Axle system

Abstract

The present invention relates to an axle unit (10) and an axle system (100), wherein the axle unit (10), in particular intended for use in a utility vehicle on an axle element (2), comprises an axle element (2), a fastening element (4), a friction element (6) and a link element (8), wherein the axle element (2) extends along a tube axis (A) and has an outer lateral surface (M), wherein the fastening element (4) has a fastening-side receiving region (42) for receiving the friction element (6), wherein the link element (8) has a link-side receiving region (82) which is designed at least for regionally form-fitting engagement with the friction element (6), wherein the friction element (6) is designed to secure the link element (8) against displacement and / or rotation relative to the axle element (2) by way of an increased friction effect.

Description

[0001] SAF-HOLLAND GmbH MSP Ref: 49144 PT-WO CB / MF

[0002] Axle system

[0003] The present invention relates to an axle unit, in particular for use in a commercial vehicle, and an axle system.

[0004] Various technical solutions for fixing a trailing arm to an axle tube are known from the prior art, particularly suitable for use in heavy commercial vehicles. Common link-axle tube connections are preferably implemented using welded-on axle lugs or recesses in the axle tube. Furthermore, they are usually based on permanent clamping connections with a T-nut-like positive fit between a hard-material element and the trailing arm, which causes high stress and notch effects on the trailing arm. Moreover, such connection designs are very maintenance-intensive and costly to manufacture due to their many components and are limited to specific types of control arms. The typically high weight of such link-axle connections represents a further disadvantage.

[0005] The object of the present invention is to provide connecting elements that enable simplified assembly and manufacturing of an axle unit and an axle system. Furthermore, the stress and notch effects on the axle tube should be reduced in order to increase the service life of the axle tube.

[0006] This problem is solved with an axle unit according to claim 1 and an axle system according to claim 10.49144 PT- WO CB / MF © According to the invention, an axle unit, in particular for use in a commercial vehicle on an axle element, is provided, comprising an axle element, a fastening element, a friction element and a steering element, wherein the axle element extends along a tubular axis and has an outer cylindrical surface, wherein the fastening element has a fastening-side receiving area for receiving the friction element, wherein the steering element has a steering-side receiving area which is designed at least for a partial positive engagement with the friction element and the fastening element, wherein the friction element is designed to secure the steering element against displacement and / or rotation relative to the axle element by means of an increased friction effect.A key aspect of the invention is to fix the steering linkage to the axle element by means of a friction element, preferably by means of a positive locking connection, thereby achieving a detachable connection between the steering linkage and the axle element. Furthermore, this avoids local stress peaks that occur with material-bonded and positive-locking connections on the axle element. The axle element is preferably a round axle, which is commonly used in the chassis of commercial vehicles. Round axles preferably have a circular cross-sectional geometry. Alternatively or additionally, the axle element can also have an approximately square cross-section with rounded edges. The friction element increases compatibility with different steering linkage designs, so that the axle unit is not limited to a single axle element or steering linkage type.Composite control arms, consisting of at least two different materials, preferably fiber-reinforced composite, are particularly preferred. Composite control arms are preferred because they allow for a stable, lightweight construction. However, such composite control arms are not readily weldable and are also more susceptible to local stress peaks, which can occur in clamped control arm-axle tube connections. The use of a friction element therefore improves the connection between the axle element and the composite control arm, as these disadvantages can be avoided or at least mitigated. The control arm element has a control arm-side receiving area designed to create a positive fit with the friction element. Furthermore, the fastening element has a fastening-side receiving area for the positive-locking reception of the friction element.The friction element generates an adhesive force on the steering element through increased friction, thereby strengthening the force transmission between the steering element and the axle element. This secures the steering element against both axial displacement and rotation relative to the axle element.

[0007] In one embodiment, the fastening element is partially or completely tubular and arranged coaxially on the axle element, so that the fastening element partially or completely surrounds the axle element. Preferably, the fastening element is designed as a wrap-like component that is arranged coaxially on the outer surface of the axle element, so that it completely or at least largely surrounds the axle element. This enclosure is preferably complete, so that there is a complete positive fit between the axle element and the fastening element. Alternatively, the enclosure of the axle element can also be only partial, which is simpler to implement and saves material and weight.

[0008] In one embodiment, the fastening element is welded and / or shrink-fitted to the outer surface of the axle element. To secure the fastening element, it is preferably shrink-fitted onto the axle element. For this purpose, the fastening element is temporarily expanded under the influence of heat. This creates a brief, heat-induced clearance between the inner surface of the heated fastening element and the outer surface of the axle element, enabling precise positioning of the fastening element on the axle element. Cooling of the fastening element creates an interference fit between the fastening element and the axle element. This is particularly advantageous because, unlike welding the two components together, it avoids structural changes and the resulting residual stresses in the material.

[0009] In a particularly preferred embodiment, where the axle assembly is subjected to particularly high bending and rotational forces as well as impacts,49144 PT-WO CB / MF ©, the shrink-fitting process is subsequently supplemented by a welding process. Preferably, the spot welds of the fastening element at the transitions from the fastening element to the axle element, which are expected to be subject to low stresses, are additionally reinforced with weld seams. This creates a permanent connection that exhibits very high strength in order to secure the fastening element against both axial and tangential displacement relative to the axle element.

[0010] In one embodiment, the fastening element is integrally formed with the axle element. A one-piece embodiment is particularly advantageous if the fastening element and the axle element are made of the same material and / or if this material is heat-sensitive or non-weldable. In this case, a further joining method can be omitted, which simplifies the overall manufacturing process.

[0011] In one embodiment, the receiving area on the fastening side is designed as a recess that penetrates the fastening element completely or partially. Particularly when the fastening element is entirely tubular, it is advantageous to design the receiving area on the fastening side as a recess to achieve a positive fit between the fastening element and the steering element. Furthermore, it is advantageous in terms of weight and material savings if the recess penetrates the fastening element completely. For fastening elements made of lightweight materials, recesses that only partially penetrate the fastening element are preferred in order not to impair its strength.

[0012] In one embodiment, the recess is oval. Recesses typically have a substantially oval cross-sectional area, which allows for a uniform distribution of the forces acting under load. The receiving area on the fastening side is preferably defined by a longitudinal length extending orthogonally to the tube axis and a transverse length extending parallel to the tube axis. The longitudinal length is in a ratio of 1.4 to 2.5, preferably 1.6 to 2, to the transverse length, so that a material web as wide as possible remains at the circumferential edges of the fastening element, and sufficient material also remains in the circumferential direction to ensure a sufficiently large receiving surface with the steering element.With a longitudinal length-to-transverse length ratio between 1.4 and 2.5, the ratio is adjusted so that the receiving area exhibits sufficient stability both with respect to the remaining material at the circumferential edge and in the circumferential direction. The preferred ratio range between 1.6 and 2 ensures an elongated embodiment of the receiving area with optimal stability conditions, which is essentially suitable for common axle units.

[0013] In one embodiment, the receiving area on the fastening side has a rectangular cross-sectional geometry when the fastening element is partially tubular. Because the receiving area is only partially tubular, the recessed section where the fastening element does not engage the axle element can be used as a recess for the positive locking of the friction element. This recess is essentially rectangular and curved to match the tubular geometry of the axle element. This embodiment offers the particular advantage that the friction element provides a larger friction surface on the axle element, thus resulting in improved adhesion of the steering element.

[0014] In one embodiment, the friction element has a projection in the area where the steering element is fixed, which is designed for positive engagement with the steering-side receiving area. In the case of a partially tubular fastening element with a rectangular cross-section of the receiving area, the steering element is fixed by a projection of the friction element, which prevents axial and / or tangential displacement of the steering element relative to the axle element.

[0015] In one embodiment, the handlebar-side receiving area is designed as a recess, which is preferably rectangular with rounded corners. For positive locking, the friction element has a projection in the case of partially tubular fasteners and an engagement geometry in the case of fully tubular fasteners, which engages in the recess of the handlebar element in the locked position. To reduce stress concentrations and thus increase the service life of the handlebar element, the corners in the edge region of the recess are preferably rounded.

[0016] In one embodiment, the friction element between the steering linkage and the axle element is elastically deformed and preferably pre-tensioned against the mounting-side receiving area and against the steering linkage-side receiving area. To increase the grip of the steering linkage, the friction element, which consists of an elastically deformable material, is pressed under pressure into the steering linkage and the mounting-side receiving area to achieve a pre-tensioned state.

[0017] In one embodiment, two fastening elements are arranged or formed on the axle element, spaced apart from each other along the tube axis and designed to each accommodate a control arm element. Preferably, the two control arm elements are spaced apart from each other on the axle element to ensure optimal distribution of the acting loads, so that the axle element is subjected to uniform stress.

[0018] In one embodiment, the two fastening elements are arranged in such a way that the receiving areas on the fastening element side extend parallel to each other and are essentially planar to each other.

[0019] In one embodiment, at least one collar is formed on the fastening element, which secures the steering element against displacement relative to the axle element, essentially parallel to the tube axis. The collar also provides a positive locking connection between the steering element and the fastening element, so that the combination of positive and frictional locking ensures an optimal connection between the axle unit and the axle system. Furthermore, the collar advantageously serves as an assembly aid against which the steering element can be positioned and subsequently fixed in a predetermined installation position using the clamping unit.

[0020] In one embodiment, the friction element is made of a rubber-like, and in particular permanently elastic, deformable material. For shock absorption in the area of ​​the handlebar mount, the friction element consists of an elastic, preferably rubber-like material that can be pre-tensioned in both the handlebar-side and mounting-side areas to increase the adhesive effect for securing the handlebar element. Rubber as a material for the friction element offers the advantage of vibration damping, which extends the service life of the axle assembly, especially under periodic continuous loads. This embodiment is particularly advantageous when using fracture-prone handlebar elements made of fiber-reinforced composite materials, ensuring stable and resilient mounting combined with a significant reduction in stress concentration.

[0021] In one embodiment, at least one steering element is a composite material steering link. Steering elements made of composite materials, particularly fiber-reinforced composites, are more prone to brittle fracture and local stress peaks compared to spring steel steering links. Accordingly, a stable, low-stress, and resilient mounting is advantageous when using such steering links. This is achieved by pre-tensioning the friction element in the steering link and / or mounting-side receiving areas, thereby creating an adhesive effect. Furthermore, the elastic rubber material from which the friction element is preferably manufactured supports the shock absorption of the fixed steering element during operation of the commercial vehicle.

[0022] In one embodiment, a three-dimensional bushing is arranged in a bearing eye of the control arm element for mounting the axle unit to the frame of a commercial vehicle. It is known from the prior art that three-dimensional bushings are typically used in conjunction with simple sheet metal control arms in commercial vehicles. However, due to the shock-absorbing and notch-resistant properties of the friction element, it is also possible to use brittle-fracture-prone composite control arms together with a three-dimensional bushing for mounting the axle unit.

[0023] According to the invention, an axle system is provided, comprising an axle unit and at least one clamping unit, wherein the at least one clamping unit is designed to secure the positive and frictional connection between the axle element and the steering linkage provided by the fastening element. In addition to the positive and frictional connection via the friction element, the arrangement of the steering linkage is secured by a clamping unit, which preferably comprises force-fit and / or material-fit clamping elements. The axle system benefits from the particularly low-stress and low-notch connection between the axle element and the at least one steering linkage and preferably has an improved service life.

[0024] In one embodiment, the at least one clamping unit comprises two clamping elements and a clamping plate with screw connections, arranged on the axle unit such that the steering element is positively and positively locked to the axle element against displacement and / or rotation relative to the axle element. Typically, clamping elements such as U-bolts with a corresponding curved clamping plate and / or screw connections are preferably used for additional fixation of the steering element to the axle element. These offer a simple locking solution with low maintenance requirements.

[0025] Further advantages and characteristic features of the present invention will become apparent from the following description with reference to the accompanying figures. Identical features are used with the same reference numerals in the figures, even if they are part of different embodiments. It is understood that individual features explicitly described only for a specific embodiment may also be used in other embodiments of the invention, unless this is precluded by technical constraints. 49144 PT- WO CB / MF ©

[0026] They show:

[0027] Fig. 1 shows a partially cutaway view of an embodiment of an axle system with a tubular fastening element;

[0028] Fig. 2 shows a detailed view of an embodiment of an axle system with a tubular fastening element;

[0029] Fig. 3 shows a side view of an embodiment of an axle system with a partially tubular fastening element;

[0030] Fig. 4 shows a perspective view of an embodiment of an axle system;

[0031] Fig. 5 shows a side view of a connection consisting of an axle element and a fully tubular fastening element;

[0032] Fig. 6 shows a side view of an embodiment of an axle system; and

[0033] Fig. 7 shows a side view of an embodiment of an axle unit.

[0034] Figure 1 shows a frontal sectional view of the axle system 100 with a fully tubular fastening element 4, in which the axle element 2 is preferably designed as a tubular round axle, on whose outer surface M a fully tubular fastening element 4 is arranged coaxially in a form-fitting manner. This fastening element 4 has a receiving area 42 on the fastening side, designed as a recess 44, on or in which a friction element 6 made of a rubber-like, elastic material is pre-tensioned. A control arm element 8 is fixed to the axle element 2 via this friction element 6, at least frictionally and preferably also in a form-fitting manner. Preferably, the friction element 6 is designed to secure the control arm element 8 against axial and / or tangential displacement relative to the axle element 2 and, in particular, to act as a vibration damper.For securing the steering element 8, it has a steering-side receiving area 82 designed as a recess 84, which engages positively in the engagement geometry of the friction element 6. For additional positive and force-fit securing of the steering element 8, a clamping unit 9 is provided, comprising two clamping elements 92 arranged on the fastening element, which are fixed via a clamping plate 94 with a screw connection 96.

[0035] Figure 2 shows a sectional view of an embodiment of an axle system 100 in a side view, focusing in particular on the connection point between the axle element 2 and the control arm element 8. Advantageously, the friction element 6 has an approximately rectangular cross-sectional geometry with rounded corner regions that engage positively in the recess 44 of the fastening element 4. The rounded corner regions are designed in particular to reduce the notch effect on the axle element 2 when the axle unit 10 is subjected to bending stress, thereby increasing the service life of the axle element 2.

[0036] Figure 3 shows a side view of an embodiment of an axle system 100 with a partially tubular fastening element 4. Similar to the embodiments shown in Figures 1 and 2, the partially tubular fastening element 4 is arranged coaxially to the tube axis A on the outer surface M of the axle element 2 and has a receiving area 42 on the fastening side. In the embodiment shown in Figure 3, this receiving area has a rectangular cross-section, so that it engages positively in the recessed area of ​​the fastening element 4, which does not completely enclose the axle element 2. The steering element 8 is arranged in a positive-locking manner on the friction element 6 at its steering-side receiving area 82, which is designed as a recess 84. For this positive-locking arrangement, the friction element 6 is provided with a local projection 66 in the receiving area of ​​the steering element 8.For additional force-fit and form-fit securing of the steering element 8, the axle system 100 has a clamping unit 9. This advantageously has two clamping elements 92, a curved clamping plate 94 and corresponding screw connections 96 for fixing these.

[0037] Figure 4 shows a perspective view of an embodiment of an axle system 100 similar to the embodiments shown in Figures 1 to 3. The fastening element 4 is arranged coaxially to the tube axis A on the outer surface M of the axle element 2 and has a receiving area 42 on the fastening side. A link element 8 is positively and frictionally locked to the axle element 2 via the friction element 6, which is hidden in Figure 4. In addition, the axle unit 10 is secured against axial displacement and / or rotation relative to the axle element 2 by a clamping unit 9, which preferably comprises two clamping elements 92, a curved clamping plate 94, and corresponding screw connections 96 for fixing it.In this embodiment, Figure 4 advantageously shows a composite control arm made of a fracture-sensitive fiber composite material, which is shock-damped and fixed to the axle element 2 by means of the elastic friction element 6. For mounting the axle unit 10 to a frame of a commercial vehicle, a 3-dimensional bushing 89 (see Fig. 6) is preferably arranged in a bearing eye 88 of the control arm element 8.

[0038] Figure 5 shows a side view of a connection between an axle element 2 and a fully tubular fastening element 4, wherein the fastening element 4 is arranged coaxially to the axle element 2. The fastening-side receiving area 42, which is designed to receive a friction element 6, advantageously has an oval-shaped geometry, wherein the longitudinal length extends orthogonally to the tube axis A and is arranged substantially centrally on the fastening element 4.

[0039] Figure 6 shows a side view of an embodiment of an axle system 100. Similar to the embodiments shown in Figures 1 to 5, the fastening element 4 is arranged coaxially with the axle element 2. The fastening element 4 has a mounting-side receiving area 42 in which the steering element 8 is positively and frictionally secured. For this purpose, the steering element 8 has a steering-side receiving area 82 designed as a recess 84, which is designed to engage positively in the mounting-side receiving area 42 of the fastening element 4. Additional securing of the steering element 8 against axial displacement and / or rotation relative to the axle element 2 is provided by a clamping unit 9, which typically comprises two clamping elements 92, a curved clamping plate 94, and corresponding screw connections 96 for fixing these.In this embodiment, as shown in Figure 4, a composite control arm made of a fracture-sensitive fiber composite material is depicted. This is mounted to the axle element 2 with shock damping by the elastic friction element 6. Furthermore, a 3-dimensional bushing 89 is arranged in a bearing eye 88 of the control arm element 8, which is designed to mount the axle unit 10 to a frame of a commercial vehicle.

[0040] Figure 7 shows a partially cutaway view of an embodiment of an axle unit 10, in which the steering element 8 is fixed to a collar 46 of the fastening element 4 parallel to the axle element 2. The fastening element 4 is arranged on an axle element 2, which is designed as a round axle and extends along a tubular axis A, and is not completely tubular. The steering element 8 is fixed at a distance from the axle element 2 by the collar 46, so that the steering element 8 has essentially no direct contact surface with the axle element 2. Reference numeral list:

[0041] 2 axle element

[0042] 4 Fastening element

[0043] 6 friction element

[0044] 8 handlebar element

[0045] 9 clamping unit

[0046] 10 axle units

[0047] 42 Mounting-side receiving area 44 Recess

[0048] 46 collars

[0049] 66 lead

[0050] 82 Handlebar-side mounting area

[0051] 84 Jump back

[0052] 88 Bearing eye

[0053] 89 3-dimensional socket

[0054] 92 clamping element

[0055] 94 clamping plate

[0056] 96 screw connection

[0057] 100 axle system

[0058] M Outer surface area

[0059] A pipe axis

Claims

49144 PT- WO CB / MF © Claims 1. Axle unit (10), in particular for use in a commercial vehicle on an axle element (2), comprising an axle element (2), a fastening element (4), a friction element (6) and a steering element (8), wherein the axle element (2) extends along a tube axis (A) and has an outer lateral surface (M), wherein the fastening element (4) has a fastening-side receiving area (42) for receiving the friction element (6), wherein the steering element (8) has a steering-side receiving area (82) which is designed at least for a partial positive engagement with the friction element (6), wherein the friction element (6) is designed to secure the steering element (8) against displacement and / or rotation relative to the axle element (2) by means of an increased friction effect.

2. Axle unit (10) according to claim 1 , wherein the fastening element (4) is partially or completely tubular and arranged coaxially on the axle element (2) such that the fastening element (4) partially or completely surrounds the axle element (2).

3. Axle unit (10) according to one of the preceding claims, wherein the fastening element (4) is welded and / or shrunk onto the outer lateral surface (M) of the axle element (2).

4. Axle unit (10) according to claim 2, wherein the fastening element (4) is formed integrally with the axle element (2). 49144 PT- WO CB / MF © 5. Axle unit (10) according to one of the preceding claims, wherein the receiving area (42) on the fastening side is designed as a recess (44) which completely or partially penetrates the fastening element (4).

6. Axle unit (10) according to claim 5, the recess (44) is oval-shaped.

7. Axle unit (10) according to one of the preceding claims, wherein the friction element (6) has a projection (66) in the area of ​​the fixing of the steering element (8) which is designed for positive engagement with the steering-side receiving area (82).

8. Axle unit (10) according to one of the preceding claims, wherein the handlebar-side receiving area (82) is designed as a recess (84), which is preferably rectangular with rounded corners.

9. Axle unit (10) according to one of the preceding claims, wherein the friction element (6) between the steering element (8) and the axle element (2) is elastically deformed and preferably pre-tensioned against the mounting-side receiving area (42) and against the steering-side receiving area (82).

10. Axle unit (10) according to one of the preceding claims, wherein two fastening elements (4) are arranged or formed on the axle element (2) which are arranged spaced apart from each other along the tube axis (A) and are designed to each accommodate a steering element (8).

11. Axle unit (10) according to one of the preceding claims, wherein at least a collar (46) is formed on the fastening element (4)49144 PT- WO CB / MF © which secures the steering element (8) substantially parallel to the tube axis (A) against displacement relative to the axle element (2).

12. Axle unit (10) according to one of the preceding claims, wherein the steering element (8) is a composite steering element.

13. Axle unit (10) according to one of the preceding claims, wherein a 3-dimensional bushing (89) is arranged in a bearing eye (88) of the steering element (8) for the purpose of mounting the axle unit (10) on a frame of a commercial vehicle.

14. Axle system (100), comprising an axle unit (10) according to claims 1-13 and at least one clamping unit (9), wherein at least one clamping unit (9) is designed to secure the positive and frictional connection between the axle element (2) and the steering element (8) provided by the fastening element (4).

15. Axle system (100) according to claim 14, wherein the at least one clamping unit (9) comprises two clamping elements (92) and a clamping plate (94) with screw connections (96) arranged on the axle unit (10) such that the steering element (8) is fixed to the axle element (2) against displacement and / or rotation relative to the axle element (2) by force and form locking. - 16 / 17 -

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