Wheel hub drive device

Abstract

The invention relates to a wheel hub drive device (1) comprising: - a wheel carrier (7), - a wheel bearing (8) comprising a first bearing shell (9) non-rotatably connected to the wheel carrier (7) and a second bearing shell (10) arranged coaxially and rotatably to the first bearing shell (9), - an electric machine (3) comprising a rotor (13) and a stator (14) non-rotatably connected to the wheel carrier (7), and - a brake device (4). According to the invention, it is provided that: - the electric machine (3) is designed as an external rotor, and - a friction area (28) of the brake device (4) is arranged axially between the wheel carrier (7) and the stator (14).

Description

The invention relates to a wheel hub drive device according to the features of claim 1.As described in DE 10 2009 035 176 A1, a wheel hub drive for a motor vehicle is known from the prior art. It comprises an electric machine and a disc brake system, both of which are arranged radially inside a rim. A stator of the electric machine has a cutout. A brake caliper of the disc brake system is arranged in this recess.The invention is based on the object of specifying a wheel hub drive device which is improved compared with the prior art.The object is achieved according to the invention by a wheel hub drive device having the features of claim 1.Advantageous embodiments of the invention are the subject matter of the dependent claims.A wheel hub drive device has a wheel carrier, a wheel bearing, an electric machine and a brake device. The wheel bearing has a first bearing shell connected to the wheel carrier in a rotationally fixed manner and a second bearing shell arranged coaxially and rotatably with respect to the first bearing shell. The electric machine has a rotor and a stator which is connected to the wheel carrier in a rotationally fixed manner. The wheel hub drive device thus forms, in particular, an electric wheel hub drive for a vehicle.According to the invention, the electric machine is designed as an external rotor and a friction region of the brake device is arranged axially between the wheel carrier and the stator.In one embodiment, the brake device is designed as a disc brake with an external brake caliper.In one embodiment, the brake device has a brake disc and a brake disc holder, wherein the brake disc holder is arranged axially between a rotor carrier and a wheel carrier section of the wheel carrier.In one embodiment, the brake disk holder is arranged at least partially radially overlapping with the stator.In one embodiment, the electric machine is designed as an axial flux machine, wherein a cylinder section of the rotor carrier is arranged radially outside the stator and axially overlapping the stator.In one embodiment, the brake disk holder is directly connected to the cylinder portion.In one embodiment, the brake disk holder has a first axial section which is directly connected to the cylinder section and extends in the direction of the wheel carrier section, a first radial section which adjoins the first axial section radially inward, a second axial section which adjoins the first radial section in the direction of the wheel carrier section, and a second radial section which adjoins the second axial section radially outward.In one embodiment, the first radial section is arranged at least partially radially overlapping with the stator.In one embodiment, the second radial section is arranged so as to completely overlap radially with respect to the stator.In one embodiment, the brake disc and / or the brake caliper are / is arranged at least partially radially overlapping with the stator and / or with the rotor. The present invention facilitates the arrangement of the electric machine and the brake device within a wheel of the vehicle, i.e. in particular within a wheel interior radially delimited by the wheel.In the context of the present application, the term "external rotor" is used as follows: At least a part of the rotor and / or of the rotor carrier is arranged radially outside the stator.It is particularly advantageously provided in particular that the cylinder section of the rotor carrier is arranged radially outside the stator and axially overlapping the stator.In the context of the present application, a "wheel carrier section" is understood to mean in particular that part of the wheel carrier which is arranged radially overlapping with the brake disc.In the context of the present application, the term "wheel" is understood to mean a unit of wheel disk and rim.In the context of the present application, a cylinder section of the rotor carrier is understood to mean, in particular, that part of the rotor carrier which is arranged axially overlapping with the stator.Exemplary embodiments of the invention are explained in more detail below with reference to a drawing.The following shows: FIG. 1 shows a schematic sectional illustration of a wheel hub drive device.FIG. 1 shows a schematic sectional illustration of an embodiment of a wheel hub drive device 1 for a vehicle, wherein the sectional plane runs through a rotational axis A, about which in particular a wheel 2 of the vehicle and rotating components of the wheel hub drive device 1 rotate. For reasons of clarity, FIG. 1 shows only one half of the cut wheel hub drive device 1, up to the axis of rotation A.The solution illustrated in FIG. 1 by way of example and described in more detail below facilitates an arrangement of an electric machine 3 and a brake device 4 within the wheel 2 likewise illustrated in FIG. 1. The wheel 2 comprises a rim 5 and a wheel disk 6.The wheel hub drive device 1 has a wheel carrier 7, a wheel bearing 8, the electric machine 3 and the brake device 4. The wheel bearing 8 has a first bearing shell 9 connected to the wheel carrier 7 in a rotationally fixed manner and a second bearing shell 10 arranged coaxially and rotatably with respect to the first bearing shell 9. In the embodiment shown, the first bearing shell 9 is a radially outer bearing shell and the second bearing shell 10 is a radially inner bearing shell in the embodiment shown.In the embodiment shown, the second bearing shell 10 is a component of a wheel hub 11, i.e. the wheel hub 11 and the second bearing shell 10 are formed in one piece and / or in one piece. In other embodiments, the second bearing shell 10 is, for example, a separate component connected to the wheel hub 11.In the embodiment shown, the wheel bearing 8 is designed as a rolling bearing, in particular as a ball bearing. It has a seal 12 on both sides in the axial direction.The electric machine 3 has a rotor 13 and a stator 14 connected to the wheel carrier 7 in a rotationally fixed manner. In the embodiment shown, the stator 14 is connected to the wheel carrier 7 in a rotationally fixed manner by means of a stator carrier 15.In the embodiment shown, a screw connection of the first bearing shell 9 and the stator carrier 15 to the wheel carrier 7 is provided. For this purpose, in the embodiment shown, a fastening section 16 of the stator carrier 15 is arranged in the axial direction on a side of the wheel carrier 7 facing the wheel hub 11, and the first layer shell 9 is arranged in the axial direction on a side of the fastening section 16 of the stator carrier 15 facing the wheel hub 11 and thus facing away from the wheel carrier 7.FIG. 1 shows a screw 17 which is screwed into the first bearing shell 9 in the axial direction through the wheel carrier 7 and the fastening section 16 of the stator carrier 15, a head 18 of the screw 17 being supported on the wheel carrier 7. Advantageously, further such screw connections are provided distributed, in particular uniformly distributed, over a circumference of the first bearing shell 9.In the embodiment shown, the rotor 13 is connected to the wheel hub 11 in a rotationally fixed manner by means of a rotor carrier 19, i.e. the wheel hub 11 is connected to the rotor carrier 19 and via the latter to the rotor 13 in such a way that they always rotate at the same angular speed. In the embodiment shown, a fastening section 20 of the rotor carrier 19 is arranged in the axial direction on a side of the wheel hub 11 facing away from the wheel carrier 7. In the embodiment shown, the wheel 2, in particular its wheel disk 6, is arranged in the axial direction on a side of the fastening section 20 of the rotor carrier 19 facing away from the wheel hub 11.FIG. 1 shows a wheel screw 21 which is screwed into the wheel hub 11 in the axial direction through the wheel 2, in particular through its wheel disk 6, and the fastening section 20 of the rotor carrier 19, a head 22 of the wheel screw 21 being supported on the wheel 2, in particular on its wheel disk 6. Advantageously, further such screw connections are provided distributed, in particular uniformly distributed, over a circumference of the wheel hub 11. By means of the respective screw connection, both the wheel 2 and the rotor carrier 19 are connected to the wheel hub 11 in a rotationally fixed manner.The rotor carrier 19 is advantageously additionally connected to the wheel hub 11 in a rotationally fixed manner via a further connection solution, not shown here, for example via further screw connections, which connect only the rotor carrier 19, but not the wheel 2, to the wheel hub 11. This makes it possible to remove the wheel 2, for example in order to carry out a wheel change, without the rotor carrier 19 thereby coming loose from the wheel hub 11.The electric machine 3 is designed as an axial flow machine and as an external rotor. At least a part of the rotor 13 and / or of the rotor carrier 19 is arranged radially outside the stator 14. In the embodiment shown, only a part of the rotor carrier 19, in particular a cylinder section 23 of the rotor carrier 19, is arranged radially outside the stator 14. This cylinder section 23 of the rotor carrier 19 is also arranged axially overlapping with the stator 14.In the embodiment shown, the fastening section 20 of the rotor carrier 19 is adjoined in the radial direction outwards by a connecting section 24, at the end of which the cylinder section 23 adjoins axially in the direction of the wheel carrier 7. The rotor 13 is arranged on an inner side of this cylinder section 23 of the rotor carrier 19 in the radial direction and on both sides of the stator 14 in the axial direction.The brake device 4 is designed as a disc brake with an external brake caliper 25. It has a brake disc 26 and a brake disc holder 27.A friction region 28 of the brake device 4 is arranged axially between the wheel carrier 7, in particular a wheel carrier section 29 of the wheel carrier 7 radially overlapping the brake disc 26, and the stator 14. This friction region 28 is in particular a region on both sides of the brake disc 26 in the axial direction, which is bounded by the brake caliper 25 in the axial direction and in which brake pads are pressed against both friction surface sides of the brake disc 26 during a braking operation. In the embodiment shown, the brake caliper 25 is arranged on the wheel carrier 7, more precisely on this wheel carrier section 29, more precisely on a side of this wheel carrier section 29 facing the rotor carrier 19 in the axial direction.In the embodiment shown, the brake disk holder 27 is arranged axially between the rotor carrier 19 and the wheel carrier section 29 of the wheel carrier 7.The brake disk holder 27 is arranged at least partially radially overlapping with the stator 14.In the embodiment shown, the brake disc holder 27 is directly connected to the cylinder section 23 of the rotor carrier 19.In the embodiment shown, the brake disk holder 27 has a first axial section 30 which is directly connected to the cylinder section 23 and extends axially in the direction of the wheel carrier section 29, a first radial section 31 which adjoins the first axial section 30 radially inward, a second axial section 32 which adjoins the first radial section 31 axially in the direction of the wheel carrier section 29, and a second radial section 33 which adjoins the second axial section 32 radially outward. On this second radial section 33, in particular on its radially outer end, the brake disc 26 is arranged in the embodiment shown. The first axial section 30 forms in particular an axial extension of the cylinder section 23 in the direction of the wheel carrier section 29, i.e. it is arranged on an axial end side of the cylinder section 23 in the direction of the wheel carrier section 29.In the embodiment shown, the first radial section 31 is arranged at least partially radially overlapping with the stator 14.In the embodiment shown, the second radial section 33 is arranged so as to completely overlap radially with respect to the stator 14.In the embodiment shown, the brake disc 26 and the brake caliper 25 are each arranged at least partially radially overlapping with respect to the stator 14 and with respect to the rotor 13.The terms "axial" or "axial direction" and "radial" or "radial direction" used relate in particular to the axis of rotation A.List of reference characters1 Wheel hub drive device 2 Wheel 3 Electric machine 4 Brake device 5 Rim 6 Wheel disk 7 Wheel carrier 8 Wheel bearing 9 First bearing shell 10 Second bearing shell 11 Wheel hub 12 Seal 13 Rotor 14 Stator 15 Stator carrier 16 Fastening section of the stator carrier 17 Screw 18 Head of the screw 19 Rotor carrier 20 Fastening section of the rotor carrier 21 Wheel screw 22 Head of the wheel screw 23 Cylinder section 24 Connecting section 25 Brake caliper 26 Brake disk 27 Brake disk holder 28 Friction region 29 Wheel carrier section 30 First axial section 31 First radial section 32 Second axial section 33 Second radial section A Axis of rotationReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2009 035 176 A1

[0002]

Claims

Wheel hub drive device (1), having - a wheel carrier (7), - a wheel bearing (8) which has a first bearing shell (9) which is connected to the wheel carrier (7) in a rotationally fixed manner and a second bearing shell (10) which is arranged coaxially and rotatably with respect to the first bearing shell (9), - an electric machine (3) which has a rotor (13) and a stator (14) which is connected to the wheel carrier (7) in a rotationally fixed manner, and - a brake device (4), characterized in that - the electric machine (3) is designed as an external rotor, and - a friction region (28) of the brake device (4) is arranged axially between the wheel carrier (7) and the stator (14).Wheel hub drive device (1) according to Claim 1, characterized in that the brake device (4) is designed as a disc brake with an external brake caliper (25).Wheel hub drive device (1) according to Claim 2, characterized in that the brake device (4) has a brake disc (26) and a brake disc holder (27), wherein the brake disc holder (27) is arranged axially between a rotor carrier (19) and a wheel carrier section (29) of the wheel carrier (7).Wheel hub drive device (1) according to Claim 3, characterized in that the brake disc holder (27) is arranged at least partially radially overlapping with the stator (14).Wheel hub drive device (1) according to Claim 3 or 4, characterized in that the electric machine (3) is designed as an axial flux machine, wherein a cylinder section (23) of the rotor carrier (19) is arranged radially outside the stator (14) and axially overlapping with the stator (14).Wheel hub drive device (1) according to claim 5, characterised in that the brake disc holder (27) is directly connected to the cylinder portion (23).Wheel hub drive device (1) according to Claim 6, characterized in that the brake disc holder (27) has a first axial section (30) which is connected directly to the cylinder section (23) and extends in the direction of the wheel carrier section (29), a first radial section (31) which adjoins the first axial section (30) radially inwards, a second axial section (32) which adjoins the first radial section (31) in the direction of the wheel carrier section (29), and a second radial section (33) which adjoins the second axial section (32) radially outwards.Wheel hub drive device (1) according to Claim 7, characterized in that the first radial section (31) is arranged at least partially radially overlapping the stator (14).Wheel hub drive device (1) according to claim 7 or 8, characterised in that the second radial section (33) is arranged completely radially overlapping the stator (14).Wheel hub drive device (1) according to one of Claims 2 to 9, characterized in that the brake disc (26) and / or the brake caliper (25) are / is arranged at least partially radially overlapping with respect to the stator (14) and / or with respect to the rotor (13).

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