Rigid axle having an axle carrier with a crank-shaped continuous tubular member and an electric machine fixed to the axle carrier

Abstract

The present invention relates to a rigid axle (10) having an axle carrier (12) in whose longitudinal end regions (12a, 12b) wheel hub assemblies (14, 16) are arranged, each assembly (14, 16) having a rotatable wheel flange (14a, 16a) for fixing a wheel (R) to the flange (14a, 16a), the carrier (12) being formed with a crank region (12c) located between the regions (12a, 12b) and in the region (12c) an energy converter (40) is provided. A functional assembly (36, 38) having the above components is arranged, the functional assembly being connected to the flanges (14a, 16a) for transmitting rotational motion between the converter (40) and the flanges (14a, 16a), the converter (40) being usable as at least one of: i) an electric motor drive unit for transmitting torque from the converter (40) to the flanges (14a, 16a), ii) a generator induction unit for generating electric energy by transmitting torque from the flanges (14a, 16a) to the converter (40). The carrier (12) has a crank-shaped tubular member (12) continuous from region (12a, 12b) to region (12a, 12b).

Description

[Technical field]

[0001] The invention relates to a rigid axle for a motor vehicle, comprising an axle carrier, the distance between the longitudinal end regions of which in the axial direction defines the axial direction of the rigid axle, in which wheel hub assemblies are arranged one by one, each wheel hub assembly having a wheel flange rotatable relative to the axle carrier, each wheel flange being configured for fixing a wheel non-rotatably to the wheel flange, the axle carrier being crank-shaped with a crank region located axially between its longitudinal end regions, in which an electromechanical functional assembly is arranged with an electric energy converter, which is connected to the at least one wheel flange for transmitting a rotational movement between the energy converter and the at least one wheel flange, whereby the electric energy converter is divided into two functional units: i) an electric motor drive unit for transmitting torque from the energy converter to at least one wheel flange; and ii) a generator induction unit for generating electrical energy by transferring torque from at least one wheel flange to an energy converter. [Background technology]

[0002] Such a rigid axle is known from Valx International of Veghel (the Netherlands), under the designation "E2!HD". The axle carrier of this known rigid axle is formed from three straight tube sections, of which the two axially outer tube sections, each supporting a wheel hub assembly, are arranged coaxially with a common tube axis, and a tube section axially centrally located between the two axially outer tube sections is arranged with its tube axis parallel to but offset from the common tube axis of the axially outer tube sections.

[0003] The central tube section is connected at each of its axial longitudinal ends to the respective longitudinal ends of the other of the axially outer tube sections by means of a flat connecting plate, the two flat connecting plates being parallel to each other and perpendicular to the tube axes of the axially outer and central tube sections.

[0004] The electrical energy converter of the known axle "E2!HD" is used as a generator for generating electrical energy for electrical consumers of the vehicle in which the axle is mounted. In the known axle, only one of the two wheel hub assemblies is connected to transmit torque to the electrical energy converter which functions only as a generator.

[0005] Rigid axles such as the rigid axle of the present invention are primarily used as leading axles, i.e., as the axles in front of the axles actually driven by the main drive of each vehicle, and / or as axles of a towed vehicle that is towed by a towing vehicle. Typically, such rigid axles are part of a multi-axle rear axle configuration of a vehicle.

[0006] A rigid axle with an electric energy converter under the product name "SAF TRAKe" is known from SAF-Holland. The electric energy converter of the rigid axle is capable of providing traction support and torque to the wheel flange and the wheels flange-connected to the wheel flange when operating as a motor, and of slowing down the vehicle as an eddy current brake when operating as a generator, recovering kinetic energy and storing it as electric energy, or of continuously generating electric energy and supplying it to electric consumers such as a cooling device.

[0007] The known rigid axle "SAF TRAKe" has a split straight tubular axle carrier, in the axial longitudinal center of which a differential gear is arranged. The housing of the differential gear supports an electric energy converter, the armature shaft of which is kinematically connected to the differential gear. The electric energy converter can thus transmit torque to both wheel flanges via the differential gear as an electric motor or be driven by the wheels flanged to the wheel flanges as a generator. The differential gear is thus integrated into the support structure of the known rigid axle.

[0008] The electromechanical functional assembly of the Valx E2!HD axle, which acts as a generator, is not integrated into the axle support structure, but an axle made from multiple parts has many joints and can therefore have a lower load capacity than would be possible for a given installation volume. Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE DISCLOSURE The object of the present invention is to provide a robust, rigid axle which has a simple design, a high load capacity and allows the widest possible range of utilisation of electrical energy converters. [Means for solving the problem]

[0010] The invention solves this problem in that, in a rigid axle of the type mentioned at the beginning, the axle carrier has a crank-shaped tubular element which is formed so as to be continuous from one longitudinal end region to the other longitudinal end region.

[0011] By using continuous uninterrupted tubular members on the axle carrier, which preferably form the main structural components of the axle carrier, the axle carrier can be made to have high rigidity with a relatively low weight. Furthermore, in contrast to the known axle "E2!HD", no axially overlapping tube sections are required, each of which projects into a solid connecting plate connecting the tube sections, and no solid connecting plate is required. This allows a reduction in weight.

[0012] Due to the known arrangement of the electro-mechanical functional assembly in the crank region of the axle carrier, the electro-mechanical functional assembly may further be arranged outside the force flow of the chassis, with the rigid axle being used to define the force flow.

[0013] The continuous tubular member forms the main structural component of the axle carrier if it represents at least 75% of the mass of the axle carrier, measured without the electric machine, or if it already ensures the function of the axle carrier itself, since for example a wheel hub assembly can be attached to the tubular member, which can then be attached as an axle carrier to the vehicle body via bearing means such as spring links. To facilitate the attachment of the axle carrier to the vehicle body and / or to facilitate the arrangement of further elements, such as the above-mentioned at least one electric energy converter, on the axle carrier, at least one further auxiliary element, such as a bearing frame, a holder, a mounting structure or / and a fastening structure, can be arranged on and connected to the tubular member. In such a case, the axle carrier is formed by the tubular member and the at least one auxiliary element arranged on the tubular member.

[0014] The tubular member of the axle carrier is preferably one-piece. In a less preferred embodiment, it may consist of several tubular members, which are preferably joined by welding. Preferably, the tubular member of the axle carrier is manufactured in one piece by deformation of a shaped blank. The tubular member of the axle carrier is thus preferably seam-free, which results in a particularly high stability and strength. This seam-freeness concerns the axle carrier tubular member itself. However, the seam-freeness does not exclude the possibility that other members, such as the at least one auxiliary member mentioned above, are attached, in particular welded, to the axle carrier tubular member. The axle carrier tubular member is thus preferably seam-free, but does not necessarily have to be the axle carrier itself.

[0015] Basically, it should not be excluded that further members of the axle carrier are axially connected to the tubular member. Preferably, however, each longitudinal end region of the tubular member is also a longitudinal end region of the axle carrier. Additionally or alternatively, it is preferred that the crank region of the axle carrier is also a crank region of the tubular member.

[0016] Since the rigid axles preferably form the roll axis of the vehicle on which they are mounted, the longitudinal end regions of the axle carriers are preferably formed coaxially to a common first extension axis on the axle carrier, which is preferably likewise coaxial to the wheel flange rotation axis about which both wheel flanges of each longitudinal end region of the axle carrier are rotatable relative to the axle carrier.

[0017] The crank region preferably extends along a first axis of extension and at a distance from the first axis of extension. Although the crank region extends in a curved trajectory, it is preferred that the crank region has a straight portion extending along a second axis of extension parallel to the first axis of extension and at a distance from the first axis of extension in order to facilitate the accommodation of the at least one electric energy converter in the crank region. The straight portion extends linearly and without curvature in the axial direction of the rigid axle.

[0018] Preferably, the axle carrier, in particular the longitudinal end regions of the tubular member, are also formed so as to extend straight and without curvature in the axial direction.

[0019] In order to ensure a continuous tubular shape of the tubular member of the axle carrier, the axle carrier, in particular its tubular member, preferably has one tubular connection region between each longitudinal end region and the crank region, connecting the longitudinal end region with the crank region.

[0020] In order to increase the stiffness and stability of the axle carrier, the connection region preferably extends obliquely, i.e. is inclined at an angle of less than 90°, in particular less than 70°, more preferably less than 55°, to the first axis of extension, while at the same time, in order to provide a crank region that is axially long enough for the arrangement of at least one electromagnetic functional assembly, the connection region is likewise preferably inclined at an angle of at least 25°, in particular at least 30°, more preferably at least 35°, to the first axis of extension.

[0021] Also preferably, the continuous tubular member of the axle carrier is a flat member in the sense that the trajectory which it follows between its longitudinal end regions is a flat trajectory, for example if all curvilinear axes of the tubular member are parallel to one another. Preferably, the tubular member is locally curved, preferably only locally curved, at the transitions between the longitudinal end regions and the respectively adjacent connection regions and at the transitions between the connection regions and the crank regions adjacent to the connection regions.

[0022] As previously described, the wheel flanges are arranged on the axle carrier for rotation about a common wheel flange rotation axis to form a vehicle roll axis for a vehicle mounting the rigid axle. The tubular member of the axle carrier has at least one of the following features in continuous form to enhance its member stiffness and member strength: a) the tubular member extends along its track from longitudinal end region to longitudinal end region without buckling with respect to a buckling axis oriented transversely to the wheel flange rotation axis; b) the tubular member extends along its trajectory from longitudinal end region to longitudinal end region without abrupt changes in shape and / or size of its outer covering surface; and c) the tubular member extends along its trajectory from longitudinal end region to longitudinal end region without any abrupt changes in the shape and / or size of its inner covering surface;

[0023] Preferably, the tubular member has at least two of the three listed characteristics, particularly preferably all three, whereby the tubular member is considered to be buckled if it is bent about a buckling axis that extends transversely, in particular perpendicularly, to the wheel flange rotation axis with a buckling radius of less than 5 mm.

[0024] An abrupt change in shape exists, for example, when the cross-section occupied by each covering surface in a cross-section perpendicular to the trajectory of the tubular member between the longitudinal end regions of the tubular member changes by more than 20% with respect to the smaller of the two surfaces at the transition, within an extension of less than 3 mm along the trajectory of the tubular member.Similarly, an abrupt change in shape exists, for example, when the ratio of the height to the width of the cross-section occupied by each covering surface in a cross-section perpendicular to the trajectory of the tubular member between the longitudinal end regions of the tubular member changes by more than 20% with respect to the smaller of the two ratios at the transition, within an extension of less than 3 mm along the trajectory of the tubular member.

[0025] Features a) and / or b) and / or c) avoid undesirable notch effects on the tubular member and increase its strength and stability.

[0026] To transmit torque between the wheel flange and the electromechanical functional assembly, the electromechanical functional assembly is preferably connected to at least one wheel flange in a torque-transmitting manner by means of a drive shaft. The drive shaft may be connected to the wheel flange in a non-rotatable manner with respect to the wheel flange rotation axis and in its opposite end region may be non-rotatably connected to a rotatable part of the electromechanical functional assembly. The non-rotatable arrangement of the drive shaft with respect to the other rotatable member can be achieved, for example, by means of a spline profile.

[0027] In order to be able to establish a connection for transmitting torque from an electro-mechanical functional assembly arranged outside the tubular member of the axle carrier to the wheel flanges rotatably arranged in the longitudinal end regions of the tubular member or the axle carrier, the tubular member of the axle carrier preferably has a through-opening passing through the wall of the tubular member through which the drive shaft extends, the through-opening forming a weakened portion of the structure of the tubular member, which is still less than in the case of a tubular member completely disassembled into three parts, of which two axially adjacent tubular members in each case are arranged with tube axes parallel to each other but offset from each other by more than a tube diameter.

[0028] The through opening is preferably formed in the above-mentioned connection region, since it is preferably inclined with respect to the common first extension axis of the longitudinal end regions and thus facilitates the passage of a drive shaft, which likewise preferably extends parallel to the first extension axis, through the through opening.

[0029] For connecting a rigid axle to a vehicle which is fitted with the rigid axle, the rigid axle preferably has at least one spring link connected to the axle carrier and extending transversely, in particular perpendicularly, to the axle carrier. Since the spring link stiffens the axle carrier or the tubular member at the point of connection with the axle carrier, a through opening is formed in the tubular member of the axle carrier to avoid unnecessary weakening of the axle carrier in the area where the axle carrier is connected with the spring link.

[0030] Basically, the spring link may be connected to the axle carrier in any way. Preferably, the spring link is connected to the axle carrier by a clamp. In a specific embodiment, the spring link may be connected to the axle carrier by at least two fastening means spaced apart in the axial direction of the rigid axle. In this case, a through opening is preferably formed between the two fastening means. A preferred clamping fastening means considered is a bracket, which is fixed to one of the spring link and the axle carrier and which surrounds the respective other of the axle carrier and the spring link.

[0031] Again, the spring link is preferably connected to the axle carrier in the region of the above-mentioned connection region which connects the longitudinal end region of the tubular member or axle carrier with its crank region.

[0032] Preferably, the rigid axle for connection to the vehicle body has two spring links spaced apart in the axial direction, each spring link being connected to an axle carrier. Preferably, the spring links and their connections to the axle carrier are identical or mirror-symmetrical with respect to a mirror-symmetrical plane perpendicular to the trajectory of the tubular member at the axial center in order to obtain identical axle reactions, such as force reactions, in both axial end regions of the rigid axle during driving movements under identical external influences.

[0033] In order to prevent dirt and / or moisture from reaching the tubular member through the through opening, a cover element may be arranged on the tubular member of the axle carrier, which covers the through opening. In order to nevertheless allow the drive shaft to pass through the wall of the tubular member, the cover element may have a through opening, through which the drive shaft passes, preferably spaced axially from the through opening and collinear with the through opening. Preferably, the cross section of the through opening is inclined at an angle in the range of 75° to 105° to the extension direction of the drive shaft, particularly preferably perpendicular to the extension direction of the drive shaft. This makes it easier to arrange a shaft seal in the edge region of the cover element, which delimits the through opening radially outward. However, such an inclined through opening makes it difficult for dirt and liquid to enter the tubular member even without the arrangement of a shaft seal, especially if the through opening is spaced axially from the through opening.

[0034] The tubular member of the axle carrier is preferably made of steel. The cover member may be made of a material different from that of the tubular member, for example plastic, which may be particularly easy to form into complex shapes, for example by casting or injection molding.

[0035] Basically, the electric energy converter may be directly connected to the wheel flange by a drive shaft in a torque transmitting manner. In this case, the electric energy converter forms an electromechanical functional assembly. Depending on whether the electric energy converter is operated as a generator or as a motor, the electromechanical functional assembly may preferably include a gear in order to adapt the input or output operating parameters of the electric energy converter to the operating parameters of the at least one wheel flange specified by the operating mode. The input side of the gear is connected to the electric energy converter in a torque transmitting manner and the output side is connected to the at least one wheel flange in a torque transmitting manner.

[0036] Basically, the gears can have any structure. Preferably, the gears are planetary gears, which make it possible to achieve high transmission ratios without offsets in a very compact installation space. The planetary gears can be multi-stage, but preferably a single-stage planetary gear is sufficient.

[0037] The electrical energy converter is preferably an electrical synchronous machine capable of operating both as a motor and as a generator.

[0038] In order to avoid the resulting yaw moment acting on the rigid axle when using only one electro-mechanical functional assembly which only interacts with one of the two wheel flanges of the axle carrier, a dedicated electro-mechanical functional assembly with an electric energy converter is preferably arranged in the crank region for each wheel flange of the wheel hub assembly arranged in different longitudinal end regions of the rigid axle. For the further electro-mechanical functional assemblies, the statements made above and below regarding the electro-mechanical functional assemblies apply with regard to the advantageous structure of the further electro-mechanical functional assemblies and the advantageous configuration of the interaction of the further electro-mechanical functional assemblies and the arrangement of the further electro-mechanical functional assemblies on the axle carrier and / or on the wheel flanges connected to the further electro-mechanical functional assemblies in a torque transmitting manner.

[0039] Each electrical energy converter is in turn connected to a respective wheel flange for transmitting rotational motion between the energy converter and the wheel flange of a separate wheel hub assembly.

[0040] Preferably, each electric energy converter is operable independently of the operating state of the other electric energy converters, which makes it unnecessary to use a differential gear to distribute the torque of the drive to both wheel flanges of the axle.

[0041] The rigid axle may comprise a control device or may be connected to a control device of the vehicle on which the rigid axle is mounted. The control device is configured to control the at least one electromechanical functional assembly, in particular its electric energy converter, for operation. For example, the control device can switch the electric energy converter cooperating with the control device between operation as a motor and operation as a generator, and in operation as a motor, the output power and / or the output rotation speed of the electric energy converter can be set. The rigid axle, in particular the at least one electromechanical functional assembly, more preferably its electric energy converter, can comprise an electrical coupling formation, such as a plug and / or a socket, by means of which a connection with the vehicle-side control device can be established.

[0042] If the electric energy converter can also operate as a generator, the rigid axle or the vehicle equipped with the rigid axle may have an electric energy storage device connected to the electric energy converter for transferring current, in which the electric energy converter can store the electric energy generated in operation as a generator. To transfer current to the at least one electric energy converter or to extract current from the at least one electric energy converter, the rigid axle, in particular the at least one electromechanical functional assembly, particularly preferably the at least one electric energy converter, may have further coupling formations such as plugs and / or sockets.

[0043] In order to provide a rigid axle which acts symmetrically in terms of running dynamics, the axle carrier is preferably formed with mirror symmetry about its axial centre.

[0044] Additionally or alternatively, identical parts may be used, one of the electromechanical functional assemblies being transferable to the other electromechanical functional assembly by a 180° rotation about an axis of symmetry perpendicular to the axial direction of the rigid axle and by a translational displacement, i.e., if two electromechanical functional assemblies are used, it is preferred that they are identical.

[0045] The invention will now be described in more detail with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0046] [Figure 1] FIG. 1 is a perspective view showing a schematic diagram of an embodiment of the rigid axle of the present application according to the present invention; [Diagram 2] FIG. 2 shows the rigid axle of FIG. 1 as viewed along the roll axis of the vehicle on which the rigid axle is mounted. [Diagram 3] FIG. 3 shows the rigid axle of FIGS. 1 and 2 as viewed along the yaw axis of a vehicle on which the rigid axle is mounted. [Figure 4] FIG. 3 is a schematic cross-sectional view of the left side of the rigid axle of FIG. 2, taken along a cross-sectional axis perpendicular to the roll axis and including the wheel flange rotation axis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Figures 1, 2 and 3 show a schematic representation of an embodiment according to the invention of the rigid axle of the present application, which is designated by the reference number 10. Figure 1 shows the rigid axle 10 in a perspective view, Figure 2 shows it in a front view and Figure 3 shows it in a top view. Figure 2 corresponds to a view along the roll axis of a vehicle equipped with the rigid axle 10 in a ready-to-drive state. Figure 3 corresponds to a view along the yaw axis of a vehicle equipped with the rigid axle 10 in a ready-to-drive state.

[0048] The rigid axle 10 includes an axle carrier 12 having disposed at its longitudinal end regions 12a, 12b a wheel hub assembly 14 or 16, respectively.

[0049] The axle carrier 12 includes a crank-shaped tubular member 18 that extends continuously and integrally from one longitudinal end region 12a to the other longitudinal end region 12b of the axle carrier 12. The longitudinal end regions 12a and 12b of the axle carrier 12 are also the longitudinal end regions 18a and 18b of the tubular member 18.

[0050] The longitudinal end regions 12a and 12b of the axle carrier 12 are coaxial with respect to a common first extension axis E1 that defines the axial direction of the rigid axle 10, and are spaced apart from each other along the first extension axis E1. Between the two longitudinal end regions 12a and 12b in the axial direction, the axle carrier 12 has a crank region 12c that extends at a distance from the first extension axis E1.

[0051] In this example, the crank region 12c is formed as a straight section 13 which extends along a second axis E2 which is parallel to the first axis E1 but spaced apart from the first axis E1. The crank region 12c of the axle carrier 12 is connected to the longitudinal end region 12a by a connection region 12d and to the longitudinal end region 12b by a connection region 12e.

[0052] The aforementioned regions of the crank region 12c and the connection regions 12d and 12e of the axle carrier 12 are also the regions of the crank region 18c and the connection regions 18d and 18e of the tubular member 18.

[0053] In the illustrated embodiment, the axle carrier 12 and the wheel hub assemblies 14 and 16 are mirror symmetrical with respect to a mirror symmetry plane SE perpendicular to the first extension axis E1, so that it is sufficient to describe the features of the axle carrier 12 and the wheel hub assemblies 14 or 16 only in relation to one axial half of the rigid axle 10, because the description also applies to the respective other axial half of the rigid axle 10, under the above-mentioned conditions of mirror symmetry.

[0054] The wheel hub assemblies 14 and 16 each have a wheel flange 14a or 16a which is rotatable relative to the axle carrier 12 about a common wheel flange rotation axis RDA which is coaxial with the first extension axis E1. Together with each wheel flange 14a or 16a, a brake disc 14b or 16b is rotatable about the common wheel flange rotation axis RDA. A brake caliper carrier 14c (see Figures 2, 3 and 4) or 16c fixed to the axle carrier allows a brake caliper (not shown) to be arranged fixedly on the axle carrier in a manner known per se in order to be able to brake the wheel flange 14a or 16a which is arranged on each brake disc 14b and 16b. Further, the wheel hub assemblies 14 and 16 each have a rolling bearing 14d and 16d, by which the wheel flange 14a or 16a and the brake disc 14b or 16b are received in the tubular member 18 or axle carrier 12 so as to rotate about a common wheel flange rotation axis RDA.

[0055] Instead of disc brakes, the rigid axle 10 shown may be provided with drum brakes.

[0056] The connection regions 12d and 12e are provided with fastening devices 20 or 22 for connecting the axle carrier 12 to spring links 24 or 26 shown in Figures 2 and 3. The fastening devices 20 and 22 also satisfy the above-mentioned mirror symmetry condition with respect to the plane SE.

[0057] The fastening device 20 comprises as fastening means a short U-bracket 28a and a long U-bracket 28b which surround the tubular member 18 and thus the axle carrier 12 in the connection region 18d or 12d with a respective shell member 30 arranged therebetween. The straight sides of the U-bracket 28a and the U-bracket 28b thereby penetrate and fasten the cover member 32 arranged in the connection region 18d. The fastening devices 20 and 22 fasten the axle carrier 12 to the spring link 24 or 26 by means of a clamp.

[0058] In the crank region 12c, the axle carrier 12 includes two substantially identical holders 34 rotated relative to each other by 180° about a rotation axis D that intersects both the first extension axis E1 and the second extension axis E2, each of which supports an electromechanical functional assembly 36 or 38.

[0059] Holder 34 is a holder formed from a bent metal member and is connected, preferably by threading or welding, to tubular member 18 at crank region 18c of tubular member 18.

[0060] The electromechanical functional assemblies 36 and 38 are identically constructed in the embodiment shown, only rotated 180° relative to each other about the axis of rotation D. It is therefore sufficient to describe one of the electromechanical functional assemblies, which description is also applicable to the respective other electromechanical functional assembly under the above-mentioned arrangement conditions.

[0061] The axis of rotation D extends parallel to the yaw axis of the vehicle when the rigid axle 10 is mounted in a vehicle ready for operation.

[0062] The electromechanical functional assembly 36 includes an electric energy converter 40, in the illustrated example a rotary synchronous motor, which by means of its permanent magnet excited rotor can operate not only as a motor but also as a generator for recovering kinetic energy or in general for producing electrical energy.

[0063] A gear 42, in the illustrated example a planetary gear, is torque-transmittingly connected to the rotor 41 of the electric energy converter 40, which is only shown in Figure 4, on the side of the electric energy converter 40 axially closer to the wheel hub assembly 14. A coupling element 44 (see Figure 4) of the gear 42, functionally opposite to the connection with the rotor 41, is non-rotatably, i.e. torque-transmittingly connected to the wheel flange 14a by a drive shaft 46.

[0064] As can be seen particularly clearly in FIG. 4, the drive shaft 46 extends coaxially with the wheel flange rotation axis RDA. The drive shaft 46 extends through a through opening 48 in a side wall 49 of the cover member 32 perpendicular to the wheel flange rotation axis RDA or the first extension direction axis E1, and further extends through a through opening 50 in a wall 52 of the tubular member 18. After passing through the through opening 50, the drive shaft 46 extends inside the tubular member 18 until it reaches the wheel flange 14a, which is non-rotatably connected to the drive shaft 46. The through opening 50 is covered by the cover member 32, so that dirt and liquids are difficult to flow into the tubular member 18 through the through opening 50.

[0065] The through opening 50 is located axially between the two U-brackets 28a and 28b of the fastening device 20 or 22. The inevitable weakening of the tubular member 18 caused by the through opening 50 can therefore be at least partially compensated for by the fastening device 20 or 22 and the spring link 24 or 26 bridging its U-brackets 28a and 28b, respectively.

[0066] On the one hand, the electromechanical functional assembly 36 can act as a motor to drive the wheel flange 14a to rotate, or can be driven to rotate as a generator by a wheel R (shown in dotted lines in FIG. 2) that is flange-connected to the wheel flange 14a and used to generate electric current.

[0067] The functional assembly 36 further includes a controller 54 for controlling the operation of the electric energy converter 40. The controller may be coupled, for example via a CAN bus or a LIN bus, to a controller of the vehicle in which the rigid axle 10 is mounted.

[0068] In Figures 2 and 3, which supplement the above description, the spring links 24 and 26 are shown as trailing links, and the spring links 24 and 26 are connected to the axle carrier 12 via hydraulic shock absorbers 56 or 58, respectively, in a manner known per se, for damping relative movement between the spring links 24 and 26 and the axle carrier 12.

[0069] 2, 3 and 4 show, in addition to the extension axes E1 and E2, a curved trajectory VB along which the tubular member 18 extends between its longitudinal end regions 18a and 18b. In particular, in FIG. 3, it is recognized that the trajectory VB lies in the plane formed by the extension axes E1 and E2, so that the trajectory VB is a flat trajectory and therefore the tubular member 18 is a flat tubular member 18. In the longitudinal end regions 12a or 18a and 12b or 18b as well as in the crank region 12c or 18c, the trajectory VB coincides with the first extension axis E1 or the second extension axis E2.

[0070] As can be seen in particular in Fig. 4, the tubular member 18 has a generally constant tubular cross section, both in shape and size, extending from one longitudinal end region 12a or 18a to the opposite longitudinal end region 12b or 18b. The tubular member 18 extends without buckling along its trajectory VB and is curved only in the transitions between the longitudinal end region 12a or 18a and the connecting region 12d or 18d, between the longitudinal end region 12b or 18b and the connecting region 12e or 18e, between the connecting region 12d or 18d and the crank region 12c or 18c, and between the crank region 12c and the connecting region 12e or 18e, all the curve axes of the aforementioned curved regions being parallel to one another and, for example, perpendicular to the projection plane of Fig. 2. This avoids undesirable notch effects on the tubular member 18 and thus on the axle carrier 12, increasing their strength and thus their service life. [Explanation of symbols]

[0071] 10 rigid axle 12 Axle carrier 12a, 12b Longitudinal end regions 12c crank area 12d, 12e Connection area 13 Straight section 14, 16 Wheel hub assembly 14a, 16a Wheel flange 14b, 16b brake disc 14c, 16c brake caliper carrier 14d, 16d Rolling bearings 18 Tubular member 18a, 18b Longitudinal end regions 18c crank area 18d, 18e Connection area 20, 22 Fastening device 24, 26 Spring link 28a, 28b U-bracket 30 Shell member 32 Cover member 34 Holder 36, 38 Electromechanical Functional Assembly 40 Electrical Energy Converter 41 Rotor 42 Gear 44 Connected Elements 46 Drive shaft 48 Passage opening 49 Side wall 50 Through opening 52 Wall 54 Control device 56, 58 Hydraulic shock absorber D Rotational Axis E1 First extension direction axis E2 Second extension axis R wheel RDA Wheel flange rotating shaft SE plane, mirror symmetry plane VB orbit

Claims

1. A rigid axle (10) for a motor vehicle includes an axle carrier (12) having a wheel hub assembly (14, 16) disposed at each of the longitudinal end regions (12a, 12b) in an axial direction of the axle carrier, the distance between the longitudinal end regions defining an axial direction of the rigid axle (10), each wheel hub assembly (14, 16) having a wheel flange (14a, 16a) rotatable relative to the axle carrier (12), each wheel flange (14a, 16a) configured to non-rotatably fix a wheel (R) to the wheel flange (14a, 16a), the axle carrier (12) being configured to support the wheel hub assembly (14, 16) and the axle carrier (12) being configured to support the wheel hub assembly (14, 16). The carrier is crank-shaped in a crank region (12c) located axially between the longitudinal end regions (12a, 12b) of the carrier, in which an electromechanical functional assembly (36, 38) is arranged with at least one electric energy converter (40), which is connected to at least one of the wheel flanges (14a, 16a) for transmitting a rotational movement between the energy converter (40) and the at least one of the wheel flanges (14a, 16a), whereby the electric energy converter (40) is divided into two functional units: i) an electric motor drive unit for transmitting torque from an energy converter (40) to at least one of said wheel flanges (14a, 16a); and ii) a generator induction unit for generating electrical energy by transmitting torque from at least one of said wheel flanges (14a, 16a) to an energy converter (40); A rigid axle (10) that can be used as at least one of 1. A rigid axle (10) comprising an axle carrier (12) having a crank-shaped tubular member (18) formed so as to be continuous from one longitudinal end region (18a) to the other longitudinal end region (18b) of the tubular member.

2. 2. A rigid axle (10) according to claim 1, characterized in that the longitudinal end regions (18a, 18b) of the tubular member (18) are also longitudinal end regions (12a, 12b) of the axle carrier (12) and / or the crank region (12c) of the axle carrier (12) is also the crank region (18c) of the tubular member (18).

3. 3. A rigid axle (10) according to claim 1 or 2, characterized in that the longitudinal end regions (12a, 12b) of the axle carrier (12) are formed coaxially with respect to a common first extension axis (E1) on the axle carrier (12), the crank region (12c) extends along the first extension axis (E1) at a distance from the first extension axis (E1), and the axle carrier (12) has, between each longitudinal end region (12a, 12b) and the crank region (12c), a tubular connection region (12d, 12e) connecting the longitudinal end region (12a, 12b) with the crank region (12c).

4. 4. The rigid axle (10) according to claim 3, characterized in that the crank region (12c) has a straight portion (13) extending along a second axis of extension (E2) extending parallel to the first axis of extension (E1) and at a distance from the first axis of extension.

5. Wheel flanges (14a, 16a) are arranged on an axle carrier (12) for rotation about a common wheel flange rotation axis (RDA), the tubular member (18) of the axle carrier (12) having the following features in continuous form: a) said tubular member (18) extends along its trajectory (VB) from longitudinal end region (18a, 18b) to longitudinal end region (18a, 18b) without buckling with respect to a buckling axis oriented transversely to said wheel flange rotation axis (RDA); b) said tubular member (18) extends along its trajectory (VB) from longitudinal end region (18a, 18b) to longitudinal end region (18a, 18b) without any abrupt changes in shape and / or size of its outer covering surface; and c) said tubular member (18) extends along its trajectory (VB) from longitudinal end region (18a, 18b) to longitudinal end region (18a, 18b) without any abrupt changes in shape and / or size of its inner covering surface; 5. A rigid axle (10) according to any one of claims 1 to 4, characterized in that it comprises at least one of the following:

6. 6. The rigid axle (10) according to claim 1, characterized in that the electrical function assembly (36, 38) is connected in torque-transmitting manner to at least one wheel flange (14a, 16a) by means of a drive shaft (46), and the tubular member (18) of the axle carrier (12) has a through opening (50) passing through a wall (52) of said tubular member (18), through which the drive shaft (46) extends.

7. 7. The rigid axle (10) according to claim 6, characterized in that the rigid axle (10) has spring links (24, 26) connected to the axle carrier (10) and extending transversely to the axle carrier (12), and through openings (50) are formed in a tubular member (18) of the axle carrier (12) in the connection region of the axle carrier (12) with the spring links (24, 26).

8. 8. The rigid axle (10) according to claim 7, characterized in that the spring links (24, 26) are connected to the axle carrier (12) by at least two fastening means (28a, 28b) spaced apart in the axial direction of the rigid axle (10), and the through opening (50) is formed between the two fastening means (28a, 28b).

9. 9. A rigid axle (10) according to any one of claims 6 to 8, characterized in that a cover member (32) is arranged on the tubular member (18) of the axle carrier (12), said cover member (32) covering a through opening (50) and having a through opening (48) axially spaced from and collinear with said through opening (50), and through which a drive shaft (46) also extends.

10. 10. The rigid axle (10) according to any one of claims 1 to 9, characterized in that the electro-mechanical functional assembly (36, 38) comprises a gear (42) connected to an electric energy converter (40) on the input side to transmit torque and connected to at least one wheel flange (14a, 16a) on the output side to transmit torque.

11. 11. A rigid axle (10) according to any one of claims 1 to 10, characterized in that in the crank region (12c) for each wheel flange (14a, 16a) of wheel hub assemblies (14, 16) arranged in different longitudinal end regions (12a, 12b) of the axle carrier (12) an electromechanical functional assembly (36, 38) is arranged with an electric energy converter (40), each electric energy converter (36, 38) being connected to each wheel flange (14a, 16a) for transmitting a rotational movement between the energy converter (40) and the wheel flange (14a, 16a) of the other wheel hub assembly (14, 16).

12. 12. The rigid axle (10) according to claim 11, characterized in that each of the electric energy converters (40) is operable independently of the operating state of each of the other electric energy converters.

13. 13. A rigid axle (10) according to claim 11 or 12, characterized in that the axle carrier (12) is formed mirror-symmetrically with respect to the axial center of the axle carrier and / or that one of the electro-mechanical function assemblies (36, 38) is transferable to the other electro-mechanical function assembly (36, 38) by a rotation of 180° around an axis of symmetry (D) perpendicular to the axial direction of the rigid axle (10) and by a translational displacement.

14. 14. The rigid axle (10) according to any one of claims 1 to 13, characterized in that it comprises a control device (54) electrically connected to the at least one electric energy converter (40) and / or an electric energy storage device electrically connected to the at least one electric energy converter (40).

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