Wheel hub drive for a motor vehicle and motor vehicle

Abstract

The invention relates to a wheel hub drive (10) for a motor vehicle, comprising a wheel carrier (12), a wheel bearing (14) which has a first bearing shell (16) connected in a rotationally fixed manner to the wheel carrier (12) and a second bearing shell (20) arranged coaxially and rotatably to the first bearing shell (16), an electric machine (24) which has a rotor (30) and a stator (26) connected in a rotationally fixed manner to the wheel carrier (12), a braking device (54) which has a first braking element (56) connected in a rotationally fixed manner to the wheel carrier (12) and a second braking element (58) connected in a rotationally fixed manner to the second bearing shell (20), and a vehicle wheel (40) connected in a rotationally fixed manner to the second bearing shell (20), which vehicle wheel has a wheel disc (46) and a rim (42), wherein the second braking element (58) is arranged bypassing the second bearing shell (20) and bypassing the wheel disc (46) and is connected to the rim (42) in a rotationally fixed manner, bypassing the rotor (30).

Description

[0001] The invention relates to a wheel hub drive for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1. Furthermore, the invention relates to a motor vehicle with at least one such wheel hub drive.

[0002] WO 2022 / 096504 A1 discloses a wheel system for a vehicle, comprising a stator, a rotor and a pivot bearing.

[0003] The object of the present invention is to provide a wheel hub drive for a motor vehicle and a motor vehicle with at least one such wheel hub drive, so that a particularly advantageous braking capability can be realized in a particularly space-saving manner.

[0004] This object is achieved by a wheel hub drive having the features of patent claim 1 and by a motor vehicle having the features of patent claim 11. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] A first aspect of the invention relates to a wheel hub drive, also referred to as a wheel hub drive device or wheel hub drive unit, for a motor vehicle, also simply referred to as a vehicle, which is preferably designed as a motor vehicle, in particular as a passenger car. This means that the motor vehicle, in its fully manufactured state, has the wheel hub drive and can be driven by means of the wheel hub drive, in particular purely electrically. Thus, the wheel hub drive is preferably an electric wheel hub drive, by means of which the motor vehicle can be driven, in particular purely electrically. For example, in its fully manufactured state, the motor vehicle has at least or exactly two vehicle axles, which are arranged one behind the other and thus consecutively in the longitudinal direction of the motor vehicle and are simply also referred to as axles.The respective vehicle axle has at least or exactly two respective vehicle wheels, also simply referred to as wheels, wherein the respective vehicle wheels of the respective vehicle axle are arranged on opposite sides of the motor vehicle in the transverse direction of the motor vehicle. The vehicle wheels of the motor vehicle are ground contact elements by means of which the motor vehicle can be or is supported downwards on a ground in the vertical direction of the motor vehicle. If the motor vehicle is driven along the ground while the motor vehicle is supported downwards on the ground in the vertical direction of the motor vehicle via the ground contact elements, the ground contact elements roll, in particular directly, on the ground. As will be explained in more detail below, in particular exactly a first of the vehicle wheels is a component of the wheel hub drive, which thus has the first vehicle wheel.When reference is made below to the vehicle wheel, this refers to the first vehicle wheel of the wheel hub drive, unless otherwise stated. The vehicle wheel can be driven, in particular purely electrically, by means of the wheel hub drive. The aforementioned wheel hub drive is also referred to as the first wheel hub drive, whereby when reference is made previously and hereinafter to the wheel hub drive, this refers, unless otherwise stated, to the first wheel hub drive. For example, the motor vehicle can have at least one second wheel hub drive provided in addition to the wheel hub drive, which can, for example, in particular precisely, comprise a second of the vehicle wheels, wherein the second vehicle wheel can be driven, in particular purely electrically, by means of the second wheel hub drive. It is preferably provided that the first vehicle wheel and the second vehicle wheel are the vehicle wheels of the same vehicle axle.The previous and following statements regarding the first wheel hub drive can easily be transferred to the second wheel hub drive and vice versa, and the previous and following statements regarding the first vehicle wheel can easily be transferred to the second vehicle wheel and vice versa.

[0006] The wheel hub drive (first wheel hub drive) has a wheel carrier and a wheel bearing, which has a first bearing shell that is connected to the wheel carrier, in particular permanently and in a rotationally fixed manner, and a second bearing shell that is arranged coaxially and rotatably to the first bearing shell. This means that the second bearing shell is rotatable about a wheel rotation axis relative to the first bearing shell and relative to the wheel carrier, wherein the second bearing shell is arranged coaxially to the first bearing shell with respect to the wheel rotation axis. The wheel bearing is preferably a rolling bearing. The rotation axis is also referred to as the main rotation axis or is a main rotation axis of the wheel hub drive. It is conceivable that the first bearing shell and the wheel carrier are formed separately from one another and are connected to one another, in particular permanently and in a rotationally fixed manner.Furthermore, it would generally be conceivable for the first bearing shell and the wheel carrier to be formed integrally with one another and thus connected to one another, in particular permanently and in a rotationally fixed manner. The feature that two components, such as the first bearing shell and the wheel carrier, are formed integrally with one another, is to be understood that the components formed integrally with one another are formed from a single piece, so that the components are formed integrally or in one piece with one another. This means that the components formed integrally with one another are not formed separately from one another and connected to one another, but rather the components are formed from a single piece, that is to say by a body formed from a single piece and thus formed integrally, that is to say integrally manufactured, which is a monoblock.

[0007] For example, the wheel bearing has rolling elements. For example, the first bearing shell forms at least one first raceway for the rolling elements, and the second bearing shell forms, for example, at least one second raceway for the rolling elements. In particular, when the second bearing shell rotates about the axis of rotation relative to the first bearing shell, the rolling elements roll on the first raceway and on the second raceway, in particular directly in each case, so that, for example, they actually touch the first raceway and the second raceway, in particular directly in each case.

[0008] The wheel hub drive also has an electric machine which has a stator which is connected to the wheel carrier, in particular permanently and in a rotationally fixed manner. The electric machine preferably has a rotor. The rotor can be driven by means of the stator and can therefore rotate about a machine axis of rotation relative to the stator. It is preferably provided that the rotor is arranged coaxially to the bearing shells, so that the machine axis of rotation preferably coincides with the wheel axis of rotation or main axis of rotation. By driving the rotor, the second bearing shell can be driven by means of the rotor and can therefore rotate about the wheel axis of rotation relative to the first bearing shell and relative to the wheel carrier. The wheel hub drive also has the vehicle wheel (first vehicle wheel). The vehicle wheel has a rim and a wheel disc.In this case, for example, a tire, which is made in particular of rubber and is designed separately from the wheel disc and separately from the rim and can be a component of the vehicle wheel, is mounted on the rim and thus fastened to the rim. In particular, when the vehicle wheel rolls, in particular directly, on the aforementioned ground, the tire rolls or rolls, in particular directly, on the ground. The vehicle wheel is connected in a rotationally fixed manner to the second bearing shell, in particular such that the wheel disc is connected in a rotationally fixed manner to the second bearing shell, in particular such that the wheel disc is connected in a rotationally fixed manner to the second bearing shell, so that preferably the vehicle wheel is connected in a rotationally fixed manner to the second bearing shell via the wheel disc.In particular, it is provided that the vehicle wheel is connected to the second bearing shell in a non-destructively detachable manner such that the vehicle wheel is connected to the second bearing shell in a rotationally fixed manner, in particular via the wheel disc.

[0009] The wheel hub drive also has a braking device, which very preferably is or forms a service brake for the motor vehicle. Very particularly, the braking device is a friction brake. The braking device has a first braking element, which is in particular permanently connected to the wheel carrier in a rotationally fixed manner, and a second braking element, which is in particular permanently connected to the second bearing shell, in particular permanently connected to the second bearing shell. By means of the braking elements, the second bearing shell and thus the vehicle wheel can be braked with respect to rotations occurring about the wheel rotation axis and relative to the first bearing shell and thus relative to the wheel carrier through the interaction of the braking elements, in particular in a frictional, i.e. frictionally engaged, manner, whereby the motor vehicle or the vehicle wheel can be braked. In particular, to brake the vehicle wheel, the braking elements can be brought into interaction, in particular in a frictional, i.e. frictionally engaged, manner.This means, in particular, that the braking elements can be brought into interaction in order to brake the second bearing shell relative to the first bearing shell and thus relative to the wheel carrier, in particular with regard to the aforementioned rotations of the second bearing shell and thus of the vehicle wheel about the wheel rotation axis and relative to the first bearing shell and relative to the wheel carrier. In other words, by actuating the braking device in particular hydraulically, the braking elements can be brought into interaction, in particular direct interaction, in such a way that the braking elements interact, in particular directly, with one another, in particular such that the braking elements rub, in particular directly, against one another. As a result, the second bearing shell and thus the vehicle wheel can be braked with regard to their respective rotations about the wheel rotation axis and relative to the first bearing shell and relative to the wheel carrier.This allows the vehicle wheel or motor vehicle to be braked. The second braking element is connected, in particular permanently, to the bearing shell 20 in a rotationally fixed manner.

[0010] In order to be able to realize a particularly advantageous braking capability, in particular of the vehicle wheel, in a particularly space-saving manner, it is provided according to the invention that the second braking element is connected to the rim in a rotationally fixed manner, bypassing the second bearing shell and bypassing the wheel disc and bypassing the rotor, in particular permanently, and is therefore connected to the rim in a rotationally fixed manner, in particular permanently.The feature that the second brake element is connected to the rim in a rotationally fixed manner, bypassing the second bearing shell, the wheel disc, and the rotor, means that, with respect to a force flow along which forces and torques can be or are transmitted between the second brake element and the rim, in particular in order to brake the vehicle wheel by means of the braking device, neither the second bearing shell nor the wheel disc nor the rotor is arranged in the force flow between the second brake element and the rim. In other words, the second bearing shell is not arranged in the force flow between the second brake element and the rim, and the wheel disc is also not arranged in the force flow between the second brake element and the rim, and the rotor is also not arranged in the force flow between the second brake element and the rim.Thus, when the vehicle wheel is braked by means of the braking device, the forces and torques intended to brake the vehicle wheel do not flow or stream via the second bearing shell, the wheel disc, or the rotor on their way from the second brake element to the rim or vice versa. This allows the aforementioned force flow, also referred to as the force path, to be kept particularly short. The forces and / or torques that occur when the vehicle wheel is braked by means of the braking device and are designed or intended to brake the vehicle wheel are also referred to as braking forces.Thus, when the vehicle wheel is braked by means of the braking device, the braking forces generated and designed to brake the vehicle wheel do not flow or stream from the second braking element to or onto the rim or vice versa via the second bearing shell, the wheel disc, or the rotor. As a result, the force flow via which the braking forces can be or are transmitted between the second braking element and the rim in order to brake the vehicle wheel by means of the braking device can be kept particularly low, whereby the vehicle wheel can be braked effectively and efficiently. In addition, a particularly space-saving arrangement for the line of sight tracking can be realized, so that a particularly compact and therefore space-saving design of the wheel hub drive can be achieved.Furthermore, the wheel hub drive can be designed to be particularly lightweight, so that excessively high unsprung masses can be avoided.

[0011] In the context of the present disclosure, the feature that two components such as the first bearing shell or the second bearing shell and the wheel disc or the vehicle wheel are connected to one another in a rotationally fixed manner is to be understood as meaning that the components connected to one another in a rotationally fixed manner are arranged coaxially to one another and, in particular when the components are driven, rotate together or simultaneously about a component rotation axis common to the components, such as the rotation axis, at the same angular velocity, in particular relative to a reference element such as a wheel carrier.In other words, two elements, such as the second bearing shell and the vehicle wheel, are connected to one another in a rotationally fixed manner if they are arranged coaxially to one another, in particular with respect to their component rotation axis or with respect to a rotational symmetry axis, and if they are connected to one another in such a way that they always rotate at the same angular velocity. An element is connected to a housing in a rotationally fixed manner if it cannot be rotated relative to the housing. Thus, for example, an element is connected to the wheel carrier in a rotationally fixed manner if it cannot be rotated relative to the wheel carrier.

[0012] The feature that two components are connected or coupled to one another in a torque-transmitting manner means that the components are coupled or connected to one another in such a way that torque can be transmitted between the components. If the components are connected or coupled to one another in a rotationally fixed manner, the components are also connected or coupled to one another in a torque-transmitting manner. Two components connected to one another in a torque-transmitting manner can thus be connected to one another in a rotationally fixed manner. Furthermore, it is conceivable that two components connected to one another in a torque-transmitting manner are connected to one another in a torque-transmitting manner via an intermediate transmission unit, so that torque can be transmitted between the components via the transmission unit, while the components are connected to one another in a torque-transmitting manner, although the components can be rotatable relative to one another.

[0013] The feature that two components, such as the second bearing shell and the vehicle wheel, in particular the wheel disc, are permanently connected or coupled to one another in a torque-transmitting manner, is to be understood as meaning that a switching element is not provided which can be switched between a coupling state that connects or couples the components to one another in a torque-transmitting manner and a decoupling state in which no torque can be transmitted between the components via the switching element. Rather, the components are always and therefore permanently torque-transmitting, i.e. connected or coupled to one another in such a way that torque can be transmitted between the components. Thus, for example, one of the components can be driven by the other component, or vice versa.

[0014] In particular, the feature that two components such as the second bearing shell and the vehicle wheel, in particular the wheel disc, are permanently connected or coupled to one another in a rotationally fixed manner is to be understood as meaning that a switching element is not provided which can be switched between a coupling state which connects or couples the components to one another in a rotationally fixed manner and a decoupling state in which the components are decoupled from one another and can be rotated relative to one another, so that no torque can be transmitted between the components via the switching element, but rather the components are always connected or coupled to one another, thus permanently connected or coupled to one another in a rotationally fixed manner.

[0015] Furthermore, the feature that two components can be connected or coupled to one another in a rotationally fixed manner means that the components are assigned a switching element that can be switched between at least one coupling state and at least one decoupling state. In the coupling state, the components are connected or coupled to one another in a rotationally fixed manner by means of the switching element. In the decoupling state, the components are decoupled from one another, so that in the decoupling state the components can be rotated relative to one another about the component rotation axis. The same applies to the feature that two components can be connected or coupled to one another in a torque-transmitting manner.Thus, for example, the feature that two components can be connected or coupled to one another in a torque-transmitting manner is to be understood as meaning that a switching element is assigned to the components, wherein the switching element can be switched between at least one connected state and at least one released state. In the connected state, the components are coupled or connected to one another in a torque-transmitting manner by means of the switching element, so that torques can be transmitted between the components, in particular via the switching element. In the released state, the components are decoupled from one another, so that in the released state, no torque can be transmitted between the components via the switching element.

[0016] In order to be able to realize a design of the wheel hub drive that is particularly weight- and space-efficient, one embodiment of the invention provides for the wheel disc and the rotor carrier to be designed as a single piece, in particular with one another. The feature that two elements, such as the wheel disc and the rotor carrier, are designed as a single piece, in particular with one another, means that the elements are not screwed together and in particular are not connected to one another in a non-destructively detachable manner, but rather the elements are, for example, cast or produced by casting or forged, i.e. produced by forging, or welded, i.e., for example, welded to one another. In other words, it is conceivable for the elements designed as a single piece to be formed separately from one another and are not connected to one another in a non-destructively detachable manner and, in this case, are in particular welded to one another.In particular, it is conceivable for the elements constructed in one piece, such as the wheel disc and the rotor carrier, to be constructed in one piece. The feature that two elements are constructed in one piece means that the elements are not formed separately from one another and connected to one another, but rather the elements are formed from a single piece and thus constructed in one piece, so that the elements are formed by a body constructed in one piece, i.e. formed from a single piece and thus integrally manufactured, designed as a monoblock. Elements constructed in one piece are therefore also constructed in one piece, i.e. constructed in one piece with one another.Elements constructed in one piece, such as the wheel disc and the rotor carrier, can be constructed in one piece or separately and connected to one another, in particular in a manner that cannot be removed non-destructively, but are not screwed together. In other words, elements constructed in one piece and connected to one another in a manner that cannot be removed non-destructively are connected to one another using a connection technique other than screws and are connected to one another, in particular in a materially bonded manner and / or in a manner that cannot be removed non-destructively.

[0017] The feature “radially overlapping” is to be understood as follows: Two elements, in particular those which are essentially rotationally symmetrical, are arranged radially, in particular with respect to one another, in particular with respect to a common axis which runs, for example, in the radial direction of the wheel hub drive and / or in the radial direction of the wheel hub drive, if they are each arranged at least partially in a region of the same radial coordinates, in particular the same angular coordinates. The feature “axially overlapping” is to be understood as follows: Two elements are arranged axially overlapping, in particular with respect to one another, with respect to a common axis which runs, in particular, in the axial direction of the wheel hub drive and / or in the axial direction of the wheel hub drive, if they are each arranged at least partially in a region of the same axial coordinates.

[0018] The feature that a first component, such as the second bearing shell, is arranged radially within a second component, such as the first bearing shell, means that the first component is arranged in a region of smaller radii, particularly relative to the wheel's rotational axis. In other words, the first component is arranged further inward than the second component in the radial direction of the wheel hub drive.The feature that a first component is arranged axially within a second component is to be understood as meaning that the first component is arranged axially on a side oriented or pointing towards the centre of the vehicle, and is therefore arranged axially closer to the centre of the vehicle, also referred to as the centre of the vehicle, than the second component in the installation position of the wheel hub drive, which assumes its installation position in the fully manufactured state of the motor vehicle, and in particular when the motor vehicle is driving straight ahead, that is to say when a steering system of the motor vehicle is set to cause the motor vehicle to drive straight ahead.

[0019] The axial direction of the wheel hub drive, whose radial direction is perpendicular to the axial direction of the wheel hub drive, coincides with the wheel rotation axis. The term "radial" refers to the radial direction of the wheel hub drive, and the term "axial" refers to the axial direction of the wheel hub drive. In other words, the term "radial" means the radial direction of the wheel hub drive, while the term "axial" means the axial direction of the wheel hub drive. When reference is made above and below to the radial direction, this means the radial direction of the wheel hub drive, unless otherwise stated. When reference is made above and below to the axial direction, this means the axial direction of the wheel hub drive, unless otherwise stated.

[0020] , in particular permanently, connected to one another in a rotationally fixed manner. By driving the second bearing shell, that is to say by rotating the second bearing shell about the wheel rotation axis and relative to the first bearing shell and relative to the wheel carrier, the wheel disc and, for example, via the wheel disc, the rim and thus, for example, the tire can be driven, whereby the vehicle wheel and thus the vehicle, in particular the motor vehicle, can be driven, in particular purely electrically, by means of the rotor. In particular, the second bearing shell can be driven by means of the rotor and thereby rotated about the wheel rotation axis relative to the first bearing shell.

[0021] Preferably, it is provided that the second brake element is formed separately from the rim and is connected to the rim in a rotationally fixed manner, bypassing the second bearing shell and bypassing the wheel disc and bypassing the rotor, that is to say is connected to the rim in a rotationally fixed manner, in particular permanently.

[0022] In principle, it would be conceivable for the rim and the wheel disc to be formed integrally with one another, thus forming a single piece and thus being connected to one another in a rotationally fixed manner. However, it is also conceivable for the rim and the wheel disc to be formed separately from one another and connected to one another in a rotationally fixed manner, in particular in a non-destructively detachable manner. In other words, for example, the rim and the wheel disc can be formed separately from one another and connected to one another in a non-destructively detachable manner such that the rim and the wheel disc are connected, in particular permanently, in a rotationally fixed manner.

[0023] In a particularly advantageous embodiment of the invention, the wheel hub drive has at least one connection element by means of which the second braking element is connected to the rim, in particular permanently and non-rotatably, bypassing the second bearing shell, the wheel disc, and the rotor. The at least one connection element is arranged at least partially radially outside the first braking element and radially outside the second braking element. This enables a particularly compact design of the wheel hub drive, and the second braking element can be connected to the rim in a particularly space-saving and simple manner, in particular in a non-destructive manner.In particular, if the second brake element is connected to the rim in a non-destructive, detachable and rotationally fixed manner, in particular by means of the connecting element, the second brake element can be exchanged and thus replaced with a new part of the brake element, for example in the event of corresponding wear of the second brake element.

[0024] In order to realize a particularly space-saving way of the wheel hub drive, it has proven particularly advantageous if at least a radially outer part of the connecting element is arranged radially outside the stator and radially outside the rotor.

[0025] A further embodiment is characterized in that the connecting element is arranged axially, i.e., viewed in the axial direction of the wheel hub drive, on a side of the stator facing away from the wheel disc. This allows for a particularly compact design and simple manufacture, especially assembly, of the wheel hub drive.

[0026] In order to be able to connect the second brake element to the rim in a particularly space-saving manner, in particular in a non-destructively detachable manner, a further embodiment of the invention provides that the connecting element has a first toothed ring arranged coaxially to the rim and thus in particular coaxially to the wheel rotation axis and permanently connected to the rim in a rotationally fixed manner, such that the second brake element can be arranged or is arranged in a rotationally fixed and axially displaceable manner relative to the rim by means of the first toothed ring. In other words, the first toothed ring allows, in particular during manufacture and thus during assembly of the wheel hub drive, that while the second brake element is connected to the rim in a rotationally fixed manner, the second brake element is axially displaceable relative to the rim.This can, for example, also apply to a fully manufactured state of the wheel hub drive, or in a fully manufactured state of the wheel hub drive, the second brake element is connected to the rim in a rotationally fixed manner, in particular permanently, by means of the first toothed ring, and in a fully manufactured state of the wheel hub drive, relative movements between the second brake element and the rim, for example in the axial direction of the wheel hub drive, are prevented.

[0027] By means of the first toothed ring, for example, the second brake element is non-destructively detachably connected to the rim such that the second brake element is connected to the rim in a rotationally fixed manner. The second brake element, which is preferably formed separately from the rim, is non-destructively detachably connected to the rim such that the second brake element is connected to the rim in a rotationally fixed manner. Thus, for example, the first toothed ring enables advantageous removal of the second brake element from the rim, thereby enabling, for example, advantageous maintenance or replacement of the second brake element.

[0028] In order to achieve particularly effective and efficient braking in a particularly space-saving manner, a further embodiment of the invention provides for the second braking element to be designed as a brake disc and the first braking element as an internal brake caliper. The feature that the brake caliper is an internal brake caliper is understood in particular to mean that the brake caliper is arranged at least partially radially within the brake disc, wherein the brake caliper is preferably arranged at least partially axially overlapping the brake disc.

[0029] In order to realize a particularly space-saving and cost-effective design of the wheel hub drive, a further embodiment of the invention provides for the second braking element to be designed as a brake drum, which is arranged radially outside the stator and axially on a side of the stator facing away from the wheel disc. In this case, the first braking element is, for example, a brake shoe, also referred to as a brake pad.

[0030] In a further, particularly advantageous embodiment of the invention, the wheel hub drive has a connecting ring, which is in particular permanently connected to the wheel disc in a rotationally fixed manner, which is arranged radially outside the stator and has receiving openings, for example designed as bores, for receiving screws for fastening the rim to the connecting ring. Thus, for example, in particular precisely, a respective one of the screws is arranged in a respective one of the receiving openings, wherein, for example, the rim, which is in particular designed separately from the wheel disc, is connected to the wheel disc in a rotationally fixed manner, in particular permanently, by means of the screws. Very particularly, the wheel disc and the rim are detachably connected to one another in a non-destructive manner by means of the screws arranged in the receiving openings, such that the wheel disc and the rim are connected to one another in a rotationally fixed manner, in particular permanently connected to one another.This allows, for example, the wheel disc to remain rotationally connected to the second bearing shell while the rim is removed from the wheel disc, for example, together with the second brake element. Subsequently, the tire can be changed and / or the second brake element can be serviced, in particular replaced, in a particularly time- and cost-effective manner.

[0031] In order to be able to realize a particularly advantageous braking capability in a particularly space-saving manner, it is provided in a further embodiment of the invention that the braking elements are designed as friction elements, wherein the braking device has a friction region in which the friction elements of the braking device can be brought into frictional, i.e. frictionally engaged and in particular direct interaction, in order to thereby brake the second bearing shell and thus the vehicle wheel, in particular with regard to rotations around the wheel rotation axis and relative to the wheel carrier.

[0032] Therefore, in order to achieve a particularly compact design, it has proven particularly advantageous if the friction region is arranged at least partially radially overlapping the stator and / or the rotor. Preferably, the electrical machine is designed as a

[0033] In order to be able to realize a particularly space-saving and weight-efficient design of the wheel hub drive, it is provided according to the invention that a connection point, by means of and at which the rotor carrier of the rotor is connected to the vehicle wheel, in particular to the rim, is arranged radially inside the rim and on an axial inner side of the wheel disc.

[0034] The electric machine is preferably designed as an external rotor, i.e. as an external rotor machine, which is also referred to as an external rotor motor. This means, for example, that the stator is connected to the wheel carrier on its radially inner side. For example, at least one rotor carrier section of a rotor carrier of the electric machine that carries the rotor is arranged radially outside the stator, wherein, for example, the rotor carrier section is designed as a cylindrical section, thus as a cylindrical section of the rotor carrier, the cylindrical section of which is cylindrical, for example, at least on the outer circumference and / or inner circumference, and thus has the shape of a right circular cylinder. Very preferably, the electric machine is designed as an axial flux machine (AFM), which is also referred to as an axial flux motor.

[0035] Most preferably, the first bearing shell is a radially outer bearing ring of the wheel bearing, which is fixed to the wheel carrier. This means, in particular, that the first bearing shell is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier. Preferably, the second bearing shell is a radially inner bearing ring of the wheel bearing, wherein, for example, the vehicle wheel, in particular the wheel disc, is screwed to the second bearing shell and is thereby detachably connected to the second bearing shell in a non-destructive manner such that the wheel disc and thus the vehicle wheel is / are connected, in particular permanently, in a rotationally fixed manner to the second bearing shell.

[0036] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably designed as a motor vehicle, in particular as a passenger car, whose interior, also referred to as a passenger cell or passenger compartment, is formed by a motor vehicle structure designed, for example, as a self-supporting body. The motor vehicle has at least one wheel hub drive according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0037] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0038] The drawing shows: Fig. 1 shows a partial schematic and sectional side view of a first embodiment of a wheel hub drive for a motor vehicle; and Fig. 2 shows a partial schematic and sectional side view of a second embodiment of the wheel hub drive.

[0039] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0040] Fig. 1 shows a partial schematic and sectional side view, thus a schematic longitudinal sectional view, of a first embodiment of a wheel hub drive 10, also referred to as a wheel hub drive device or wheel hub drive unit, for a motor vehicle, also simply referred to as a vehicle. The wheel hub drive 10 has a wheel carrier 12 and a wheel bearing 14, which has a first bearing shell 16 that is connected to the wheel carrier 12, in particular permanently, in a rotationally fixed manner. The wheel bearing 14 is designed as a rolling bearing. In the first embodiment, the wheel carrier 12 and the first bearing shell 16 are formed separately from one another and are connected to one another, in particular permanently, in a rotationally fixed manner.For this purpose, at least one or more screws 18 are provided, wherein the bearing shell 16 is screwed to the wheel carrier 12 by means of the screw 18 and is thereby detachably connected to the wheel carrier 12 in such a non-destructive manner that the bearing shell 16 is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier 12. The wheel bearing 14 has a second bearing shell 20 arranged coaxially and rotatably relative to the first bearing shell 16. This means that the bearing shell 20 is arranged coaxially to the bearing shell 16 and is rotatable about a wheel rotation axis 22 relative to the bearing shell 16 and relative to the wheel carrier 12. The wheel rotation axis 22 is also referred to as the main rotation axis.

[0041] The wheel hub drive 10 also has an electric machine 24, which in the first embodiment is designed as an axial flux machine (AFM). The axial flux machine is also referred to as an axial flux motor. The electric machine 24 is designed as an external rotor. The electric machine 24 has a stator 26 and a stator carrier 28, also referred to as a stator mount. The stator 26 is designed separately from the wheel carrier 12 and is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier 12. For this purpose, the stator 26, which is designed separately from the stator carrier 28, is connected, in particular permanently, in a rotationally fixed manner to the stator carrier 28. In the present case, the stator carrier 28 is designed separately from the wheel carrier 12 and is connected, in particular permanently, to the wheel carrier 12.In the first embodiment, the stator carrier 28 is screwed to the wheel carrier 12 by means of the screw 18 and is thereby connected to the wheel carrier 12 in a rotationally fixed manner, in particular permanently, by means of the screw 18. In particular, for example, the stator carrier 28 is screwed to the wheel carrier 12 by means of the screw 18 and is thereby detachably connected to the wheel carrier 12 in a non-destructive manner such that the wheel carrier 12 and the stator carrier 28 are connected to one another, in particular permanently, in a rotationally fixed manner. The electric machine 24 also has a rotor 30 with rotor elements 32 and 34. The rotor 30 can be driven by the stator 26 and is thereby rotatable about a machine axis of rotation 36 relative to the stator 26. In the present case, the rotor 30 is arranged coaxially to the bearing shell 16 so that the machine axis of rotation 36 coincides with the wheel axis of rotation 22.

[0042] The stator 26 is or comprises, for example, a laminated core, also referred to as a stator lamination stack. It is also conceivable for the stator 26 to have magnets, in particular permanent magnets, which can be held on the stator lamination stack and thus supported by the stator lamination stack. It is also conceivable for the stator 26 to have at least one winding which can be held on the stator lamination stack. The stator 26 is, for example, a magnetically active element by means of which a magnetic flux is to be or is guided, which magnetic flux can be generated or is generated by the electric machine 24, for example, during operation of the electric machine 24, in particular in order to drive the rotor 30 and thus rotate it about the machine rotation axis 36 relative to the stator 26. In the present case, the stator 26 is screwed to the wheel carrier 12 by means of the screw 18 and is thereby fastened to the wheel carrier 12 in a rotationally fixed manner, in particular permanently.

[0043] The rotor elements 32 and 34 are spaced apart from one another in the axial direction of the electric machine 24, the radial direction of which runs perpendicular to the axial direction of the electric machine 24. The axial direction of the electric machine 24 coincides with the main axis of rotation. At least a partial region T of the stator 26 is arranged between the rotor elements 32 and 34 in the axial direction of the wheel hub drive 10, the radial direction of which runs perpendicular to the axial direction of the wheel hub drive 10, in such a way that the rotor element 32, viewed along the main axis of rotation and towards the rotor element 34, is at least partially overlapped by the partial region T, i.e., bridged, and that the rotor element 34, viewed along the main axis of rotation and towards the rotor element 32, is at least partially overlapped by the partial region T, i.e., covered.The axial direction of the wheel hub drive 10 coincides with the axial direction of the electric machine 24 and thus with the main axis of rotation, wherein the radial direction of the wheel hub drive 10 coincides with the radial direction of the electric machine 24.

[0044] The electric machine 24 has a rotor carrier 35, wherein the rotor 30 and thus the rotor elements 32 and 34 are formed separately from the rotor carrier 35 and are connected, in particular permanently, in a rotationally fixed manner to the rotor carrier 35. The rotor carrier 35 has a rotor carrier section 37 which is formed as a cylindrical section. The cylindrical section is cylindrical on the outer circumference and / or inner circumference, i.e., in the form of a right circular cylinder. The rotor carrier 35 has a rotor cover 38 which is formed separately from the rotor carrier section 37 and is connected, in particular permanently, in a rotationally fixed manner to the rotor carrier section 37. In the present case, the rotor cover 38 is connected to the rotor carrier section 37 in a non-destructively detachable manner such that the rotor cover 38 and the rotor carrier section 37 are connected to one another, in particular permanently, in a rotationally fixed manner.In the first embodiment, the rotor cover 38 is screwed to the rotor carrier section 37 by means of at least one screw 39 and is thereby detachably connected to the rotor carrier section 37 in a non-destructive manner such that the rotor cover 38 and the rotor carrier section 37 are connected to one another, in particular permanently and in a rotationally fixed manner. The rotor element 32, which is formed separately from the rotor carrier 35 and thus separately from the rotor carrier section 37 and separately from the rotor cover 38, is connected to the rotor cover 38 in a rotationally fixed manner, in particular permanently and in a rotationally fixed manner, in particular bypassing the rotor carrier section 37. The rotor elements 32 and 34 are connected to the rotor carrier 35, in particular permanently and in a rotationally fixed manner. In particular, the rotor carrier 35 is formed separately from the rotor 30 and is connected to the rotor 30, in particular permanently and in a rotationally fixed manner.By means of the rotor 30, the second bearing shell 20 can be driven and thereby rotated about the wheel rotation axis 22 relative to the first bearing shell 16 and relative to the wheel carrier 22.

[0045] In particular, the stator 26, in particular in contrast to the stator carrier 28, is a magnetically active element by means of which the magnetic flux is to be or is guided. Furthermore, for example, the rotor 30, in particular in contrast to the rotor carrier 35, is a magnetically active element by means of which the aforementioned magnetic flux is to be or is guided, which can be or is generated by the electric machine 24 during operation of the electric machine 24, in particular in order to thereby drive the rotor 30.

[0046] The rotor 30 is or comprises, for example, a laminated core, also referred to as a rotor core. Furthermore, it is conceivable that the rotor 30 has magnets, in particular permanent magnets, which can be held on the rotor core and thus supported by the rotor core. Furthermore, it is conceivable that the rotor 30 has at least one winding, also referred to as a rotor winding, which can be held on the rotor core.

[0047] The wheel hub drive 10 also has a vehicle wheel 40, which is connected, in particular permanently, in a rotationally fixed manner to the second bearing shell 20. The vehicle wheel 40 has a rim 42, the rim base of which is designated by 44. The vehicle wheel 40 also has a wheel disc 46, which in this case is connected, in particular permanently, in a rotationally fixed manner to the bearing shell 20, so that, for example, the vehicle wheel 40 is connected, in particular permanently, in a rotationally fixed manner to the bearing shell 20 via the wheel disc 46. The rim 42 and the wheel disc 46 form a wheel unit of the vehicle wheel 40 and are components of the wheel unit of the vehicle wheel 40. A tire, not shown in the figures and made of rubber, for example, can be mounted on the rim 42, in particular on the rim base 44, which tire is thus formed separately from the rim 42 and separately from the wheel disc 46 and is fastened to the rim 42.

[0048] The wheel disc 46 has a particularly central fastening region 48, which has at least one opening 50, here designed as a through-opening, in which a screw 52, ​​also referred to as a wheel bolt, is received. By means of the screw 52, ​​which is designed separately from the vehicle wheel 40 and separately from the bearing shell 20, the wheel disc 46 and thus the vehicle wheel 40 are screwed to the bearing shell 20, whereby the vehicle wheel 40 is non-destructively detachably connected to the bearing shell 20 such that the vehicle wheel 40 is connected, in particular permanently, in a rotationally fixed manner to the bearing shell 20. Thus, the vehicle wheel 40 is rotatable with the bearing shell 20 about the wheel rotation axis 22 relative to the bearing shell 16 and relative to the wheel carrier 12.If the bearing shell 20 is thus driven by means of the rotor 30 and thereby rotated about the wheel rotation axis 22 relative to the bearing shell 16 and relative to the wheel carrier 12, the vehicle wheel 40 is thereby driven and thus rotated about the wheel rotation axis 22 relative to the bearing shell 16 and relative to the wheel carrier 12.

[0049] The wheel hub drive 10 also has a braking device 54 designed to brake the vehicle wheel 40, which in the first embodiment is designed as a disc brake. The braking device 54 has a first braking element 56, which in the first embodiment is designed as an internal brake caliper. Furthermore, the braking device 54 has a second braking element 58, which in the first embodiment is designed as a brake disc. The braking elements 56 and 58 are friction elements of the braking device 54. The braking element 56 is connected, in particular permanently, to the wheel carrier 12 in a rotationally fixed manner.The braking device 54 also has a friction region B, in which the braking elements 56 and 58 can be brought into, in particular direct, frictional, i.e., frictionally engaged interaction, in order to thereby brake the vehicle wheel 40 with respect to its rotations about the wheel rotation axis 22 and relative to the bearing shell 16 and the wheel carrier 12. The second braking element 58 is, in particular permanently, connected to the bearing shell 20 in a rotationally fixed manner, which will be explained in more detail below.

[0050] In order to be able to realize advantageous braking capability in a particularly space-saving manner, it is provided in the wheel hub drive that the second braking element 58 is connected to the rim 42 in a rotationally fixed manner, bypassing the second bearing shell 20 and bypassing the wheel disc 46 and bypassing the rotor 30, in particular permanently, and thus in particular permanently connected to the rim 42 in a rotationally fixed manner.

[0051] In the first embodiment, a connecting element 60, by means of which the second brake element 58 is connected to the rim 42 in a rotationally fixed manner, bypassing the second bearing shell 20 and bypassing the wheel disc 46 and bypassing the rotor 30, in particular permanently, is arranged at least partially radially outside the first brake element 56 and thus partially radially outside the second brake element 58. In the first embodiment, at least a radially outer part of the connecting element 60 is arranged radially outside the stator 26 and radially outside the rotor 30. Furthermore, the connecting element 60 is arranged axially, that is, viewed in the axial direction of the wheel hub drive 10, on a side S of the stator 26 axially facing away from the wheel disc 46.

[0052] In the first embodiment, the connecting element 60 has a first toothed ring 62 arranged coaxially to the rim 42 and thus coaxially to the bearing shell 20 and permanently connected to the rim 42 in a rotationally fixed manner. The toothed ring 62 can be formed separately from the rim 42 and permanently connected to the rim 42 in a rotationally fixed manner, or the toothed ring 62 can be formed integrally with the rim 42 and thus permanently connected to the rim 42 in a rotationally fixed manner. The toothed ring 62 is designed or configured such that, by means of the first toothed ring 62, the second braking element 58 can be arranged or arranged in a rotationally fixed and axially displaceable manner relative to the rim 42, in particular at least during production of the wheel hub drive 10 and / or in the fully manufactured state of the wheel hub drive 10.

[0053] The connecting element 60 has a second toothed ring 64 corresponding to the first toothed ring 62, which is permanently connected to the second brake element 58 in a rotationally fixed manner. In particular, the toothed rings 62 and 64 are formed separately from one another and, in particular, permanently connected to one another in a rotationally fixed manner. In the present case, both toothed rings 62 and 64 are arranged radially outside the brake elements 56 and 58, and the toothed rings 62 and 64 are arranged so as to axially overlap the brake elements 56 and 58. Thus, the connecting element 60 is arranged so as to axially overlap the brake elements 56 and 58.

[0054] In the first embodiment, the wheel hub drive 10 has a connecting ring 66 that is connected, in particular permanently, in a rotationally fixed manner to the wheel disc 46. In the first embodiment, the connecting ring 66 is formed integrally with the wheel disc 46 and is thereby connected, in particular permanently, in a rotationally fixed manner to the wheel disc 46. The connecting ring 66 is arranged radially outside the stator 26. The connecting ring 66 has receiving openings, of which Fig. 1 a receiving opening designated 68 can be seen. The receiving opening 68 is designed as a through-opening in the present case. The previous and following explanations regarding the receiving opening 68 can easily be transferred to the other receiving openings of the connecting ring 66 and vice versa. A screw 70 is arranged, in particular precisely, in the receiving opening 68. For example, the receiving opening 68 is designed as a bore. By means of the screw 70, the rim 42, which is formed separately from the wheel disc 46, is detachably connected to the wheel disc 46 in a non-destructive manner such that the rim 42 and the wheel disc 46 are connected to one another, in particular permanently, in a rotationally fixed manner. In other words, the rim 42 is fastened to the wheel disc 46 by means of the screw 70 and is thereby connected, in particular permanently, in a rotationally fixed manner to the rim 42.

[0055] The wheel bearing 14 has first rolling elements 72, which form, for example, a first row of rolling elements. The wheel bearing 14 has second rolling elements 74, which form, for example, a second row of rolling elements. The rolling elements 74 follow the rolling elements 72 in the axial direction of the wheel hub drive 10 toward the wheel disc 46, so that the second row of rolling elements follows the first row of rolling elements in the axial direction of the wheel hub drive 10 toward the wheel disc 46. The bearing shell 16 forms a first raceway L1 for the rolling elements 72 and a second raceway L2 for the rolling elements 74. The bearing shell 20 forms a third raceway L3 for the rolling elements 72 and a fourth raceway L4 for the rolling elements 74. If the bearing shells 16 and 20 rotate relative to one another about the main axis of rotation (wheel axis of rotation 22), the rolling elements 72 roll directly on the raceways L1 and L3 and the rolling elements 74 roll directly on the raceways L2 and L4.The rotor elements 32 and 34 are, for example, disc-shaped and thus designed as rotor discs of the rotor 30.

[0056] In Fig. 1, an arrow 76 illustrates a line element which is designed, in particular, separately from the stator carrier 28 and separately from the stator 26 and which can, for example, be regarded as representative of a plurality of line elements. In other words, the arrow 76 illustrates, for example, at least or precisely one line element or a plurality of line elements. The line element is designed, for example, as a high-voltage line which is designed, for example, to transmit electrical current with an electrical voltage which is preferably greater than 50 volts, in particular greater than 60 volts, and very preferably amounts to several hundred volts. The electrical machine 24 is preferably a high-voltage component whose electrical voltage, in particular electrical operating and rated voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and very preferably amounts to several hundred volts.The conducting element can, for example, be used to supply the stator 26 with electrical energy, in particular here to drive the rotor 30. Alternatively or additionally, electrical energy can be dissipated via the conducting element, which energy can be provided or is provided, for example, by the stator 26 or by the electric machine 24. It can be seen that the conducting element runs at least partially in the stator carrier 28, i.e., within the stator carrier 28. Thus, for example, the stator carrier 28 has a channel running within the stator carrier 28, through which the conducting element runs. In particular, the conducting element is electrically connected to the stator 26.

[0057] Fig.2 shows a detail of a schematic and sectional side view, thus a schematic longitudinal sectional view, of a second embodiment of the wheel hub drive 10. In the second embodiment, the braking device 54 is designed as a drum brake. The braking element 58 is designed as a brake drum, which in this case is formed separately from the rim 42 and is, in particular, permanently and non-rotatably connected to the rim 42. The braking element 56 is designed as a brake shoe, which is, in particular, permanently and non-rotatably connected to the wheel carrier 12. More particularly, the braking element 56 is formed separately from the wheel carrier 12 and, in particular, permanently and non-rotatably connected to the wheel carrier 12.

[0058] In the first embodiment, for example, the braking element 58 is connected to the rim 42 in a non-destructively releasable and rotationally fixed manner by means of the connecting element 60. In the second embodiment, for example, the second braking element 58 is not connected to the rim 42 in a non-destructively releasable and rotationally fixed manner, so that in the second embodiment, the rim 42, together with the braking element 58, is screwed to the wheel disc 46 by means of the screw 70, also referred to as the rim screw, and is thereby connected to the wheel disc 46 in a rotationally fixed manner. List of reference symbols 10 Wheel hub drive 12 wheel carriers 14 wheel bearings 16 first bearing shell 18 screw 20 second bearing shell 22 Wheel rotation axis 24 electric machine 26 Stator 28 stator carriers 30 rotors 32 Rotor element 34 Rotor element 35 Rotor carrier section 36 Machine rotation axis 37 Rotor carrier section 38 rotor cover 39 screw 40 vehicle wheel 42 rim 44 rim base 46 Wheel disc 48 Mounting area 50 opening 52 screw 54 Braking device 56 first brake element 58 second brake element 60 connecting element 62 first gear ring 64 second gear ring 66 connecting ring 68 receiving opening 70 screw 72 first rolling element 74 second rolling element 76 Arrow B Friction area L1 career L2 career L3 career L4 career T sub-area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 096504 A1

[0002]

Claims

[1] Wheel hub drive (10) for a motor vehicle, comprising a wheel carrier (12), a wheel bearing (14) having a first bearing shell (16) connected in a rotationally fixed manner to the wheel carrier (12) and a second bearing shell (20) arranged coaxially and rotatably to the first bearing shell (16), an electric machine (24) having a rotor (30) and a stator (26) connected in a rotationally fixed manner to the wheel carrier (12), a braking device (54) having a first braking element (56) connected in a rotationally fixed manner to the wheel carrier (12) and a second braking element (58) connected in a rotationally fixed manner to the second bearing shell (20), and a vehicle wheel (40) having a wheel disc (46) and a rim (42) connected in a rotationally fixed manner to the second bearing shell (20), characterized by that the second brake element (58) is connected to the rim (42) in a rotationally fixed manner, bypassing the second bearing shell (20) and bypassing the wheel disc (46) and bypassing the rotor (30). [2] Wheel hub drive (10) according to claim 1, characterized by that a connecting element (60), by means of which the second brake element (58) is connected to the rim (42) in a rotationally fixed manner, bypassing the second bearing shell (20) and bypassing the wheel disc (46) and bypassing the rotor (30), is arranged at least partially radially outside the first brake element (56) and radially outside the second brake element (58). [3] Wheel hub drive (10) according to claim 2, characterized by that at least a radially outer part of the connecting element (60) is arranged radially outside the stator (26) and radially outside the rotor (30). [4] Wheel hub drive (10) according to claim 2 or 3, characterized by that the connecting element (60) is arranged axially on a side (S) of the stator (26) axially remote from the wheel disc (46). [5] Wheel hub drive (10) according to one of claims 2 to 4, characterized bythat the connecting element (60) has a first toothed ring (62) arranged coaxially to the rim (42) and permanently connected to the rim (42) in a rotationally fixed manner, such that by means of the first toothed ring (62) the second braking element (58) can be arranged in a rotationally fixed and axially displaceable manner relative to the rim (42). [6] Wheel hub drive (10) according to one of claims 2 to 5, characterized by that the second brake element (58) is designed as a brake disc and the first brake element (56) as an internal brake caliper. [7] Wheel hub drive (10) according to one of claims 2 to 5, characterized by that the second brake element (58) is designed as a brake drum which is arranged radially outside the stator (26) and axially on a side (S) of the stator axially remote from the wheel disc (46). [8] Wheel hub drive (10) according to one of the preceding claims, characterized bya connecting ring (66) which is connected to the wheel disc (46) in a rotationally fixed manner and which is arranged radially outside the stator (26) and has receiving openings (68) for receiving screws (70) for fastening the rim (42) to the connecting ring (66). [9] Wheel hub drive (10) according to one of the preceding claims, characterized by that the braking elements (56, 58) are designed as friction elements, wherein the braking device (54) has a friction region (B) in which the friction elements of the braking device can be brought into frictional interaction in order to thereby brake the vehicle wheel (40). [10] Wheel hub drive (10) according to claim 9, characterized by that the friction region (B) is arranged at least partially in radial overlap with the stator (26) and / or the rotor (30). [11] Motor vehicle, with at least one wheel hub drive (10) according to one of the preceding claims.

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