ELECTROMOTIVE DRIVE WHEEL ARRANGEMENT

Abstract

An electromotive drive wheel arrangement for a motor vehicle comprises: a stator that is connectable to a wheel carrier in a rotationally fixed manner and that supports a coil-like winding, and a rotor rotatably supported relative to the stator and configured in the form of a wheel rim and arranged at least partially radially outside around the stator, wherein the wheel rim comprises a rim base and a rim star, connected to each other, wherein the rim base includes at least partially a fiber-reinforced plastic, and in the rim base several magnets are integrated in a material connection, and that the rim star includes at least partially a metal material.

Claims

1.-15. (canceled)

16. An electromotive drive wheel arrangement for a motor vehicle, comprising: a stator connectable in a rotationally fixed manner to a wheel carrier and supporting a coil-like winding; and a rotor in the form of a wheel rim and rotatably supported relative to the stator, and arranged at least partially radially outside around the stator; wherein the wheel rim includes a rim base and a rim star, connected to each other, wherein the rim base includes at least partially a fibre-reinforced plastic, wherein a plurality of magnets are integrated in the rim base by a material connection, and wherein the rim star includes at least partially a metal material.

17. The electromotive drive wheel arrangement of claim 16, wherein the fibre-reinforced plastic of the rotor is made from a plastic matrix and a semi-finished fibre product.

18. The electromotive drive wheel arrangement of claim 16, wherein the magnets of the rotor are permanent magnets.

19. The electromotive drive wheel arrangement of claim 18, wherein the permanent magnets are connected to the semi-finished fibre product.

20. The electromotive drive wheel arrangement of claim 19, wherein the permanent magnets have a plurality of connection portions for being connected to the semi-finished fibre product.

21. The electromotive drive wheel arrangement of claim 16, wherein the magnets are in the form of coils made from metal wires embroidered into the semi-finished fibre product.

22. The electromotive drive wheel arrangement of claim 16, wherein the rotor forms a motor housing at least partially around the stator.

23. The electromotive drive wheel arrangement of claim 22, wherein the rim star has a closed shape and forms a side wall of the motor housing.

24. The electromotive drive wheel arrangement of claim 16, wherein the stator comprises a wheel hub fixed to the rim star and rotatably supported on the stator, wherein the rim star is sealed relative to the wheel hub.

25. The electromotive drive wheel arrangement of claim 22, wherein a side wall of the motor housing arranged opposite to the rim star is connected to the rim base or formed integrally with the rim base, so that the stator is arranged between the rim star and the side wall arranged opposite to the rim star.

26. The electromotive drive wheel arrangement of claim 25, wherein a sealing element is arranged between the side wall arranged opposite to the rim star, and the stator.

27. The electromotive drive wheel arrangement of claim 16, wherein the rim base and the rim star are connected to each other at least in one of a force-locking and a form-locking manner, and a seal is provided between the rim base and the rim star.

28. The electromotive drive wheel arrangement of claim 16, wherein the rim base and the rim star are materially connected to each other.

29. The electromotive drive wheel arrangement of claim 16, wherein at least one metal strip, rotatable with the magnets, is integrated by a material connection in the rim base.

30. The electromotive drive wheel arrangement of claim 16, wherein a brake disc is rotationally fixedly connected to the rim star or the rim base.

Description

SUMMARY OF THE DRAWINGS

[0028] Example embodiments are described in the following using the drawings, which include:

[0029] FIG. 1 is a diagonal front view of an exemplary electromotive wheel hub drive arrangement;

[0030] FIG. 2 is a front view of the electromotive wheel hub drive arrangement of FIG. 1;

[0031] FIG. 3 is a schematic representation of a stator of the wheel hub drive arrangement of FIG. 1 in a longitudinal sectional view;

[0032] FIG. 4 is a longitudinal sectional view through the wheel hub arrangement of FIG. 2 along the section line IV-IV;

[0033] FIG. 5a sectional view through the wheel hub arrangement of FIG. 2 along the section line V-V;

[0034] FIG. 6a is a schematically a cut-out portion of the rim base of FIG. 4 in an enlarged representation in a first possible embodiment of the imbedding of the magnets;

[0035] FIG. 6b is a cut-out portion of the rim base of FIG. 4 in an enlarged representation in a second possible embodiment of the imbedding of the magnets;

[0036] FIG. 6c is a cut-out portion of the rim base of FIG. 4 in an enlarged representation in a third possible embodiment of the imbedding of the magnets;

[0037] FIG. 7a is a permanent magnet of the wheel hub arrangement of FIG. 1 as shown in detail in a perspective view; and

[0038] FIG. 7b is a permanent magnet of a modified embodiment for a wheel hub.

DESCRIPTION

[0039] FIGS. 1 to 7, which in the following are described together, show an electromotive drive wheel arrangement 1. The drive wheel arrangement 1 comprises a rotor 2 and a stator 3, which are arranged around an axis of rotation 4. The drive wheel arrangement 1 is connected via the stator 3 to a wheel carrier not shown in the Figures.

[0040] The rotor 2 is made in the form of a wheel rim and comprises a radially outside arranged rim base 10 and a rim star 20, which are connected to each other in particular in a form-locking and force-locking way. Thus, between the rim base 10 and the rim star 20 a circumferentially extending, completely closed contact region 28 is formed, which in its extension can vary across the circumference. The rim base 10 is made from, i.e., at least partially or substantially comprises, fiber-reinforced plastic, which comprises a semi-finished fiber product and a plastic matrix. The layer structure and the fiber alignment vary across the extension of the semi-finished product, to adapt the mechanical properties of the rim base 10 to the loadings. In particular the semi-finished fiber product can be structured such that an as high as possible stiffness is achieved against ovalisation due to the vertical wheel forces. The rim base 10 can be produced in any suitable primary forming process for fiber-reinforced plastic. Depending on the manufacturing process used, the semi-finished fiber products are either dry and the plastic matrix is afterwards introduced, for example by means of resin injection methods, or the semi-finished fiber products are in advance impregnated with the plastic matrix, for example by means of winding methods. Reinforcements made from a different material, in particular a metal material, which have a reinforcing effect or serve for protection against damages of the fiber-reinforced plastic, can be connected in a force-locking, form-locking way or by means of material connection to the fiber reinforced plastic. On the rim base 10, a tire, not shown in the Figures, can be mounted, so that a bead of the tire rests in the outer rim shoulder 15 and the other bead of the tire in the inner rim shoulder 16. For this, the rim base 10 comprises an outer rim flange 11 and an inner rim flange 12, which axially secure the tire at the respective sides of the rim base 10, as well as an outer hump 13 and an inner hump 14, which prevent an axial displacement of the wheel respectively inwards during loading when driving around a bend. The above named portions, which serve for the axial retainment of the tire, can in particular be reinforced by metal reinforcements.

[0041] In the rim base 10, several magnets 17, which produce the excitation field of the electromotive drive wheel arrangement 1, are integrated by material connection. The magnets 17 are formed as permanent magnets 36 in the illustrated embodiments. Alternatively, the magnets 17 can be formed as electromagnets in shape of a coil of metal wires. FIG. 6a shows schematically a first embodiment of the integration of the permanent magnets 36 in the rim base 10, in which the permanent magnets 36 are partially enclosed by fiber-reinforced plastic, while the part of the magnets, which is not enclosed by fiber-reinforced plastic, is exposed. FIG. 6b shows schematically a second embodiment of the integration of the permanent magnets 36 in the rim base 10, in which the permanent magnets 36 are completely enclosed across the whole circumference by the fiber-reinforced plastic. FIG. 6c shows schematically a third embodiment of the integration of the permanent magnets 36 in the rim base 10, in which the permanent magnets 36 are partially enclosed by the fiber-reinforced plastic, while the part of the permanent magnets 36, which is not enclosed by the fiber-reinforced plastic, is surrounded by a protection layer 43. The protection layer 43 can consist of the fiber-reinforced plastic, the plastic matrix or a different material. The shown embodiments are in particular designed such that the permanent magnets 36 are protected as far as possible from outer environmental influences, which can lead to corrosion.

[0042] For the material connective integration of the permanent magnets 36 into the rim base 10, these can be connected to the semi-finished fiber product. This can in particular be achieved, depending on the layer structure of the semi-finished fiber product, by means of sewing-on or embroidering-onto the layer structure of the semi-finished fiber product. For this, permanent magnets 36 comprise connection portions 37 in shape of an eyelet, as shown in FIG. 7a). For an optimised controlling of the manufacturing processes the permanent magnets 36 can have inclined faces 38 for removal from a die. An alternative embodiment of the permanent magnets 36, in which the connection portions 37 are omitted, is shown in FIG. 7b. The permanent magnets 36 according to this variant are in particular introduced between two or more layers of the semi-finished fiber product. The embodiments of the permanent magnets 36, shown in the two FIGS. 7a and 7b have a substantially straight shape. The permanent magnets 36 can in particular also be formed in a shape following the profile of the rim base 10, i.e. corresponding to an extruded annular ring segment. A possible embodiment provides, that for reducing the magnetic resistance one or more metal strips circumferentially extending radially outside the magnets 17 are integrated in a material connection way into the rim base.

[0043] The rim star 20 is made of, i.e. comprises at least a metal material, wherein in an embodiment according to the invention individual portions can be manufactured from different materials. The rim star 20 comprises a centrally positioned wheel seat 21, accommodating centrally a wheel hub 31. Radially outside, the wheel seat 21 is surrounded in particular by five attachment holes 22, without limiting the number of attachment holes 22 thereto. By means of the attachment holes 22, connection elements 26, in particular screws, can be inserted and fixed to connection portions 32, in particular threads, provided in the wheel hub 31, so that the rim star 20 and the wheel hub 31 are rigidly connected to each other. Furthermore, the rim star 20 has several spokes 23, extending from the wheel seat 21 as far as possible radially outwards up to the contact region 28, wherein the spokes 23 can in particular have a straight as well as a curved shape. The spokes 23 can in particular be designed as multi-spoke such as Y-spoke for example. Between the spokes 23, walls 24 extend radially and in circumferential direction, so that the rim star 20 has a closed shape. This can in particular be achieved such that the casting- or forging-skin, formed during the primary forming by means of casting or forging of the rim star 20 between the spokes 23, is not removed. The spokes 23 and the walls 24 can be formed such that a closed wheel disc is achieved.

[0044] The stator 3 is a component arranged around the axis of rotation 4, which radially outside is partially enclosed by the rotor, in particular by the rim base 10. The stator 3 comprises several stator teeth 5, distributed around the circumference and extending radially outwards, with coil-like windings, which are not shown for simplicity in the Figure. The coil-like windings are connected to a power- and control-electronics system, not shown, and produce during current supply a magnetic field. The magnetic field interacts magnetically with the excitation field and, thus, produces in that manner the motor torque of the drive wheel arrangement 1. For optimisation of the magnetic flow, the outwards arranged ends of the stator teeth 5 are formed as pole shoes 6, which are arranged radially inside relative to the magnets 17 of the rotor 2. Between the pole shoes 6 and the magnets 17 the air gap 44 is arranged, which should be configured as small as possible and constant for a high efficiency of the electromotor during driving operation. This can be achieved by a high stiffness of the rim base 10 against ovalisation due to vertical wheel forces. The stiffness can for example be optimised by means of a corresponding, above described design of the semi-finished fiber product or by means of reinforcements in the fiber-reinforced plastic.

[0045] Furthermore, the stator 3 comprises a central portion 8, having on one side, in FIG. 3 on the left sidea connection portion 7 to the wheel carrier of the vehicle. By means of the connection portion 7, the stator 3 is connected to the wheel carrier in a rotationally fixed way, so that all relative rotational degrees of freedom and at least a relative translatory degree of freedom is captivated between the components, and thus a torque introduced into the stator 3 is supported by the wheel carrier. On the opposite sidein FIG. 3 on the right sidethe stator 3 has a journal 9, which can accommodate a rotatable bearing element. The stator 3 is shown in a one-part embodiment. Alternatively, the stator 3 can also be formed from several parts, to integrate for example the connection portion 7 and the journal 9. On the journal 9 a wheel bearing 30 is mounted, which rotatably supports the wheel hub 31. The wheel hub 31 is again, as described above, connected to the rim base 10 in a rotationally fixed manner by means of connection elements 26.

[0046] The rim base 10 is connected at its radial inwards side in a material connection to a side wall 18 of a motor housing 35, so that the stator 3 is arranged between the side walls 18 and the rim star 20. The side wall 18 can, in this case, be manufactured from the same material as the rim base 10 or from a different material. As the rim star 20 is made in a closed shape from spokes 23 and walls 24, the rim star 20 takes over the function of a second side wall 25 of the motor housing 35.

[0047] The side wall 18, the rim base 10 and the rim star 20 thus together form the motor housing 35, which is sealed relative to outside environmental influences. For this, a sealing element 33 is provided between a radially inward end of the side wall 18 and the stator. The sealing element 33 can in particular be a radial shaft sealing ring or an axial shaft sealing ring. The diameter of the sealing running face is selected as small as possible, so that the wear on the sealing element 33, with sufficient construction space for the connection between the stator 3 and the wheel carrier of the vehicle, can be reduced. The side wall 18 and the rim base 10 are connected to each other in a material connection, so that a seal is provided between the two components. The rim star 20 and the rim base 10 are connected force- and form-lockingly to each other. For this, as shown in FIG. 5, connection elements 40 are passed through openings 10 in the rim base 10 and are fixed in connection regions 29 of the rim star 20 in the area of the spokes 23. The connection elements 40 are in particular configured in the form of screws enclosed by sleeves 41, and the connection regions 29 of the rim star 20 are in particular formed as blind holes with a threaded portion. The connection elements 40 can in particular be glued to the rim base 10, the rim star 20 and the sleeves 41. The sleeves 41 take on a sealing function and absorb shearing forces, which act on the connection elements 40 due to the force- and torque transmission. For this, in particular, the sleeves 41 can be glued structurally to the rim base 10 and the rim star 20 and for example can be manufactured from an elastomer material. In the contact region 28 a seal 42 is provided between the rim base 10 and the rim star, which seal in the area of the spokes 23 comprises an intermediate layer with function regions for transmitting forces and torque as well as for sealing. The intermediate layer can furthermore decouple the two components such that a contact corrosion between the different materials of the rim base 10 and the rim star 20 is prevented. The contact region 28 is formed narrower the area of the walls 24 than in the area of the spokes 23; and the seal 42 is made from a sealing compound, so that in this area (28) substantially only a sealing effect and secondarily a force- and torque-transmission results. The intermediate layer and the sealing compound form together a complete circumferential seal in the contact region 28. Alternatively, the contact region 28 can be formed wider in the area of the walls 24, so that along the whole circumference a sealing effect as well as a force- and torque-transmission are achieved. Between the rim star 20 and the wheel hub 31, a sealing press-fit is used as the seal 34. Because of the connection elements 26 a biasing force is produced, so that the wheel hub 31 and the rim star 20 have a force-locking connection to each other. The biasing force of the connection elements 26 is selected to be so large that the resulting pressing produces a sealing effect between the wheel hub 31 and the rim star 20. The connection portions 32 on the wheel hub 31 are formed as through bores with thread. Thus, for sealing between the connection portion 32 and the connection element 26 a further seal 27 is provided. Alternatively the connection portions 32 can be formed as blind holes, so that the seal 27 can be omitted.

[0048] A possible embodiment provides that a brake disc is non-rotationally connected to the rim base 10 or the rim star 20. The non-rotational connection can for example be made by means of a material connection between the brake disc and the rim base 10 or the rim star 20.

LIST OF REFERENCE NUMBERS

[0049] 1 drive wheel arrangement

[0050] 2 rotor

[0051] 3 stator

[0052] 4 axis of rotation

[0053] 5 stator tooth

[0054] 6 pole shoe

[0055] 7 connection portion

[0056] 8 central portion

[0057] 9 journal

[0058] 10 rim base

[0059] 11 outer rim flange

[0060] 12 inner rim flange

[0061] 13 outer hump

[0062] 14 inner hump

[0063] 15 outer rim shoulder

[0064] 16 inner rim shoulder

[0065] 17 magnet

[0066] 18 side wall

[0067] 19 opening

[0068] 20 rim star

[0069] 21 wheel seat

[0070] 22 attachment hole

[0071] 23 spoke

[0072] 24 wall

[0073] 25 side wall

[0074] 26 connection element

[0075] 27 seal

[0076] 28 contact region

[0077] 29 connection region

[0078] 30 wheel carrier

[0079] 31 wheel hub

[0080] 32 connection portion

[0081] 33 seal element

[0082] 34 seal

[0083] 35 motor housing

[0084] 36 permanent magnet

[0085] 37 connection portion

[0086] 38 tapered inclined face for removal from a die

[0087] 39 metal strip

[0088] 40 connection element

[0089] 41 sleeve

[0090] 42 seal

[0091] 43 protection layer

[0092] 44 air gap