Wheel hub drive for a motor vehicle as well as 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) non-rotatably connected to the wheel carrier (12) and a second bearing shell (18) arranged coaxially and rotatably to the first bearing shell (16), a vehicle wheel (20) non-rotatably connected to the second bearing shell (18) and which has a wheel disc (24) and a rim (26), an electric machine (28) which has a stator (30) non-rotatably connected to the wheel carrier (12) and a rotor (32) integrated into the vehicle wheel (20) and is designed as an externally running radial flux machine, wherein a connection point (V) by means of which a rotor carrier (34) of the wheel hub drive (10) supporting the rotor (32) is connected to the vehicle wheel (20) is radially located inside the rim (26) and on an axial inner surface (S) of the wheel disc (24) is ordered.

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] DE 11 2009 003 757 B4 discloses a wheel drive device having a cylindrical inner housing supported by a vehicle body via a suspension.

[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 space- and weight-efficient design of the wheel hub drive can be realized.

[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 10. 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. 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 of the motor vehicle 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, for example, 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 via 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, whose interior, also referred to as the passenger cell or passenger compartment, is formed, for example, by a motor vehicle structure designed in particular as a self-supporting body, is driven along the ground while the motor vehicle is supported on the ground downwards in the vertical direction of the vehicle via the ground contact elements, the ground contact elements roll, in particular directly, on the ground. The wheel hub drive is also referred to as the first wheel hub drive. When reference is made above and below to the wheel hub drive, this shall mean, unless otherwise stated, the first wheel hub drive. For example, the wheel hub drive has, in particular precisely, a first of the vehicle wheels of one of the vehicle axles. When reference is made above and below to the vehicle wheel, this shall mean, unless otherwise stated, the first vehicle wheel.The vehicle wheel is also simply referred to as a wheel. Thus, the first vehicle wheel can be driven, in particular purely electrically, by means of the first wheel hub drive. For example, in its fully manufactured state, the motor vehicle has a second wheel hub drive provided in addition to the first wheel hub drive, by means of which, in particular precisely, a second of the vehicle wheels of the motor vehicle can be driven, in particular purely electrically, wherein it is conceivable that the second wheel hub drive comprises the second vehicle wheel. Preferably, the first vehicle wheel and the second vehicle wheel are the vehicle wheels of the same vehicle axle. When reference is made above and below to the vehicle wheel, this refers to the first vehicle wheel, unless otherwise stated.The previous and following statements regarding the first wheel hub drive and the first vehicle wheel can also be readily applied to the second wheel hub drive and the second vehicle wheel and vice versa.

[0006] The wheel hub drive has a wheel carrier and a wheel bearing. The wheel bearing is preferably designed as a rolling bearing. The wheel bearing has a first bearing shell, which is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier. The wheel bearing also has a second bearing shell, which is arranged coaxially and rotatably to the first bearing shell. This means that the second bearing shell is rotatable about an axis of rotation, also referred to as the wheel rotation axis, relative to the first bearing shell and relative to the wheel carrier. Furthermore, the bearing shells are arranged coaxially to one another, in particular with respect to the rotation axis.

[0007] The wheel hub drive also has the aforementioned vehicle wheel, which is connected in a rotationally fixed manner to the second bearing shell. Thus, in particular, the vehicle wheel is formed separately from the second bearing shell and connected in a rotationally fixed manner to the second bearing shell. Furthermore, it is preferably provided that the first bearing shell is formed separately from the wheel carrier and, in particular permanently, is connected in a rotationally fixed manner to the wheel carrier. Since the vehicle wheel is connected in a rotationally fixed manner to the second bearing shell, the vehicle wheel is rotatable about the rotation axis relative to the first bearing shell and also relative to the wheel carrier with the second bearing shell.

[0008] The wheel hub drive also has an electric machine. The electric machine has a stator which is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier. The electric machine also has a rotor which can be driven by means of the stator and is thus rotatable about a machine axis of rotation relative to the stator and also relative to the wheel carrier. In particular, the vehicle wheel can be driven by means of the electric machine via the rotor. For example, the rotor is arranged coaxially to the second bearing shell so that the machine axis of rotation preferably coincides with the axis of rotation. The rotor is integrated into the vehicle wheel, which is also simply referred to as the wheel. This can be understood in particular to mean that a rotor carrier, by which the rotor is carried, is formed integrally, i.e., as one piece with the vehicle wheel.In particular, it is provided that the rotor is formed separately from the rotor carrier and is connected, in particular permanently, to the rotor carrier in a rotationally fixed manner. In particular, the rotor is or comprises, for example, a laminated core, also referred to as a rotor laminated core. Alternatively or additionally, the rotor can comprise at least one or more magnets, in particular permanent magnets, which are held, for example, on the rotor laminated core and thus supported by the rotor laminated core. Alternatively or additionally, the rotor can, for example, have at least one winding, also referred to as a rotor winding, which is held on the rotor laminated core and thus supported by the rotor laminated core.In particular, the rotor, in particular in contrast to the rotor carrier, is a magnetically active element by means of which, for example, a magnetic flux is to be guided, which can be generated by the electric machine, for example, during operation of the electric machine, in particular in order to drive the second bearing shell and thus the vehicle wheel and thus to rotate it about the wheel rotation axis relative to the first bearing shell and relative to the wheel carrier.

[0009] Furthermore, it is provided that the electric machine is designed as an externally rotating radial flux machine. In other words, the electric machine is designed as an external rotor, which is also referred to as an external rotor machine, wherein the electric machine is a radial flux machine (RFM).

[0010] The wheel hub drive has, for example, a stator carrier, by means of which the stator is held on the wheel carrier in a rotationally fixed manner. In particular, it is provided that the stator is formed separately from the stator carrier and is connected to the stator carrier in a rotationally fixed manner, in particular permanently. For example, the stator carrier is connected to the wheel carrier in a rotationally fixed manner, in particular permanently. It can be provided that the stator carrier is formed separately from the wheel carrier and is connected to the wheel carrier in a rotationally fixed manner, in particular permanently. In particular, the stator is or comprises, for example, a laminated core, also referred to as a stator laminated core. Alternatively or additionally, the stator can comprise at least one or more magnets, in particular permanent magnets, which are held, for example, on the stator laminated core and are thus carried by the stator laminated core.Alternatively or additionally, for example, the stator can have at least one winding, also referred to as a stator winding, which can be held on the stator core and thus supported by the stator core. In particular, the stator, particularly in contrast to the stator support, is a magnetically active element by means of which, for example, the aforementioned magnetic flux is to be guided, which, for example, can be generated or is generated by the electric machine during operation of the electric machine, in particular in order to drive the vehicle wheel or the second bearing shell as well as the vehicle wheel.

[0011] Preferably, the electrical machine is a high-voltage component whose electrical voltage, in particular electrical operating or nominal voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and most preferably amounts to several hundred volts.

[0012] In particular, the wheel bearing supports the vehicle wheel on the wheel carrier, particularly so that it can rotate about the axis of rotation relative to the wheel carrier. The wheel bearing is most preferably designed as a rolling bearing.

[0013] For example, the vehicle wheel has a wheel disc which is connected to the second bearing shell in a rotationally fixed manner, so that the vehicle wheel is preferably connected to the second bearing shell in a rotationally fixed manner via the wheel disc. Furthermore, the vehicle wheel has, for example, a rim which is connected to the wheel disc in a rotationally fixed manner, in particular permanently. In principle, it would be conceivable for the rim and the wheel disc to be formed separately from one another and, in particular permanently, connected to one another in a rotationally fixed manner, or for the wheel disc and the rim to be integral, i.e. formed from a single piece and thus, in particular permanently, connected to one another in a rotationally fixed manner. The rim is connected to the second bearing shell in a rotationally fixed manner via the wheel disc.

[0014] 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 wheel hub drive 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.

[0015] The aforementioned axis of rotation runs in the axial direction of the wheel hub drive, whose radial direction is perpendicular to the axial direction of the wheel hub drive. References to the axial direction above and below refer to the axial direction of the wheel hub drive, unless otherwise stated. References to the radial direction above and below refer to the radial direction of the wheel hub drive, unless otherwise stated.

[0016] In the context of the present disclosure, the feature "radially overlapping" is to be understood as follows: Two elements, in particular at least substantially rotationally symmetrical, are arranged radially, in particular overlapping one another, in particular with respect to a common axis running, 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 term "radial" refers to the radial direction of the wheel hub drive. In other words, the term "radial" means the radial direction of the wheel hub drive.

[0017] 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 running 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. In the context of the present disclosure, the term “axial” is to be understood as the axial direction of the wheel hub drive. In other words, the term “axial” means the axial direction of the wheel hub drive. In other words, “axial” refers to the axial direction of the wheel hub drive.

[0018] In the context of the present disclosure, the feature that a first component is arranged radially within a second component is to be understood as meaning that the first component is arranged in a region of smaller radii than the second component, in particular with respect to the axis of rotation (wheel axis of rotation), also referred to as the main axis of rotation. Furthermore, the feature that a first component is arranged axially within a second component is to be understood as meaning that in the installed position of the wheel hub drive, which assumes its installed position in the fully manufactured state of the motor vehicle having the wheel hub drive, and in particular with respect to straight-ahead travel of the motor vehicle, that is to say in particular when a steering system of the motor vehicle is set to cause the motor vehicle to travel straight ahead, the first component, which is arranged axially within the second component,is arranged on one side of the second component toward a center of the motor vehicle, also referred to as the vehicle center, thus the first component is arranged on a side of the second component facing the center of the motor vehicle, so that the first component is arranged further inward, i.e. closer to the center of the motor vehicle, than the second component, particularly when viewed in the transverse direction of the motor vehicle. Thus, the axial inner side of the wheel disc is understood to mean a side of the wheel disc that faces the wheel carrier in the axial direction of the wheel hub drive. If the steering of the motor vehicle is set, for example, to cause the motor vehicle to travel straight ahead, the inner side of the wheel disc faces inward in the axial direction of the wheel hub drive and in the transverse direction of the vehicle, thus toward the vehicle center and in particular toward the wheel carrier.

[0019] For example, a tire, particularly made of rubber, of the first vehicle wheel is attached to the rim, so that the tire is, so to speak, mounted on the rim. In particular, when the vehicle wheel rolls along the ground, the tire rolls, particularly directly, along the ground.

[0020] Because the electric machine is designed as an external rotor, hence also referred to as an external rotor motor, the stator, for example, is connected to the wheel carrier or the stator carrier on its radially inner side, and at least one rotor carrier section of the rotor carrier is arranged radially outside the stator, wherein, for example, the rotor carrier section is a cylindrical section of the rotor carrier. In particular, the cylindrical section is understood to be a section of the rotor carrier whose section is cylindrical on the outer circumference and preferably also on the inner circumference, thus having the shape of a particularly right circular cylinder.

[0021] In the context of the present disclosure, the feature that two components, such as the wheel carrier and the first bearing shell, 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 main rotation axis (rotation axis), at the same angular velocity, in particular relative to a reference element, such as a wheel carrier. In other words, two elements 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, an element is connected to the wheel carrier in a rotationally fixed manner if it cannot be rotated relative to the wheel carrier.

[0022] 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.

[0023] The feature that two components are permanently connected or coupled to one another in a torque-transmitting manner does not mean that a switching element is provided that 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.

[0024] In particular, the feature that two components 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.

[0025] 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.

[0026] 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 can be constructed separately and connected to one another in a manner that is not non-destructively detachable, but can not be screwed together. In other words, elements constructed in one piece and connected to one another in a manner that is not non-destructively detachable are connected to one another by a connection technique other than screws and can be connected to one another in a materially bonded manner and / or can be connected to one another in a manner that is not non-destructively detachable.

[0027] A further embodiment is characterized in that the wheel disc, the rotor carrier, and the rim are formed as one piece, particularly together, thereby enabling a particularly space- and weight-efficient design of the wheel hub drive. It is very preferably provided that the wheel disc, the rotor carrier, and the rim are formed as one piece.

[0028] In order to realize a particularly space-saving and weight-efficient as well as simple design of the wheel hub drive, a further embodiment of the invention provides that the wheel hub drive has a fastening ring that is designed, in particular formed, as a single piece with the wheel disc, wherein the rim is designed or formed separately from the wheel disc and is fastened directly, i.e. directly to the fastening ring, in particular in a non-destructive manner. For example, the rim is directly and thus directly screwed to the fastening ring and thereby directly fastened to the fastening ring, so that, for example, the rim is fastened to the fastening ring by screws, i.e. by means of at least one or more screws, in particular in a non-destructive manner.This allows, for example, a wheel and / or tire change to be carried out particularly easily without having to disassemble the electric machine. For this purpose, the rim, in particular with the tire attached to it, is detached from the fastening ring and thus from the wheel disc, in particular in a non-destructive manner. After that, the rim, or a rim to which another tire is attached, can be directly attached to the fastening ring, in particular in a non-destructive manner. In particular, it is preferably provided that the fastening ring is formed integrally with the wheel disc.

[0029] It has proven particularly advantageous if the fastening ring is arranged radially outside the rotor, which allows a particularly space-saving design of the wheel hub drive to be realized.

[0030] A further embodiment is characterized in that the fastening ring is arranged radially inside the connection point and thus at least partially radially overlapping the stator, whereby a particularly compact design of the wheel hub drive can be achieved.

[0031] In order to be able to realize a particularly compact design of the wheel hub drive, it is provided in a further embodiment of the invention that the second bearing shell is arranged at least partially radially inside and at least partially axially overlapping the first bearing shell. Thus, the first bearing shell is preferably a radially outer bearing ring of the wheel bearing, which is fixed to the wheel carrier and whose radially outer bearing ring is connected, in particular permanently, in a rotationally fixed manner to the wheel carrier. The second bearing shell is thus, for example, a radially inner bearing ring of the wheel bearing, whose radially inner bearing ring is connected, in particular in a non-destructively detachable manner, to the vehicle wheel, in particular to the wheel disc, in such a way that the radially inner bearing ring is connected in a rotationally fixed manner to the vehicle wheel, in particular to the wheel disc.For this purpose, for example, the vehicle wheel, in particular the wheel disc, is screwed to the second bearing shell, whereby, for example, the vehicle wheel, in particular the wheel disc, is non-destructively detachable and non-rotatably connected to the second bearing shell.

[0032] In order to achieve a particularly compact design of the wheel hub drive, a further embodiment of the invention provides that the first bearing shell forms a first raceway for rolling elements of the wheel bearing, while the second bearing shell forms a second raceway for the rolling elements of the wheel bearing. If the second bearing shell rotates about the axis of rotation relative to the first bearing shell, the rolling elements of the wheel bearing roll, in particular directly, on the first raceway and, in particular directly, on the second raceway.

[0033] A second aspect of the invention relates to a motor vehicle, also simply referred to as a vehicle and preferably designed as a motor vehicle, in particular as a passenger car, which has at least one wheel hub drive according to the first aspect of the invention.

[0034] 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.

[0035] 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; Fig. 2 shows a partial schematic and sectional side view of a second embodiment of the wheel hub drive; and Fig. 3 shows a partial schematic and sectional side view of a third embodiment of the wheel hub drive.

[0036] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0037] Fig. 1 shows a partial schematic and sectional side view 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, which is preferably designed as a motor vehicle, in particular as a passenger car. The wheel hub drive 10 has a wheel carrier 12 and a wheel bearing 14, which has a first bearing shell 16 and a second bearing shell 18. The bearing shell 16 is connected to the wheel carrier 12 in a rotationally fixed manner. In the first embodiment, the bearing shell 16 is formed separately from the wheel carrier 12 and is connected to the wheel carrier 12 in a rotationally fixed manner. In the present case, the bearing shell 16 is screwed to the wheel carrier 12 and is thereby connected to the wheel carrier 12 in a rotationally fixed manner. Fig. 1 shows a screw 21, by means of which the bearing shell 16 is screwed to the wheel carrier 12. The second bearing shell 18 is arranged rotatably relative to the first bearing shell 16 and thus rotatably relative to the wheel carrier 12. The bearing shell 18 is rotatable about an axis of rotation D, also referred to as the main axis of rotation or wheel axis of rotation, relative to the bearing shell 16 and thus also relative to the wheel carrier 12. The wheel hub drive 10, whose axial direction coincides with the axis of rotation D, also has a vehicle wheel 20, which is also simply referred to as a wheel. The vehicle wheel 20 is a ground contact element of the motor vehicle. The vehicle wheel 20 is connected in a rotationally fixed manner to the bearing shell 18. In the present case, the vehicle wheel 20 is formed separately from the bearing shell 18 and is connected in a rotationally fixed manner to the bearing shell 18. In Fig. 1 shows a screw 22, also referred to as a wheel bolt, by means of which the vehicle wheel 20 is screwed to the bearing shell 18, thereby connecting the bearing shell 18 and the vehicle wheel 20 in a rotationally fixed manner. The vehicle wheel 20 has a wheel disc 24 and a rim 26. For example, a tire (not shown in the figures and made of rubber, for example), in particular of the vehicle wheel 20, is attached to the rim 26, so that the tire is, so to speak, mounted on the rim 26.

[0038] The wheel hub drive 10, whose radial direction runs perpendicular to the axial direction of the wheel hub drive 10, also has an electric machine 28, by means of which the vehicle wheel 20 and thus the bearing shell 18 can be driven and thus rotated about the axis of rotation D relative to the bearing shell 16 and relative to the wheel carrier 12. The electric machine 28 has a stator 30, which is connected in a rotationally fixed manner to the wheel carrier 12. In particular, the stator 30 is formed separately from the wheel carrier 12 and is at least indirectly connected in a rotationally fixed manner to the wheel carrier 12. Furthermore, the electric machine 28 has a rotor 32, which can be driven by the stator 30 and is thus rotatable about a machine axis of rotation M relative to the stator 30. In the first embodiment, the electric machine 28 is arranged coaxially to the bearing shell 18, so that the machine axis of rotation M coincides with the axis of rotation D.It can also be seen that the bearing shell 18 is arranged coaxially with the bearing shell 16. The rotor 32 is integrated into the vehicle wheel 20. This particularly means the following: The wheel hub drive 10 has a rotor carrier 34, by which the rotor 32 is supported. The rotor 32 is formed separately from the rotor carrier 34 and, in particular, is permanently connected to the rotor carrier 34 in a rotationally fixed manner. As will be explained in more detail below, the rotor carrier 34 is formed integrally with the vehicle wheel 20.

[0039] The wheel hub drive 10 also has a stator carrier 37, by which the stator 30 is supported. The stator 30 is formed separately from the stator carrier 37 and, in particular, is permanently connected to the stator carrier 37 in a rotationally fixed manner. In the first embodiment, the stator carrier 37 is formed separately from the wheel carrier 12 and, in particular, is permanently connected to the wheel carrier 12 in a rotationally fixed manner.

[0040] Furthermore, it is provided that the electric machine 28 is designed as an externally rotating radial flux machine. This means that the electric machine 28 is designed as an external rotor, thus also as an external rotor motor. The rotor carrier 34 has a rotor carrier section RA, which in this case is designed as a cylindrical section. The rotor carrier section RA is therefore cylindrical on the outer circumference and, for example, also on the inner circumference, thus in the form of a particularly right circular cylinder. The stator 30 is arranged at least partially radially within the rotor carrier section RA and in particular is arranged at least partially axially overlapping the rotor carrier section RA.Conversely, the rotor carrier section RA of the rotor carrier 37, which is designed as a cylinder section, is arranged radially outside the stator 30, in particular in this case such that the rotor carrier section RA is arranged at least partially axially overlapping the stator 30.

[0041] In order to be able to realize a particularly space- and weight-efficient design of the wheel hub drive 10, it is provided in the wheel hub drive that a connection point V, by means of which the rotor carrier 34 of the wheel hub drive 10 carrying the rotor 32 is connected to the vehicle wheel 20, is arranged radially inside the rim 26 and on an axial inner side S of the wheel disc 24. In the first embodiment, the wheel disc 24 and the rotor carrier 34 are designed as one piece with one another, in the present case such that in the first embodiment the wheel disc 24 and the rotor carrier 34 are designed as one piece with one another, i.e. are formed from a single piece.

[0042] In the first embodiment, the rim 26 is formed separately from the wheel disc 24 and thus also separately from the rotor carrier 34, wherein the rim 26 is connected to the wheel disc 24 in a rotationally fixed manner. In the present case, the rim 26 is non-destructively detachable and non-rotatably connected to the wheel disc 24. This is realized in the first embodiment in such a way that the rim 26 is screwed to the wheel disc 24, whereby the rim 26 is non-destructively detachable and non-rotatably connected to the wheel disc 24. In Fig. 1 shows a screw 36 by means of which the rim 26 is screwed to the wheel disc 24.

[0043] In the first embodiment, the wheel hub drive 10 has a fastening ring 38 which is formed integrally with the wheel disc 24. In the first embodiment, the fastening ring 38 is formed integrally with the wheel disc 24, so that in the first embodiment, the fastening ring 38 and the wheel disc 24 are formed integrally with one another, i.e., are formed from a single piece. The rim 26 is formed separately from the wheel disc 24 and separately from the fastening ring 38, i.e., it is designed and fastened directly and, in this case, non-destructively detachably to the fastening ring 38, in this case such that the rim 26 is screwed to the fastening ring 38 by means of the screw 36. It can also be seen that the fastening ring 38 is arranged radially outside the rotor 32 and also radially outside the rotor carrier 34 and also radially outside the stator 30.In the first embodiment, the fastening ring 38 is arranged radially outside the connection point V.

[0044] The second bearing shell 18 is arranged at least partially radially within and at least partially axially overlapping the first bearing shell 16. In the first embodiment, the wheel bearing 14 has first rolling elements 40, which form a first row of rolling elements. The wheel bearing 14 also has second rolling elements 42, which form a second row of rolling elements arranged following the first row of rolling elements in the axial direction of the wheel hub drive 10. The bearing shell 16 forms a first raceway L1 for the rolling elements 40 and a second raceway L2 for the rolling elements 42. The bearing shell 18 forms a third raceway L3 for the rolling elements 40 and a fourth raceway L4 for the rolling elements 42. If the bearing shell 18 rotates about the axis of rotation D relative to the bearing shell 16, the rolling elements 40 roll, in particular directly, on the raceways L1 and L3, and the rolling elements 42 roll, in particular directly, on the raceways L2 and L4.

[0045] Fig. 2 shows a second embodiment of the wheel hub drive 10. In the second embodiment, the fastening ring 38 is also formed integrally with the wheel disc 24 such that the fastening ring 38 is formed integrally with the wheel disc 24. In the second embodiment, the fastening ring 38 is arranged radially within the connection point V1 and at least radially overlapping the stator 30.

[0046] Finally, Fig.3 shows a third embodiment of the wheel hub drive 10. In the third embodiment, the wheel disc 24, the rotor carrier 34, and the rim 26 are formed integrally with one another, in the present case such that in the third embodiment, the wheel disc 24, the rotor carrier 34, and the rim 26 are formed integrally with one another. The rotor carrier 34 is characterized in particular in that the rotor carrier 34 protrudes from the wheel disc 24 and, in the axial direction toward the wheel carrier 12, from the inner side S, and thus extends from the wheel disc 24 and, in the axial direction of the wheel hub drive 10, from the inner side S toward the wheel carrier 12.

[0047] A separation point, also referred to as a separation, between the rim 26 and the wheel disc 24, as provided for example in the first and second embodiments, can, for example, be nested axially or radially. List of reference symbols 10 Wheel hub drive 12 wheel carriers 14 wheel bearings 16 first bearing shell 18 second bearing shell 20 vehicle wheel 21 Screw 22 screw 24 wheel disc 26 rim 28 electric machine 30 Stator 32 rotors 34 rotor carrier 36 screw 37 Stator carrier 38 Mounting ring 40 first rolling element 42 second rolling element D axis of rotation L1 career L2 career L3 career L4 career M Machine rotation axis RA rotor carrier section V connection point 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] DE 11 2009 003 757 B4

[0002]

Claims

[1] 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 (18) arranged coaxially and rotatably to the first bearing shell (16), a vehicle wheel (20) connected in a rotationally fixed manner to the second bearing shell (18), which vehicle wheel has a wheel disc (24) and a rim (26), an electric machine (28) which has a stator (30) connected in a rotationally fixed manner to the wheel carrier (12) and a rotor (32) integrated into the vehicle wheel (20), and which is designed as an externally rotating radial flux machine, characterized by that a connection point (V), by means of which a rotor carrier (34) of the wheel hub drive (10) carrying the rotor (32) is connected to the vehicle wheel (20), is arranged radially inside the rim (26) and on an axial inner side (S) of the wheel disc (24). [2] Wheel hub drive (10) according to claim 1, characterized by that the wheel disc (24) and the rotor carrier (34) are made in one piece. [3] Wheel hub drive (10) according to claim 2, characterized by that the wheel disc (24) and the rotor carrier (34) and the rim (26) are designed as one piece. [4] Wheel hub drive (10) according to claim 1 or 2, characterized by a fastening ring (38) which is made in one piece with the wheel disc (24) and to which the rim (26) which is made separately from the wheel disc (24) is directly fastened. [5] Wheel hub drive (10) according to claim 4, characterized by that the fastening ring (38) is arranged radially outside the rotor (32) and / or radially inside the rotor carrier (34) [6] Wheel hub drive (10) according to claim 4 or 5, characterized by that the fastening ring (38) is arranged radially inside the connection point (V) and at least partially radially overlapping the stator (30). [7] Wheel hub drive (10) according to one of the preceding claims, characterized by that the second bearing shell (18) is arranged at least partially radially inside and axially overlapping the first bearing shell (14). [8] Wheel hub drive (10) according to claim 7, characterized by that the first bearing shell (16) forms a first raceway (L1) for rolling elements (40) of the wheel bearing (14), wherein the second bearing shell (18) forms a second raceway (L3) for the rolling elements (40) of the wheel bearing (14). [9] Motor vehicle, with at least one wheel hub drive (10) according to one of the preceding claims.

Images