Independent suspension

Abstract

The invention relates to an independent wheel suspension (3), in particular for an agricultural vehicle (1), with a first mass (M1) that can be arranged on a vehicle frame (10) and a second mass (M2) that carries a vehicle wheel (5) and is resiliently supported relative to the first mass (M1) by a spring (8), the movements of which relative to the first mass (M1) are guided by a linear guide (4), wherein the linear guide (4) has an inner guide element (4.1, 4.2) that is axially movable in an outer guide element (13.1, 13.2), wherein the outer guide element (13.1, 13.2) is arranged on the first mass (M1) and the inner guide element (4.1, 4.2) is arranged on the second mass (M2).

Description

[0001] The invention relates to an independent wheel suspension, in particular for an agricultural vehicle, comprising a first mass which can be arranged on a vehicle frame and a second mass which carries a vehicle wheel and is resiliently supported relative to the first mass via a suspension, the movements of which second mass relative to the first mass are guided via a linear guide, wherein the linear guide has at least one inner guide element which is guided axially movably in an outer guide element.

[0002] Such independent wheel suspensions are frequently used in agricultural vehicles, particularly in self-propelled agricultural machines used to apply pesticides or fertilizers to agricultural land. In such vehicles with multiple independent wheel suspensions, the individual vehicle wheels can move independently of one another in the vertical direction and, in particular, can be compressed and extended independently of one another. This design has proven particularly advantageous for ride comfort on uneven agricultural land. Furthermore, it allows a uniform height of the vehicle frame to be achieved despite uneven ground, which allows, for example, field sprayers to apply pesticides evenly.Furthermore, independent wheel suspensions, particularly in comparison to axles arranged between the vehicle wheels of a track, can often achieve a greater clear passage height below the vehicle frame, thus avoiding damage or impairment when driving over particularly tall crops and protecting the crop population.

[0003] Agricultural vehicles typically comprise a first mass with a vehicle frame, which supports, in particular, the vehicle drive, the body, and the payload of the respective vehicle. The first mass assigned to the vehicle frame is usually spring-supported by several independent wheel suspensions, each supporting a second mass. The suspension can absorb vibrations, which can result, for example, from uneven ground on the often unevenly undulating cultivated areas, so that their impact on the first mass is significantly reduced. In agricultural vehicles, this allows a stable and smooth driving position to be achieved, which is beneficial, for example, for the even application of pesticides or fertilizers.

[0004] The second mass, which is usually unsprung, typically carries the respective vehicle wheel suspended via the independent wheel suspension. To guide the vehicle wheels, particularly to guide vertical or spring movements of the vehicle wheels, such independent wheel suspensions often feature a linear guide. The linear guide can improve the handling and, in particular, the driving stability of the agricultural vehicle.

[0005] Typically, the linear guide comprises at least two elements that are axially movable relative to one another. Often, an inner guide element is used, which is guided in a correspondingly designed outer guide element. For example, US 2022 / 0134826 A1 discloses an independent wheel suspension for an agricultural vehicle, in which a steering knuckle carrier assigned to the second mass has two parallel bores as outer guide elements, in which two rod-shaped elements assigned to the first mass are arranged for axial movement for linear guidance. US 2012 / 0241230 A1 describes a vehicle with multiple independent wheel suspensions, in which the linear guides are formed by two parallel rods that are movably guided in sleeves assigned to the second mass, the rods themselves belonging to the first mass.

[0006] Such independent wheel suspensions have proven themselves in practice for agricultural vehicles. However, the design described above can prove prone to failure under unfavorable conditions. Particularly in confined spaces, such as those typically found within the rotational contour of an agricultural vehicle wheel, this can lead to jamming between the inner and outer guide elements of the linear guide or increased wear due to excessive friction.

[0007] Against this background, the invention sets itself the task of specifying an independent wheel suspension which is particularly suitable for use in confined space conditions and which also enables a reliable and failure-resistant linear guide.

[0008] This object is achieved in an independent wheel suspension of the type described above by the features of patent claim 1. Advantageous further developments are specified in the dependent subclaims.

[0009] The outer guide element is arranged on the first mass and the inner guide element on the second mass, whereby tilting and / or other disturbances in the linear guide can be reliably avoided, especially in confined installation space conditions.

[0010] From a design perspective, it is advantageous in this context if the second mass comprises a steering knuckle mounted on a steering knuckle support. The steering knuckle allows the respective vehicle wheel to be securely and accurately connected to the independent wheel suspension.

[0011] Furthermore, it is preferred if the steering knuckle can be connected to a rim of the vehicle wheel. With such a design, the vehicle wheel can be easily and user-friendly replaced by dismantling the rim, for example, in the event of a defect or when switching between vehicle wheels with different wheel widths.

[0012] In this context, a structurally advantageous development of the invention provides for the steering knuckle carrier to carry a wheel hub that supports the vehicle wheel. The resulting structure has proven to be particularly robust against vibrations and also low-maintenance, which can be particularly advantageous under the often adverse conditions encountered in agriculture.

[0013] In a further advantageous development of the invention, it is proposed that the steering knuckle support have four connection points for attaching two inner guide elements of the linear guide. The inner guide elements can be attached to the steering knuckle support reliably and securely via the connection points. The attachment can be detachable, allowing easy replacement of the inner guide elements. Alternatively, the connection points can also be designed for permanent, non-detachable attachment of the inner guide elements, for example, through a material-to-material joining process.

[0014] It has also proven advantageous if the connection points for the parallel and essentially perpendicular arrangement of the inner guide elements are arranged rectangularly. This allows the inner guide elements to be easily attached to the steering knuckle support in a parallel and essentially perpendicular arrangement. A vertical arrangement, particularly a vertical arrangement with respect to the rotational axis of the vehicle wheel, allows for low-wear and reliable linear guidance. A parallel arrangement of two inner guide elements has proven to be particularly resistant to failure and favorable for the flow of force in linear guidance.

[0015] It is further proposed that the connection points be arranged on four struts arranged in an X-shape. Such an X- or cross-shaped design of the steering knuckle carrier has proven to be particularly material-efficient. Since the steering knuckle carrier is assigned to the unsprung mass, the handling of the agricultural vehicle can often be significantly improved by saving material at this point. In particular, undesirable, disruptive wheel load fluctuations or accelerations can be minimized by reducing mass. Such a design of the steering knuckle carrier can also prove particularly favorable for the force flow of loads occurring during driving. The forces resulting from the loads can be diverted or absorbed via the beams of the X- or cross-shaped steering knuckle carrier.

[0016] A further advantageous design may be one in which the two inner guide elements are guided in two outer guide elements arranged on a steering knuckle upper section rigidly coupled to the vehicle frame. This results in a design in which the inner guide elements are reliably guided over the longest possible spring travel. Furthermore, such a construction has proven particularly resistant to failure, particularly under adverse environmental conditions. In this context, it is preferred if the shape of the outer guide elements is adapted to the shape of the inner guide elements. In particular, their diameters can be adapted to one another.

[0017] Furthermore, it has proven structurally advantageous for the steering knuckle support to have a symmetrical design, particularly an axisymmetric design with respect to its longitudinal center axis. This results in favorable load paths for absorbing the forces occurring in the linear guide.

[0018] Furthermore, a design in which the steering knuckle support is formed in one piece may be preferred. A one-piece construction can be advantageous in terms of maintenance and repair. Furthermore, a one-piece construction generally has little or no mechanical weaknesses, so such a construction can be particularly robust and fail-safe.

[0019] With regard to the design of the steering knuckle support, it is proposed that it have an angled cross-sectional shape. This cross-sectional shape allows the available installation space to be utilized particularly advantageously. Furthermore, this design allows the linear guide to be positioned as close as possible to the wheel's longitudinal plane, thus avoiding disturbing torques and unwanted loads on the linear guide during driving.

[0020] In this context, it is preferable from a design perspective for the steering knuckle carrier to be concavely curved. This allows the linear guide to be easily positioned near the wheel's longitudinal plane or the wheel contact point, even with a concave steering knuckle carrier.

[0021] In this context, it is further proposed as structurally advantageous that a region of the steering knuckle carrier radially distant from the rotational axis of the vehicle wheel is further away from a vehicle longitudinal axis than a region radially close to the rotational axis of the vehicle wheel.

[0022] It is further proposed that the linear guide be arranged within the rotational contour of the vehicle wheel, essentially perpendicular to its rotational axis. This largely eliminates high frictional forces on the linear guide and unwanted torques. This results in a maintenance-friendly, low-wear design that also enables the agricultural vehicle to maintain a stable driving position.

[0023] An advantageous development of the invention provides that the suspension comprises at least two spring cylinders arranged between the steering knuckle support and the upper section of the steering knuckle. This allows the forces occurring between the vehicle frame and the vehicle wheel to be cushioned, resulting in improved ride comfort and increased driving safety, especially on uneven surfaces.

[0024] With regard to the suspension, it is further proposed that the at least two spring cylinders be arranged parallel to the inner guide elements of the linear guide. This makes it possible to easily ensure reliable and comfortable suspension of the vertical movements of the vehicle wheel. The two, four, or more spring cylinders, in particular, can preferably be arranged symmetrically with respect to the wheel hub.

[0025] In this context, it has also proven advantageous for the suspension to be steerable around the steering axis together with the linear guide. With such an independent wheel suspension, the suspension of the agricultural vehicle can thus also be adjusted during cornering, regardless of the steering angle of the respective vehicle wheel. This further improves the vehicle's driving stability and handling.

[0026] Furthermore, stops arranged in the area of ​​the steering knuckle support's connection points are proposed to limit the spring travel. Such stops can be used to reliably limit the spring travel.

[0027] It has also proven advantageous if the spring travel for compression and rebound is essentially the same length. This results in a largely symmetrical suspension design. Alternatively, it may also be preferable to design the spring travel for compression and rebound with different lengths, especially in cases where a preferred direction can be defined.

[0028] An advantageous development of the invention further provides for the steering knuckle support to be arranged essentially vertically. This allows the springy vertical movements of the vehicle wheel to be guided precisely and in a low-wear manner via the linear guide.

[0029] In an advantageous development of the invention, the linear guide is arranged within the width of the rim. This advantageously results in small lever arms between the linear guide and a wheel longitudinal plane passing through the wheel contact point. This allows unwanted disturbing torques and the associated transverse or frictional forces acting on the linear guide to be reliably reduced, which can benefit a low-wear and maintenance-friendly design.

[0030] In this context, it is particularly preferred if the linear guide is arranged in the longitudinal plane of the wheel running through the vehicle wheel or offset parallel to it at a distance. With such an arrangement, unwanted disturbing torques and the associated frictional forces can be further minimized. The loads on the components of the independent wheel suspension can be reduced, thereby increasing their service life. If the longitudinal plane of the wheel runs at an angle to the vertical, the linear guide can also be arranged at a corresponding angle to enable parallel guidance.

[0031] In this context, it may be particularly preferred if the distance between the longitudinal plane of the wheel running through the vehicle wheel and the linear guide is less than one-third, in particular less than one-quarter, of the rim width. The smaller the distance, the shorter the lever arm between the linear guide and the wheel contact point, which potentially causes disturbing torques and adverse frictional forces. Against this background, the distance between the longitudinal plane of the wheel running through the vehicle wheel and the linear guide can preferably also be less than one-fifth, less than one-sixth, less than one-eighth, or less than one-tenth of the rim width.

[0032] In this context, it is also structurally preferred if the linear guide can be steered together with the vehicle wheel around a steering axis. Such a design enables precise, reliable linear guidance of the vehicle wheel in any driving situation, regardless of the set steering angle or steering angle of the respective vehicle wheel.

[0033] In another preferred design, the steering axis runs at an angle to the linear guide. It is particularly preferred in this context if an extension of the steering axis intersects the contact patch of the vehicle wheel as close as possible to its center point, i.e., as close as possible to the wheel's longitudinal plane. This allows for stable, safe handling, particularly when cornering. Such a design also allows the driver to receive accurate feedback on the driving condition.

[0034] Another advantageous design feature provides that, in the plane of the rotational axis of the vehicle wheel, the distance between the linear guide and the wheel's longitudinal plane is smaller than the distance between the linear guide and the steering axis. The loads acting on the components of the independent wheel suspension, particularly torques, can be reduced by such a design. The wear resistance of the independent wheel suspension can thus be improved.

[0035] In this context, it has proven particularly advantageous from a design perspective if the distance between the linear guide and the wheel's longitudinal plane is less than half, preferably less than a third, and particularly preferably less than a quarter of the distance between the linear guide and the steering axle. This can result in a further reduction in the loads acting on the components of the independent wheel suspension.

[0036] In an advantageous development of the invention, it is proposed that the linear guide be designed as a double guide with two cylindrical inner guide elements arranged on either side of the rotational axis of the vehicle wheel. Such a double guide with cylindrical inner guide elements allows for even load distribution and reliable guidance of the vertical movements of the vehicle wheel relative to the vehicle frame. It is particularly preferred in this context if the two cylindrical inner guide elements are arranged symmetrically with respect to the rotational axis of the vehicle wheel. Furthermore, such cylindrical inner guide elements are comparatively easy to manufacture.

[0037] Furthermore, it is proposed that the linear guide be adjustable relative to the vehicle frame via a height adjustment. The height adjustment allows the frame height to be adjusted vertically, for example, so that the established vegetation is disturbed as little as possible when the vehicle passes over it. Furthermore, the height adjustment allows a simple setting of a predetermined working height for attachments or tools. Preferably, an independent height adjustment on each independent wheel suspension enables slope compensation transversely and / or longitudinally to the direction of travel of the vehicle, which can prove advantageous, for example, on sloping or sloping surfaces.

[0038] From a design perspective, it is preferable in this context if the height adjustment has at least two adjusting elements that extend both diagonally to the steering axis and diagonally to the linear guide. These adjusting elements allow for time-saving and precise height adjustment. The adjusting elements can be coupled to a vehicle control system.

[0039] In an advantageous development of the invention, it is proposed that the linear guide be adjustable transversely to a vehicle's longitudinal axis via a track width adjustment. The track width adjustment allows the vehicle's track width to be easily adjusted. This allows the track width to be adjusted to different track widths or tramline systems on various agricultural land. The horizontal track width adjustment protects the crop and enables cross-farm use of the vehicles on farmland with different specified track widths.

[0040] Furthermore, it has proven advantageous to position the linear guide below the vehicle frame. This allows the vehicle frame to be reliably cushioned and guided relative to the usable surface in a simple and reliable manner.

[0041] Further details and advantages of the invention are explained below with the aid of the accompanying drawings according to Fig. 1a to 8 are explained. They show: Fig. 1a a perspective view of an agricultural vehicle with multiple independent wheel suspensions; Fig. 1b a side view of another agricultural vehicle with multiple independent wheel suspensions; Fig. 2 a perspective view of an independent wheel suspension of an agricultural vehicle including vehicle wheel; Fig. 3 a perspective view of the independent wheel suspension as shown in Fig. 2 without vehicle wheel; Fig. 4 a partially sectioned rear view of the independent wheel suspension as shown in Fig. 3; Fig. 5a a sectional view of the independent wheel suspension as shown in Fig. 4; Fig. 5b a detailed view of the independent wheel suspension as shown in Fig. 5a; Fig. 6ac various side views of the independent suspension as shown in Fig. 3; Fig. 7ab two perspective views of another independent wheel suspension, and Fig. 8 a partially sectioned rear view of the independent wheel suspension as shown in Fig. 7a.

[0042] The representations in the Fig. 1a to 8 each show an agricultural vehicle 1 in various, partly sectional and / or perspective views. The agricultural vehicle 1 is a self-propelled field sprayer for applying, in particular, liquid crop protection agents and / or fertilizers on agricultural land N, for example grain fields or vegetable fields, cf. Fig. 1a and b. The agricultural vehicle 1 has a front-mounted driver's cab and includes a storage container for holding the substance to be applied, as well as a boom with several application devices for applying the substance across a working width behind the vehicle 1.

[0043] Instead of a field sprayer, the agricultural vehicle 1 may also be another self-propelled agricultural machine, for example, a machine for soil or crop cultivation. In particular, the agricultural vehicle 1 may also be an autonomously self-propelled machine, such as a field robot.

[0044] The agricultural vehicle 1 has a vehicle frame 10, which carries, for example, the vehicle drive, the payload as well as other components and attachments of the agricultural vehicle 1. Furthermore, the agricultural vehicle 1 comprises a chassis 2 with several independent wheel suspensions 3. In the embodiments according to the illustrations in Fig. 1a and b, the agricultural vehicle 1 is provided with a total of four vehicle wheels 5 arranged on two vehicle axles, each of which is connected to the vehicle frame 10 via an independent wheel suspension 3. However, designs with three or more vehicle axles and / or a correspondingly increased number of vehicle wheels 5, such as six or eight vehicle wheels 5, are also conceivable.

[0045] Because the vehicle wheels 5 are suspended via the independent wheel suspensions 3, a uniform height of the vehicle frame 10 can be achieved even on uneven surfaces N, which allows, for example, the uniform application of crop protection products or fertilizers with field sprayers. Furthermore, the independent wheel suspensions 3, particularly compared to chassis 2 with axles arranged between the vehicle wheels 5 of a track, allow a comparatively large clearance height below the vehicle frame 10 to be achieved, thereby largely avoiding damage or other impairments when driving over tall crops and protecting the crop population.

[0046] The vehicle wheels 5 are each detachably attached to the agricultural vehicle 1 via a steering knuckle 14 which rotatably supports the respective wheel hub 7, cf. Fig. 5a and b. The steering knuckle 14 further comprises a drive unit 16 and a brake unit 17 for the respective vehicle wheel 5.

[0047] To guide vertical movements, in particular spring movements of the respective vehicle wheel 5, the independent wheel suspensions 3 each comprise a linear guide 4, cf. for example Fig. 2 or Fig. 4. The linear guides 4 have a low-wear design and also allow the agricultural vehicle 1 to have a stable, safe driving position even on uneven surfaces. Before discussing the structural design of the linear guides 4, which is responsible for achieving the aforementioned advantages, the following will first be explained using the illustrations in Fig. 2 to 4 the basic structure of the independent wheel suspensions 3 and the structure of the linear guides 4 are explained.

[0048] The respective linear guides 4 are designed as double guides with two inner guide elements 4.1, 4.2 each, see. Fig. 3. Alternatively, more inner guide elements can be provided. The inner guide elements 4.1, 4.2 have a cylindrical shape. They are designed as pin-shaped round rods. For weight reasons, the inner guide elements 4.1, 4.2 can preferably be designed as hollow cylinders with a circular cross-section. Alternatively, the inner guide elements 4.1, 4.2 can also be made of solid material and / or have a different cross-sectional shape. The inner guide elements 4.1, 4.2 are arranged on both sides of the wheel hub 7, i.e., on both sides of the rotational axis R of the vehicle wheel 5, cf. Fig. 3.

[0049] As is also the case according to the Fig. As can be seen in Figure 3, the inner guide elements 4.1, 4.2 are arranged on an X-shaped steering knuckle support 12. The steering knuckle support 12, to which the steering knuckle 14 is attached, has a total of four connection points 12.1, 12.2, 12.3, 12.4 for connecting the inner guide elements 4.1, 4.2, see Figure 3. Fig. 3. The connection points 12.1, 12.2, 12.3, 12.4 are located near the ends of the X-shaped or cross-shaped struts 24.1, 24.2, 24.3, 24.4 of the steering knuckle support 12. The connection points 12.1, 12.2, 12.3, 12.4 are each platform-like. They are circular in shape and have a slightly larger diameter than the inner guide elements 4.1, 4.2.

[0050] Due to the arrangement on the steering knuckle carrier 12, which is rigidly connected to the wheel hub 7 and thus also rigidly connected to the vehicle wheel 5, the inner guide elements 4.1, 4.2 are also rigidly connected to the wheel hub 7 and the vehicle wheel 5, cf. Fig. 2 and Fig. 3. Vertical movements of the vehicle wheel 5, such as those that occur during driving, particularly on uneven surfaces, are transmitted directly to the inner guide elements 4.1, 4.2, so that they execute the corresponding vertical movements.

[0051] Two connection points 12.1, 12.2 and 12.3, 12.4 of the steering knuckle support 12 are located opposite each other in the vertical direction, with the respective inner guide element 4.1, 4.2 being fastened between the opposing connection points 12.1, 12.2 and 12.3, 12.4 in a substantially vertical orientation. With a view to improving ease of maintenance and / or repair, a detachable fastening of the inner guide elements 4.1, 4.2 to the connection points 12.1, 12.2, 12.3, 12.4 may be preferred. Alternatively, the inner guide elements 4.1, 4.2 can also be permanently and non-destructively detachably fastened between the connection points 12.1, 12.2, 12.3, 12.4.

[0052] The inner guide elements 4.1, 4.2 are arranged coaxially to correspondingly designed outer guide elements 13.1, 13.2, cf. Fig. 3. The outer guide elements 13.1, 13.2 are sleeve-shaped. They form guide tubes for the inner guide elements 4.1, 4.2 and accommodate them in an axially movable manner. The outer guide elements 13.1, 13.2 encompass the inner guide elements 4.1, 4.2 at their outer circumference at least over a part of the length of the inner guide elements 4.1, 4.2. As can be seen from the illustrations in Fig. 6a to c, the inner guide elements 4.1, 4.2 are encompassed by the respective outer guide element 13.1, 13.2 over approximately half of their axial length. However, embodiments are also conceivable in which the inner guide elements 4.1, 4.2 are encompassed by the respective outer guide element 13.1, 13.2 only over a smaller portion of their axial length, for example 2 / 5 or 1 / 3. Alternatively, the outer guide element 13.1, 13.2 can also be formed over a larger axial length portion of the respective inner guide element 4.1, 4.2, for example 3 / 5 or 2 / 3. However, the ratios of the axial lengths of the inner guide elements 4.1, 4.2 and the outer guide elements 13.1, 13.2 influence the available spring travel. This will be explained below with reference to the illustrations according to Fig. 6a to c are explained in more detail. Furthermore, a design in which the outer guide elements 13.1, 13.2 are not continuous and thus have a single continuous guide area, but rather two or more separate guide areas, may prove advantageous in terms of material savings.

[0053] The outer guide elements 13.1, 13.2 are rigidly connected to the vehicle frame 10 in the axial direction, see. Fig. 2 and Fig. 3. For this purpose, the outer guide elements 13.1, 13.2 are each connected to a retaining element 18.1, 18.2 on their side oriented toward the vehicle center or the vehicle's longitudinal axis X. The retaining elements 18.1, 18.2 are arranged on a steering knuckle upper part 18 and extend in a fork-like manner toward the outer guide elements 13.1, 13.2, see. Fig. 3. The steering knuckle upper part 18 is mounted in a steering knuckle bearing 15, see. Fig. 3. The steering knuckle bearing 15 is in turn rigidly connected to the vehicle frame 10.

[0054] The following is based on the illustration according to Fig. 4 explains the arrangement of the linear guide 4 relative to the vehicle wheel 5. The linear guide 4 is arranged within the rotational contour 5 of the vehicle wheel 5. The linear guide 4 is arranged at a distance A1 in the direction of the vehicle center or the vehicle longitudinal axis X from the wheel longitudinal plane E. The wheel longitudinal plane E extends centrally through the width of the vehicle wheel 5, cf. Fig. 4. The distance A1 corresponds to the length of the lever arm between the wheel contact point and the linear guide 4, which under unfavourable circumstances can lead to increased wear and / or undesirable friction forces that reduce driving comfort.

[0055] Conventionally, the vehicle wheel 5 comprises a rim 6 and a tire 19 mounted on the rim 6, see also Fig. 1b. The rim 6 is attached to the wheel hub 7 via fasteners. The linear guide 4 is arranged within the width B of the rim 6, see. Fig. 4. As in Fig. 4, the width B of the rim 6 generally corresponds to the width of the vehicle wheel 5. However, embodiments are also conceivable in which the width B of the rim 6 differs from the width of the vehicle wheel 5. The distance A1 between the linear guide 4 and the wheel longitudinal plane E is, as shown in Fig. 4 significantly less than one fifth of the width B of the rim 6. The smallest possible distance A1 is preferred, but the distance A1 can also be larger under challenging installation space conditions or other restrictions, for example a quarter or a third of the width B of the rim 6.

[0056] The representation in Fig. 4 also shows that the linear guide 4 is arranged substantially perpendicular to the rotational axis R of the vehicle wheel 5. With a vertically arranged vehicle wheel 5, and thus rotating about a horizontally extending rotational axis R, a substantially vertically aligned linear guide 4 results. The linear guide 4 is arranged offset parallel to the wheel longitudinal plane E at a distance A1.

[0057] A linear guide 4 arranged essentially perpendicular to the rotational axis R of the vehicle wheel 5 has the advantage that its components are subjected to comparatively even loads. In particular, the upper and lower areas of the inner guide elements 4.1, 4.2 and the outer guide elements 13.1, 13.2 are subjected to comparatively large bearing forces. This is generally not the case with a linear guide 4 arranged obliquely to the rotational axis R, since the oblique position can subject one side of the linear guide 4 to greater loads. This can lead to increased wear, noise generation, and reduced driving comfort.

[0058] The representations in Fig. 2 to 8 show independent wheel suspensions 3 in which the respective vehicle wheel 5 is steerable about a steering axis L. As the Fig. As can be seen from Figure 3, the upper steering knuckle part 18 is rotatably received in a steering knuckle bearing 15 for this purpose. Furthermore, a steering lever 18.3 extends from the upper steering knuckle part 18. A steering cylinder 20 is attached to its end facing away from the upper steering knuckle part 18. The steering cylinder 20 is connected to the vehicle frame 10 at its end facing away from the steering lever 18.3, for which an arm 10.1 is provided (see Figure 3). Fig. 3. By actuating the steering cylinder 20, the steering knuckle upper part 18 can be pivoted in a known manner about the steering axis L. Since the steering knuckle upper part 18 is rigidly connected to the steering knuckle carrier 12, which carries the steering knuckle 14 and, above it, the wheel hub 7 and the vehicle wheel 5, the pivoting movement about the steering axis L leads to a turning of the vehicle wheel 5. The linear guide 4 can be steered together with the vehicle wheel 5 about the steering axis L, cf. Fig. 3 and Fig. 4.

[0059] The representation in Fig. 4 further shows that the steering axis L extends obliquely to the vertical. The steering axis L runs through the steering knuckle bearing 15 and through the contact point of the vehicle wheel 5 on the ground. In this respect, the steering axis L also runs obliquely to the linear guide 4, which extends essentially in the vertical direction. In the plane of the rotational axis R of the vehicle wheel 5, the distance A1 between the linear guide 4 and the wheel longitudinal plane E is smaller than the distance A2 between the linear guide 4 and the steering axis L, see also Fig. 4. The distance A1 is less than half of the distance A2.

[0060] The representations according to the Fig. 5a and Fig. 5b show sectional views through the independent wheel suspension 3 in the plane of the rotation axis R, whereby in the illustration according to Fig. 5b the vehicle wheel 5 including rim 6 is hidden. The illustrations illustrate the arrangement of the steering knuckle carrier 12 and the associated components steering knuckle 14, wheel hub 7 and linear guide 4. The steering knuckle carrier 12 is in turn connected to the vehicle frame 10 via the outer guide elements 13.1, 13.2 and the steering knuckle upper part 18. The steering knuckle carrier 12 is positioned essentially perpendicular to the axis of rotation R of the vehicle wheel 5, so that it is aligned vertically with a neutral wheel camber. If the vehicle wheel 5 is inclined, for example to achieve a positive or negative wheel camber, the steering knuckle carrier 12 and thus also the linear guide 4 can be aligned accordingly obliquely to the vertical. Alternatively, the steering knuckle carrier 12 can also be aligned essentially vertically with a inclined position of the vehicle wheel 5.

[0061] The representations according to Fig. 6a-c illustrate the range of motion of the steering knuckle carrier 12 for guiding and absorbing vertical movements of the vehicle wheel 5. The illustration according to Fig. 6a shows the steering knuckle support 12 at a normal level, in which the vehicle wheel 5 is neither compressed nor extended. The illustration according to Fig. 6b shows a fully compressed state and the representation according to Fig. 6c a fully rebounded state.

[0062] As can be seen from the comparison of the representations in Fig. As can be seen in Figures 6a and b, the steering knuckle support 12 moves vertically upward during compression. This movement is guided by the linear guide 4. In the fully compressed position, the outer guide elements 13.1, 13.2 rest with their undersides against a respective lower stop 21.1, 21.2. The stops 21.1, 21.2 are formed on the lower struts 24.2, 24.4 of the steering knuckle support 12 in the area of ​​the connection points 12.2 and 12.4 and serve to limit the spring travel.

[0063] Comparing the representations according to Fig. 6a and c show that the steering knuckle support 12 moves downward in a vertical direction during rebound. This movement is also guided by the linear guide 4. In the fully rebounded position, the outer guide elements 13.1, 13.2 rest with their upper sides against an upper stop 22.1, 22.2. The stops 22.1, 22.2 are formed on the upper legs of the steering knuckle support 12 in the area of ​​the connection points 12.1 and 12.3. The spring travel can be adjusted via the axial lengths of the inner guide elements 4.1, 4.2 and the outer guide elements 13.1, 13.2 and the arrangement of the stops 21.1, 21.2, 21.3, 21.4.

[0064] The linear guide 4 is coupled to a suspension 8 for the suspension of the vehicle frame 10, see. Fig. 3. The suspension 8 comprises two spring cylinders 8.1, 8.2, which are arranged essentially parallel to the inner guide elements 4.1, 4.2. The spring cylinders 8.1, 8.2 are each arranged offset next to the inner guide elements 4.1, 4.2 in the direction of the rotational axis R of the vehicle wheel 5, see. Fig. 6a-c. They are also arranged slightly offset in the direction of the vehicle's longitudinal axis X. The spring cylinders 8.1, 8.2, specifically their cylinder rods, are attached to two attachment points 23.1, 23.2, which are located in the region of the lower end of the steering knuckle support 12, see. Fig. 6a-c. At their ends opposite the cylinder rod, the spring cylinders 8.1, 8.2 are attached to the upper part of the steering knuckle 18. This arrangement allows the suspension 8 to be steered around the steering axis L together with the linear guide 4.

[0065] The following is based on the illustration in Fig. 3 explains how the components of the independent wheel suspension 3 are distributed between the sprung first mass M1 and the unsprung second mass M2. As shown in the illustration, Fig. As can be seen from Figure 3, the steering knuckle upper part 18 is mounted in the steering knuckle bearing 15 so as to be steerable about the steering axis L. The steering knuckle bearing 15 is rigidly connected to the vehicle frame 10, which is why the steering knuckle bearing 15 and the steering knuckle upper part 15 are assigned to the sprung first mass M1. Furthermore, the outer guide elements 13.1, 13.2 are also assigned to the first mass M1, since they are firmly coupled to the steering knuckle upper part 15, see Figure 3. Fig. 3.

[0066] The unsprung mass M2 includes all components of the independent wheel suspension 3 which are assigned to the vehicle wheel 5. These include, as shown in Fig. 4 to 5b in particular the steering knuckle 4, the wheel hub 7, the drive unit 16 as well as the brake unit 17 and also the steering knuckle carrier 12. The inner guide elements 4.1, 4.2 are fastened to the steering knuckle carrier 12, which is why they are also assigned to the unsprung second mass M2.

[0067] In the following, based on the illustration in Fig. Figure 3 explains the arrangement of the connection points 12.1, 12.2, 12.3, 12.4 for attaching the inner guide elements 4.1, 4.2 of the linear guide 4. The four connection points 12.1, 12.2, 12.3, 12.4 are arranged rectangularly, so that the inner guide elements 4.1, 4.2 are aligned parallel and essentially perpendicular. The connection points 12.1, 12.2, 12.3, 12.4 are provided at the ends of four X-shaped struts 24.1, 24.2, 24.3, 24.4 of the steering knuckle support 12 (see Figure 3). Fig. 3. Compared to a steering knuckle carrier 12 with a rectangular base, the X-shaped structure results in a not inconsiderable saving of material.

[0068] According to the illustration Fig. 3 further shows that there is a larger recess between the two lower struts 24.2 and 24.4 than between the two upper struts 24.1 and 24.3. The design of the recesses between the respective struts 24.1, 24.2, 24.3, and 24.4 can be adapted, in particular, to the loads expected during operation of the vehicle 1.

[0069] The two lower struts 24.2 and 24.4 also each have a fastening point 23.1, 23.2 for fastening a spring cylinder 8.1, 8.2 of the suspension 8, cf. Fig. 6a. The spring cylinders 8.1, 8.2 extend between the steering knuckle support 12 and the steering knuckle upper part 15, cf. Fig. 3.

[0070] In the area of ​​the connection points 12.1, 12.2, 12.3, 12.4, as explained above, stops 21.1, 21.2, 22.1, 22.2 are provided, which serve to limit the spring travel W, cf. Fig. 6a. The stops 21.1, 21.2, 22.1, 22.2 interact with the upper and lower sides of the outer guide elements 13.1, 13.2.

[0071] The one-piece steering knuckle support 12 has a symmetrical structure with respect to a longitudinal center axis Y extending vertically through it, cf. Fig. 6b. In cross-section, the steering knuckle support 12 is angled, cf. Fig. 5b. In particular, the steering knuckle support 12, which is arranged substantially vertically, has a concave curvature, so that a region close to the rotational axis R of the vehicle wheel 5 in the radial direction is arranged closer to the vehicle longitudinal axis X than regions that are further away from the rotational axis R in the radial direction.

[0072] The representations in Fig. 7a to 8 show an embodiment of the independent wheel suspension 3, which has a height adjustment 9 for adjusting the height of the vehicle frame 10. Using the height adjustment 9, the vehicle frame 10 can be moved to a height at which it causes no or only non-critical collisions with the vegetation growing on the usable area N when driving over it. For low-growing plants or for safe road travel, the vehicle frame 10 can be moved to a lower position using the height adjustment 9.

[0073] The height adjustment 9 comprises two adjusting elements 9.1, 9.2, which are designed as hydraulic cylinders. By actuating the adjusting elements 9.1, 9.2, the height of the vehicle frame 10 can be adjusted. For this purpose, the adjusting elements 9.1, 9.2 can be coupled to a control system, for example, an on-board control system of the vehicle 1. Instead of hydraulic cylinders, adjusting elements 9.1, 9.2 based on a different principle, such as mechanical adjusting elements 9.1, 9.2, can also be used.

[0074] Furthermore, the height adjustment 9 has two inner height guide elements 9.3, 9.4, which are guided in two correspondingly designed outer height guide elements 9.5, 9.6, cf. Fig. 7b, which ensure reliable, trouble-free guidance of the height adjustment. The inner height guide elements 9.3, 9.4 and the outer height guide elements 9.5, 9.6 are arranged parallel to the adjusting elements 9.1, 9.2, see. Fig. 8.

[0075] The height adjustment 9, comprising the adjusting elements 9.1, 9.2, the inner height guide elements 9.3, 9.4 and the outer height guide elements 9.5, 9.6, extend both obliquely to the steering axis L and obliquely to the linear guide 4, cf. Fig. 8. According to the presentation in Fig. 8, the angle enclosed between the vertical and the height adjustment 9 is smaller than the angle enclosed between the vertical and the steering axis L. However, other angle relationships are also conceivable in this context, for example, in cases where different installation space conditions exist.

[0076] Regardless of the set height of the vehicle frame 10, the linear guide 4 is always arranged below the vehicle frame 10, cf. for example Fig. 7a and b.

[0077] In addition to a height adjustment 9, the agricultural vehicle 1 also includes a track width adjustment 11, which is explained below using the illustrations in Fig. 2 and Fig. 5b. The track width adjustment 11 allows the independent wheel suspension 3, and thus also the linear guide 4, to be moved transversely to the vehicle's longitudinal axis X. This allows different track widths to be set, so that the agricultural vehicle 1 can be used across farms on cultivated areas N with different tramline systems.

[0078] The track width adjustment 11 has a displacement profile 11.1, which can be moved transversely to the vehicle's longitudinal axis X, cf. Fig.5b. The sliding profile 11.1 is slidably mounted in a hollow profile 10.2 of the vehicle frame 10. The steering knuckle bearing 15 is attached to the sliding profile 11.1, on which, as explained above, the entire assembly of the independent wheel suspension 3 is arranged. Therefore, a changed track width does not change the basic function and the fundamental angular relationships of the independent wheel suspension 3, particularly with regard to the linear guide 4 and the spring 8.

[0079] The independent wheel suspension 3 described above is characterized by a reliable and fault-resistant linear guide 4, in which tilting and / or other faults in the linear guide can be reliably avoided, particularly in confined installation space conditions. Reference symbol: 1 agricultural vehicle 2 chassis 3 Independent suspension 4 Linear guide 4.1 Internal guide element 4.2 Internal guide element 5 vehicle wheel 6 rim 7 Wheel hub 8 Suspension 8.1 Spring cylinder 8.2 Spring cylinder 9 Height adjustment 9.1 Control element 9.2 Control element 9.3 Internal height guide element 9.4 Internal height guide element 9.5 External height guide element 9.6 External height guide element 10 vehicle frames 10.1 Arm 10.2 Hollow profile 11 Track width adjustment 11.1 Shift profile 12 steering knuckle carriers 12.1 Connection point 12.2 Connection point 12.3 Connection point 12.4 Connection point 13.1 External guide element 13.2 External guide element 14 steering knuckles 15 steering knuckle bearings 16 Drive unit 17 Brake unit 18 Steering knuckle upper part 18.1 Holding element 18.2 Holding element 18.3 Steering lever 19 vehicle tires 20 steering cylinders 21.1 Stop 21.2 Stop 22.1 Stop 22.2 Stop 23.1 Attachment point 23.2 Attachment point 24.1 Strut 24.2 Strut 24.3 Strut 24.4 Strut A1 distance A2 distance B Width E Wheel longitudinal plane L steering axle M1 first mass M2 second mass R rotation axis W travel X Vehicle longitudinal axis Y longitudinal center axis 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] US 2022 / 0134826 A1

[0005] US 2012 / 0241230 A1

[0005]

Claims

[1] Independent wheel suspension, in particular for an agricultural vehicle (1), with a first mass (M1) which can be arranged on a vehicle frame (10) and a second mass (M2) which is resiliently supported relative to the first mass (M1) via a spring (8) and carries a vehicle wheel (5), the movements of which relative to the first mass (M1) are guided via a linear guide (4), wherein the linear guide (4) has at least one inner guide element (4.1, 4.2) which is guided axially movably in an outer guide element (13.1, 13.2), characterized by that the outer guide element (13.1, 13.2) is arranged on the first mass (M1) and the inner guide element (4.1, 4.2) is arranged on the second mass (M2). [2] Independent wheel suspension according to claim 1, characterized by that the second mass (M2) comprises a steering knuckle (14) arranged on a steering knuckle support (12). [3] Independent wheel suspension according to claim 2, characterized bythat the steering knuckle (14) can be connected to a rim (6) of the vehicle wheel (5). [4] Independent wheel suspension according to one of claims 2 or 3, characterized by that the steering knuckle carrier (12) carries a wheel hub (7) supporting the vehicle wheel (5). [5] Independent wheel suspension according to one of the preceding claims, characterized by that the steering knuckle support (12) has four connection points (12.1, 12.2, 12.3, 12.4) for fastening two inner guide elements (4.1, 4.2) of the linear guide (4). [6] Independent wheel suspension according to claim 5, characterized by that the connection points (12.1, 12.2, 12.3, 12.4) are arranged rectangularly for the parallel and essentially vertical arrangement of the inner guide elements (4.1, 4.2). [7] Independent wheel suspension according to one of claims 5 or 6, characterized bythat the connection points (12.1, 12.2, 12.3, 12.4) are arranged on four X-shaped struts (24.1, 24.2, 24.3, 24.4) of the steering knuckle support (12). [8] Independent wheel suspension according to one of claims 5 to 7, characterized by that the two inner guide elements (4.1, 4.2) are guided in two outer guide elements (13.1, 13.2) which are arranged on a steering knuckle upper part (18) rigidly coupled to the vehicle frame (10). [9] Independent wheel suspension according to one of claims 5 to 8, characterized by that the steering knuckle support (12) has a symmetrical structure, in particular an axisymmetric structure with respect to a longitudinal central axis (Y). [10] Independent wheel suspension according to one of claims 5 to 9, characterized by that the steering knuckle support (12) has an angled cross-sectional shape. [11] Independent wheel suspension according to claim 10, characterized by that the steering knuckle support (12) is concavely curved. [12] Independent wheel suspension according to one of the preceding claims, characterized by that the suspension (8) comprises at least two spring cylinders (8.1, 8.2) which are arranged between the steering knuckle support (12) and the steering knuckle upper part (18). [13] Independent wheel suspension according to one of claims 5 to 12, characterized by stops (21.1, 21.2, 22.1, 22.2) arranged in the area of ​​the connection points (12.1, 12.2, 12.3, 12.4) of the steering knuckle carrier (12) to limit the spring travel (W). [14] Independent wheel suspension according to one of the preceding claims, characterized by that the spring travel (W) for compression and rebound are essentially the same length. [15] Independent wheel suspension according to one of the preceding claims, characterized by that the steering knuckle support (12) is arranged substantially vertically.

Images