Wheel hub and system consisting of a brake disc and a wheel hub

Abstract

wheel hub (1) comprising - a collar area (12) located on the outside in a radial direction and - an inner core region viewed in the radial direction (11), wherein the inner core area (11) has a greater axial extent than the outer collar area (12), and wherein the wheel hub (1) has a substantially axially extending primary recess (21) in the inner core area (11) for attaching a brake disc (2), Preferably, the ratio between a radial distance (A1) between an axis of rotation (A) and the primary recess (21) and a radially dimensioned diameter (D) of the wheel hub (1) assumes a value between 0.6 and 0.3.

Description

[0001] The present invention relates to a wheel hub and a system consisting of a brake disc and a wheel hub.

[0002] Wheel hubs are well known from the prior art. They serve to connect a wheel to an axle element, for example, to the axle of a commercial vehicle. Brake discs are typically attached to the wheel hub in a rotationally fixed manner. Usually, the brake discs are bolted to the wheel hub from the brake disc side. This limits the clamping length, i.e., the total thickness formed by the connected elements and the fastener in the direction of connection, due to the generally flat brake disc or adapter element and the available space on the vehicle facing away from the visible side of the mounted wheel hub. Consequently, the fastener, such as a bolt, must have a correspondingly high strength to apply the necessary clamping forces. Furthermore, no further increase in braking torque can be achieved.

[0003] In view of the prior art described above, it is therefore an object of the present invention to provide an improved wheel hub with which, in particular, a clamping length can be achieved when connecting the brake disc to the wheel hub compared to the prior art.

[0004] This problem is solved by a wheel hub according to claim 1 and a system comprising a brake disc and a wheel hub according to claim 14. Further advantages and features of the invention will become apparent from the dependent claims, the description, and the accompanying figures.

[0005] According to the invention, a wheel hub is provided comprising a collar region located on the outer side in the radial direction and a core region located on the inner side in the radial direction, wherein the inner core region has a greater axial extent than the outer collar region (i.e., the inner core region is thicker than the outer collar region when viewed axially), and wherein the wheel hub has a substantially axially extending primary recess in the inner core region for connecting a brake disc. Compared to the prior art, the positioning of the primary recess according to the invention allows for greater clamping lengths. This advantageously enables higher clamping forces to be achieved, which in turn allow for higher braking torques.Furthermore, thermal effects caused by heat generation in the brake disc during braking can be compensated for more effectively compared to wheel hubs, whose primary recesses for connecting the brake disc allow for shorter clamping lengths. A collar area is essentially an annular or border-shaped end of the wheel hub. When the wheel hub is mounted, the collar area forms the outermost circumferential region of the wheel hub, preferably sealing it off on one side in both the radial and axial directions. Advantageously, the collar area serves as a connection point for a wheel rim or facilitates the mounting of a wheel rim. For example, the ratio of the radial extent of the collar area to the diameter of the wheel hub is between 0.1 and 0.3, preferably between 0.15 and 0.25, and particularly preferably between 0.21 and 0.24.In this design, the collar area faces the visible side of the vehicle when assembled. Specifically, the collar area is designed to have a substantially constant thickness in the radial direction, measured in the axial direction. Here, "thickness" refers to the extent of the collar area occupied by the collar area as it rotates around an axis of rotation during operation. This means that any local indentations are disregarded when determining the thickness. "Substantially axial" can be understood to mean that the relevant direction may form an angle of at most 15°, preferably at most 10°, and particularly preferably at most 5° with the ideal axial direction. The ideal axial direction is, in particular, the direction of the wheel axle or the direction along the axis of rotation of the wheel hub.Furthermore, the core area is designed to change its axial thickness in the radial direction. Preferably, the core area comprises a central cavity designed to receive an axle element. The core area is specifically designed to abut the axle element and, in the assembled state, at least partially encloses the axle element, for example, an axle stub. It is also preferred that the core area and the collar area connect directly to each other or merge into one another in the radial direction. Preferably, the ratio of the radial extent of the core area to the diameter of the wheel hub is between 0.3 and 0.7, preferably between 0.35 and 0.55, and most preferably between 0.4 and 0.5. Preferably, the primary recess is a bore, in particular a through bore.Furthermore, it is preferably provided that the wheel hub is designed for attaching a flat brake disc, for example, a brake disc 1 to 3 cm thick in the axial direction. It is also conceivable that the primary recess is located in the half facing the axis of rotation, preferably in the first third facing the axis of rotation, or particularly preferably in the first quarter facing the axis of rotation of the core area or the wheel hub. In particular, it is provided that the wheel hub is formed in one piece or integrally, i.e., the wheel hub is not composed of several components, but rather the brake disc, axle, and wheel or wheel rim can be attached to a single component, i.e., the wheel hub. For example, the wheel hub is forged or cast in one piece.

[0006] Preferably, the core area comprises substantially radially extending rib elements. Preferably, the rib elements run parallel to the wheel axis in the axial direction. At their end facing the collar area, the rib elements are bent radially outwards. The rib elements advantageously eliminate the need for a solid core area, thus saving weight and material at the wheel hub. It is particularly preferred that, viewed in the circumferential direction, the rib elements terminate in an area on the cantilever element where no secondary recess is provided. The secondary recesses preferably serve to connect the wheel or wheel rim to the wheel hub. Preferably, the rib element terminates centrally between two secondary recesses adjacent to each other in the circumferential direction.This allows for a reduction in the weight of the wheel hub with the same axle load, provided the stress distribution is homogeneous. In this context, "essentially radially extending" means, in particular, that the rib elements may form an angle of a maximum of 10°, preferably a maximum of 5°, and most preferably a maximum of 2° with the ideal radial direction. The ideal radial direction is, in particular, the radial direction to the wheel axis or the axis of rotation of the wheel hub.

[0007] Advantageously, the rib elements connect the core area to the collar area, particularly exclusively. "Connect" in this context can mean, among other things, that the rib elements are designed, particularly exclusively, for the transmission of force and / or moment between the core area and the collar area. This allows for a particularly compact wheel hub. In other words, this can mean that the rib elements form the part of the core area that is connected to the collar area.

[0008] It is advantageous for a rib element to have several primary recesses. For example, exactly two primary recesses are provided in the rib element, specifically in each rib element. This allows for a larger brake disc mounting surface, as two primary recesses can share a common brake disc mounting surface.

[0009] Preferably, the primary recesses, realized as a pair in a rib element, are arranged centrally between two adjacent secondary recesses when viewed in the direction of rotation. For example, it is provided that, viewed in the direction of rotation, a rib element or no rib element opens alternately between each pair of adjacent secondary recesses. Preferably, the axially extending primary recesses are arranged, when viewed radially, in that region of the rib element where the rib elements, in particular the outer surfaces of the rib element associated with it, extend substantially axially to the wheel axis. The primary recesses can be incorporated into the rib element at its end where it meets the wheel axis in the collar region.

[0010] Alternatively, each rib element could have exactly one primary recess. This would allow for narrower rib elements compared to those with multiple primary recesses. Preferably, the rib elements terminate centrally in the circumferential direction, in a region between two adjacent secondary recesses. Preferably, the primary recesses are arranged radially in the region of the rib element where the rib elements, particularly the outer surfaces associated with the rib element, run substantially axially to the wheel axis. In other words, the primary recess is integrated into the rib element at the end where it meets the wheel axis, adjacent to the collar area.

[0011] In a further embodiment of the present invention, the collar area is provided with a material thinning. This material thinning advantageously reduces the overall weight of the wheel hub. Preferably, the material thinning is provided as a recess between two adjacent secondary recesses, which expediently extends axially into the collar area. In particular, the recesses are arranged on the side of the collar area facing the brake disc in the assembled state. This advantageously allows the side of the collar area facing away from the brake disc to be designed as a flat surface, in order to provide the flattest possible contact surface for attaching the wheel.Preferably, the ratio between the local thickness of the collar area and the thickness of the collar area measured, for example, in the area of ​​the secondary recesses, assumes a value between 0.05 and 0.5, more preferably between 0.1 and 0.25, and most preferably between 0.15 and 0.2. Surprisingly, it has been found that such material dilutions, particularly for ratios between 0.15 and 0.2, do not negatively affect the stability of the collar area.

[0012] Preferably, the outer collar area has a secondary recess, with the primary recess extending further axially than the secondary recess. This provides the recess for attaching the brake disc that allows for a greater clamping length, since the secondary recesses are located in the thinner collar area.

[0013] It is advantageous that the ratio between the axial extent of the primary recess and the axial extent of the secondary recess shall be between 0.05 and 0.45, preferably 0.01 and 0.35 and particularly preferably 0.01 and 0.2.

[0014] In a further embodiment of the present invention, the primary and secondary recesses are arranged offset from one another in the axial direction. For example, the opening of the primary recess facing the collar area does not close flush with one side of the collar area. The primary recess is preferably set back axially from the secondary opening or from the collar area. This allows fastening elements, such as screws, coming from the outside of the vehicle to be positioned on the wheel hub in such a way that they do not protrude axially from the collar area. Thus, the fastening elements can be at least partially protected.

[0015] Advantageously, at least one, preferably all, primary recesses completely penetrate the core area and / or the wheel hub. This allows for particularly easy installation of the brake disc. In particular, this enables the brake disc to be mounted and tightened from the opposite side of the wheel hub. Preferably, the primary recesses are arranged offset from the secondary recesses in one direction of rotation. This results in a particularly mechanically robust wheel hub.

[0016] Advantageously, the ratio between the axial extent of the primary recess and the total axial extent of the wheel hub is designed to be between 0.5 and 0.98, preferably between 0.75 and 0.95, and most preferably between 0.78 and 0.88. Achieving a ratio between 0.78 and 0.88 advantageously allows for the greatest possible clamping length without increasing the axial extent of the wheel hub.

[0017] Preferably, the ratio between the radial distance between the axis of rotation and the primary recess and the radial diameter of the wheel hub is between 0.3 and 0.6, preferably between 0.35 and 0.55, and most preferably between 0.4 and 0.5. By realizing these ratios, the primary recess can be positioned as close as possible to the wheel axis in the wheel hub. Here, the axial thickness of the wheel hub is greatest in the radial direction, allowing for correspondingly long clamping lengths. Preferably, any profiling of the wheel hub on the side of the core area facing the cavity is taken into account when arranging the primary recesses.

[0018] In a further embodiment of the present invention, the ratio between the radial distance between the axis of rotation and the primary recess and the axial length of the primary recess is between 0.65 and 0.85, preferably between 0.7 and 0.78, and particularly preferably between 0.72 and 0.77. In these embodiments, the primary recess extends further than its radial distance between the axis of rotation and the primary recess. Particularly for the ratio between 0.72 and 0.77, primary recesses with the largest possible clamping lengths are achieved, which also have a comparatively small distance to the axis of rotation.

[0019] Preferably, a clear area is arranged between two rib elements, particularly between each rib element, viewed in the direction of rotation. This allows cooling air to reach the brake disc through the clear area(s), thus cooling it.

[0020] In a preferred embodiment, the area measured in the circumferential direction and associated with the rib elements is 0.3 to 0.5 times larger than the area associated with the clear space. It has been found that such large clear spaces are achievable without compromising the stability of the wheel hub. This surprisingly feasible design allows for a particularly lightweight wheel hub and, additionally, increases the cooling effect of the brake disc.

[0021] Advantageously, the primary recess extends radially over the entire length of the rib element, or the primary recess is formed at least partially by a sleeve-shaped section projecting from the rib element, preferably axially. Due to the primary recesses extending completely into the rib element, the fastener intended for connection can be inserted and guided relatively easily and is at least partially, preferably largely, protected within the primary recess. In the case of the sleeve-shaped section, it is advantageously unnecessary to design the rib element parallel to the wheel axle over as long a distance as possible. This means that greater design freedom is achieved in the rib elements, since the sleeve-shaped section ensures the increased clamping length.

[0022] In a further embodiment of the present invention, the primary recess opens to one side into a brake disc mounting surface, the brake disc mounting surface preferably being either interrupted or continuous in the direction of rotation. In the assembled state, the brake disc or an adapter element rests directly against the brake disc mounting surface. In particular, one end of the ribbed element provides the brake disc mounting surface. In the case of a continuous brake disc mounting surface, a continuous, flat contact area can be provided, while in the case of an interrupted brake disc mounting surface, material and weight of the wheel hub can be advantageously saved.

[0023] According to the invention, a system consisting of a brake disc and a wheel hub according to the invention is also provided, wherein the brake disc can be attached to the wheel hub, in particular to the brake disc mounting surface, by means of a fastening element guided through the primary recess. All features and advantages described for the wheel hub according to the invention can also be transferred analogously to the system according to the invention consisting of the brake disc and the wheel hub, and vice versa. In particular, it is provided that the brake disc mounting surface is arranged on the side of the wheel hub opposite the collar area in the axial direction. This allows primary recesses to be realized that extend axially between the brake disc mounting surface and the collar area, thus enabling the greatest possible clamping length. In this case, the fastening element extends completely through the primary recess.Preferably, the fastening device comprises a screw and optionally a nut.

[0024] According to a further embodiment of the present invention, a thread is provided on the brake disc side, for example in the brake disc or in the form of a nut resting against the brake disc. This makes it possible to connect the brake disc via a fastening element that is inserted into the primary recess from the outside of the vehicle when the wheel hub is mounted onto the axle element during assembly.

[0025] A method for mounting a brake disc to a wheel hub is also provided, comprising the following steps: - Providing a wheel hub according to the invention, - Inserting a fastener into the primary recess and - Attaching the brake disc to the wheel hub using the fastening device. All features and advantages described for the wheel hub according to the invention can also be applied analogously to the method for mounting the brake disc to the wheel hub, and vice versa. Preferably, the brake disc is mounted onto the wheel hub until it rests against the brake disc mounting surface. The brake disc is then fastened using the fastening device by inserting the fastening element into and through the primary recess. Preferably, the width of the primary recess, viewed radially, is adapted to the corresponding dimensions of the fastening device so that the fastening element fills the primary recess as completely as possible. This advantageously restricts the movement of the fastening element, which, for example, simplifies the mounting of the brake disc.

[0026] According to a further embodiment of the present invention, it is provided that the fastening means is inserted into the primary recess of the wheel hub adjacent to the axle element from the outside of the vehicle.

[0027] Further advantages and features will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying figures. These show: Fig. 1: a wheel hub according to a first exemplary embodiment of the present invention Fig. 2: a wheel hub according to a second exemplary embodiment of the present invention and Fig. 3 a wheel hub according to a third exemplary embodiment of the present invention

[0028] In the Fig. Figures 1a to 1c show a wheel hub 1 according to a first exemplary embodiment of the present invention. In this case, the Fig. 1a two perspective views, in which Fig. 1b each a top view of a rear (left) and a front (right) of the wheel hub 1 and in Fig. Figure 1c illustrates a sectional view. Such a wheel hub 1 serves to attach a wheel to an axle element, for example, a journal, a shaft, or an axle. In addition to attaching the wheel, it is also provided that a brake disc 2 is rotationally fixed to the wheel hub 1. Preferably, the wheel hub 2 is for a commercial vehicle. In particular, it is provided that the wheel hub 1 is designed as a single piece or integrally. That is, the single-piece wheel hub 1 has both primary recesses 21 for attaching the brake disc 2 to the wheel hub 1 and secondary recesses 22 for attaching the wheel to the wheel hub 1. Essential components of the integrally designed wheel hub 1 are a collar region 12 located on the outer side in the radial direction and a core region 11 located on the inner side in the radial direction, wherein the core region 11 is thicker than the collar region 12.Preferably, the collar region 12 is essentially annular in shape, i.e., the thickness of the collar region 12, measured in the axial direction, is essentially constant in the radial direction. In this context, the thickness is understood to be the space-filling extent of the collar region 12 as it rotates around the axis of rotation A during operation. Local material thinnings 18 in the direction of rotation U are disregarded in such a measurement. Preferably, such local material thinnings 18 are incorporated into the collar region 12 at regular or equidistant intervals in the direction of rotation U, thereby advantageously reducing the overall weight of the wheel hub 1. For example, the material thinnings 18 are arranged between two adjacent secondary recesses 22. Here, the material thinnings 18 are preferably recesses on the back side of the collar region 12, i.e.,the side facing the brake disc 2 in the assembled state. In contrast to the collar region 12, the axial thickness of the core region 11 changes with increasing radial distance from the axis of rotation A. Preferably, the thickness of the core region 11 is at its maximum in the area where the wheel hub 1 rests against the axle element in the assembled state. Furthermore, the core region 11 is provided to have substantially radially extending rib elements 5, with a clear area 15 forming between two adjacent rib elements 5. In particular, the rib elements 5 are designed such that, viewed axially, they run parallel to the wheel axis A in certain areas and are bent radially outwards towards the collar region 12. This causes the wheel hub 1 to widen in the axial direction.In the area where the rib elements 5 run substantially parallel to the wheel axis A, their outer surface defines an outer surface 14. Preferably, the ratio between the distance A3 between the wheel axis A and the outer surface 14 and the diameter D of the wheel hub 1 is between 0.3 and 0.8, preferably between 0.45 and 0.75, and most preferably between 0.48 and 0.58. Furthermore, the ratio between the length of the area where the outer surface 14 runs substantially parallel to the wheel axis A and the total length of the wheel hub A in the axial direction is between 0.2 and 0.5, preferably between 0.25 and 0.45, and most preferably between 0.32 and 0.42. It is also conceivable that the clear area 15, viewed radially, is arranged substantially in line with the material thinning 18. .

[0029] Furthermore, it is preferably provided that the rib element 5 connects directly to the collar region 12 at a first end and transitions at a second end into the region where the rib element 5 forms the outer surface 14 of the shell, which runs parallel to the wheel axis A. In particular, it is provided that the primary recess 21, through which the brake disc 2 is connected to the wheel hub 1, is arranged in the core region 11, preferably in a region located between the wheel axis A and the outer surface 14 of the shell. Here, the primary recess 21 extends substantially axially. Furthermore, it is provided in the Fig. In the embodiment shown in Figure 1, the primary recess 21 extends over the entire rib element 5. By arranging the primary recess 21 in the thicker core area 11, longer clamping lengths can advantageously be achieved than if the primary recess 21 were located in the collar area 12 for connecting the brake disc 2. This increased clamping length advantageously results in a higher clamping force, which ultimately allows for higher braking torques. Furthermore, thermal effects can be compensated for relatively well by this design arrangement of the primary recesses 21. In addition, it is possible in the Fig. In the embodiment shown in Figure 1, the core area 11 has a brake disc support surface 25 into which the primary recess 21 opens. In the assembled state, the brake disc 2 rests against the brake disc support surface 25. In the present embodiment, two primary recesses 21 are assigned to each rib element 5 or extend through the respective rib element 5. Advantageously, the ratio between a radial distance A1 between the axis of rotation A and the primary recess 21 and a radial diameter D of the wheel hub 1 is between 0.6 and 0.3, preferably between 0.55 and 0.35, and particularly preferably between 0.4 and 0.5. Furthermore, the rib elements 5 are structured on their radially outer side.This allows for targeted further material savings, which have a positive effect on the overall weight of wheel hub 1.

[0030] In the Fig. Figure 1c shows a sectional view of the wheel hub 1. Preferably, the ratio between the radial distance A1 between the axis of rotation A and the primary recess 21 and the axial length of the primary recess 21 is between 0.65 and 0.85, preferably between 0.7 and 0.78, and particularly preferably between 0.72 and 0.77. The primary recess 21 extends from a first opening on the brake disc mounting surface 25 to a second opening on the axially opposite side. The second opening is located at the level of the collar region 12 without being flush with any side of the collar region 12.

[0031] In the Fig. Figures 2a to 2c show a wheel hub 1 according to a second exemplary embodiment of the present invention. In this case, the Fig. 2a two perspective views, in which Fig. 2b each a top view of a rear (left) and a front (right) of the wheel hub 1 and in Fig. 2c illustrates a sectional view. The one in the Fig. The embodiment shown in 2a to 2c differs substantially from the embodiment shown in the Fig. 2a to 2c such that each rib element 5 is assigned a primary recess 21. Furthermore, it is provided that the primary recess 21 extends at least partially into a sleeve-shaped section 26 that projects from the rib element 5. The sleeve-shaped section 26 projects axially from the rib element 5 in the direction of the collar area 12. Furthermore, it is provided that the clear areas 15 between two adjacent rib elements 5 are arranged radially congruently or along a line with the secondary recesses 22. Furthermore, it is provided that each first opening of the primary recesses 21 is assigned a brake disc mounting surface 25. As the Fig. As can be seen from 2c, the second opening closes flush with an outer side of the collar area 12 when viewed in the axial direction.

[0032] In the Fig. Figures 3a to 3c show a wheel hub 1 according to a second exemplary embodiment of the present invention. In this case, the Fig. 3a two perspective views, in which Fig. 3b each a top view of a rear (left) and a front (right) of the wheel hub 1 and in Fig. Figure 3c illustrates a sectional view. The embodiment essentially corresponds to that shown in the Fig. 1a to 1c, without the rib elements 5 being structured.

[0033] In the Fig. Figures 4a to 4c show a wheel hub 1 according to a second exemplary embodiment of the present invention. In this case, the Fig. 4a two perspective views, in which Fig. 4b each a top view of a rear (left) and a front (right) of the wheel hub 1 and in Fig. Figure 4c illustrates a sectional view. The embodiment essentially corresponds to that shown in the Fig.2a to 2c, without the rib elements 5 being structured. Reference symbol: 1 wheel hub 2 brake discs 5 rib element 11 Core area 12 Collar area 15 light area 18 Material thinning 21 Primary recess 22 Secondary recess 25 Brake disc mounting surface 26 sleeve-shaped section A axis of rotation A1 Distance between the axis of rotation and the primary recess A2 Distance between the axis of rotation and the outer surface of the shell A3 Extension length of the primary recess U Direction of rotation Diameter

Claims

[1] Wheel hub (1) comprising - a collar area (12) located on the outside in a radial direction and - an inner core region viewed in the radial direction (11), wherein the inner core area (11) has a greater axial extent than the outer collar area (12), and wherein the wheel hub (1) has a substantially axially extending primary recess (21) in the inner core area (11) for attaching a brake disc (2), Preferably, the ratio between a radial distance (A1) between an axis of rotation (A) and the primary recess (21) and a radially dimensioned diameter (D) of the wheel hub (1) assumes a value between 0.6 and 0.

3. [2] Wheel hub (1) according to claim 1, wherein the core area (11) comprises substantially radially extending rib elements (5). [3] Wheel hub according to claim 2, wherein the rib elements (5) connect the core area (11) with the collar area (12). [4] Wheel hub according to claim 2 or 3, wherein each rib element (5) has exactly one primary recess (21). [5] Wheel hub (1) according to one of the preceding claims, wherein the outer collar area (12) has a secondary recess (22), wherein the primary recess (11) extends further in the axial direction than the secondary recess (12). [6] Wheel hub according to one of the preceding claims, wherein at least one, preferably all, primary recess(s) (21) completely penetrates the core area (11) and / or the wheel hub (1). [7] Wheel hub according to one of the preceding claims, wherein the primary recesses (21) are arranged offset in a direction of rotation (U) relative to secondary recesses (22). [8] Wheel hub (1) according to one of the preceding claims, wherein the ratio between the axial extent of the primary recess (21) and the total axial extent of the wheel hub (1) is between 0.5 and 0.98, preferably 0.75 and 0.95 and particularly preferably between 0.8 and 0.

93. [9] Wheel hub (1) according to one of the preceding claims, wherein the ratio between the radial distance (A1) between the axis of rotation (A) and the primary recess (21) and the radially dimensioned diameter (D) of the wheel hub (1) is between 0.55 and 0.35 and preferably between 0.4 and 0.

5. [10] Wheel hub (1) according to one of the preceding claims, wherein, viewed in the direction of rotation (U), a clear area (15) is arranged between two rib elements (5). [11] Wheel hub (1) according to claim 10, wherein the area measured in the direction of rotation (U) which is assigned to the rib elements (5) is 0.3 to 0.5 times larger than the area which is assigned to the clear area (18). [12] Wheel hub (1) according to one of the preceding claims, wherein the primary recess (11) extends in the radial direction over the entire length of the rib element (5), or, wherein the primary recess (21) is formed at least partially by a sleeve-shaped portion (26) which projects from the rib element (5), preferably in the axial direction. [13] Wheel hub (1) according to one of the preceding claims, wherein the primary recess (21) opens to one side into a brake disc mounting surface (25), wherein preferably the brake disc mounting surface (25) is interrupted or continuous when viewed in the direction of rotation (U). [14] System comprising a brake disc (2) and a wheel hub (1) according to one of the preceding claims, wherein the brake disc (2) can be attached to the wheel hub (21), in particular to the brake disc mounting surface (25), by means of a fastening means guided through the primary recess (21).

Images