DE102023117146A1 - commercial vehicle rigid axle for torque vectoring operation - Google Patents

Abstract

The invention relates to a rigid vehicle axle (10) for a commercial vehicle (20) having an input element (11) for receiving a drive torque generated by a drive device (22). The rigid vehicle axle (10) also has a first wheel shaft (12a) and a second wheel shaft (12b) which can be drivenly connected to wheels (24) of the commercial vehicle (20). The rigid vehicle axle (10) also has a transverse differential (13) which is drivenly connected to the input element (11), the first wheel shaft (12a) and the second wheel shaft (12b) for distributing the received drive torque to the first wheel shaft (12a) and the second wheel shaft (12b). The rigid vehicle axle (10) also has an axle bridge (14) in which the first wheel shaft (12a), the second wheel shaft (12b) and the transverse differential (13) are accommodated. The vehicle rigid axle (10) also has a rotating electric machine (15) which is or can be connected in a driving manner to the first wheel shaft (12a) and/or the transverse differential (13) in order to vary the drive torque distributed to the first wheel shaft (12a) and/or the second wheel shaft (12b). The rotating electric machine (15) is attached and/or carried on the axle bridge (14).

Description

The invention relates to a rigid vehicle axle for a commercial vehicle (e.g. for a truck or bus), a commercial vehicle with such a rigid vehicle axle and a modular rigid vehicle axle system.

In order to improve yaw control and thus vehicle stability, especially when cornering, torque vectoring concepts are known in the state of the art, in which drive torque is actively distributed to the individual wheels of a vehicle.

One way to implement a corresponding yaw control is, for example, to provide independently controllable electric wheel hub motors on an axle, so that a different drive torque can be allocated to the left and right wheels of an axle. Since the size and thus the installation space required for such wheel hub motors increases with increasing power, it is generally not possible to install wheel hub motors with any desired power. The aforementioned concept is therefore disadvantageous, particularly in the commercial vehicle sector, where large drive torque differences or large torque vectors are usually required due to the size and weight of the vehicles.

Furthermore, the use of rigid axles has proven successful in the commercial vehicle sector, particularly with regard to their directional stability and robustness.

The object of the invention is to provide an improved solution for targeted drive torque distribution to the wheels of an axle. Preferably, an object of the invention is to provide a solution by means of which torque vectoring can be implemented on a rigid axle of a commercial vehicle.

These objects can be achieved with the features of the independent claims. Advantageous embodiments and applications of the invention are the subject of the dependent claims and are explained in more detail in the following description with partial reference to the figures.

A first independent aspect of the present disclosure relates to a rigid vehicle axle for a commercial vehicle (e.g. for a truck or for a bus).

The vehicle rigid axle has an input element for receiving a drive torque generated by a drive device (e.g. by an internal combustion engine and/or by an electric motor). For example, the input element can be designed to connect a drive shaft (e.g. cardan shaft), in particular connected to the drive device.

Furthermore, the vehicle rigid axle has a first (e.g. left) wheel shaft and a second (e.g. right) wheel shaft, wherein the first wheel shaft and second wheel shaft can be connected to wheels of the commercial vehicle.

The vehicle's rigid axle also has a transverse differential (e.g. a transfer case) that is drivingly connected to the input element, the first wheel shaft and the second wheel shaft. For example, the transverse differential can comprise a differential cage (e.g. firmly connected to a ring gear), differential gears mounted in the differential cage, a first axle shaft gear connected to the first wheel shaft and/or a second axle shaft gear connected to the second wheel shaft. The transverse differential is preferably used to distribute the received drive torque to the first wheel shaft and the second wheel shaft, e.g. to enable speed differences between the first wheel shaft and the second wheel shaft when cornering.

The vehicle rigid axle also has an axle bridge in which the first wheel shaft, the second wheel shaft and the transverse differential are accommodated (at least in sections).

Furthermore, the vehicle rigid axle has one, preferably only one, rotating electrical machine (e.g. a three-phase motor) which is or can be connected to the first wheel shaft and/or the transverse differential (directly or indirectly, such as via a transmission device). The rotating electrical machine is preferably used to vary the drive torque distributed to the first and/or second wheel shaft, e.g. to enable torque vectoring operation. The primary purpose of the rotating electrical machine should therefore preferably not be to provide a drive torque to propel the commercial vehicle (this can be done via the drive device, for example), but rather to influence (e.g. increase or decrease) a drive torque provided (by the drive device) to the respective wheel shafts. Accordingly, the rotating electrical machine can also be understood in this context, for example, as an (electromagnetic) actuator.

In this case, the rotating electrical machine is attached and/or supported (e.g. in the middle on the outside) to the axle bridge. This advantageously makes it possible to provide an electrical torque vectoring system for a commercial vehicle. which is based on the known concept of a rigid axle. In contrast to subtractive, e.g. brake-based, torque vectoring systems, no additional dynamic power supply is required to compensate for the drive torque absorbed, e.g. by brakes. A further advantage is that by using appropriate transmission devices, it can be ensured that the rotating electric machine does not rotate when driving on a straight stretch and a correspondingly high level of efficiency can be achieved. Ultimately, the vehicle rigid axle disclosed here also enables the use of correspondingly powerful electric machines (e.g. with an output of 80 kW), as is required to generate the large drive torque differences sometimes required in the commercial vehicle sector.

According to a first aspect, the axle bridge can have a fastening section (e.g. on the axle bridge side) (e.g. a flange section). The fastening section can be arranged, for example, in the middle and/or on the outside of the axle bridge. The rotating electrical machine can be fastened (e.g. detachably) (e.g. flanged) and/or carried on the fastening section. In an advantageous manner, this can provide secure storage of the rotating electrical machine, preferably without the need for additional mounts for the rotating electrical machine on the commercial vehicle. Furthermore, this can simplify the manufacture of the commercial vehicle, since the pre-assembled rigid vehicle axle including the rotating electrical machine can be attached to the commercial vehicle in one work step.

According to a further aspect, the rotating electrical machine can have a power (e.g. rated power) of at least 20 kW, preferably at least 30 kW, particularly preferably at least 40 kW. In an advantageous manner, the drive torque differences required in the commercial vehicle sector for torque vectoring operation can thereby be provided.

According to a further aspect, the axle bridge can have a first axle bridge shell (e.g. a first axle bridge half shell) and a second axle bridge shell (e.g. a second axle bridge half shell). The first axle bridge shell and the second axle bridge shell can be connected to one another (e.g. welded) to form a tubular body. Alternatively, the axle bridge can also be formed in one piece, e.g. as a one-piece cast part.

According to a further aspect, the vehicle axle can have two wheel carriers (e.g. a first wheel carrier and a second wheel carrier), the two wheel carriers being connected to one another via the axle bridge. For example, each of the two wheel carriers can be fastened (e.g. flanged) and/or supported on the axle bridge (e.g. each on a front end region of the axle bridge). Preferably, each of the two wheel carriers has a braking device (e.g. a drum brake), a wheel bearing, a planetary gear, and/or a connection point (e.g. in the form of several blind holes) for fastening at least one of the wheels of the commercial vehicle. This advantageously enables stable mounting of the wheel carriers.

According to a further aspect, the vehicle rigid axle can be designed to increase the drive torque distributed to the first wheel shaft and (simultaneously) reduce the drive torque distributed to the second wheel shaft by operating the rotating electric machine in a first (e.g. anti-clockwise) direction of rotation. Furthermore, the vehicle rigid axle can be designed to reduce the drive torque distributed to the first wheel shaft and (simultaneously) increase the drive torque distributed to the second wheel shaft by operating the rotating electric machine in a second (e.g. clockwise) direction of rotation (e.g. opposite to the first direction of rotation). The vehicle rigid axle is thus preferably designed to redistribute the drive torque from the first wheel shaft to the second wheel shaft or vice versa depending on the direction of rotation of the rotating electric machine. In an advantageous manner, an electrical torque control with the aforementioned advantages over subtractive, e.g. brake-based, torque controls can thus be provided.

According to a further aspect, the rotating electric machine can have a power take-off (e.g. a power take-off shaft) which can be connected to an auxiliary unit (e.g. a compressor and/or a pump) of the commercial vehicle. The rotating electric machine can thus preferably be designed to provide torque to both the first wheel shaft or the transverse differential and to an auxiliary unit of the commercial vehicle. In an advantageous manner, this makes it possible to achieve efficient dual use of the rotating electric machine, which is sometimes only required for the electric torque control in certain operating situations.

According to a further aspect, the vehicle axle can have a transmission device (e.g. in the form of several meshing gears). The rotating electric machine can be connected to the first wheel via the transmission device. shaft and/or the transverse differential (e.g. its differential cage). The transmission device can preferably interact directly with the first wheel shaft and/or the transverse differential. For example, the transmission device can have a wheel shaft output component that is or can be directly connected to the first wheel shaft. In addition or alternatively, the transmission device can have a transverse differential output component that is or can be directly connected to the transverse differential. However, it is also possible for a wheel coupling device to be arranged between the transmission device or its wheel shaft output component and the first wheel shaft. In addition or alternatively, a (further) differential coupling device can also be arranged between the transmission device or its transverse differential output component and the transverse differential.

In a preferred embodiment, the transmission device can comprise two planetary gears, preferably coupled to one another. For example, the transmission device can have a first planetary gear and a second planetary gear. The first planetary gear can have a first ring gear, a first sun gear, a first planet carrier and a plurality of first planet gears. Furthermore, the second planetary gear can have a second ring gear, a second sun gear, a second planet carrier and a plurality of second planet gears. The rotating electrical machine can be or can be connected to the transverse differential via the first planetary gear, for example, while the rotating electrical machine can be or can be connected to the first wheel shaft via the second planetary gear.

In one possible embodiment, the first ring gear can be firmly connected to the axle bridge. The first planet carrier can be connected to the transverse differential. For example, the first planet carrier can be connected in a rotationally fixed manner to the differential carrier of the transverse differential and/or to a ring gear of the transverse differential that is firmly connected to the differential carrier. The first sun gear can be arranged around the first wheel shaft. The plurality of first planet gears can be rotatably mounted on the first planet carrier and can be in meshing engagement with the first ring gear and the first sun gear. The second ring gear can be arranged rotatably around the first wheel shaft and can be or can be connected to the rotating electrical machine. The second planet carrier can be rotationally fixedly connected to the first wheel shaft. The second sun gear can be arranged around the first wheel shaft and can be rotationally fixedly connected or coupled to the first sun gear. The plurality of second planet gears can be rotatably mounted on the second planet carrier and can be in meshing engagement with the second ring gear and the second sun gear.

In a further possible embodiment, the first ring gear can be arranged around the first wheel shaft. The first planet carrier can be connected to the transverse differential. For example, the first planet carrier can be connected in a rotationally fixed manner to the differential carrier of the transverse differential and/or to a ring gear of the transverse differential that is firmly connected to the differential carrier. The first sun gear can be arranged around the first wheel shaft and can be or can be connected in a driving manner to the rotating electrical machine. The plurality of first planet gears can be rotatably mounted on the first planet carrier and can be in meshing engagement with the first ring gear and the first sun gear. The second ring gear can be rotatably arranged around the first wheel shaft and can be connected or coupled to the first ring gear in a rotationally fixed manner. The second planet carrier can be connected in a rotationally fixed manner to the first wheel shaft. The second sun gear can be firmly coupled to the axle bridge. The plurality of second planet gears can be rotatably mounted on the second planet carrier and can be in meshing engagement with the second ring gear and the second sun gear.

According to a further aspect, the rotating electrical machine can have a housing (e.g. made of metal). The housing can have a housing section (e.g. on the housing side) (e.g. a flange section) for connecting to a fastening section of the axle bridge. Preferably, parts of the vehicle axle, e.g. the first and second wheel shafts and the transverse differential, are thus enclosed by the axle bridge, while the rotating electrical machine and possibly other components (see below) are enclosed by the housing of the rotating electrical machine. As will be described in more detail below, this can advantageously enable a modular approach to manufacturing the vehicle rigid axle.

According to a further aspect, the transmission device can be arranged at least partially in the housing. For example, at least parts of the transmission device can be carried by the housing or mounted on the housing (e.g. on its inner wall). In addition or alternatively, the transmission device can also be arranged at least partially outside the axle bridge. Preferably, the transmission device is therefore not completely accommodated in the axle bridge. By integrating the transmission device or By integrating parts of the transmission device into the housing, a module can be advantageously provided, e.g. one that can be flanged onto the axle bridge, via which a torque vectoring functionality can be easily integrated into an existing axle bridge.

According to a further aspect, the vehicle axle can have a clutch device (e.g. a friction clutch device). The clutch device can be designed to drive the rotating electric machine to the first wheel shaft and/or the transverse differential in a first clutch state and to drive the rotating electric machine to the first wheel shaft and/or the transverse differential in a second clutch state. The clutch device can, for example, have a wheel clutch device arranged between the transmission device and the first wheel shaft. In addition or alternatively, the clutch device can also have a differential clutch device arranged between the transmission device and the transverse differential. In an advantageous manner, this can, for example, realize complete decoupling of the rotating electric machine from the drive train in operating states in which no torque vectoring is required (e.g. while driving straight ahead on a motorway). In one possible embodiment, the clutch device is arranged outside the axle bridge, e.g. in the housing of the rotating electric machine.

According to a further aspect, the vehicle axle can have a differential lock. The differential lock can be designed to couple the first wheel shaft and the second wheel shaft to one another in a rotationally fixed manner. For example, the differential lock can be designed to block the rotating electrical machine or to block a rotation of a rotor of the rotating electrical machine. For this purpose, the differential lock can have, for example, a clutch and/or brake (for a positive and/or non-positive connection). The differential lock is preferably arranged outside the axle bridge, e.g. in the housing of the rotating electrical machine.

According to a further aspect, the vehicle axle can have an inverter unit for generating three-phase current. For example, the inverter unit can be designed to convert a direct voltage provided by a battery device of the commercial vehicle into an alternating voltage. Preferably, the alternating voltage or the three-phase current is used to drive the rotating electrical machine. In one embodiment, the inverter unit (e.g. together with a stator and rotor of the rotating electrical machine) is accommodated in the housing of the rotating electrical machine.

The disclosure also relates to a commercial vehicle. A commercial vehicle can generally be understood as a vehicle which, due to its design and equipment, is specifically designed for transporting people, transporting goods or towing trailers. For example, the commercial vehicle can be a truck, a semi-trailer, a construction vehicle, a bus and/or an agricultural machine (e.g. a tractor).

The commercial vehicle has a rigid vehicle axle as described in this document. Accordingly, the features described in this document in connection with the rigid vehicle axle should also be disclosed and claimable in connection with the commercial vehicle. For example, the rigid vehicle axle can be designed as a rear axle of the commercial vehicle. Furthermore, the commercial vehicle can have a drive device (e.g. an internal combustion engine and/or an electric motor) for generating a drive torque (e.g. for propelling the commercial vehicle). The drive device can be or can be connected to the input element of the rigid vehicle axle. Preferably, however, the rotating electric machine is not directly connected to the input element.

According to one aspect, the rotating electric machine can be arranged behind or in front of the axle bridge in the vehicle's longitudinal direction. For example, the rotating electric machine can be attached to a middle and (with respect to the vehicle's longitudinal direction) rear region of the axle bridge.

In addition or alternatively, the rotating electrical machine can have a rotor shaft that can rotate about a rotation axis and can be oriented transversely to the vehicle's longitudinal direction. For example, the rotating electrical machine can be installed in the commercial vehicle transversely to the vehicle's longitudinal direction or can be designed as a transverse motor.

According to a further aspect, the commercial vehicle can have a vehicle axle (e.g. designed as a steered front axle) or another vehicle axle. This vehicle axle can have a hydrostatic auxiliary drive. The hydrostatic auxiliary drive can, for example, be switched on as needed or temporarily to support propulsion by the vehicle's rigid axle. Preferably, the hydrostatic auxiliary drive comprises several hydraulic motors, each of which, for example, assigned to a wheel (e.g. front wheel) of the commercial vehicle.

Furthermore, the commercial vehicle can have a control device (e.g. a control unit) which is designed to operate the hydrostatic auxiliary drive and the rotating electric machine together (e.g. coordinated with one another) depending on at least one operating variable of the commercial vehicle (e.g. vehicle speed, vehicle acceleration, axle load distribution and/or differential speed between wheels of the commercial vehicle). In an advantageous manner, effective yaw control of the commercial vehicle can be provided by coordinating the main and auxiliary drives.

The disclosure further relates to a modular vehicle rigid axle system for a commercial vehicle. The modular vehicle rigid axle system has a vehicle rigid axle that can be adapted either as a first vehicle rigid axle (which, for example, enables torque vectoring operation) or (or and) as a second vehicle rigid axle (which, for example, does not enable corresponding torque vectoring operation). The vehicle rigid axle can, for example, be a vehicle rigid axle as disclosed herein. Accordingly, the features described in this document in connection with the vehicle rigid axle should also be disclosed and claimable in connection with the modular vehicle rigid axle system.

The first rigid vehicle axle and the second rigid vehicle axle can each have: an input element for receiving a drive torque generated by a drive device (e.g. an internal combustion engine); a first wheel shaft and a second wheel shaft that can be driven to wheels of the commercial vehicle; a transverse differential that is driven to the input element, the first wheel shaft and the second wheel shaft, preferably for distributing the coupled drive torque to the first wheel shaft and the second wheel shaft; and an axle bridge in which the first wheel shaft, the second wheel shaft and the transverse differential are accommodated. The input element, the first wheel shaft, the second wheel shaft, the transverse differential and/or the axle bridge of the first rigid vehicle axle and the second rigid vehicle axle are designed identically (e.g. designed as identical parts).

This has the advantage that the production costs for the first and second rigid vehicle axles can be reduced considerably by using many identical parts. This means that rigid vehicle axles can also be produced cost-efficiently in small quantities. This can be particularly important when transitioning from commercial vehicles without the corresponding torque vectoring functionality to commercial vehicles with the corresponding torque vectoring functionality.

Preferably, only the first rigid vehicle axle further comprises one, preferably exclusively one, rotating electrical machine (e.g. a three-phase motor) which is or can be connected (e.g. via a transmission device) to the first wheel shaft and/or the transverse differential of the first rigid vehicle axle. Preferably, this rotating electrical machine is used to vary the drive torque distributed to the first wheel shaft and/or to the second wheel shaft of the first rigid vehicle axle, e.g. to enable torque vectoring operation. In this case, it can be provided that the rotating electrical machine is fastened and/or carried (e.g. centrally and/or externally) to the axle bridge of the first rigid vehicle axle.

Overall, this makes it possible to advantageously provide a modular construction system for rigid vehicle axles that are either provided with a rotating electric machine for commercial vehicles with a torque vectoring functionality or without a rotating electric machine for commercial vehicles without a corresponding torque vectoring functionality. By means of such a modular construction system, production costs can be reduced considerably in an advantageous manner.

According to one aspect, only the first rigid vehicle axle can have a transmission device via which the rotating electric machine is or can be connected in a driving manner to the first wheel shaft and/or the transverse differential.

In addition or alternatively, only the first rigid vehicle axle can have a coupling device which is designed to drive-connect the rotating electric machine to the first wheel shaft and/or the transverse differential in a first coupling state and to drive-disconnect the rotating electric machine from the first wheel shaft and/or the transverse differential in a second coupling state.

In addition or alternatively, only the first rigid vehicle axle can have an inverter unit for generating three-phase current.

In addition or alternatively, the first rigid vehicle axle and the second rigid vehicle axle can each have a fastening section (e.g. a flange section), preferably for attaching the rotating electrical machine. While in the first rigid vehicle axle the rotating electrical machine can be (actually) fastened (e.g. flanged) and/or carried to the fastening section, in the case of the second rigid vehicle axle the corresponding fastening section can be blind-flanged and/or covered.

• 1A eine schematische Seitenansicht einer Achsbrücke einer Fahrzeugstarrachse für ein Nutzfahrzeug gemäß einer Ausführungsform ohne montierte rotierende elektrische Maschine;
• 1B eine perspektivische Ansicht einer Achsbrücke einer Fahrzeugstarrachse für ein Nutzfahrzeug gemäß einer Ausführungsform mit montierter rotierender elektrischer Maschine;
• 1C eine schematische Darstellung einer rotierenden elektrischen Maschine zur Anbringung an eine Fahrzeugstarrachse gemäß einer Ausführungsform;
• 2A eine schematische Darstellung einer Fahrzeugstarrachse für ein Nutzfahrzeug gemäß einer Ausführungsform;
• 2B eine schematische Darstellung einer Fahrzeugstarrachse für ein Nutzfahrzeug gemäß einer weiteren Ausführungsform;
• 3 eine schematische Darstellung eines Nutzfahrzeugs gemäß einer Ausführungsform; und
• 4 eine schematische Darstellung eines modularen Fahrzeugstarrachsensystems gemäß einer Ausführungsform.

The embodiments and features described above can be combined with one another as desired. Further details and advantages are described below with reference to the attached drawings. They show:

• 1A a schematic side view of an axle bridge of a rigid vehicle axle for a commercial vehicle according to an embodiment without a mounted rotating electric machine;
• 1B a perspective view of an axle bridge of a rigid vehicle axle for a commercial vehicle according to an embodiment with a mounted rotating electric machine;
• 1C a schematic representation of a rotating electric machine for attachment to a vehicle rigid axle according to an embodiment;
• 2A a schematic representation of a rigid vehicle axle for a commercial vehicle according to an embodiment;
• 2B a schematic representation of a rigid vehicle axle for a commercial vehicle according to a further embodiment;
• 3 a schematic representation of a commercial vehicle according to an embodiment; and
• 4 a schematic representation of a modular vehicle rigid axle system according to an embodiment.

The embodiments shown in the figures correspond at least partially, so that similar or identical parts are provided with the same reference numerals and for their explanation reference is also made to the description of the other embodiments or figures in order to avoid repetition.

The figures show at least a section of a rigid vehicle axle 10 for a commercial vehicle 20. The rigid vehicle axle 10 can be used, for example, as a (e.g. non-steerable) rear axle in a commercial vehicle 20, such as a truck or bus.

The vehicle rigid axle 10 has an input element 11, a first wheel shaft 12a, a second wheel shaft 12b, a transverse differential 13, an axle bridge 14 and a rotating electric machine 15 (see e.g. 2A and 2B) .

The input element 11 preferably serves to receive a drive torque generated by a drive device 22 (e.g. by an internal combustion engine and/or by an electric motor) of the commercial vehicle 20. The input element 11, the first wheel shaft 12a and the second wheel shaft 12b are drivingly connected to the transverse differential 13 (e.g. in the form of a transfer case).

For example, the transverse differential 13 may comprise a differential cage 13a, differential gears 13b mounted in the differential cage 13a, a first axle shaft gear 13c.1 and a second axle shaft gear 13c.2 (see e.g. 2A and 2B) The first axle shaft gear 13c.1 can be connected (in a rotationally fixed manner) to the first wheel shaft 12a. The second axle shaft gear 13c.2 can be connected (in a rotationally fixed manner) to the second wheel shaft 12b. The first axle shaft gear 13c.1 and/or the second axle shaft gear 13c.2 can be in meshing engagement with the differential gears 13b. The transverse differential 13 is preferably used to distribute the received drive torque to the first wheel shaft 12a and the second wheel shaft 12b.

The input element 11, the first wheel shaft 12a, the second wheel shaft 12b, and/or the transverse differential 13 can be accommodated in the axle bridge 14, at least in sections.

The axle bridge 14 can be an immovable and/or rigid hollow body (cf. 1A) . The axle bridge 14 or the hollow body can be made of (e.g. rigid) steel. Two wheel carriers 16 of the vehicle's rigid axle 10 can be connected to one another (e.g. permanently) via the axle bridge 14 (cf. 3 ). In one embodiment, the axle bridge 14 can have two interconnected (e.g. welded) axle bridge shells (e.g. axle bridge half shells). The axle bridge 14 or the two axle bridge shells can delimit or enclose a receiving space of the axle bridge. The input element 11, the first wheel shaft 12a, the second wheel shaft 12b, and/or the transverse differential 13 can be arranged at least in sections in this receiving frame.

The rotating electrical machine 15 (e.g. a three-phase motor) is preferably arranged outside the axle bridge 14 (cf. 1B) . The rotating electrical machine 15 can be fastened (e.g. screwed) (e.g. in the middle) to the outside of the axle bridge 14 (e.g. detachably). The rotating electrical machine 15 can be arranged, for example, in the vehicle's longitudinal direction L behind the axle bridge 14 (cf. 3 ). The rotating electric The mechanical machine 15 can be held by the axle bridge 14 or carried by the axle bridge 14. The axle bridge 14 can have a (first) fastening section 14a (e.g. a flange section). As shown by way of example in 1A As shown, the (first) fastening section 14a can be arranged in a central region of the axle bridge 14. Furthermore, the axle bridge 14 (e.g. on the front side) can have further fastening sections (e.g. further flange sections) for attaching the wheel carriers 16.

The rotating electrical machine 15 can have a (second) fastening section 15a corresponding to the (first) fastening section 14a of the axle bridge 14 (cf. 1C ). The (first) fastening section 14a of the axle bridge 14 and the (second) fastening section 15a of the rotating electrical machine 15 can be connected to one another in a force-fitting and/or form-fitting manner, for example by means of fastening elements (e.g. screws) and/or can be designed to transmit a load exerted by the rotating electrical machine 15, preferably a weight force, from the rotating electrical machine 15 to the axle bridge 14.

The rotating electrical machine 15 can have a housing 15c (e.g. a metal housing) or can be enclosed by a housing 15c (see e.g. 1B and 1C ). The housing 15c can have a housing section 15c.1 (e.g. in the form of a flange section on the housing side) for connection to a fastening section 14a of the axle bridge 14. Accordingly, the housing section 15c.1 can form the (second) fastening section 15a of the rotating electrical machine 15. The housing 15c of the rotating electrical machine 15 can be screwed and/or riveted to the axle bridge 14 (e.g. via the housing section 15c.1).

The rotating electric machine 15 is preferably used to vary the drive torque distributed to the first wheel shaft 12a and/or the second wheel shaft 12b. For example, torque vectoring operation can be enabled by means of the rotating electric machine 15, as will be described in more detail below. For this purpose, it is provided that the rotating electric machine 15 is or can be connected to the first wheel shaft 12a and/or the transverse differential 13 (e.g. via a transmission device 17). For example, the first wheel shaft 12a can be driven directly or indirectly (e.g. via the transmission device 17) by means of the rotating electric machine 15. In addition or alternatively, the transverse differential 13 (e.g. its differential cage 13a) can be driven directly or indirectly (e.g. via the transmission device 17) by means of the rotating electric machine 15. The rotating electric machine 15 can be designed to actively influence or vary a drive torque distribution between the first wheel shaft 12a and the second wheel shaft 12b.

The rotating electrical machine 15 can have a power (e.g. rated power) between 30 kW and 80 kW. The rotating electrical machine 15 can, as exemplified in 1C is shown, have a rotor-stator unit 15d. The rotor-stator unit 15d can have a stator and a rotor (e.g. equipped with permanent magnets). The stator can be arranged in a rotationally fixed manner within the housing 15c. The rotor can be rotatably mounted on the stator and have a rotor shaft that can rotate about an axis of rotation. Accordingly, the rotor or the rotor shaft can be housed by the housing 15c and/or accommodated in the housing 15c. The rotor shaft or the axis of rotation is preferably oriented transversely to the vehicle's longitudinal direction L. For example, the rotating electrical machine 15 can be designed as a transverse motor.

The rotating electric machine 15 may further comprise a power take-off 15b (cf. 1C ). The power take-off 15b can be coupled to the rotor or the rotor shaft or can be permanently connected in a driving manner. Accordingly, at least part of the power of the rotating electrical machine 15 can be provided at the power take-off 15b. The power take-off 15b can in turn be connected in a driving manner to an auxiliary unit (not shown) of the commercial vehicle 20 (e.g. to a compressor and/or a pump).

Furthermore, the vehicle rigid axle 10 can have an inverter unit 19 (cf. 1C ). The inverter unit 19 can preferably (also) be housed by the housing 15c of the rotating electrical machine 15 and/or be accommodated in the housing 15c (cf. 1C ). The inverter unit 19 can be integrated, for example, in the housing 15c or in the rotating electrical machine 15. Accordingly, the inverter unit 19 can be arranged outside the axle bridge 14. The inverter unit 19 can be designed to generate three-phase current (preferably for the rotating electrical machine 15). Accordingly, the inverter unit 19 can be designed, for example, to convert a direct voltage into an alternating voltage.

Furthermore, the vehicle rigid axle 10 can have a transmission device 17 (e.g. an offset transmission device). The rotating electric machine 15 can be or can be connected in a driving manner to the first wheel shaft 12a and/or the transverse differential 13 via the transmission device 17. For example, the transmission device 17 may have an input component 17.1 (e.g. a drive wheel) (cf. 1C ), which is or can be connected in a driving manner to the rotating electrical machine 15 (e.g. its rotor shaft). The input component 17.1 can be or can be connected in a driving manner directly to the rotating electrical machine 15. Alternatively, the input component 17.1 can also be or can be connected in a driving manner indirectly, e.g. via a coupling device 18 of the vehicle's rigid axle 10, to the rotating electrical machine 15. Furthermore, the transmission device 17 can have a wheel shaft output component 17.2 (e.g. an output gear) which is or can be connected in a driving manner to the first wheel shaft 12a (e.g. directly or indirectly, such as via a coupling gear connected in a rotationally fixed manner to the wheel shaft 12a). In addition or alternatively, the transmission device 17 can have a transverse differential output component 17.3 (e.g. another output gear) which is or can be connected in a driving manner to the transverse differential 13 (e.g. directly or indirectly, such as via another coupling gear connected in a rotationally fixed manner to the transverse differential 13). Preferably, the transverse differential output component 17.3 is or can be connected in a driving manner to a differential cage 13a of the transverse differential 13.

In one embodiment, the transmission device 17 (e.g. together with the rotor-stator unit 15d) can be accommodated in the housing 15c of the rotating electrical machine 15 (at least in sections) (cf. 1C ). For example, parts of the transmission device 17 can be attached to an inner side of the housing 15c in a rotationally fixed manner or can be mounted so that they can rotate. The rotating electrical machine 15 and the transmission device 17 can thus form a module (if necessary together with the inverter unit 19) or can be designed as a module. As a result, the corresponding components can be attached to the corresponding vehicle rigid axle in one work step (e.g. when retrofitting a vehicle rigid axle without torque vectoring operation) and/or detached from the corresponding vehicle rigid axle (e.g. when carrying out maintenance work).

However, it is also possible that the transmission device 17 or parts of the transmission device 17 are accommodated in the axle bridge 14, as is shown by way of example in the 2A and 2B shown.

The gear device 17 can, for example, have several gears that mesh with one another. However, it is also possible for the gear device 17 to comprise a chain and/or gear drive. In a preferred embodiment, the gear device 17 has a first planetary gear 17a and a second planetary gear 17b. The first planetary gear 17a can have a first ring gear 17a.1, a first sun gear 17a.2, a first planet carrier 17a.3 and several first planet gears 17a.4, 17a.5. Furthermore, the second planetary gear 17b can have a second ring gear 17b.1, a second sun gear 17b.2, a second planet carrier 17b.3 and several second planet gears 17b.4, 17b.5. The first planetary gear 17a and second planetary gear 17b are preferably coupled to one another. For example, the first ring gear 17a.1 of the first planetary gear 17a and the second ring gear 17b.1 of the second planetary gear 17b can be connected or coupled to one another in a rotationally fixed manner. Alternatively, the first sun gear 17a.2 of the first planetary gear 17a and the second sun gear 17b.2 of the second planetary gear 17b can also be connected or coupled to one another in a rotationally fixed manner.

2A shows a possible design of the transmission device 17. In this, for example, the first ring gear 17a.1 can be firmly connected to the axle bridge 14. The first planet carrier 17a.3 can be connected to the transverse differential 13. For example, the first planet carrier 17a.3 can be connected in a rotationally fixed manner to a differential cage 13a of the transverse differential 13. The first sun gear 17a.2 can be arranged around the first wheel shaft 12a. For example, the first wheel shaft 12a can be guided (freely rotatable) through the first sun gear 17a.2. The several (e.g. three) first planet gears 17a.4, 17a.5 can be rotatably mounted on the first planet carrier 17a.3 and can be in meshing engagement with the first ring gear 17a.1 and the first sun gear 17a.2. The second ring gear 17b.1 can be arranged to rotate around the first wheel shaft 12a and be drivingly connected or connectable to the rotating electrical machine 15. For example, the second ring gear 17b.1 can be in meshing engagement with a rotor wheel 15e that is connected in a rotationally fixed manner to the rotor shaft. The second planet carrier 17b.3 can be connected in a rotationally fixed manner to the first wheel shaft 12a. For example, the second planet carrier 17b.3 can be welded to the first wheel shaft 12a. The second sun gear 17b.2 can be arranged around the first wheel shaft 12a. For example, the first wheel shaft 12a can be guided (freely rotatable) through the second sun gear 17b.2. The first sun gear 17a.2 and the second sun gear 17b.2 can be connected or coupled to one another in a rotationally fixed manner. The plurality of second planetary gears 17b.4, 17b.5 can be rotatably mounted on the second planet carrier 17b.3 and can be in meshing engagement with the second ring gear 17b.1 and the second sun gear 17b.2.

2B shows another possible embodiment of the transmission device 17. In this the first ring gear 17a.1 can be arranged around the first wheel shaft 12a. The first planet carrier 17a.3 can be connected to the transverse differential 13. For example, the first planet carrier 17a.3 can be connected in a rotationally fixed manner to a differential cage 13a of the transverse differential 13. The first sun gear 17a.2 can be arranged around the first wheel shaft 12a. For example, the first wheel shaft 12a can be guided (freely rotatable) through the first sun gear 17a.2. The first sun gear 17a.2 can also be drivingly connected or connectable to the rotating electrical machine 15. For example, the first sun gear 17a.2 can be in meshing engagement with a rotor wheel 15e that is connected in a rotationally fixed manner to the rotor shaft. The plurality (e.g. three) first planetary gears 17a.4, 17a.5 can be rotatably mounted on the first planetary carrier 17a.3 and can be in meshing engagement with the first ring gear 17a.1 and the first sun gear 17a.2. The second ring gear 17b.1 can be arranged to be rotatable around the first gear shaft 12a and can be connected or coupled in a rotationally fixed manner to the first ring gear 17a.1. The second planetary carrier 17b.3 can be connected in a rotationally fixed manner to the first gear shaft 12a. For example, the second planetary carrier 17b.3 can be welded to the first gear shaft 12a. The second sun gear 17b.2 can be firmly connected or coupled to the axle bridge 14. The plurality of second planetary gears 17b.4, 17b.5 can be rotatably mounted on the second planet carrier 17b.3 and can be in meshing engagement with the second ring gear 17b.1 and the second sun gear 17b.2.

Overall, it can be achieved that by operating the rotating electrical machine 15 in a first direction of rotation, the drive torque distributed to the first wheel shaft 12a is increased and the drive torque distributed to the second wheel shaft 12b is reduced. In addition or alternatively, by operating the rotating electrical machine 15 in a second direction of rotation, preferably opposite to the first direction of rotation, the drive torque distributed to the first wheel shaft 12a can be reduced and the drive torque distributed to the second wheel shaft 12b can be increased.

In the case of the embodiment described above, for example, assuming a torque M _input applied to the input element 11 and a torque M _EM applied by the rotating electrical machine 15, depending on the direction of rotation of the rotating electrical machine 15, a torque of M ₁ = (M _input ± M _EM )/2 can be set on the first wheel shaft 12a and a torque of M ₂ = (M _input ∓ M _EM )/2 can be set on the second wheel shaft 12b. With M _EM ≠ 0, an electrical torque control can thus be implemented. While with M _EM = 0, the effect of a classic differential can be present.

3 shows a schematic representation of a commercial vehicle 20, having a rigid vehicle axle 10, as described herein. For example, the rigid vehicle axle 10 forms a rear axle of the commercial vehicle 20. Furthermore, the commercial vehicle 20 can have a drive device 22 for generating a drive torque. For example, the drive device 22 can be an internal combustion engine or an electric motor. The drive device 22 can be or can be connected to the input element 11 of the rigid vehicle axle 10 (e.g. via a cardan shaft). Accordingly, the rear axle of the commercial vehicle 20 can be a driven axle.

Furthermore, the commercial vehicle 20 can have a further vehicle axle 25. For example, the further vehicle axle 25 can be designed as a steered front axle. The further vehicle axle 25 can have a hydrostatic auxiliary drive 26. For example, the hydrostatic auxiliary drive 26 can comprise several hydraulic motors 27 (e.g. wheel hub hydraulic motors). The several hydraulic motors 27 can each be assigned to a wheel 24 of the further vehicle axle 25. For example only, the further vehicle axle 25 can have a steerable left wheel and a steerable right wheel, wherein the left wheel can be driven by a left hydraulic motor of the several hydraulic motors 27, while the right wheel can be driven by a separate right hydraulic motor of the several hydraulic motors 27.

Furthermore, the commercial vehicle 20 can have a supply circuit 30 for supplying the hydrostatic auxiliary drive 26 or the several hydraulic motors 27 with hydraulic fluid (e.g. oil).

The supply circuit 30 can have a container 31 (e.g. oil container) for storing the hydraulic fluid. The supply circuit 30 can have a feed pump 32 (e.g. a hydraulic constant pump) for conveying a volume flow of the hydraulic fluid. The feed pump 32 is preferably connected to a power take-off of the drive device 22 and/or the power take-off 15b of the rotating electrical machine 15. The supply circuit 30 can also have a filter 33 (e.g. low-pressure filter) and/or a pressure relief valve 34. The supply circuit 30 preferably also has a control unit 35 with hydraulic control and regulating valves. The control unit 35 can be designed to divide the volume flow conveyed by the feed pump 32 into partial flows, each of which is assigned to one of the several hydraulic motors 27. For example, the control unit 35 can be designed to selectively supply or drive only the left hydraulic motor with hydraulic fluid, to supply or drive only the right hydraulic motor with hydraulic fluid, or to supply or drive both hydraulic motors with hydraulic fluid. The supply circuit 30 can also have a return filter 36 and/or a heat exchanger 37 (e.g. cooler).

The commercial vehicle 20 can further comprise a control device 28, which can be designed to operate the hydrostatic auxiliary drive 26 and the rotating electric machine 15 jointly (e.g. coordinated with one another) depending on at least one operating variable of the commercial vehicle 20.

For example, the control device 28 can be designed to operate the rotating electrical machine 15 in a first direction of rotation (preferably in order to thereby increase the drive torque distributed to the first wheel shaft 12a and reduce the drive torque distributed to the second wheel shaft 12b) and at the same time operate the left hydraulic motor with a higher power than the right hydraulic motor, e.g. in order to thereby support torque vectoring. In addition or alternatively, the control device 28 can also be designed to operate the rotating electrical machine 15 in a second direction of rotation (preferably in order to thereby increase the drive torque distributed to the second wheel shaft 12b and reduce the drive torque distributed to the first wheel shaft 12a) and at the same time operate the right hydraulic motor with a higher power than the left hydraulic motor.

4 illustrates a modular vehicle rigid axle system. The modular vehicle rigid axle system has a vehicle rigid axle 10, which can be adapted either as a first vehicle rigid axle 10.1 or (or and) as a second vehicle rigid axle 10.2.

The first rigid vehicle axle 10.1 and the second rigid vehicle axle 10.2 each have an input element 11, a first wheel shaft 12a, a second wheel shaft 12, a transverse differential 13 and an axle bridge 14, whereby only the axle bridge 14 is shown here as an example. The first wheel shaft 12a, the second wheel shaft 12b and the transverse differential 13 are accommodated in the axle bridge 14. The input element 11, the first wheel shaft 12a, the second wheel shaft 12b, the transverse differential 13 and the axle bridge 14 of the first rigid vehicle axle 10.1 and the second rigid vehicle axle 10.2 are designed identically (e.g. as identical parts).

To enable torque vectoring operation, (only) the first rigid vehicle axle 10.1 further comprises a rotating electrical machine 15 (e.g. a three-phase motor). This is or can be connected in a driving manner to the first wheel shaft 12a and/or the transverse differential 13 (e.g. via a transmission device 17) and is fastened and/or carried (e.g. centrally and/or externally) on the axle bridge 14 of the first rigid vehicle axle 10.1.

In contrast, the second vehicle rigid axle 10.2 does not have a corresponding rotating electric machine 15 to enable torque vectoring operation. In the second vehicle rigid axle 10.2, for example, the corresponding fastening section 14a for attaching the rotating electric machine 15 can be blind-flanged and/or covered.

In an advantageous manner, a modular construction system can thereby be provided using identical parts, in which the vehicle rigid axle 10 is designed, depending on the desired application, either with a rotating electric machine 15 to enable a torque vectoring functionality or without a rotating electric machine 15, i.e. without a corresponding torque vectoring functionality.

Although the invention has been described with reference to particular embodiments, it will be apparent to one skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. Accordingly, the invention is not intended to be limited to the disclosed embodiments, but is intended to include all embodiments falling within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the subclaims independently of the claims referred to.

list of reference symbols

10

vehicle rigid axle

11

input element

12a

first wheel shaft

12b

second wheel shaft

13

transverse differential

13a

differential cage

13b

balance wheel

13c.1

First axle shaft gear

13c.2

Second axle shaft gear

14

axle bridge

14a

mounting section of the axle bridge

15

Rotating electric machine

15a

mounting section of the rotating electrical machine

15b

power take-off

15c

Housing

15c.1

housing section

15d

rotor-stator unit

15e

rotor wheel

16

wheel carrier

17

transmission device

17.1

input component

17.2

wheel shaft output component

17.3

cross-differential output component

17a

First planetary gear

17a.1

First Ring Gear

17a.2

First Sun Wheel

17a.3

First planet carrier

17a.4, 17a.5

First planetary gear

17b

Second planetary gear

17b.1

Second Ring Gear

17b.2

second sun gear

17b.3

second planet carrier

17b.4, 17b.5

second planetary gear

18

coupling device

19

inverter unit

20

commercial vehicle

22

drive device

24

wheel

25

Additional vehicle axle

26

Hydrostatic auxiliary drive

27

hydraulic motor

28

control device

Claims (15)

Rigid vehicle axle (10) for a commercial vehicle (20), preferably a truck or a bus, comprising: an input element (11) for receiving a drive torque generated by a drive device (22), preferably an internal combustion engine; a first wheel shaft (12a) and a second wheel shaft (12b) which can be drivenly connected to wheels (24) of the commercial vehicle (20); a transverse differential (13) which is drivenly connected to the input element (11), the first wheel shaft (12a) and the second wheel shaft (12b) for distributing the received drive torque to the first wheel shaft (12a) and the second wheel shaft (12b); an axle bridge (14) in which the first wheel shaft (12a), the second wheel shaft (12b) and the transverse differential (13) are accommodated; and one, preferably exclusively one, rotating electric machine (15) which is or can be connected in a driving manner to the first wheel shaft (12a) and/or the transverse differential (13) for varying the drive torque distributed to the first wheel shaft (12a) and/or the second wheel shaft (12b), preferably for enabling torque vectoring operation; wherein the rotating electric machine (15) is fastened and/or carried on the axle bridge (14), preferably centrally on the outside. Vehicle rigid axle (10) after claim 1 , wherein: the axle bridge (14) has a fastening section (14a), preferably arranged centrally on the outside of the axle bridge (14), to which the rotating electrical machine (15) is fastened and/or carried, preferably detachably, preferably on a side of the axle bridge (14) opposite the input element (11). Vehicle rigid axle (10) after claim 1 or 2 , wherein: the rotating electrical machine (15) has a power of at least 20 kW, preferably at least 30 kW, particularly preferably at least 40 kW. Rigid vehicle axle (10) according to one of the preceding claims, wherein: the axle bridge (14) has: a first axle bridge shell and a second axle bridge shell, which are connected to one another, preferably welded, to form a tubular body; and/or the vehicle axle (10) further has: two wheel carriers (16) which are connected to one another via the axle bridge (14), wherein preferably each of the two wheel carriers (16) has: a braking device, a wheel bearing, a planetary gear, and/or a connection point for fastening at least one of the wheels (24) of the commercial vehicle (20). Vehicle rigid axle (10) according to one of the preceding claims, wherein the vehicle rigid axle (10) is designed to increase the drive torque distributed to the first wheel shaft (12a) and to reduce the drive torque distributed to the second wheel shaft (12b) by operating the rotating electrical machine (15) in a first direction of rotation; and to reduce the drive torque distributed to the first wheel shaft (12a) and to increase the drive torque distributed to the second wheel shaft (12b) by operating the rotating electrical machine (15) in a second direction of rotation, preferably opposite to the first direction of rotation. Rigid vehicle axle (10) according to one of the preceding claims, wherein: the rotating electric machine (15) has a power take-off (15b) which can be connected in a driving manner to an auxiliary unit of the commercial vehicle (20). Rigid vehicle axle (10) according to one of the preceding claims, further comprising: a transmission device (17) via which the rotating electric machine (15) is or can be connected in a driving manner to the first wheel shaft (12a) and/or the transverse differential (13), wherein preferably: the transmission device (17) comprises two planetary gears coupled to one another. Vehicle rigid axle (10) according to one of the preceding claims, wherein: the rotating electrical machine (15) has a housing (15c), which preferably has a housing section (15c.1) for connection to a fastening section (14a) of the axle bridge (14). Vehicle rigid axle (10) after claim 7 and 8 , wherein: the transmission device (17) is at least partially arranged in the housing (15c) and/or at least partially arranged outside the axle bridge (14). Rigid vehicle axle (10) according to one of the preceding claims, further comprising: a coupling device (18) which is designed: in a first coupling state, to drive-connect the rotating electrical machine (15) to the first wheel shaft (12a) and/or the transverse differential (13) and in a second coupling state, to drive-disconnect the rotating electrical machine (15) from the first wheel shaft (12a) and/or the transverse differential (13), wherein the coupling device (18) is preferably arranged outside the axle bridge (14); and/or a differential lock which is designed to couple the first wheel shaft (12a) and the second wheel shaft (12b) to one another in a rotationally fixed manner, wherein the differential lock is preferably arranged outside the axle bridge (14). Rigid vehicle axle (10) according to one of the preceding claims, further comprising: an inverter unit (19) for generating three-phase current, which is preferably accommodated in a housing (15c) of the rotating electrical machine (15). Commercial vehicle (20), preferably a truck or bus, comprising: a rigid vehicle axle (10) according to one of the preceding claims; and a drive device (22) for generating a drive torque, wherein the drive device (22) is or can be connected to the input element (11) in a driving manner. Commercial vehicle (20) to claim 12 , wherein the rotating electrical machine (15): is arranged behind or in front of the axle bridge (14) in the vehicle longitudinal direction (L); and/or has a rotor shaft which is rotatable about an axis of rotation and is oriented transversely to the vehicle longitudinal direction (L). Commercial vehicle (20) to claim 12 or 13 , further comprising: a further vehicle axle (25), preferably a steered front axle, having a hydrostatic auxiliary drive (26), preferably comprising a plurality of hydraulic motors (27); and a control device (28) which is designed to operate the hydrostatic auxiliary drive (26) and the rotating electrical machine (15) together, preferably in a coordinated manner, depending on at least one operating variable of the commercial vehicle (20). Modular vehicle rigid axle system for a commercial vehicle (20), comprising: a vehicle rigid axle (10), wherein the vehicle rigid axle (10) can be optionally adapted as a first vehicle rigid axle (10.1) or as a second vehicle rigid axle (10.2), wherein the first vehicle rigid axle (10.1) and the second vehicle rigid axle (10.2) each have: - an input element (11) for receiving a drive torque generated by a drive device (22), preferably an internal combustion engine; - a first wheel shaft (12a) and a second wheel shaft (12b), which can be connected in a driving manner to wheels (24) of the commercial vehicle (20); - a transverse differential (13), which is connected in a driving manner to the input element (11), the first wheel shaft (12a) and the second wheel shaft (12b), for dividing the coupled drive torque between the first wheel shaft (12a) and the second wheel shaft (12b); - an axle bridge (14) in which the first wheel shaft (12a), the second wheel shaft (12b) and the transverse differential (13) are accommodated; wherein the input element (11), the first wheel shaft (12a), the second wheel shaft (12b), the transverse differential (13) and/or the axle bridge (14) of the first vehicle rigid axle (10.1) and the second vehicle rigid axle (10.2) are of identical design; and wherein only the first rigid vehicle axle (10.1) further comprises a rotating electrical machine (15) which is or can be drivenly connected to the first wheel shaft (12a) and/or the transverse differential (13) of the first rigid vehicle axle (10.1) for varying the drive torque distributed to the first wheel shaft (12a) and/or the second wheel shaft (12b) of the first rigid vehicle axle (10.1), wherein the rotating electrical machine (15) is fastened and/or carried, preferably centrally on the outside, to the axle bridge (14) of the first rigid vehicle axle (10.1).

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