the inner element can be inserted.

6. The bearing assembly according to claim 1 or 2, characterized in that: The outer element comprises a further retaining element by means of which the bearing assembly can be retained on the housing.

7. Use of a bearing assembly according to any one of claims 1 to 6 for supporting a vehicle wheel unit of a motor vehicle.

8. A method for manufacturing a bearing assembly according to any one of claims 1 to 7, comprising the following method steps: - manufacturing the inner element, the outer element and the first row of rolling elements and the second row of rollers; - introducing a first row of rolling elements into said outer element; - introducing the inner element into the outer element so that the rolling elements of the first row are in contact with corresponding surface areas of the inner element and the outer element; - Introducing the roller between the outer element and the inner element such that the roller comes into contact with corresponding surface areas of the inner element and the outer element.

9. The method according to claim 8, characterized in that After the rollers of the second row of rolling elements have been introduced, a bearing cage is inserted for guiding the rollers.

10. The method according to claim 9, characterized in that The method further comprises the following method steps before inserting a retaining element which is retained on the inner element or the outer element and comprises a sliding surface for the roller: - measuring the distance of the outer end side of the roller from the abutment surface for the retaining element, - Depending on the measured distance, the retaining element is processed so that when the retaining element is subsequently brought into abutment against the abutment surface, the end side of the roller is acted upon by the sliding surface of the retaining element with a predetermined contact force.

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