Bearing device with compression body for reducing preload; assembly method of the bearing device; wheel bearing unit and axle drive

Abstract

The invention relates to a bearing device (1) for a drive component of a motor vehicle, comprising a hub (2) and a double-row rolling bearing (3), wherein the rolling bearing (3) in turn has two axially offset outer rings (4a, 4b) pressed into the hub (2), two axially adjacent inner rings (5a, 5b) and two rolling element groups (6a, 6b), each guided between an outer ring (4a, 4b) and an inner ring (5a, 5b), wherein the inner rings (5a, 5b) are supported directly against one another with mutually facing axial end faces (7a, 7b), and wherein the outer rings (4a, 4b) are prestressed against mutually opposite counter surfaces (8a, 8b) of a radial projection (9) of the hub (2) and axially between an outer ring (4b) and the counter surface (8b) assigned to it compression body (10). Furthermore, the invention relates to a method for assembling this bearing device (1), a wheel bearing unit (15), and an axle drive (16).

Description

[0001] The invention relates to a bearing device for a drive component (preferably for a wheel bearing or an axle drive) of a motor vehicle, in particular for a truck, comprising a hub and a double-row rolling bearing, wherein the rolling bearing in turn has two axially offset outer rings pressed into the hub, two axially adjacent inner rings, and two rolling element groups, each guided / received between an outer ring and an inner ring, and wherein the inner rings are supported directly against one another with their axial end faces facing one another. Furthermore, the invention relates to an assembly method for this bearing device. The invention also relates to a wheel bearing unit and an axle drive, each equipped with the bearing device.

[0002] The applicant is aware of internal prior art that has already been filed as a German patent application with the German Patent and Trademark Office, but has not yet been made available to the public. This patent application has the DE application number 10 2022 129 622.9, dated November 9, 2022. This patent application discloses a wheel bearing unit in which the inner rings of a double-row rolling bearing are positively and non-positively connected to each other at the respective facing axial end faces.

[0003] Furthermore, designs are known from the prior art in which the inner rings are coupled to one another via additional intermediate rings.

[0004] Bearings are already known in which a relatively wide preload range must be implemented during assembly, which is primarily due to the large number of different components and the associated large tolerances. At the very least, the inner rings are designed with a relatively complex design, resulting in significant manufacturing costs.

[0005] It is therefore an object of the present invention to provide a solution which is easy to manufacture and in which the preload range to be implemented during assembly for sufficient preload is significantly reduced and thus a specific preload value can be easily and reliably set.

[0006] This is achieved according to the invention in that the outer rings are preloaded against oppositely facing mating surfaces of a radial projection of the hub and a compression body is inserted / clamped axially between an outer ring and the mating surface (of the projection) assigned to it.

[0007] Such a compression body, which is specifically axially compressed during the axial pressing of the corresponding outer ring into the hub, provides a simple means of achieving sufficient preload in the rolling bearing while maintaining the smallest possible preload range. This makes it possible to avoid the effort of measuring all components during production. A relatively narrow and targeted preload range is automatically established by exerting a force on the compression body. Since the spring characteristics of the rolling bearing and the compression body are known, adjustments can be made accordingly during assembly. Finally, it is even possible to select larger manufacturing tolerances without this affecting the preload range in the rolling bearing. The result is significantly simpler assembly and production of the bearing device.

[0008] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0009] Accordingly, it is advantageous if the compression body is (at least partially) elastically deformable. Alternatively, however, it is also possible to design the compression body to be exclusively plastically deformable. This further simplifies the assembly process and, in particular, prevents the outer ring from being accidentally pushed out of its press fit (due to a restoring force of the compression body).

[0010] In any case, the compression of the outer ring, which is in direct contact with the compression body, in the hub is selected such that a pressing force supporting the outer ring is many times greater than a counterforce / restoring force exerted by the compression body on the outer ring.

[0011] In particular, it is advantageous if the compression body is made of a softer material than the outer ring. Light metals and plastics are preferred as possible materials for forming the compression body.

[0012] If the compression body is designed as a ring, it is particularly easy to manufacture.

[0013] Depending on the desired preload, it is also expedient if the compression body has a rectangular cross-section, a circular or oval cross-section, or a C-shaped or U-shaped cross-section.

[0014] Furthermore, the invention relates to a method for assembling a bearing device according to the invention according to at least one of the previously described embodiments, wherein in a first step, a first outer ring is pressed into the hub until it axially rests against the radial projection (of the hub), and in a second step, the compression body is inserted on an axial side of the projection facing away from the first outer ring and then a second outer ring is pressed into the hub until it (second outer ring) comes into contact with the compression body and the compression body is in turn pressed / pressed against the projection by means of the second outer ring, wherein furthermore the inner rings coupled to the outer rings by means of the rolling element groups are axially pressed together. This pressing of the two inner rings together preferably takes place with simultaneous compression of the compression body.

[0015] Furthermore, the invention relates to a wheel bearing unit for supporting a motor vehicle tire of a motor vehicle, in particular a truck, with a bearing device according to the invention according to at least one of the previously described embodiments and an axle journal onto which the inner rings of the bearing device are pressed.

[0016] According to a likewise preferred embodiment, it is advantageous if an axle transmission is provided for a motor vehicle, such as a truck, which axle transmission is equipped with a bearing device according to the invention according to at least one of the previously described embodiments and also has a transmission shaft onto which the inner rings of the bearing device are pressed.

[0017] The invention will now be explained in more detail below with reference to figures, in which context various embodiments are also shown.

[0018] They show: Fig. 1 a longitudinal sectional view of a bearing device according to the invention according to a first embodiment, wherein the basic structure of the bearing device can be clearly seen, Fig. 2 a longitudinal sectional view of a bearing device according to the invention according to a second embodiment, which differs from the first embodiment in particular by the design of a compression body arranged between an outer ring and a projection of a hub, wherein the compression body is now no longer provided with a rectangular but a circular cross-section, Fig. 3 a longitudinal sectional view of a bearing device according to the invention according to a third embodiment, in which the compression body now has an oval cross-section, and Fig. 4 a longitudinal sectional view of a bearing device according to the invention according to a fourth embodiment, wherein the compression body has a C-shaped cross section.

[0019] The figures are merely schematic in nature and serve exclusively to understand the invention. The same elements are provided with the same reference numerals. Furthermore, the different features of the various embodiments can, in principle, be freely combined with one another.

[0020] With regard to the first embodiment, Fig. 1 shows a general view of a bearing device 1 according to the invention. The bearing device 1 is preferably used in a drive train / drive component of a motor vehicle. Thus, the bearing device 1 serves to support a drive component of a motor vehicle, preferably a truck.

[0021] The bearing device 1 has a hub 2 / a hub body. The hub 2 represents a type of housing and, in the fully assembled state, firmly accommodates a double-row rolling bearing 3, which is described in more detail below. The rolling bearing 3 is accommodated (radially, ie perpendicular to a longitudinal axis / rotational axis of the rolling bearing 3) within the hub 2. A Fig. 1, the shaft 14 is rotatably mounted relative to the hub 2 by means of the rolling bearing 3. The shaft 14 can be considered a component of the bearing device 1, but in the present embodiment, it is not considered a component of the bearing device 1.

[0022] Regarding the preferred area of ​​application, Fig. 1, it is also pointed out that the bearing device 1 is preferably used in a wheel bearing unit 15 / a wheel bearing of a motor vehicle for supporting a motor vehicle tire of the motor vehicle. The hub 2 thus represents a wheel hub, while the shaft 14 then forms an axle journal 12. In further embodiments, it is alternatively possible to use the bearing device 1 in an axle transmission 16, which is also indicated, wherein the supported shaft 14 is, for example, a transmission shaft 13 (transmission output shaft) that is mounted relative to the hub 2 designed as a housing.

[0023] The double-row rolling bearing 3 is pressed into the hub 2. The rolling bearing 3 is implemented as a double-row / double roller bearing, namely a double tapered roller bearing (in an O-arrangement), but can also be implemented in other ways in further designs, for example as a double cylindrical roller bearing or double ball bearing.

[0024] The double-row rolling bearing 3 is composed of two bearing sections 17a, 17b arranged and configured essentially symmetrically to one another. A first bearing section is designated by the reference numeral 17a and has a (first) outer ring 4a, a (first) inner ring 5a, and a (first) rolling element group 6a, which are radially guided between the first outer ring 4a and the first inner ring 5a. A second bearing section 17b, designated by the reference numeral 17b, accordingly has a (second) outer ring 4b, a (second) inner ring 5b, and a (second) rolling element group 6b, which in turn is guided between the second outer ring 4b and the second inner ring 5b. For the sake of clarity, only a single rolling element is shown in each of the figures for each rolling element group 6a, 6b.

[0025] It can also be seen that each of the outer rings 4a, 4b is pressed into the hub 2 and is thus held in the hub 2 by a press fit (radially).

[0026] The first outer ring 4a is in the fully assembled position of the bearing device 1 according to Fig. 1 is pressed / placed axially against a radial projection 9 of the hub 2 from a first axial side 11a (on a first counter surface 8a). The first outer ring 4a is thus pressed into an inner shell region 18 of the hub 2 relative to the first axial side 11a of the projection 9.

[0027] The second outer ring 4b is in the fully assembled position of the bearing device 1 according to Fig. 1 is pressed / placed axially (i.e., in the longitudinal direction / along a longitudinal axis / axis of rotation of the rolling bearing 3) against the radial projection 9 from a second axial side 11b (on a second counter surface 8b), which faces away from the first axial side 11a. The second outer ring 4b is thus pressed / placed against the second axial side 11b of the projection 9 in an inner shell region 18 of the hub 2.

[0028] With regard to the second bearing section 17b, it can also be seen that, according to the invention, a compression body 10 is inserted axially between the projection 9 and the second outer ring 4b. Thus, unlike the first outer ring 4a, the second outer ring 4b does not bear directly against the projection 9, but is supported thereon with the interposition of the compression body 10. The second outer ring 4b is thus (indirectly) supported on the projection 9 from the second axial side 11b via the compression body 10, while the first outer ring 4a is supported on the projection 9 directly from the first axial side 11a.

[0029] The compression body 10 is deliberately made of a softer material than the outer rings 4a, 4b and can be formed, for example, from a plastic or a light metal. The compression body 10, in particular, has a greater axial compressibility than the respective outer rings 4a and 4b.

[0030] With regard to the two inner rings 5a, 5b, it can also be seen that, in the fully assembled state, they abut one another with their mutually facing end faces 7a, 7b and are also preferably pressed against one another / axially against one another. Due to the shape of the rolling element groups 6a, 6b between the respective outer ring 4a, 4b and the inner ring 5a, 5b, the entire bearing device 1 is cleverly clamped during assembly.

[0031] During an assembly process, in a first step, the first outer ring 4a is pressed into the hub 2 until it axially rests against the radial projection 9 (on the first mating surface 8a). In a second step, the compression body 10 is first inserted onto the axial side 11b of the projection 9 facing away from the first outer ring 4a. Subsequently, the second outer ring 4b is pressed into the hub 2 until it comes into contact with the compression body 10 and in turn presses the compression body 10 against the projection 9 (on the second mating surface 8b). In the fully assembled state, the compression body 10 is then arranged in an axially (elastically and / or plastically) compressed manner between the second outer ring 4b and the projection 9. Furthermore, in this second step, the inner rings 5a, 5b coupled to the outer rings 5a, 5b by means of the rolling element groups 6a, 6b are axially pressed together.

[0032] The compression body 10, as described below with reference to the various embodiments of the Fig. 1 to 4, can have different cross sections. The compression body 10 is preferably annular. In the first embodiment of the Fig. 1, the compression body 10 is provided with a rectangular cross-section. In Fig. 2, the compression body 10 is provided with a circular cross-section / a circular cross-section, in Fig. 3 with an oval cross-section and in Fig. 4 with a profiled cross-section, in particular a C-shaped cross-section.

[0033] Regarding the Fig. 2 to 4, it should also be noted that the further structure of these further embodiments corresponds to that of the first embodiment.

[0034] In principle, it should be noted that in the Fig.2 to 4, the bearing device 1 can be seen in somewhat greater detail, revealing axial seals 19a, 19b. In addition, cages 20a, 20b for the rolling element groups 6a, 6b are visible. A connecting element / clamp 21 for additionally securing the two inner rings 5a, 5b to each other is also shown. These additional components can, of course, also be used in the first embodiment.

[0035] In other words, according to the invention, a targeted adjustment of the bearing to the housing is achieved using compression elements (compression body 10), such as compression rings, without having to measure all components during production. Thus, the narrow / targeted preload range is automatically established by exerting a force on the compression body 10. Since the spring characteristics of the bearing / rolling bearing 3 and the compression body 10 are known, adjustments can be made accordingly. Furthermore, the bearing device 1 according to the invention enables larger manufacturing tolerances without affecting the preload range in the bearing.

[0036] Preferably, a (first) outer ring 4a is pressed into the hub collar (protrusion 9) until it stops (here on an inboard side). On the other side (outboard), however, a compression body 10 is clamped between the (second) outer ring 4b and the hub collar.

[0037] A corresponding spring characteristic curve is created for each element during development. This characteristic curve is also imported into the assembly line if necessary.

[0038] The compression body 10 is intentionally too wide from the start to create a relatively high preload in the bearing. This serves to generate the spring characteristic, which differs significantly from the target spring characteristic (making it easier to readjust). During assembly, the actual spring characteristic is compared with the target spring characteristic. This results in a specific deviation value: This value is the distance in millimeters by which the outer ring should be pressed further toward the hub flange. This can be achieved in various ways, but the preferred method is a press with force-displacement measurement.

[0039] Overall, the bearing device 1 thus has two inner rings 5a, 5b (outboard and inboard), two outer rings 4a, 4b (outboard and inboard), a hub 2 (also called housing or flange), two tapered roller rows / rolling element groups 6a, 6b (outboard and inboard) and a compression body 10 in different designs / cross-sections (circular = 360°). List of reference symbols 1 storage device 2 Hub 3 rolling bearings 4a first outer ring 4b second outer ring 5a first inner ring 5b second inner ring 6a first rolling element group 6b second rolling element group 7a Front side of the first inner ring 7b Front side of the second inner ring 8a first counter surface 8b second counter surface 9 lead 10 compression bodies 11a first axial side 11b second axial side 12 axle journals 13 Gear shaft 14 Wave 15 Wheel bearing unit 16 axle drives 17a first camp section 17b second camp section 18 Inner jacket area 19a first seal 19b second seal 20a first cage 20b second cage 21 bracket QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 129 622.9

[0002]

Claims

[1] Bearing device (1) for a drive component of a motor vehicle, with a hub (2) and a double-row rolling bearing (3), wherein the rolling bearing (3) in turn has two axially offset outer rings (4a, 4b) pressed into the hub (2), two axially adjacent inner rings (5a, 5b) and two rolling element groups (6a, 6b), each guided between an outer ring (4a, 4b) and an inner ring (5a, 5b), and wherein the inner rings (5a, 5b) are supported directly against one another with mutually facing axial end faces (7a, 7b), characterized by that the outer rings (4a, 4b) are prestressed against mutually opposite counter surfaces (8a, 8b) of a radial projection (9) of the hub (2) and a compression body (10) is inserted axially between an outer ring (4b) and the counter surface (8b) assigned to it. [2] Bearing device (1) according to claim 1, characterized by that the compression body (10) is elastically deformable. [3] Bearing device (1) according to claim 1 or 2, characterized by that the compression body (10) is made of a softer material than the outer ring (4a, 4b). [4] Bearing device (1) according to one of claims 1 to 3, characterized by that the compression body (10) is designed as a ring. [5] Bearing device (1) according to one of claims 1 to 4, characterized by that the compression body (10) has a rectangular cross-section. [6] Bearing device (1) according to one of claims 1 to 4, characterized by that the compression body (10) has a circular or oval cross-section. [7] Bearing device (1) according to one of claims 1 to 4, characterized by that the compression body (10) has a C-shaped or U-shaped cross-section. [8] Method for assembling a bearing device (1) according to one of claims 1 to 7, wherein in a first step a first outer ring (4a) is pressed into the hub (2) until it axially rests against the radial projection (9), and in a second step the compression body (10) is inserted on an axial side (11b) of the projection (9) facing away from the first outer ring (4a) and then a second outer ring (4b) is pressed into the hub (2) until it comes into contact with the compression body (10) and the compression body (10) is in turn pressed against the projection (9) by means of the second outer ring (4b), wherein furthermore the inner rings (5a, 5b) coupled to the outer rings (5a, 5b) by means of the rolling body groups (6a, 6b) are axially pressed together. [9] Wheel bearing unit (15) for supporting a motor vehicle tire of a motor vehicle, with a bearing device (1) according to one of claims 1 to 7 and an axle journal (12) onto which the inner rings (5a, 5b) are pressed. [10] Axle transmission (16) for a motor vehicle, with a bearing device (1) according to one of claims 1 to 7 and a transmission shaft (13) onto which the inner rings (5a, 5b) are pressed.

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